special - ALUMINIUM-Nachrichten – ALU-WEB.DE

Special: aluminium
smelting industry
power upgrade
of isal potlines 1-3
The ‘ap Technology’
smelter of the future
History of intensive
mixing for carbon paste
Novel gas cleaning for
anode baking furnace
ABB
Five hundred participants
at arabal 2012 conference
Volume 89 · January / February 2013
International Journal for Industry, Research and Application1/2

Melting Furnaces
State-of-the-art scrap and dross remelting
Leading technology in the aluminum casthouse
There are many benefi
fi
Major benefits
Common features and advantages of
Hertwich melting furnaces
Integrated scrap preheating and gasifi
HERTWICH ENGINEERING GMBH

CONTENTS
Volker Karow
Chefredakteur
Editor in Chief
Aluminiumindustrie
startet optimistisch
ins neue Jahr
Optimistic start for the
aluminium industry
in the new year
Aktuelle Zahlen zum globalen Wirtschaftswachstum
2012 lagen bei Redaktionsschluss
zwar noch nicht vor, doch gehen die meisten
Volkswirte von einem Zuwachs um die drei
Prozent aus. Ob die Weltkonjunktur 2013
weiter an Fahrt gewinnen wird, darüber gehen
die Einschätzungen auseinander. Weitgehende
Einigkeit besteht darin, dass Europas
Wirtschaft erneut schrumpfen wird, die USA
moderat wachsen werden und die Konjunktur
in den Schwellenländern wieder anzieht.
Für den Aluminiummarkt zeigt sich Alcoa-
Chef Klaus Kleinfeld optimistisch. Die globale
Nachfrage nach Aluminium, so seine Einschätzung,
werde im laufenden Jahr um sieben
Prozent steigen. Das reicht zwar nicht an die
Werte von 2010 (+13%) und 2011 (+10%)
heran, wäre aber ein Prozentpunkt über dem
geschätzten Zuwachs von 2012. Getragen
werde diese Entwicklung vor allem von der
Nachfrage aus der Luftfahrt- und Bauindustrie.
Für den Luftfahrtmarkt rechnet Alcoa mit
einem fast zweistelligen Wachstum.
Andere Aluminiumkonzerne sind allerdings
nicht ganz so optimistisch in ihren Prognosen
für das laufende Jahr. Hydro-Chef
Svein Richard Brandtzæg bezifferte den Zuwachs
der globalen Aluminiumnachfrage auf
einer Investorenveranstaltung Ende November
bei zwei bis vier Prozent – ohne China.
Bei den Aluminiumpreisen zeichnet sich
seit einigen Monaten eine leichte Erholung
ab. Die 3-Monats-Notierungen haben sich
von ihrem Tief im August ($1.831/t) abgesetzt,
sie lagen Mitte Januar bei 2.094 Dollar
je Tonne. Angesichts hoher weltweiter Lagerbestände
und des weiteren Zubaus von
Produktionskapazitäten – Beispiel Alcoa
Ma’aden: Die neue Hütte in Saudi-Arabien
hat im Dezember ihren ersten von 720 Elektrolyseöfen
in Betrieb genommen – ist der
Spielraum für substanzielle Preissprünge
begrenzt. Dies hält den Druck auf die Erlöse
hoch; kaum ein Branchenunternehmen, dass
nicht Effizienzprogramme fährt, um Kosten
zu senken.
Stetiger technologischer Fortschritt trägt
maßgeblich dazu bei, noch produktiver bzw.
kostensparender zu produzieren. Dass die
Hüttenbranche und ihre Ausrüster kontinuierlich
daran arbeiten, ihre Produktion
und Arbeitsabläufe immer effizienter zu gestalten,
belegen zahlreiche Beiträge in dieser
Ausgabe.
Pro domo: Der besseren Lesbarkeit wegen
werden rein englischsprachige Artikel ab
dieser Ausgabe schwarz gedruckt. Deutschenglische
Beiträge wie in diesem Editorial behalten
dagegen ihre farbige Unterscheidung.
Although the latest figures for global economic
growth in 2012 were not yet available
when we last went to press, most economists
anticipate that growth will have amounted to
around three percent. Whether world trade
will again pick up speed in 2013 is a question
on which opinions differ. It is generally
agreed, however, that Europe’s economy will
again contract, the USA will see moderate
growth and trade in the developing countries
will continue its upward trend.
As regards the aluminium market, Alcoa
CEO Klaus Kleinfeld is optimistic. During
the presentation of his company’s quarterly
results his estimation was that demand for
aluminium will rise seven percent this year.
Although that does not come up to the values
in 2010 (+13%) and 2011 (+11%), it would
still be a percentage point higher than the
estimated growth in 2012. That development
is driven above all by demand from the aviation
and building sectors. In the aviation market
Alcoa expects growth to reach almost the
two-digit level.
Other aluminium concerns, however, are
not quite so optimistic in their forecasts for
this year. At an investor conference in November
Svein Richard Brandtzæg, CEO of
Hydro, put a figure of two to four percent
on the growth of global demand for aluminium
– leaving China aside. That would correspond
to the level of general expectations
regarding world trade.
In recent months aluminium prices have
shown a slight recovery. From their low-point
in August (USD1,831/t), 3-month quotes have
improved somewhat and in mid-January stood
at USD2,094/t. In light of high aluminium
stock levels worldwide and further proliferation
of production capacities – for example,
Alcoa Ma’aden: in mid-December the new
smelter in Saudi Arabia started up the first of
its 720 pots cells – the scope for substantial
price increases is limited. This maintains the
high pressure on profits: almost every aluminium
company today is busy implementing
efficiency measures to cut costs.
Continual technological advances are contributing
decisively toward increased productivity
and cost-cutting. Many articles in this issue
bear witness that the smelter industry and
its suppliers are constantly striving to make
their production and working procedures
ever more efficient.
Editor’s note: As from this issue, articles purely
in English will be printed in black to facilitate
legibility. Contributions in both German
and English, however, such as this editorial,
will retain their colour demarcation.
ALUMINIUM · 1-2/2013 3

INHALT
EDITORIAL
Aluminiumindustrie startet optimistisch ins neue Jahr
Optimistic start for the aluminium industry in the new year ................ 3
AKTUELLES • NEWS IN BRIEF
GF Automotive veräußert deutsches Sandgussgeschäft ......................... 6
8
Aluminium China’s buyer delegations demand
for high quality equipment from overseas ......................................... 7
12 th OEA International Aluminium
Recycling Congress in Düsseldorf, 25-26 Feb 2013 .............................. 7
Amag errichtet Logistikzentrum in Rekordzeit .................................... 8
14 to 18 May 2013, Milano, Italy:
8 th Aluminium Two Thousand Congress ............................................. 9
WIRTSCHAFT • ECONOMICS
Aluminiumpreise ......................................................................... 10
Produktionsdaten der deutschen Aluminiumindustrie ..........................12
Five hundred participants at Arabal 2012 Conference .........................14
Dubal’s DX+ technology selected by Alba ........................................15
TMS2013 offers a diversity of light metals
programming and networking opportunities ....................................16
ALUMINIUM SMELTING INDUSTRY
Recent development of Dubal
aluminium reduction cell technologies ............................................18
0
The ‘AP Technology’ smelter of the future .......................................24
Möller direct pot feeding system for
greenfield and brownfield smelters ................................................28
Carbone Savoie – Cathode producer shows its metal .........................32
Fives Solios – 30 years of experience in fume desulphurisation ...........38
Alumina refinery: Outotec’s process and implementation solution .......33
Eirich: History of intensive mixing for carbon paste ..........................40
HMR’s automated stud repair line ..................................................44
Marx: Channel-type versus coreless induction furnace .......................46
Alcoa starts up potlining facility at Fjardaál Iceland smelter ...............49
Gautschi Engineering – An industry profile ......................................52
Latest News
www.alu-web.de
Advanced technology from Brochot –
A proven solution for anode slot cutting .........................................56
Diffusion and convection of alumina
in the bath of a Hall-Héroult cell ...................................................58
4 ALUMINIUM · 1-2/2013 · 4/2012

CONTENTS
Power upgrade of Isal Potlines 1-3 .................................................61
Applying computational thermodynamics
to industrial aluminium alloys ..........................................64
ECL – A privileged equipment supplier to the aluminium industry .......67
Alstom Power – Novel gas cleaning for anode baking furnace ............70
GNA cathode block sealing process ................................................72
T. T. Tomorrow – Slotting anodes and recycling carbon ......................74
Testing a new ‘STARprobe’............................................................76
Carbothermic reduction – An alternative
aluminium production process .......................................................76
52
Recycling of smelter materials through
rotary crushing and material separation ..........................................82
Meeting of the ISO Committee for analysis of
materials for primary aluminium in Switzerland ................................86
TECHNOLOGIE • TECHNOLOGY
Chips versus briquettes: How the aluminium
industry can effectively and efficiently recycle scrap ..........................87
82
Bühler Lost-Core-Technologie eröffnet weites Anwendungsspektrum
Bühler Lost Core technology opens up a wide range of applications ....89
GM welding innovation enables increased use of aluminium ...............90
APPLICATION
Aluminium: Tesla’s secret weapon in new Model S ...........................91
COMPANY NEWS WORLDWIDE
Aluminium smelting industry .........................................................92
Bauxite and alumina activities ......................................................92
Aluminium semis .........................................................................93
On the move ..............................................................................93
Suppliers ...................................................................................94
RESEARCH
Cathode wear in Hall-Héroult cells .................................................95
DOCUMENTATION
Patente .....................................................................................98
Impressum • Imprint .................................................................. 113
Vorschau • Preview ................................................................... 114
LIEFERVERZEICHNIS • SUPPLIERS DIRECTORY ........... 100
Inserenten dieser Ausgabe
List of advertisers
ABB Switzerland 37
Alteco Aluminiumtechnologie, Austria 22
Buss AG, Switzerland 21
De Winter Engineering, The Netherlands 60
Didion International Inc., USA 17
Dubai Aluminium Co. Ltd , UAE 13
Fives Solios, France 41
FLSmidth Hamburg GmbH, Germany 45
Gautschi Engineering, Switzerland 29
Glama Maschinenbau GmbH, Germany 53
Hertwich Engineering GmbH, Austria 2
Inotherm Industrieofen- und
Wärmetechnik GmbH, Germany 87, 91
Innovatherm Prof. Dr. Leisenberg
GmbH & Co. KG, Germany 35
Interall Srl, Italy 31
Precimeter Control AB, Sweden 65
R&D Carbon Ltd, Switzerland 116
Reed Exhibitions China Ltd, PR China 11
Reed Exhibitions, UAE 115
Riedhammer GmbH, Germany 19
SMS Siemag AG, Germany 50/51
TMS Minerals, Metals
& Materials Society, USA 23
T.T. Tomorrow Technology SpA, Italy 25
ALUMINIUM · 4/2012 1-2/2013 5

AKTUELLES
GF Automotive veräußert deutsches Sandgussgeschäft
Künftiger Fokus auf Druckgussgeschäft in Asien und Europa
© Georg Fischer
GF Automotive hat sein deutsches Aluminiumsandgussgeschäft
mit den Gießereien in
Friedrichshafen und Garching veräußert. In
Zukunft will sich das zum Industriekonzern
Georg Fischer gehörende Unternehmen auf
seine Eisen- und Aluminium-Druckgießereien
in Europa konz und vor allem seine bestehenden
Werke in China weiter ausbauen.
Im Werk Friedrichshafen von GF Automotive werden Antriebs- und Fahrwerksteile
aus Aluminiumsandguss hergestellt
Georg Fischer erwartet in naher Zukunft
weiteres Wachstum vor allem am asiatischen
Automobilmarkt und eine eher verhaltene
Marktlage in Europa. Daher soll die rasche
Expansion in China fortgesetzt werden. Der
Anteil des Landes am Umsatz von GF Automotive
ist in den letzten sechs Jahren von null
auf zehn Prozent gestiegen. Die Produktionskapazitäten
der beiden bestehenden Eisenund
Aluminiumdruckgießereien sollen in den
nächsten zwei Jahren um 40 Prozent erweitert
werden.
In Europa will
sich das Unternehmen
auf Aktivitäten
konzentrieren, bei
denen bereits eine
führende Marktposition
erreicht wurde
oder künftig erreicht
werden kann.
Dies trifft für das
Druckgussgeschäft
zu, nicht jedoch für
das Aluminiumsandgussgeschäft.
Die
beiden Werke in
Friedrichshafen und
Garching werden
an die MWS Industrieholding
GmbH veräußert, die damit zum
Technologieführer und größten Anbieter im
Bereich Aluminiumsandguss in Europa wird.
Yves Serra, CEO von Georg Fischer, erklärte:
„Die Integration der Aluminiumsandgussaktivitäten
in das Geschäft von MWS hat eine
bedeutende Konsolidierung innerhalb dieses
Marktsegments zur Folge und erlaubt es GF
Automotive, sich auf ihre Kernaktivitäten
zu konzentrieren.“ Um die Kontinuität des
Geschäfts zu gewährleisten soll das bisherige
Sandguss-Management laut MWS an Bord
bleiben.
Die Gießereien in Friedrichshafen und Garching
gehören seit 1999 zum Georg Fischer
Konzern und beschäftigen 250 bzw. 180 Mitarbeiter.
Sie sind auf Aluminiumsandgussteile
für Pkw, Nutzfahrzeuge und Industrieanwendungen
spezialisiert. Der Gesamtumsatz der
beiden Gießereien belief sich 2011 auf 127
Mio. Schweizer Franken. GF Automotive verzeichnete
2011 einen Umsatz von 1,7 Mrd.
Schweizer Franken.
Die MWS-Gruppe mit Sitz in Kufstein-
Schwoich ist ein österreichischer Automobilzulieferer
in Privatbesitz. Die Gruppe ist auf
Aluminiumguss spezialisiert. MWS wurde
2004 gegründet und verfügt derzeit über drei
Niederlassungen in Österreich und ein Produktionswerk
in der Slowakei. Das Unternehmen
hat insgesamt 320 Beschäftigte und
erzielte 2012 einen Umsatz von 32 Millionen
Euro.
Otto Junker und Can-Eng
Furnaces kooperieren
beim Service
Die Otto Junker Gruppe, Simmerath, und
Can-Eng Furnaces International Ltd., Niagara
Falls / Ontario, kooperieren beim Kundendienst.
Eine jüngst abgeschlossene Vereinbarung
zielt angesichts der sich wechselseitig
ergänzenden Produktpaletten darauf, die
Betreiber von Junker- bzw. Can-End-Wärmebehandlungsanlagen
in aller Welt besser zu
unterstützen. Den Kunden bietet sich damit
eine komplette Palette von Schmelz-, Gieß-,
Prozesserwärmungs- und Wärmebehandlungsanlagen
für thermische Verfahrensanwendungen.
Im Rahmen des Kundendienstes können
Kunden von Otto Junker und Can-Eng ihre
Anfragen zu Produkten der beiden Gruppen
jeweils an die geografisch nächstgelegene Vertriebsniederlassung
richten. Hauptansprechpartner
sind Tim Donofrio (Vice President,
Standard and Aluminium Products, Can-Eng
Furnaces, tdonofrio@can-eng.com), und Jan
van Treek (Verkauf Thermoprozessanlagen,
Otto Junker jvt@otto-junker.de).
Alu.Heat baut innovative
Pilot-Wärmebehandlungsanlage
Die Alu.Heat GmbH hat eine innovative Pilotanlage
zur Wärmebehandlung gebaut, die aus
einem luftumgewälzten Kammerofen, einer
Luft-/Wasserdusche, einem Wasserabschreckbad
mit Umwälzung, einer automatischen Beschickungseinrichtung
und einer Prozesssteuerung
mit entsprechender Dokumentation besteht.
Mit der zum Patent angemeldeten Luftabschreckung
unter Zugabe einer regelbaren
Wassermenge wurden die Möglichkeiten zur
Optimierung mechanischer Kennwerte deutlich
erweitert. Damit entstand eine Pilotanlage,
die den Wärmebehandlungsprozess in der
Praxis realistisch nachbildet und die Kunden
in ihrer F&E-Arbeit unterstützt.
Der gesamte Wärmebehandlungsprozess –
das Zusammenspiel von Temperatur, Zeit und
Abschreckung sowie die Planung des gesamten
Ablaufes – wird individuell auf das Bauteil
des Kunden bezogen und wissenschaftlich
dokumentiert. Die Alu.Heat-Kunden können
somit Versuche fahren, ohne ihre laufenden
Prozesse innerbetrieblich zu stören. Durch
gezielte Versuche und die Kombination aller
technischen Möglichkeiten können deutliche
Gewichtsreduzierungen pro Bauteil erzielt
werden. Einhergehend mit der Einsparung
von Gewicht und damit Material wird der
Energieverbrauch, bspw. eines Fahrzeugs, reduziert,
die Langlebigkeit des Bauteils erhöht,
seine Belastungsgrenze ausgedehnt und die
CO 2 -Emission reduziert.
6 ALUMINIUM · 1-2/2013

NEWS IN BRIEF
Aluminium China’s buyer delegations demand
for high quality equipment from overseas
© Reed Exhibitions
In 2013, ‘Aluminium China’, the leading aluminium
sourcing platform in Asia for industry
professionals and buyers from the aluminium
industry and a wide array of application industries
will expand its buyer delegation programmes
on further key Asian industry clusters
in China, South East Asia and India.
More than 14,700 visitors attended the Aluminum China 2012 trade fair
Thanks to the success of Reed Exhibition
China’s Targeted Attendee Programme for
Chinese VIP buyers at Aluminium China
2012, over 200 exhibitors already booked exhibition
space for the 2013 event occupying
80% of the overall exhibition space. Jiasheng
Wang, managing director of Ebner Industrial
Furnaces (Taicang), commented on the sidelines
of the 2012 event: “Aluminium China is
a great platform for us. Although there are numerous
trade exhibitions in China every year,
we only exhibit at a single aluminium event:
this one. We’ll exhibit here again next year.”
With its still booming economy, China is
set to remain the world’s largest aluminium
consumer throughout the next several years,
accounting for more
than 40% of global
aluminium consumption.
Carmakers like
VW, BMW, Audi
and Nissan are set
to open new production
plants in China
within the next two
years, and numerous
construction projects
are planned for the
country’s western
provinces. China’s
main application industry
sectors for
aluminium are set to
drive demand for both
finished and semi-finished products, but also
for processing machinery and equipment from
Japan, Korea and Europe. As a consequence
of rising energy costs an increasing number of
Chinese aluminium producing and processing
manufacturers have expressed strong intend
to buy modern, energy saving machinery and
equipment from overseas.
The organiser of Aluminium China 2013
will leverage this strong demand and invite
an even bigger number of 550 targeted top
buyers from China as well as procurement
delegations from selected application industry
sectors in Asia, for pre-arranged matchmaking
sessions with international exhibitors.
This combination of the supply and demand
side of the aluminium industry will present a
number of attractive business opportunities to
both parties. Reed Exhibition’s international
delegation programme for Aluminium China
2013 includes new partnerships with tour operators
and buying associations from countries
with increasing demand for equipment and
aluminium products: India, South East Asia
and Russia.
For Aluminium China 2013 the blend of
material exhibitions, high profile conferences
and the complementary trade exhibitions
Copper China 2013 and Magnesium China
2013 will again enhance the show’s success.
Additionally, the ‘China Aluminium Fabrication
Forum’, organised by the China Metal
Information Network, and a new edition of
the Lightweight Automotive Forum will give
participants a synergetic opportunity to source
and display diversified exhibits while learning
more about the key issues affecting today’s
aluminium industry.
Aluminium China 2013 will be taking place
from 2-4 July 2013 at the Shanghai New International
Expo Centre. For more details,
visit www.aluminiumchina.com/en.
12 th OEA International
Aluminium Recycling
Congress in Düsseldorf,
25-26 Feb 2013
What are the latest trends in aluminium recycling,
where are the risks and chances? Recycling
and its contribution to the raw material
supply will run like a golden thread through
the presentations and discussions of the 12 th
OEA Intl Aluminium Recycling Congress. Industry
experts will present their view on important
recycling matters. The aim of the congress
is to show a complete picture of all relevant
subjects on the recycling of aluminium.
The delegates of the congress who form the
Who is Who of the aluminium recycling world
will get a comprehensive update of the development
of aluminium recycling in Europe and
the world. Interesting encounters and discussions
are guaranteed.
Thanks to highly qualified speakers, numerous
delegates of the aluminium recycling
industry and other industries, as well as the
public from Europe and other parts of the
world, the 12 th OEA Congress in Düsseldorf
offers the ideal platform to answer questions,
to exchange and discuss information and to
look for solutions in order to cope with the
challenges the industry is facing. Topics to be
discussed include:
• The impact of increasing energy prices
• The regional and global scrap supply
• The role of the metal trade
• The political targets in terms of aluminium
recycling
• Innovations in recycling technologies
• Limits of scrap processing
• The pros and cons of recycled aluminium
content
• Markets for recycled aluminium.
Who should attend the congress? Refiners and
remelters of secondary smelters, scrap collectors
and processors, metal merchants, consumers
of recycled aluminium, parliamentarians
and authorities, national and international
associations.
There will be a simultaneous translation of
the presentations in English and German.
Further information and registration
details at www.oea-alurecycling.org
ALUMINIUM · 1-2/2013 7

AKTUELLES
Amag errichtet Logistikzentrum in Rekordzeit
Der Werksausbau der Amag Austria Metall
AG in Ranshofen liegt im Zeitplan. Anfang
Dezember wurde als erster Teil der Großinvestition
ein neues Logistikzentrum am Standort
Ranshofen fertiggestellt. Die neue Halle
weist eine Lagerkapazität von 11.000 Tonnen
auf. Mit dem Logistikzentrum wurde ein
wichtiger Schritt zur Steigerung der Produktionskapazitäten
gemacht. „Durch die optimale
Planung, Bauvorbereitung und den tat-
kräftigen Einsatz der Belegschaft sowie regionaler
Zulieferer- und Dienstleistungsbetriebe
wurde das Projekt in kürzester Zeit durchgeführt“,
erklärte Amag-Generaldirektor Gerhard
Falch.
Mit einem Volumen in Höhe von 220 Mio.
Euro, die über die nächsten Jahre hinweg in
den Werksausbau fließen, stellt das Projekt
eines der größten Investitionsvorhaben in der
europäischen Aluminiumindustrie dar. Der
Großteil der Investitionssumme fließt in die
Errichtung des neuen Warmwalzwerkes sowie
in die Erweiterung der Walzbarrengießerei
sowie in eine neue Plattenfertigung.
Mit den neuen Anlagen erweitert Amag
ihre Produktionskapazität im Walzwerk von
derzeit 150.000 Tonnen auf 225.000 Tonnen
und weitet das Produktspektrum zu größeren
Breiten und Dicken aus. Durch den Ausbau
werden mittelfristig rund 200 neue Arbeitsplätze
geschaffen.
© Amag
© Asco
Eckdaten des Fertigwarenlagers: Abmessungen: 199 x 56 Meter, Lagerfläche: 9.000 Quadratmeter
Ascojet-Trockeneisstrahlen für Motorenteile
Im Werk Untertürkeim setzt Daimler die
Trockeneisstrahl-Technologie der Schweizer
Asco Kohlensäure AG ein, um Motorenteile
wie Kolben, Zylinderköpfe und Kurbelgehäuse
schonend von Silikonrückständen, Ölen,
Fetten, Verbrennungsrückständen und anderen
Verschmutzungen oder Dichtstoffen zu
reinigen. Da diese Bauteile in der geometrischen
Messtechnik vor und nach Tests genau
ausgemessen werden, ist es wichtig, die Teile
nach den Tests so schonend zu reinigen, dass
die Messwerte nicht verfälscht werden.
Die Trockeneisreinigung stellt sicher, dass
die Oberflächen nicht beschädigt werden und
die Bauteile nach einmaligem Reinigen sauber
sind. Als Alternative kämen nur aufwendige
manuelle Reinigungsmethoden oder die
Reinigung mit Lösungsmitteln in Frage, was
zeitaufwendiger wäre. Noch wichtiger als die
Zeitersparnis bei der Reinigung
selbst ist für die Messtechnik
die Gewissheit, dass das Bauteil
nach einmaliger Reinigung vollkommen
sauber ist. Jede Doppelmessung
und Nachreinigung
bedeutet zusätzliche Kosten.
Ein spezieller Fall ist die
Reinigung von Kolben, deren
schmale Ringnut nicht einmal
Trockeneis messfähig säubert.
Dank eines an der Pistole montierten
Lichtkranzes (s. Foto)
wurde eine Lösung gefunden,
die Ringnut mit Trockeneis
soweit vorzureinigen, dass Verschmutzungsreste
anschließend im Ultraschallbad entfernt
werden können.
Rösler nimmt Hochregallager in
Betrieb
Die Rösler Oberflächentechnik GmbH hat am
Standort Memmelsdorf ein Hochregallager mit
17 Ebenen errichtet. Zwei neue Lasertechnik-
Hallen und ein Kompaktlager sind bereits im
Herbst in Betrieb gegangen. Der Spezialist für
Strahl- und Gleitschlifftechnik hat zu diesem
Zweck 8,5 Mio. Euro investiert.
Das neue Hochregallager bietet mit einer
Grundfläche von 1.400 Quadratmetern auf 17
Ebenen insgesamt 7.741 Palettenstellplätze,
die zum Einlagern von Grundstoffen (Compounds),
Schleifkörpern sowie Maschinenund
Ersatzteilen dienen. Mit dem Aufbau an
Lagerkapazitäten will Rösler noch schneller
auf Kundenwünsche reagieren.
Das Hochregallager nahm wie geplant
in der ersten Januarwoche seinen Dienst
auf. Pro Stunde können über die Lkw-Verladestation
100 Paletten aus- und eingelagert
werden. Bereits im Herbst des vergangenen
Jahres hat Rösler zwei Produktionshallen mit
einer Fläche von rund 3.500 Quadratmetern
in Betrieb genommen. In diese Neubauten
wurde vor allem der komplette Bereich der
Laserfertigung verlagert. Dazu gehören die
beiden vorhandenen Trumpf-Laserschneidanlagen
inklusive Materialkompaktlager. Neu
hinzugekommen sind zwei Abkanntpressen
mit jeweils 400 Tonnen Presskraft.
8 ALUMINIUM · 1-2/2013

NEWS IN BRIEF
14 to 18 May 2013, Milano, Italy
8 th Aluminium Two Thousand Congress
The Aluminium Two Thousand Conferences,
since their beginning in 1990, have become
not-to-be-missed events for aluminium technology
and marketing people all over the
world. The highly practical and specialist character
of these meetings, organised by Interall,
have been attracting more and more attendants
to listen to and debate an ever increasing
number of presentations from high-level
speakers.
Two years after the event in Bologna, the
international aluminium community – industry
experts, scientist and researchers from
renowned companies – will gather again: this
time in Milano, Italy, from 14 to 18 May 2013.
The 8 th Aluminium Two Thousand Congress
will offer a profound technical programme
with a record number of 120 papers on latest
technologies in the aluminium industry, especially
in the extrusion, rolling, casting and
finishing sectors. Representatives from leading
suppliers, extruders, anodisers, coaters, fabricators,
operators in the casting industry, and
from the automotive, electronic and aerospace
industries have already confirmed their participation.
During the plenary session on the first day,
specialists from different areas of the world
will speak about the aluminium market and
trends for the future. During the opening day,
ambassadors of seven of Africa’s most developed
countries will illustrate their projects
for industrialisation and business opportunities
at a forum titled ‘Aluminium for Africa
and Africa for Aluminium’.
The technical programme comprises four
parallel sessions
on the following
themes:
Session 1 will
deal with the extrusion
process,
with emphasis on
numerical modelling
and automation
systems, database
and extrusion
process monitoring.
Further presentations
will deal
with extrusions
and their various
applications, such
as aluminium for
structural application,
deformation of aluminium profiles,
safety aspects and energy savings.
Session 2 is dedicated to aluminium finishing:
anodising and hard anodising (latest
studies, nanotechnology, acid etching, plasma
electrolytic oxidation, studies of electrolysis
baths), coating (pretreatment, chrome-free
systems, eco-friendly solution for aluminium
pretreatment, aesthetic surface treatment with
high durability, corrosion protection), environmental
protection and recycling.
Session 3 is dedicated to casting and diecasting
(semi-solid casting for reducing energy,
methodology for temperature evaluation, micro-porosity
in gravity die-casting, self-cleaning
effects, casting structural alloys).
Session 4 will deal with measuring, testing
Attendees at the Aluminium Two Thousand Congress in 2011
and quality techniques (quality management
and control, measuring instruments), rolling
technology (heat transfer, new studies), advanced
forming and welding processes.
The ‘Russian Day’ for Russian speaking
delegates is another special event: the most
interesting papers with innovative content will
be repeated by the speakers in a separate full
session with simultaneous translation.
The congress programme includes three
workshops (full day) on extrusion, anodising
and coating, as well as the choice of a technical
tour out of a total of five. An attractive social
programme with a gala dinner, daily tours for
accompanying persons rounds off the event.
Further information at
www.aluminium2000.com
© Interall
Rio Tinto announces huge write-down of aluminium assets
Mining giant Rio Tinto has revealed a near
USD14 billion (after tax) write-down of its
coal and aluminium assets. The write-down of
the aluminium assets (mainly related to Rio
Tinto Alcan but also to Pacific Aluminium) is
in the range of USD10-11 billion; a further
USD3 billion write-down relates to Rio Tinto
Coal Mozambique. The final figures will be
included in Rio Tinto’s 2012 full year results
due on 14 February.
As a direct consequence of this dramatic
cut, Tom Albanese has stepped down as chief
executive. Iron Ore chief executive Sam
Walsh has been appointed as his successor
with immediate effect.
Chairman Jan du Plessis commented: “The
Rio Tinto board fully acknowledges that a
write-down of this scale in relation to the relatively
recent Mozambique acquisition is unacceptable.
We are also deeply disappointed to
have to take a further substantial write-down
in our aluminium businesses, albeit in an industry
that continues to experience significant
adverse changes globally.” Mr Plessis said
Rio Tinto will implement an “aggressive cost
reduction plan” to improve the company’s
competitive position.
Already at its investor seminar in Sydney
at the end of November, Rio Tinto said that
the annual year-end review of asset carrying
values would most likely result in further
revisions to the value of assets, notably aluminium.
The further deterioration in aluminium
market conditions in 2012, together
with strong currencies in certain regions and
high energy and raw material costs, has had
a negative impact on the current market values
in the aluminium industry.
Rio Tinto acquired Canadian aluminium
flagship Alcan in 2007. The takeover price of
USD101 a share corresponded to some ten
times Rio Tinto’s Ebitda. The mining company
has now written down USD28-29 billion or
about three quarters of the USD38 billion
paid for Alcan.
ALUMINIUM · 1-2/2013 9

WIRTSCHAFT
2004 2005 2006 2007 2008 2009 2010 2011 2012
0
50
–50
2.500
2004 2005 2006 2007 2008 2009 2010 2011 2012
2.000
1.500
1.000
2004 2005 2006 2007 2008 2009 2010 2011 2012
6.000
5.000
4.000
3.000
2.000
1.000
0
10 ALUMINIUM · 1-2/2013

WIRTSCHAFT
Produktionsdaten der deutschen Aluminiumindustrie
Primäraluminium Sekundäraluminium Walzprodukte > 0,2 mm Press- & Ziehprodukte**
Produktion
(in 1.000 t)
+/-
in % *
Produktion
(in 1.000 t)
+/-
in % *
Produktion
(in 1.000 t)
+/-
in % *
Produktion
(in 1.000 t)
Nov 35,2 -1,9 57,0 8,5 152,8 -3,5 53,2 4,7
Dez 35,9 -3,5 46,7 12,1 109,2 -11,5 30,2 -3,5
Jan 12 35,3 -4,7 54,1 7,2 145,4 -6,1 46,3 3,3
Feb 32,4 -4,1 55,6 2,6 149,3 -7,3 47,7 0,9
Mär 34,1 -8,0 57,2 -2,2 165,9 -4,5 50,4 -5,1
Apr 33,5 -6,1 53,3 0,2 147,2 -6,0 45,0 -4,9
+/-
in % *
Mai 34,4 -7,4 54,3 -4,1 160,7 -4,5 48,9 -12,7
Juni 33,0 -8,0 54,6 6,9 161,0 20,6 49,1 -0,3
Juli 34,8 -5,0 56,0 7,1 166,4 0,9 46,9 -7,4
Aug 34,9 -5,8 47,2 2,9 161,4 1,2 44,9 -11,8
Sep 33,6 -4,4 52,5 -4,3 164,5 8,1 44,6 -17,2
Okt 35,2 -2,5 53,3 -0,3 162,5 9,4 46,1 -7,4
Nov 34,2 -2,9 53,4 -6,4 152,9 0,1 42,5 -20,1
* gegenüber dem Vorjahresmonat, ** Stangen, Profile, Rohre; Mitteilung des Gesamtverbandes der Aluminiumindustrie (GDA), Düsseldorf
Primäraluminium
Sekundäraluminium
Walzprodukte > 0,2 mm
Press- und Ziehprodukte
12 ALUMINIUM · 1-2/2013

WIRTSCHAFT
Produktionsdaten der deutschen Aluminiumindustrie
Primäraluminium Sekundäraluminium Walzprodukte > 0,2 mm Press- & Ziehprodukte**
Produktion
(in 1.000 t)
+/-
in % *
Produktion
(in 1.000 t)
+/-
in % *
Produktion
(in 1.000 t)
+/-
in % *
Produktion
(in 1.000 t)
Nov 35,2 -1,9 57,0 8,5 152,8 -3,5 53,2 4,7
Dez 35,9 -3,5 46,7 12,1 109,2 -11,5 30,2 -3,5
Jan 12 35,3 -4,7 54,1 7,2 145,4 -6,1 46,3 3,3
Feb 32,4 -4,1 55,6 2,6 149,3 -7,3 47,7 0,9
Mär 34,1 -8,0 57,2 -2,2 165,9 -4,5 50,4 -5,1
Apr 33,5 -6,1 53,3 0,2 147,2 -6,0 45,0 -4,9
+/-
in % *
Mai 34,4 -7,4 54,3 -4,1 160,7 -4,5 48,9 -12,7
Juni 33,0 -8,0 54,6 6,9 161,0 20,6 49,1 -0,3
Juli 34,8 -5,0 56,0 7,1 166,4 0,9 46,9 -7,4
Aug 34,9 -5,8 47,2 2,9 161,4 1,2 44,9 -11,8
Sep 33,6 -4,4 52,5 -4,3 164,5 8,1 44,6 -17,2
Okt 35,2 -2,5 53,3 -0,3 162,5 9,4 46,1 -7,4
Nov 34,2 -2,9 53,4 -6,4 152,9 0,1 42,5 -20,1
* gegenüber dem Vorjahresmonat, ** Stangen, Profile, Rohre; Mitteilung des Gesamtverbandes der Aluminiumindustrie (GDA), Düsseldorf
Primäraluminium
Sekundäraluminium
Walzprodukte > 0,2 mm
Press- und Ziehprodukte
12 ALUMINIUM · 1-2/2013

ECONOMICS
Five hundred participants at Arabal 2012 Conference
© Arabal
Almost 500 participants – a record
number – attended the Arabal 2012 Conference
in Doha in November last year.
In his opening address to the plenary session
Mohammad Ali Al Naqi, chairman of
the Organising Committee, outlined how
things have changed since the first Arab
Aluminium Conference in 1983. “Today,
as we celebrate the 16 th occasion of
Arabal, the region has seven primary aluminium
smelters with a capacity of up to
15 percent of global production,” he said,
adding that this went along with other,
supporting projects such as calcined coal
and projects that depend on smelters’
products, like aluminium extrusion, cables
and car-wheel factories which supply
the global automotive industry. 1
Well attended – the Arabal 2012 Conference
The first day of the conference focused on
regional issues, power generation and technology.
Abdulrahman Ahmed Al Shaibi, chairman
of Qatalum, the organising host of Arabal
2012, took the audience through the steps
that the company has taken in Qatar and the
achievements realised in the aluminium industry
and industrial sector. Despite the current
global economic slowdown, he is optimistic
about future development in the aluminium
industry: “We do not expect low prices to
last; unlike many other metals, growth in aluminium
demand is positive and we expect it
to continue,” he said, being confident that the
aluminium price will follow bullish demand
forecasts.
The industrial sector in Qatar was moving
1
Note from the editor: the 15% figure does not
include the Alcoa Ma’aden smelter, which was
inaugurated in mid-December 2012.
on the right track, he noted, “supported by
incentives and industrial benefits that aim to
encourage industrial investment and to focus
on industrial projects that are based on best
available technology”, something which can
no longer be considered on a solely national
basis. “It is truly an international industry,
due to the interdependence between production
and raw material hubs, the smelting and
refining centres and the manufacturing industries,”
he said.
Mr Al Shaibi, who also spoke on behalf of
Mr Al Sada, Minister of Energy and Industry,
pointed out that the aluminium industry
was in a state of restructuring. The economic
downslide in Europe coupled with escalating
power tariffs, lack of local resources, taxation
and tightening of ecological regulations had
already resulted in the shutdown of European
aluminium smelters. “We are seeing a spate
of evolution and consolidation within the
industry. The focus of the aluminium sector
is steadily shifting, often
away from those who were
considered the traditional
leaders. Middle-Eastern
manufacturers are now
increasingly emerging as
serious contenders in the
global aluminium market,”
he said.
Qatalum CEO Tom
Petter Johansen ruled
out direct involvement in
downstream industries but
said the company’s focus
would be on capacity enhancement.
Qatalum smelter tour
Mr Al Shaibi (left) and Mr Al Naqi
Attendees of the conference had the opportunity
to visit the Qatalum smelter at Mesaieed
Industrial City. The 40-minute tour of the
facility – which consumes up to one third of
Qatar’s total power usage – started at Potline
2, then moved to the baking furnace, paste
plant and anode rodding shop and also to the
casthouse and power plant and to a building
characterised by zero net energy consumption
and zero carbon emissions.
At the paste plant ingredients are mixed to
create new (green) anodes. The baking plant
consists of furnaces where green anodes are
baked to form the black anodes used in the
reduction pots for making liquid aluminium.
The 1,350 MW power plant includes the turbine
building, seawater cooling towers, four
heat recovery steam generators for recycling
exhaust gases and finally the gas insulated
switchgear (GIS) – the connection between
the power plant and the smelter. The delegates
were accompanied by tour guides from
Qatalum to answer any questions on the plant,
processes and people.
The role of China
China’s aluminium industry was a major topic
on the final day of the Arabal conference.
Paul Adkins, director of AZ China Limited,
and Eric Zhang, analyst at SMM, spoke
about the peculiarities of the Chinese industry,
which persists with enormous production
despite heavily subsidised losses, at least in
certain provinces. According to Adkins, China
is in the top quartile of the global cost curve.
Its industry consumes scarce energy resources,
is forced to import raw materials and jeopardises
environmental integrity, yet 10 million
tonnes of new capacity are still to come
online.
“Why on earth do the Chinese persist with
making aluminium,” he asked rhetorically. His
answer: “As Westerners and as analysts and
corporates, we focus on the markets, the industry,
equities, P & L (profit & loss), capital
flows, ROI, etc. But by doing so, we can miss
the key point: for the Chinese Communist
Party, aluminium is an important conduit for
the development, urbanisation and modernisation
of China,” he said.
Eric Zhang forecast that domestic aluminium
prices will face many uncertainties in
2013 and are subject to LME aluminium
prices to a large extent. SMM expects domestic
aluminium prices to fluctuate between
RMB15,000-17,500/t (USD2,400-2,800/t) in
2013.
The role of China was a theme carried into
the next session, with a presentation by Jorge
14 ALUMINIUM · 1-2/2013

ECONOMICS
Vazquez, managing director of Harbor Aluminium
Intelligence, who spoke to delegates
on who is winning and losing in the global
aluminium industry and supply chain today.
“Who is getting the value?” he asked. “It is
not the producer for sure.” Today, consumers
are getting the greatest value ever, with
real LME aluminium prices at a cycle bottom
below USD2,000/t, compared to the historical
average of USD2,650/t and a high of about
USD4,700/t.
In his view there are two main sources of
growth in the next five years: emerging Asia
(including the Gulf) and the Americas. Over
16 million tonnes of new aluminium capacity
should hit the market by 2015, two thirds of
this in China for domestic consumption. The
Middle East too is well placed. “We see the
Middle East as the leading provider for growing
world metal needs ahead and the Americas
/ Europe / South East Asia as increasing
import players,” he said.
Outlook of the automobile industry
David Cutting, director of J. D. Power Automotive
Forecasting, spoke about the Global
Light Vehicle Market, which is heavily depend-
ent on aluminium.
The global light vehicle
market is predicted
to break through
the 100 million barrier
by 2015, almost
doubling in volume
since the end of the
1990s. Emerging markets,
led by China,
India, Brazil and Russia,
have driven much
of the recent growth
and are expected to
remain key motivators
of future growth.
Light vehicle production
growth in Asia is expected to significantly
outpace the other regions (with share of output
increasing from 48% in 2011 to 53% by
2016).
Shambhu Prasad, senior expert at Gulf
Organisation for Industrial Consulting, noted
that aluminium usage has increased to 140 kg
per car in 2011 – predominantly in the drivetrain,
chassis and suspension, and body. The
automotive industry is the largest market for
aluminium castings, which account for more
Qatalum smelter at Mesaieed Industrial City
than 50% of aluminium used in cars.
The day and the conference as a whole
wrapped up with a Culture Night at Skeikh
Faisal Bin Qassim al Thani Museum, with a
tour of the museum followed by a dinner at
Majlis hall, at which delegates could discuss
the connections made, information shared
and arguments put forward over three days
of discussion about the aluminium industry at
national, regional and international level.
© Qatalum
Dubal’s DX+ technology selected by Alba
Dubai Aluminium has signed an agreement
with Aluminium Bahrain whereby the latter will
use Dubal’s DX+ technology for Alba’s Potline
6 Bankable Feasibility Study. Tim Murray, chief
executive of Alba, pointed out that study would
determine the viability of Alba’s sixth potline expansion
project, which will boost the company’s
aluminium production capacity by approximately
400,000 tpy to 1.280 million tonnes.
Dubals’s DX+ technology is an enhanced version
of Dubal’s proven DX technology. DX+ is
designed to operate at higher amperages and
optimised performance levels. Five DX+ cells, built
in a pilot line at Dubal’s Jebel Ali site in 2010,
initially operated at 420 kA and currently operate
stably at 440 kA. At this level, the DX+ cells yield
substantially better energy efficiency and specific
energy consumption levels than DX cells, and
produce 3,37 tonnes of aluminium per pot per
day. Ultimately, DX+ cells are expected to operate
at 460 kA.
While in the UAE, the Alba delegation visited
Dubal’s Potline 8 – a dedicated 40-cell potline
within the greater smelter operations where
Dubal’s proprietary, in-house developed DX technology
has been fully operational since February
2008, and visited Dubal’s DX+ pilot section. The
Alba delegates were also accompanied on a tour
of Emal in Al Taweelah, Abu Dhabi, where 756
DX technology cells, arranged in two potlines,
have been fully operational at Emal Phase I since
the end of December 2010.
“Dubal’s reduction technologies have
been designed fully-modelled and extensively
tested. The results consistently
confirm that both DX and DX+ technology
operate stably, demonstrating not only
the robustness of their design but also the
suitability of both to the Gulf climate,” said
Abdulla Kalban, president and chief executive
of Dubal. “We are delighted that Alba
has recognised these qualities as evidenced
by the selection of DX+ technology for the
Line 6 Bankable Feasibility Study.”
Bechtel to conduct feasibility study
Alba has awarded Bechtel Canada a letter
of intent to conduct the feasibility study
for Potline 6. The study will include the
economic analysis for the construction of a new
Power Station 5. Bechtel has considerable industry-specific
experience in the region and was previously
the EPCM contractor for the Alba Potline
4 and 5 expansions. The study is expected to be
complete by the third quarter of 2013.
View of the Alba site
© Alba
ALUMINIUM · 1-2/2013 15

ALUMINIUM SMELTING INDUSTRY
TMS2013 offers a diversity of light metals
programming and networking opportunities
The Minerals, Metals & Materials Society (TMS) 142 nd Annual Meeting and
Exhibition will take place from 3 to 7 March 2013 in San Antonio, Texas, USA
“This is where the many facets of TMS
meet,” says Wolfgang Schneider, 2012
TMS President and head of the Hydro
R&D Centre in Germany, of the TMS2013
Annual Meeting and Exhibition. “It is at
the core of what we do as a professional
society and showcases the very best of
what TMS has to offer – as well as the
very best of what materials science and
engineering has to offer the world.”
processing and production topics pertinent to
the aluminium community are incorporated
throughout TMS2013’s other technical subject
areas. These include: Advanced Characterisation,
Modelling, and Performance; High
TMS2013 Exhibition: Find the expertise and
technology necessary to implement the new
concepts and approaches covered in the
TMS2013 symposia sessions at the three-day
exhibition. TMS will offer a free buffet lunch
The foundation of TMS2013 is an exceptionally
strong technical programme featuring
more than 330 sessions built from more than
3,000 abstract submissions. Topics span the
continuum of materials science and engineering,
from basic research of novel materials to
optimisation of manufacturing processes. This
breadth of programming offers attendees a
unique opportunity to network and learn from
colleagues representing other disciplines, facilitating
the transition of material innovations
from bold idea to successful product.
Contributing to the strength of TMS’s annual
meeting programming is the ‘globalisation’
of contributing authors in recent years.
For TMS2013, nearly half of the abstracts accepted
came from outside the United States.
“The TMS Annual Meeting has evolved into a
truly international event,” he says. “Not only
does this build the prestige of the conference,
but also greatly enhances the depth and quality
of the learning and perspectives that are
gained from attending it.”
TMS2013 highlights of particular interest
to the aluminium industry include:
Technical track devoted exclusively to
light metals: Representatives from the world’s
largest light metals companies and research
organisations convene to discuss breaking
developments, evolving challenges, and new
opportunities. Planned symposia specific to
the aluminium industry include: Aluminium
Alloys – Fabrication, Characterisation and Applications;
Alumina and Bauxite; Aluminium
Processing; Aluminium Reduction Technology;
Cast Shop for Aluminium Production;
Deformation, Damage, and Fracture of Light
Metals and Alloys; Electrode Technology for
Aluminium Production.
Interdisciplinary learning opportunities:
Energy management, recycling, and materials
View looking into the exhibition hall at TMS2012
Performance Materials; Materials Processing
and Production; and REWAS 2013: Enabling
Materials Resource and Sustainability.
Aluminium Keynote Session: The TMS
2013 Aluminium Keynote Session will assemble
experts representing a range of perspectives
on managing impurities in the aluminium
supply chain. “The primary goal is to bring
people together from the bauxite / alumina,
reduction, electrode, and casthouse areas to
make the point that we need to think about
impurities holistically rather than something
that affects each area separately,” says Les
Edwards, vice president of Technical Services,
Rain CII Carbon, and session chair. “Taking
this approach can change the way we develop
solutions to impurity problems.” Technical papers
presented in the session will be published
in the 2013 Light Metals proceedings.
Light Metals Division Luncheon: This
popular networking event will feature John
Mitchell, president of Rockwood Lithium
North America, as its featured speaker.
in the exhibition hall on 5 March, along with
the president’s Reception and Happy Hour
Tuesday event. Lunch items will also be available
on 4 and 6 March, to make exhibition
browsing convenient between sessions.
Essential Readings in Light Metals: Available
for sale at TMS2013 will be the just-released
Essential Readings in Light Metals, a
comprehensive collection of the most significant
papers published in the more than four
decades of the Light Metals proceedings. A
rigorous review process, based on a specific
selection criteria, has compiled about 10-15%
of all Light Metals articles into four volumes,
which can be purchased individually or as a
set. Volume topics are: Alumina and Bauxite;
Aluminium Reduction Technology; Cast Shop
for Aluminium Production; and Electrode
Technology for Aluminium Production.
For additional information on TMS2013
and to make registration and housing arrangements,
visit the conference website at
www.tms.org/tms2013.
© TMS
16 ALUMINIUM · 1-2/2013

ALUMINIUM SMELTING INDUSTRY
Recent development of Dubal
aluminium reduction cell technologies
M. Reverdy, Dubal
Dubai Aluminium (Dubal) commenced
operation in 1979 with a capacity of
90,000 tonnes a year, and it has progressively
grown to reach over one million
tonnes in 2010, predominantly using its
in-house developed D18, D20, CD20,
DX, DX+ and D18+ cell technologies.
The number of reduction cells and the
annual production capacity of these technologies
is shown in Table 1. Recent development
and results of DX+ and D18+
cell technologies will be described in this
paper.
DX cell technology started in 2005 with five
prototype cells, followed by a 40-cell demonstration
potline at Dubal in 2008. The implementation
on a large industrial scale was at
Emal Phase 1 with two potlines and an initial
production capacity of 750 000 tonnes a year
DX cells have operated at 385 kA at Dubal
since March 2012, and at 380 kA at Emal
since September 2012 [1-3]. Five DX+ cells
were started in July 2010 at Dubal at 420 kA
and are now operating at 440 kA. One potline
of 444 DX+ cells is currently under construction
at Emal Phase 2. These cells should start
production in 2013/14 at 440 kA, and they
are designed for a future potential of 460 kA.
D18 cells were recently completely redesigned
for 210 kA and low energy consumption, resulting
in seven D18+ pilot cells. These started
up in March 2012 at 200 kA because there is
no booster for this group of cells.
DX+ cell technology
DX+ cell technology is an evolution of the DX
technology for high productivity and lower
capital cost per installed tonne of capacity
[4-5]. Five DX+
demonstration
cells in Dubal
Eagle Section
are shown in
Fig. 1. The key
performance indicators
(KPIs)
are given in Table
2.
DX+ cells were designed utilising in-house,
commercial software-based mathematical
models that were developed in recent years at
Dubal. These comprise thermo-electric, magnetohydrodynamics
(MHD), mechanical, cell
gas exhaust and potroom ventilation models.
The models were originally validated on operational
DX cells and were re-confirmed on
operational DX+ cells [6]. The alignment between
the models and measurements is excellent,
instilling confidence to use these models
for further optimisation and development of
Dubal cell technologies.
In addition to increased amperage and
higher metal production per day, DX+ tech-
Reduction cell technology Amperage (kA) Number of cells Capacity (kt/y)
D18 202 513 284
D18+ 202 7 4
CD20 250 480 335
D20 249 528 367
DX 385 40 43
DX+ 440 5 6
Total 1,573 1,039
Table 1: Cell technologies at Dubal
Fig. 1: Five prototype DX+ cells in the demonstration section at Dubal
© Dubal
18 ALUMINIUM · 1-2/2013

ANODE BAKING FACILITIES
The Riedhammer anode baking facility is a key
component in a modern anode production plant.
Our plants offer many advantages such as:
• Customised design
• Excellent anode quality
• Extended furnace lifetime
• Low energy consumption
• High productivity
• Flexible equipment supply
• Safe operation
RIEDHAMMER
CARBON BAKING TECHNOLOGY
RIEDHAMMER GmbH
Klingenhofstraße 72
90411 Nürnberg
Phone: +49 911 5218 0
Fax: +49 911 5218 231
www.riedhammer.de

ALUMINIUM SMELTING INDUSTRY
KPI
Unit
Dec 2010
to
July 2011
Aug 2011
to
Feb 2012
Mar 2012
to
Sept 2012
1 Oct 2012
to
21 Nov 2012
Amperage kA 419.6 430.2 439.7 440.1
Current efficiency % 95.1 94.9 94.5 94.9
Metal production kg/pot-day 3214 3291 3345 3366
Volts per cell V 4.22* 4.22** 4.24*** 4.24***
DC specific energy kWh/kg Al 13.22* 13.25** 13.37*** 13.37***
Net carbon consumption kg/kg Al 407 412 404 0.398
Fe % 0.040 0.039 0.043 0.036
Si % 0.028 0.029 0.028 0.026
AE frequency AE/pot-day 0.191 0.085 0.071 0.046
AE duration s 9.6 10.3 10.1 10.3
PFC emissions,
CO 2 equivalent****
kg/t Al 33 16 13 9
Fig. 2, above: Historical data on HMI
Fig. 3, below: Pot voltage trend graph on HMI
Table 2: KPIs of Dubal DX+ technology –
average of the five cells
*Based on 4.35 V actual minus 0.13 V for design changes in
the industrial version of DX+
**Based on 4.32 V actual minus 0.10 V for design changes
in the industrial version of DX+
***Based on 4.31 V actual minus 0.07 V for design changes
in the industrial version of DX+
****CO 2 equivalent is calculated as in Reference [4], using
the Tier 2 method
nology has been optimised in many other ways
with respect to its sister DX technology. In spite
of increased length and width, the mass of the
DX+ optimised potshell was reduced by 21%
without any reduction in strength, thanks to improved
structural characteristics of the design.
The cell superstructure height was lowered by
more than 400 mm, and in spite of its increased
size, its mass was decreased by 12%. The overall
volume of the concrete in the potshell and busbar
supports was reduced by 35%.
Considering the amperage increase to 440
kA, the productivity of potroom in tonnes of aluminium
per square metre of covered building has
increased by 16% to 7.12 tonnes of aluminium
produced per square metre of covered building,
calculated for 360 cells and one central passage
per potroom. Capex improvement is the result of
cell productivity, which is proportional to amperage,
and of the higher number of cells per potline
corresponding to the higher rectiformer voltage
of 2,000 V DC. Further optimisation is under way.
The design of DX+ busbars has already been optimised
and the results are: decrease of cell centreline
distance by approx. 5%, reduction of busbar
mass by 20% and reduction of busbar voltage
drop by 26%. Reduced cell-to-cell distance
increases the building productivity by 4.6%.
In Table 1, the actual voltage and the corresponding
specific energy consumption have been
corrected with respect to demonstration cells
to allow for the expected improvements due to
design changes in the industrial DX+ cells to be
installed at Emal Potline 3. These improvements
include larger cross-sections of busbars and cathode
collector bars. A substantial voltage gain has
been obtained with the introduction of four-stub
anodes at the end of 2011 instead of the threestub
anodes previously used. This explains a different
voltage correction for DX+ industrial cells
for the four periods given in Table 2.
Excellent performance has been maintained in
conjunction with amperage increase. As per tradition
at Dubal, the metal purity is excellent in DX
potlines at both Dubal and Emal as well as in DX+
demonstration cells at Dubal: the metal’s low
iron and silicon content did not deteriorate with
amperage increase. Low anode effect frequency
and duration result in very low PFC emissions
(expressed in CO 2 equivalent kg/t Al in Table 1)
which are a benchmark within the industry [7].
20 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
Dubal has developed its own proprietary
cell control system, comprising microcomputer
based DCCU (Dubal Cell Control Unit)
and cell control software. DCCU has been
progressively installed since 2005 in Dubal
and also in Dubal-licensed smelters, with
1,276 cells equipped as of November 2012.
Recently, a new hardware system, based on
standard PLC (Programmable Logic Controller),
has been developed and installed on the
five DX+ demonstration cells. It has been also
chosen for Emal Phase 2.
Increased Graphical User Interface (GUI)
capabilities provide improved and more complete
information to cell operators than the
original control systems, which were generally
text based and black
and white. The new Human
Machine Interface (HMI) provides
the operators access to
all required supervisory controls,
data entries and information
about the cells in the potroom.
Two sample screen shots
from HMI are shown in Figs 2
and 3. The HMI can also display
various trend graphs for a period
of 30 minutes to 8 hours
(Fig. 3).
The PLC data are sent to
the potline server, where they
are analysed and displayed in
the same way as with DCCU
based control system. Detailed
pot traces and command interface
can be obtained from ‘iPots’
system hosted on a network
server. In addition, user specified
queries can be used in a
new web based Smelter Analytics
platform developed in-house
to provide data in an exportable
format to programs such as MS
Excel. The new ‘iRPMS’ reporting
system, equipped with a web
based interface for ease of navigation,
provides information
to the user from the potlines,
carbon plant, casthouse, etc. as
well as presenting various types
of summary overviews to the
senior management.
D18+ cell technology
The D18 technology is the result
of Dubal development of the
P69 technology first installed
in 360 cells in Dubal in 1979.
Subsequent additions brought
Busbar configuration
Al 2 O 3 feeding
D18 D18+
End risers
Pseudo point feed converted
from dual centre breaking
Four side risers with
under cell bus
Four point feeders with
bath sensing breakers
AlF 3 feeding 10 kg bags added manually Dedicated AlF 3 feeder
Alumina distribution Via crane hopper Dense phase system
Number of anodes 18 20
Anode beam control Pneumatic Electric
Number of cathode blocks 17 19
Collector bar – flexible connection Bolted Welded
Table 3: Comparison between D18 and D18+
the total number to the current 520. Further
significant advances in operating performance
are limited mainly by poor magnetohydrodynamic
(MHD) stability, by alumina
and AlF3 feeding control and by high anode
current density. A new cell design, D18+ has
For over 50 years BUSS KE and CP series Kneaders have been
the benchmark for reliable, cost-effective compounding of
anode pastes. Now we go one step further.
ALUMINIUM · 1-2/2013

ALUMINIUM SMELTING INDUSTRY
KPI
Unit
D18+, 1 June
to 21 Nov 2012
D18
Difference
Amperage kA 202 202 0
Current efficiency % 96.0 92.3 3.7
Metal production kg/pot-day 1,562 1,502 60
Volts per cell V 4.08 4.69 -0.61
DC specific energy kWh/kg Al 12.67 15.14 -2.47
Fe % 0.05 0.07 -0.02
Si % 0.02 0.03 -0.01
AE frequency AE/pot-day 0.02 0.44 -0.42
AE duration (V > 8 V) s 32 31 1
PFC emissions,
CO 2 equivalent [4]
kg/ t Al 12 247 -235
Table 4: D18+ and D18 performance comparison. D18+ is average of 5 middle pots
tion from D18 to D18+ cell design. Additionally,
the original potshell was modified to accommodate
two more cathode blocks. Fig. 3
shows the seven test cells. Table 4 gives key
performance indicators. The performance of
the D18+ cells has now exceeded the original
design targets, resulting in significant improvement
over the existing D18 cells. The
test cells are currently being fully evaluated
before implementing throughout Dubal’s
D18 potlines.
Conclusions
DX+ cell technology continues to give excellent
performance with considerable amperage
increase to 440 kA in DX+ pilot cells.
The new DX+ Pot Control System is based
upon standard market PLCs, which give increased
HMI capabilities and ensure easy
maintenance and future development.
The successful test and validation of the
D18+ cell technology has proven that it is
both technically and practically possible to
update and replace the cell technology within
an existing operating potline. Study of the
feasibility and optimal engineering pathway
is currently in progress to enable replacing
the remaining 513 D18 cells with the D18+
technology.
References
Fig. 4: Completed seven D18+ test cells in a D18 potline
been developed to modernise the original
Dubal D18 potlines and to improve their performance
and economic competitiveness [8].
The objectives behind modernising the cells
through new technology are to reduce the
specific energy consumption to below 12.9
kWh/kg Al, reduce the anode effect frequency
to below 0.10 per cell-day and to allow for a
possible further amperage in-crease of 40 kA.
The constraints were: to maintain the same
cell-to-cell centerline
distance and
the same cell
height, to keep
the amperage
availability limits
within the same
rectifiers and to
use the same gas
treatment centre.
Seven D18+
cells were constructed
and successfully
startedup
in March 2012.
Table 3 gives a list
of changes made
during the transi-
[1] Ali Al Zarouni et al., DX Cell Technology Powers
Green Field Expansion, Light Metals 2010, 339-
343.
[2] B.K. Kakkar et al., Commissioning of Emirates
Aluminium Smelter Potlines, Light Metals 2012,
721-726.
[3] Ali Al Zarouni et al., The Successful Implementation
of Dubal DX Technology at Emal, Light Metals
2012, 715-720.
[4] Ali Al Zarouni et al., DX+ an Optimized Version
of DX Technology, Light Metals 2012, 697-702.
[5] M. Reverdy et al., Advancements of Dubal High
Amperage Reduction Cell Technologies, Light Metals
2013.
[6] Abdalla Zarouni et al., Mathematical Model
Validation of Aluminum Electrolysis Cells at Dubal,
Light Metals 2013.
[7] Abdalla Zarouni et al., Achieving Low Greenhouse
Gases Emission with Dubal’s High Amperage
Cell Technology, 19 th International Symposium IC-
SOBA, Belem, Brazil, 25 Oct. to 2 Nov. 2012.
[8] S. Akhmetov et al, D18+: Potline Modernisation
at Dubal, Light Metals 2013.
Author
Michel Reverdy is Technology Transfer manager at
Dubal.
22 ALUMINIUM · 1-2/2013

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ALUMINIUM SMELTING INDUSTRY
The ‘AP Technology’ smelter of the future
The economical, energy efficient and environmentally safe solution for primary aluminium production
S. Fraysse, J.-M. Jolas, F. Charmier and O. Martin, Rio Tinto Alcan
An efficient smelter solution is made up
of many technological buildings blocks.
The degree of interaction between the
blocks is quite high and can be complex.
Rio Tinto Alcan has not only continuously
developed and optimised these blocks;
over the years, it has also developed a
global approach to its smelter solution.
The global approach, code named
Global Smelter Design (GSD), is used to
design the smelter of the future, building
global and coherent solutions based on a
functional and cross-cutting view of the
plant. The approach has been made even
more relevant by new available technologies
and products in fields as varied as
automation, robotics, data processing,
environmental expertise, innovative civil
works and new materials.
Global smelter design builds upon the
first-in-class AP Technology processes
and in particular, reduction cells to optimise
global development of the smelter
solution.
use the same generic cell equipment:
• AP6X cell, the benchmark of cell
productivity
• APXe, operating at low energy
consumption and the benchmark
environmental performance.
These two versions will make it possible to deliver
optimal solutions for greenfield projects
starting in the next few years.
The first APXe cell was started in December
2010 and has already delivered very
promising results: after less than one year of
operation, the 12.3 kWh/kg target has been
achieved with very low fluoride emission and
at particularly low gas suction rates [1].
More ambitious targets are already planned
for the coming months. Some of the innovative
solutions developed on the APXe cell can also
be deployed in existing aluminium smelters
in order to reduce their energy consumption
and environmental footprint.
An industrial demonstration of AP6X
Platform – Jonquiere, Quebec: The Rio Tinto
board of directors approved the AP60 Phase
Reduction cells to support the
existing assets optimisation
and the smelters of the future
The team which has supplied technologies to
a large number of aluminium smelter projects
over the last 40 years has had a unique opportunity
to develop and industrialise the best
cells to meet the greatest constraints and challenges.
The technical challenge of low energy: After
125 years of operation, Hall-Héroult process
cell productivity has improved dramatically
through the development of high-amperage
cells. However, improvement in energy efficiency
levelled off after the seventies. In the
coming decades, the challenge of massive demand
for aluminium in an energy-constrained
future calls for the development of low-energy
cell designs.
With the different AP cell platforms, Rio
Tinto Alcan proposes a comprehensive suite
of solutions able to take up this challenge and
to adapt to changing market trends. This offer
is based on two platforms, AP6X-APXe and
AP4X.
AP6X – APXe platform: Rio Tinto Alcan
has developed two new cell technologies that
AP Technology cells
AP Technology, sites in operation and under construction
© Rio Tinto Alcan
24 ALUMINIUM · 1-2/2013

ALUMINIUM SMELTING INDUSTRY
The ‘AP Technology’ smelter of the future
The economical, energy efficient and environmentally safe solution for primary aluminium production
S. Fraysse, J.-M. Jolas, F. Charmier and O. Martin, Rio Tinto Alcan
An efficient smelter solution is made up
of many technological buildings blocks.
The degree of interaction between the
blocks is quite high and can be complex.
Rio Tinto Alcan has not only continuously
developed and optimised these blocks;
over the years, it has also developed a
global approach to its smelter solution.
The global approach, code named
Global Smelter Design (GSD), is used to
design the smelter of the future, building
global and coherent solutions based on a
functional and cross-cutting view of the
plant. The approach has been made even
more relevant by new available technologies
and products in fields as varied as
automation, robotics, data processing,
environmental expertise, innovative civil
works and new materials.
Global smelter design builds upon the
first-in-class AP Technology processes
and in particular, reduction cells to optimise
global development of the smelter
solution.
use the same generic cell equipment:
• AP6X cell, the benchmark of cell
productivity
• APXe, operating at low energy
consumption and the benchmark
environmental performance.
These two versions will make it possible to deliver
optimal solutions for greenfield projects
starting in the next few years.
The first APXe cell was started in December
2010 and has already delivered very
promising results: after less than one year of
operation, the 12.3 kWh/kg target has been
achieved with very low fluoride emission and
at particularly low gas suction rates [1].
More ambitious targets are already planned
for the coming months. Some of the innovative
solutions developed on the APXe cell can also
be deployed in existing aluminium smelters
in order to reduce their energy consumption
and environmental footprint.
An industrial demonstration of AP6X
Platform – Jonquiere, Quebec: The Rio Tinto
board of directors approved the AP60 Phase
Reduction cells to support the
existing assets optimisation
and the smelters of the future
The team which has supplied technologies to
a large number of aluminium smelter projects
over the last 40 years has had a unique opportunity
to develop and industrialise the best
cells to meet the greatest constraints and challenges.
The technical challenge of low energy: After
125 years of operation, Hall-Héroult process
cell productivity has improved dramatically
through the development of high-amperage
cells. However, improvement in energy efficiency
levelled off after the seventies. In the
coming decades, the challenge of massive demand
for aluminium in an energy-constrained
future calls for the development of low-energy
cell designs.
With the different AP cell platforms, Rio
Tinto Alcan proposes a comprehensive suite
of solutions able to take up this challenge and
to adapt to changing market trends. This offer
is based on two platforms, AP6X-APXe and
AP4X.
AP6X – APXe platform: Rio Tinto Alcan
has developed two new cell technologies that
AP Technology cells
AP Technology, sites in operation and under construction
© Rio Tinto Alcan
24 ALUMINIUM · 1-2/2013

ALUMINIUM SMELTING INDUSTRY
AP6X – APXe platform
1 project Notice to Proceed on 14 December
2010 following completion of a comprehensive
feasibility and business evaluation study.
The Jonquiere project is to be constructed
in multiple phases to attain a production
level of 460,000 tpy. Phase 1 with a capacity
of 60,000 tpy capacity is the industrial and
commercial demonstration step. The goal is to
demonstrate, with the 38-pot section, a commercial
operating AP6X potroom, with all the
related logistics and operational challenges.
The first metal is planned for February
2013, and full production in May 2013.
This platform allows us not only to continuously
improve the AP6X pot in an industrial
and robust way, but also to develop and validate
other major improvements such as equipment
capabilities, pot oversuction using the
JIBS RTA-patented system, potroom ventilation,
industrial hygiene and environment performances,
and last but not least automation
and improved accuracy of the anode change
and positioning (‘best anode change’).
AP4X platform: The AP4X platform has
been developed according to the two same
Jonquiere project, potroom
streams: high productivity
and low energy.
This platform supports
the retrofit of existing
AP3X potlines, and
is also a solution for
smaller power blocks.
The two development
streams provide an optimised
solution suited
to each client with his
specific constraints.
The first version of
the AP4X Low Energy
has been developed in collaboration with the
Alouette smelter in Canada and the Saint Jean
de Maurienne smelter in France.
In Alouette [2] a two-year test period resulted
in the validation of a brownfield AP4X
Low Energy design capable of world-class environment
performance in terms of gas emission
and cell life. Rio Tinto Alcan is also currently
on its way to validating a 12.4 kWh/kg
AP4X technology by the end of 2013 in the
Saint Jean de Maurienne boosted section.
Global approach to a smelter
The conventional way of designing a smelter is
to consider the smelter as an assembly of process
shops linked by roads and logistics services.
This approach has not drastically changed in
the past decades, as we can see from the layouts
of the plants erected during this period.
If we change our outlook on smelters,
viewing them as global entities, then there are
new opportunities for improvement and cost
reduction. In addition to developing units, we
can deliver an improved global approach. This
new way of working has led not only to disruptive
innovations in the global management
and layout of smelters, but has also allowed
processes to be reviewed from this new viewpoint.
Some of the innovative solutions developed
using this global approach can also be
deployed in existing smelters.
From a sequential to an integrated design:
New reflections and action plans have been
implemented so as to manage a global approach
and to develop the required elements
accordingly. The construction of a global vision
of the smelter with clearly defined goals
has allowed us to challenge the conventional
‘silo’ approach and to combat the existing paradigms.
‘Open innovation’ is also a key pillar in
our approach, including as far as possible, the
technologies and solutions that can be transposed
from other industries or applications.
Global vision is a medium and long-term
vision resulting from the existing goals and
constraints, based on the aluminium industry
context. It is materialised in a holistic highlevel
roadmap, based on an e3 approach: ‘energy
efficiency’, ‘environment’ and ‘economy’,
with a high standard of health and safety. To
support this high level vision together with operational
goals and steps, we developed a multi-generation
plan, giving us previews of the
‘ideal’ new smelter over the coming decades,
and the steps in optimising existing assets.
Our conventional view of the smelter and
how we work were challenged in a variety of
ways. For example, if we compare the cost of
a smelter not shop by shop but per discipline
(concrete, electrical, structural, equipment,
etc.), we can see that the global building and
roads aspect is more expensive than all the
pots put together. Moreover, as this aspect is
not part of specific aluminium know-how, this
part can be improved with ‘open innovation’
and existing technologies and can be developed
quickly. To take the challenge further,
we can also compare some basic smelter data
such as the cubic metre of concrete or the
tonne of metallic structure to benchmark data
in other industries or applications, and then
analyse the gap and the reasons for the gap.
And finally, ‘open innovation’ starts – internally.
Integrated teams need not only development
people, but also production, HSE,
projects, engineering, business improvement
and procurement people. Such a team can
give a different approach and allow an efficient
challenge, finally leading to a global buy-in of
all the stakeholders in the chosen solutions.
External ‘open innovation’ can provide not
only technical ideas and solutions, but also
yield new methodologies and ways of working:
26 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
Lean manufacturing and flows in the smelter:
Over and beyond the long-standing tradition
of numerical simulation and test programs to
optimise and increase the reliability of cells,
there is room for optimisation of the various
flows (materials, pedestrians, vehicles, fluids)
and, consequently, of general layout, safety
and the environmental footprint. With upward
amperage creep and lower energy consumption,
this optimisation becomes a critical factor
in running a smelter in a reliable and qualityoriented
way, and also economically.
Lean manufacturing has given us basic
principles such as ‘one piece – one flow’. This
forms a good starting point to develop a flow
management philosophy that delivers the
right quantity at the right place and at the right
time. With this concept, we consider flows in
the smelter as a key activity, thus generating
a virtuous circle. We use the required technologies,
such as process automation, simulation
or data processing, to bring anodes and
liquid metal, for example, in a repeatable and
safe way, to the pots and to the casthouse as
needed. Consequently, on the one hand, we
challenge the size of the different transport
systems and make savings in smelter infrastructures,
while, on the other hand, we increase
process reliability, and show that ‘just
on time’ is a key enabler for process quality
and thus for the environmental footprint.
Moving from environmental solutions considered
as a cost to environmental challenges
seen as opportunities: The traditional way of
thinking is to consider environmental control
equipment or features as necessary costs. The
global environmental function in the typical
smelter accounts for 12% of direct costs. If we
switch to a mindset where these costs are seen
as creating opportunities, if we are ready to
challenge the old paradigms, then some basic
questions are raised:
• Why should creeping of amperage or size
of the cell automatically result in an
increase in gas suction rate?
• Is a FTC dedicated to baking furnaces the
only scrubbing option if we accept to
change the typical smelter layout and
install the baking furnace much closer to
the potrooms?
One way to answer the first question is to
redesign the cell and the suction system with
the goal of reducing specific flowrate by 50%.
If expressed this way, the objective leads to
innovative solutions which, in turn, open out
towards other avenues with respect to energy
recovery and capex reduction, while also improving
environmental performance.
With respect to the second question, existing
experience shows that there are no major
technical barriers
when considering mixing
the baking furnace
gases with cell gases
and so combining
scrubbing in a conventional
GTC, thereby
optimising costs compared
to the standard
layout.
These are only
examples. Low cost
over-suction solutions
are now also becoming
available on the market
[3] and other approaches can be investigated
to improve this business segment.
Conclusion
The aluminium industry is currently facing
increasingly tougher constraints and challenges,
whether we look at energy savings,
environmental footprint or, over and above
all, economic competitiveness. In the coming
years, this industry needs to make tremendous
improvements and to seek new optimisation
methods.
Rio Tinto Alcan is proposing the reference
solution to successfully take up this challenge.
Not only does it possess the best cell platforms
for both new smelters and for existing
assets optimisation, but it also boasts the only
industrial platform of its kind in the world for
testing the most recent cells.
Over and beyond this strong position, Rio
Tinto Alcan is able to integrate its technological
building blocks in a global approach where
the whole smelter is studied from completely
new viewpoints. The AP Technology smelter
of the future is a global and comprehensive answer
to both existing and future challenges.
References
[1] O. Martin, B. Allano,
E. Barrioz, Y. Caratini,
A. Escande and N. Favel,
Low Energy Cell Development
on AP Technology,
Light Metals 2012
pp. 569-574
[2] P. Coursol, J. Coté,
F. Laflamme, P. Thibault,
A. Blais, D. Lavoie and S.
Gosselin, The Transition
Strategy at Alouette Towards
Higher Productivity
with a Lower Energy
Consumption, Light Metals
2012, pp. 591-594.
[3] J.-N. Maltais, M. Meyer,
M. Leduc, G. Girault and
Global Smelter Design, mindset
H. Rollant, Jet Induced Boosted Suction System for
Roof Vent Emission Control: New Developments
and Outlooks, Light Metals 2012, pp. 551-556
Authors
A combined fume and gas treatment centre
Sylvie Fraysse joined the aluminium business ten
years ago, in process and engineering projects management.
She is currently in charge of the Global
Smelter Design project.
Jean-Michel Jolas has 30 years of aluminium business
experience, half spent in various production
and process management responsibilities in smelters,
and half dedicated to Reduction and Environmental
R&D. In his current position, he is managing the Environmental
R&D group and activities for the Rio
Tinto Alcan primary metal business.
In more than 20 years of aluminum business experience,
François Charmier has held various managing
positions in Technology, Project Management
and Execution, and presently in Technology Sales.
In his current position, he is leading the Technology
Transfer of AP60 to the AAR-CT AP60 Smelter
(‘Aluminerie Arvida – Centre Technologique
AP60’).
Olivier Martin has 25 years of aluminium business
experience including various international operational
positions in smelters. Since 2005, he is back
in Rio Tinto Alcan Technology group as Senior
Technology Advisor, head of the Cell Development
group.
ALUMINIUM · 1-2/2013 27

ALUMINIUM SMELTING INDUSTRY
Möller direct pot feeding system for
greenfield and brownfield smelters
C. Duwe and T. Letz, FLSmidth Hamburg
FLSmidth is a market-leading supplier
of equipment and services to the global
minerals and cement industries. With
more than 15,000 employees, FLSmidth
is a global company with headquarters in
Denmark and local presence in more than
50 countries including project and technology
centres in Denmark, India, USA and
Germany.
Over the past 130 years FLSmidth has
developed a business culture based on
three fundamental values: competence,
responsibility and cooperation. For the alumina
and bauxite industries the company
offers complete bauxite handling, storage,
crushing, grinding and settling on the red
mud side, as well as conveying and storage
systems on the white side.
Today’s aluminium smelter industry
requires the most economical, reliable and
environmentally friendly systems in each
part of the smelter. The electrolysis cells
(pots) in all modern greenfield smelters are
already or will be equipped with closed
pot feeding systems. Brownfield smelters,
which still mainly use the open type crane
feeding technology, seem more in need of
changes to the closed pot feeding system
after examining modernisation projects.
The Möller direct pot feeding system is
an innovative system that ensures constant
and reliable feeding of secondary (fluorinated)
alumina to each ore bunker of the
electrolysis cell. Since the first installations
at Vereinigte Aluminium Werke (VAW) in
Hamburg, Germany, and at Aluminij Mostar
in Bosnia-Herzegovina, the design has
continuously been improved in order to
fulfill a wide range of requirements. These
improvements include a flexibility for use
in both greenfield and brownfield smelters.
This paper presents the general design
and latest improvements of the Möller
direct pot feeding. This system will be installed
in the Emirates Aluminium (Emal)
Phase 2 greenfield project in Taweelah,
Abu Dhabi, and in a brownfield project at
Alcasa in Venezuela.
General description
The vent air from the electrolysis cells is evacuated
via gas ducts to the Gas Treatment Centres
(GTC) where primary (fresh) alumina absorbs
many of the emissions. During this cleaning
process the primary alumina becomes secondary
alumina and is stored in silos, near the
potrooms respective GTCs.
From the secondary alumina silos the direct
pot feeding system transports the secondary
alumina pneumatically to each of the electrolysis
cells. The fully automatic and absolutely
dust-free feeding process can be either continuous
or discontinuous, and it works independently
from the potroom cranes.
The smooth-working Möller direct pot feeding
system combines the ‘Möller Turbuflow’
dense phase and ‘Möller Fluidflow’ pipe air
slide transport system to take the secondary
alumina from the storage silo to distribution
pieces at the electrolysis cells. From there the
Möller Fluidflow pipe air slide feeding system
takes alumina to each of the ore bunkers of the
electrolysis cells. The Möller Turbuflow dense
phase conveying and the Möller Fluidflow
pipe air slide are both well proven transport
technologies which have established itself because
of its superior performance record.
Highlights of the Möller direct pot feeding
system complete with Möller Fluidflow pipe
air slides are:
• Highest possible performance and reliability
of continuous feeding of the electrolysis
cells for almost all kinds of secondary
Fig. 1: Process flow diagram, Möller direct pot
feeding system complete with Möller Fluidflow
pipe air slides
© FLSmidth Möller
28 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
or primary alumina qualities by Möller
Fluidflow pipe air slide
• Gas-tight pot feeding system by Möller
Fluidflow pipe air slide (no dust emission
from flange connections)
• No generation of fines, no segregation and
no scaling
• Lowest possible (over-)pressure
• Self-regulating system by filling level in
ore bunkers of cells
• Works independently of any slight overpressure
or slight under-pressure in the
ore bunkers of the electrolysis cell
• Quickest possible (emergency) refilling
of the ore bunkers of the electrolysis cells
by Möller Fluidflow pipe air slides and
high performance fans or blowers
(0.1-0.2 bar)
• Lowest possible emission to GTC gas duct
• No pulsation in the Möller Fluidflow pipe
air slide along the potroom and on top
of each cell
• Independent of the filling level of the
buffer silo
• Minimised energy consumption. Low
fluidising air amount and energy
consumption by use of frequency
controlled fans or blowers
• Minimised maintenance work as well as
minimised amount of spare parts.
Functional description
and design features
Silo discharge including material trap: The
Fig. 2: Möller rotary flow control valve and material trap
secondary alumina is discharged via Möller
rotary flow control valve and Möller Fluidflow
pipe air slide, generally from the secondary
alumina silo at the GTC, and transported to
the so-called main bin.
A specifically designed material trap is
installed to avoid any foreign particles entering
the direct pot feeding system. In greenfield
aluminium smelters, vibrating screens

ALUMINIUM SMELTING INDUSTRY
Fig. 3: Möller Fluidflow pipe air slide from secondary alumina silo to potroom
wall; main bin and Möller Fluidflow pipe air slide along potroom (Dubal)
in the GTC system already remove most
of the coarse material (e. g. from scaling effects).
However, in brownfield aluminium
smelters the existing installation situation
may not have enough space in which to install
vibrating screens. To address this, FLSmidth
enhanced the design of the material trap in
order to include the process function of a
vibrating screen. The Möller direct pot feeding
system can generally be installed at every
brownfield smelter presently operating with a
crane feeding system.
Main bin: The main bins – normally one
main bin is used for each half of a potroom –
are located right next to the potroom wall.
The main bins are always 100% filled, and
the resulting material column ensures a continuous
mass flow of secondary alumina to all
electrolysis cells, especially to the last cell at
the end of the Möller Fluidflow pipe air slide
along the potroom.
Because of the well-defined height of the
main bin, the Möller direct pot feeding system
is independent of the filling level of the secondary
alumina silo. Whether the secondary
alumina silo is full, half full or nearly empty,
the conveying capacity of the Möller direct pot
feeding system stays
the same.
Given the sufficient height between the
outlet flange of an existing secondary alumina
silo and the superstructure of the electrolysis
cell, then the Möller Fluidflow pipe air slide
can also be installed along the potroom with
an appropriate declination (downhill slope)
without a main bin.
Distribution pieces and vent domes: From
the main Möller Fluidflow pipe air slide along
the potroom the secondary alumina is transported
via the distribution pieces into the
potroom, and then to the electrolysis cells.
According to the design requirements, a sufficient
number of vent domes will be installed
on top of the distribution pieces. All necessary
venting domes are connected to the gas duct
of the GTC.
Each of the above described distribution
pieces can be connected to one (single-feed),
two (double-feed) or even more electrolysis
cells (multi-feed), as per customer requirements
resp. installation situation.
Superstructure design requirements: Each
superstructure is specially designed as part of
the electrolysis cell’s technology. Generally,
the state-of-the-art electrolysis cell technologies
already ensure sufficient space for a direct
pot feeding system.
However, clients have
Fig. 4: Möller distribution pieces and vent dome
different requirements regarding free access
for crust breakers, dosing devices and the option
for removing the ore bunkers during operation,
and these factors influence the final
design of the Möller Fluidflow pipe air slide
to be installed on top or inside of the superstructure
of the electrolysis cell.
The self-regulating and continuous filling
process of the ore bunkers of an electrolysis
cell by the Möller direct pot feeding system
is simply ingenious. If the ore bunker is full,
then the material cone level has reached the
filling spout discharge opening of the Möller
Fluidflow pipe air slide, and the mass flow is
blocked automatically. As soon as secondary
alumina is removed from the ore bunker of
the electrolysis cell, the pneumatic transport
starts again automatically and ensures a constant
and reliable mass feed rate to the pots.
The fluidising of the secondary alumina inside
the Möller Fluidflow pipe air slide works permanently
to ensure a constant bulk density.
Fluidisation air equipment: The fluidisation
air requirements for the Möller Fluidflow
pipe air slide along the potroom and on top of
the electrolysis cells are different in regard to
the fluidisation air pressure and the specific
fluidisation air amount. Therefore, the Möller
direct pot feeding system uses two different
fluidisation air sources which can either be
frequency controlled rotary piston blowers
Fig. 5: Single-feed design …
Fig. 6: … and double-feed design of the Möller direct pot feeding system
30 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
or fans. This design allows minimised energy
consumption during operation down to the
necessary minimum amount as well as minimised
fluidisation air vented into the GTC’s
gas duct.
Conclusion
Fig. 7: Variable design of the Möller Fluidflow pipe air slide on top or inside
of the electrolysis cell
The necessary flexibility of a closed pot feeding
system to serve greenfield and brownfield
aluminium smelters had already to be considered
by FLSmidth Hamburg when the Möller
direct pot feeding system was introduced at
VAW in Hamburg in 1997, and at Aluminij
Mostar, Bosnia-Herzegovina in 2001. In particular,
the latest contracts for Emal Phase 2,
Abu Dhabi (greenfield), and Alcasa, Venezuela
(brownfield), have proven the system’s high
adaptability with great success.
This system is designed to ensure a constant
and a reliable feed into the ore bunkers
of the electrolysis cells at the highest possible
standard. The lowest
possible conveying
velocities preserve the
particle size distribution
as well as the flow
ability of the secondary
alumina without
any scaling effects.
This most competitive
system is superior by
minimising wear and
maintenance as well as
energy consumption,
and last but not least
Fig. 8: Self-closed filling spout and filling process of
the ore bunker
ALUMINIUM · 1-2/2013 31

ALUMINIUM SMELTING INDUSTRY
Contract Client Smelter Type System description
2001 Aluminij Mostar brownfield
256 pots, 130 kg/h/pot (double-feed),
potroom length 600 m
2006 Dubal, Potline 8 greenfield 40 DX pots, 210 kg/h/pot (double-feed)
2007
2007
2007
IMIDRO, Hormozal
Aluminium Smelter
Rusal/Hydro, Boguchany
Aluminium Smelter
Rusal, Taishet Aluminium
Smelter
greenfield
greenfield
greenfield
2012 Emal, Phase 2 greenfield
2012 CVG Alcasa, Potline 3/4 brownfield
228 D20 pots, 170 kg/h/pot (double-feed),
potroom length 720 m
672 RA300 pots, 200 kg/h/pot (double-feed),
potroom length 1,050 m
672 RA400 pots, 200 kg/h/pot (double-feed),
potroom length 1.050 m
444 DX+ pots, 480 kg/h/pot (single-feed),
potroom length 1,520 m
400 pots, 480 kg/h/pot (single-feed),
potroom length 700 m
Tab. 1: Möller direct pot feeding system references in operation or under construction; all secondary alumina
by its high operating reliability.
In close co-operation with clients around
the world, FLSmidth Hamburg has offered and
contracted various tailor-made solutions for
the use of a Möller direct pot feeding system.
Please contact the authors for more detailed
information or to obtain support regarding
specific projects.
Authors
Dipl.-Ing. Carsten Duwe is head of Technical Department
and Dipl.-Ing. Timo Letz is area sales manager
of FLSmidth Hamburg GmbH, based in Pinneberg,
Germany. Contact: carsten.duwe@flsmidth.
com; timo.letz@flsmidth.com
Cathode producer shows its metal
M. Casasole, Carbone Savoie
© Carbone Savoie
Carbone Savoie’s plant in Notre Dame de Briançon
Aluminium has been one of the mainstays of
industrial production for several decades. It is
one of the most plentiful elements on earth,
and its lightness and strength makes it ideal for
many applications. The production of aluminium
involves electrolysis, and creating increasingly
better technology for the aluminium producers
is the specialty of Carbone Savoie.
Carbone Savoie is one of the worldwide
leading manufacturers of cathode products,
the design and production of cathode blocks,
graphitised blocks, sidewall blocks and ramming
paste. The company’s unique graphitised
block has given it a significant competitive
edge over its nearest rivals.
Since 2010, Carbone Savoie provides a
new generation of ramming paste NeO 2 . Unlike
the previous pastes and unlike all other
pastes of the market that contain toxic compounds,
NeO 2 is a 100% clean ramming paste.
This first 100% clean ramming paste contributes
towards huge progress to the aluminium
production, and it guarantees a clean and safe
environment for our customers’ and own employees.
Despite short terms uncertainties, the basis
for aluminium growth remains strong. Ramming
paste, sidewalls and cathode blocks will
be part of this trend.
Success for Carbone Savoie is underpinned
by its excellent reputation. A decisive factor
is the long life of its cathodes. The concern
ploughs a significant part of turnover back into
research and development. Carbone Savoie
sees its clients more as partners than customers,
and so offers consulting and advice
throughout the lifetime of the cathodes which
it supplies. Naturally, in such a technologically
advanced field, R & D is carried out in close
co-operation with technical departments of
universities and other research organisations.
Carbone Savoie’s long-term strategy is to
improve sustainability, and to deliver sales
commitment, as well as to develop both the
The end product, a cathode block, ready for delivery
organisation itself
and to extend
the skills of its
staff. Steps will be
taken to ensure
long-term profitability
by closely
watching aspects
like product mix,
production costs
and pricing mechanisms.
It is our vision
to let our actions NeO 2 : the first 100% clean
be directed by respect
for the environment at all levels. We strive
ramming paste
to remain the commercial and technological
leader in our business fields. We aim to remain
the most reliable company operating in
the market today and to be the manufacturer
of the best products that money can buy. Some
of our profits will continue to be directed back
into research and environmental protection. It
is what our customers expect from us in what
is a constantly changing world.
The company is anticipating and going beyond
expected new regulatory requirements
and is running a project to study further ways
of treating all fumes released by the plant.
With its outlook towards technological
innovation and environmental sustainability,
Carbone Savoie is set for a bright future.
Author
Matthieu Casasole is sales and marketing director
of Carbone Savoie, based in Vénissieux, France.
32 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
Alumina refinery
Outotec’s process and implementation solution
M. Missalla, A. Scarsella and A Koschnick, Outotec
In retrospect, it is hard to say whether
Austrian chemist Karl Josef Bayer knew
how significant his two patents – A process
for the production of aluminium hydroxide
and The pressure leaching of bauxite
with NaOH to obtain sodium aluminate
solution – would be for the future alumina
industry when he filed for them in 1888
and 1892 respectively [1]. However, it is
clear that within two years of obtaining his
patents, the first industrial alumina plant
was commissioned in 1894 in Gardanne,
France for Société Française de l’Alumine
Pure. The plant’s capacity, 1.5 tonnes per
day, was very small compared to current
plant capacities: newly implemented alumina
refineries range between 1-2 million
tonnes of alumina per year.
Implementing an entire alumina refinery
In addition to the costs for an alumina refinery,
investments are also needed for various
infrastructures such as railroads, harbours,
roads and villages. Most investors usually
rely on the traditional front end loading (FEL)
methodology for capital project planning. It involves
four phases with a decision gate after
each phase. The order of magnitude, pre-feasibility
and basic engineering phases are commonly
known as FEL 1, 2 and 3, and these
are generally contracted with a technology-independent
engineering contractor. In contrast,
FEL 4, or project implementation, is done with
an EPCM contractor. At first glance, this appears
to be the best implementation model
in terms of low capex costs, since it allows to
combine a variety of sub-process solutions,
and it ensures maximum competition among
the technology/equipment suppliers as well as
among the engineering/EPCM contractors.
However, a quick review of some recent
projects utilising the EPCM model shows that
many of interfaces in these complex projects –
both from a technological and management
perspective – have suffered significant delays
to implementation schedules as well as tremendous
cost overruns. Focussing on separate
process units instead of on a comprehensive
optimised process solution often creates operational
problems, and can transform initially
viable ‘solutions’ into a customer’s ‘problem’.
With an EPCM contract, the absence of a comprehensive
implementation approach and of
Fig. 1: A tradition of demonstrating industrial plant expertise over the last century
process guarantees leads to problems where
customers find themselves having sole liability.
Thus, the EPC/turnkey approach for the
core process area, where competent technology
solution providers are involved at an early
project stage, is increasingly favoured by the
industry where the first projects in alumina
were contracted using this model.
Outotec’s mission is to be a leading provider
for sustainable process life cycle solutions.
Its ability to offer turnkey project implementation
with full implementation and process
guarantees makes the company a preferred
choice for the industry, allowing customers to
focus on their core business.
Providing life-cycle technology process
solutions to the alumina industry
With a track record of successful EPC/turnkey
project implementations going back several
decades, Outotec has a unique value proposition:
it offers integrated engineering, project
and risk management, which aggregates value
to a customer’s investment in terms of
• Optimised, sustainable process solutions
• Guarantees for implementation within
schedule and budget
• Guarantees for final product quality,
capacity and consumption figures
• Best value for investment.
Fig. 2 : The Bayer cycle
© Outotec
ALUMINIUM · 1-2/2013 33

ALUMINIUM SMELTING INDUSTRY
Fig. 3: Alumina refinery layout
With an EPC contract, customers hand over
a significant portion of their investment risks
to the contractor. Outotec has structured its
organisation to control and cope with these
risks: within its technology competence centres,
process and engineering disciplines are
integrated using the latest design tools available.
With a global procurement organisation
and a network of approved manufacturers,
not only does Outotec have access to the most
cost-efficient supply chain, but it also has the
flexibility to react to any surprises which suddenly
appear on the market. Additionally, Outotec’s
project management teams work with
the latest management tools and procedures
for scheduling, cost control, document control
quality and HSE management. But what really
brings excellence to this organisation is Outotec’s
experienced staff – with an average age
of 40+, most of the company’s professionals
have at least 15 years of experience in industrial
projects.
Proof of this technology and project execution
excellence is supported by extensive
reference lists of successfully implemented
LSTK contracts and plants operating with
benchmark parameters for productivity and
sustainability.
Fig. 4: Temperature profile of the Bayer circuit
Fig. 5: Autoclave digestion train [2]
The Bayer process
The Bayer process is a highly integrated grinding,
leaching and recovery process. Ground
bauxite is dissolved (digested) at a high temperature
in a highly concentrated solution of
sodium hydroxide more commonly known as
‘caustic’. The next step involves other bauxite
components which do not digest and which
are separated by a thickening and security
filtration step before being washed and then
stored as red mud. The alumina-rich solution
is cooled and the aluminum tri-hydrate is precipitated
from the solution. The alumina-depleted
caustic solution next undergoes evaporation,
so increasing the caustic concentration,
and is recycled back to digestion, thus closing
the Bayer cycle. The aluminum tri-hydrate is
filtered, washed and finally thermally treated
resulting in calcined aluminum oxide as a
product (Fig. 2).
Estimating a refinery’s correct capital is not
restricted to basic tankage, and the budget for
major equipment or civil requirements also includes
interconnecting piping, conveyors and
roads. In addition to the total capital expenditure,
the operational expenditure must also be
clearly understood and optimised during the
designing and implementation of your alumina
refinery. This, in turn, helps determine future
refinery profitability and the payback period.
34 ALUMINIUM · 1-2/2013

ddilisa@innovatherm.de

ALUMINIUM SMELTING INDUSTRY
Fig. 7: Basic flow
chart for seawater
neutralisation of
red mud [4]
Fig. 6: Tube digestion [3]
It goes without saying that the aim of every
refinery is to become a low-cost producer, and
so must examine the major factors influencing
the first-quartile costs:
• Proximity to the bauxite mine
• Proximity to a deepwater harbour
• Low energy cost
• Low soda cost
• Low energy, caustic and lime
consumptions.
The first four factors depend on the location
selected as well as on available infrastructure.
The final factor depends on the bauxite mineralogy
and on selection of the technology
to be applied. Fig. 4 shows the bauxite entering
the grinding step at ambient temperature,
where it is then mixed with the spent liquor.
The ground suspension is heated to its digestion
temperature, which is determined by the
bauxite’s composition: gibbsitic bauxites need
low temperatures, while boemitic bauxites require
higher temperatures. The digested slurry
is then rapidly cooled and the green liquor
(alumina-rich solution) is separated from the
red mud. In the same figure, heat recovery is
maximised so as to minimise the addition of
live steam needed to bring the fresh slurry to
the required digestion temperature. A similar
principle can be seen when the incoming green
liquor is indirectly cooled with outgoing spent
liquor prior to precipitating alumina tri-hydrate
in the next stage. The hydrate is then fed
to the calcination stage. The figure also makes
it easy to distinguish between the white and
red sides of an alumina refinery production
site.
venture with Hatch – HOT (Hatch
Outotec) – can supply the entire
digestion tool box. The joint venture focuses
on designing and developing integrated tube
digestion and evaporation solutions using single-stream
heating in jacketed pipe technology.
This allows you to efficiently recover the
heat in the digested slurry. Fig. 6 shows the
slurry as it is heated to the digestion temperature
and then held for a time in tube reactors
to meet the reaction requirements. Next, the
slurry is flash cooled in stages to near- ambient
pressure, while using the heat from vapour to
the pre-heat incoming slurry in counterflow.
The water vapour transfers its heat to the
slurry as it condenses on the outside shell of
the jacketed pipes.
Red mud disposal: sea
water neutralisation
The residue from the Bayer process – more
commonly known as red mud – still has a
high alkaline content and must be neutralised.
Fig. 7 illustrates the basic flow
chart for neutralisation by magnesium in the
sea water. The mud / seawater mixture is held
in a reactor so that the caustic is chemically
neutralised. The hydrotalcite-rich mud and
magnesium-deficient seawater are then decanted
using a conventional clarifier.
The supernatant magnesium-deficient seawater
with the correct permits is now suitable
for environmental discharge.
The small facility shown in Fig. 8 can treat
the entire rate of red mud production from
a refinery producing four million tonnes of
product per year to environmentally acceptable
levels. The magnesium actively reacts
with the liquor phase components of red mud;
namely aluminum and hydroxide ions. During
the neutralisation process, the dissolved
magnesium levels drop from approx. 1,200
mg/l to around 300 mg/l and the aluminum
level drops to less than 5 mg/l. These net reductions
of magnesium and aluminum are the
Digestion and evaporation
The appropriate equipment for digestion must
be selected based on the kinetics of the digestion
reactions, bauxite type and target heat
recovery. Available technology for the digestion
process includes autoclaves and tube
digestors, which are selected according to
throughput, number and size. Outotec’s joint
Fig. 8: Neutralisation facility [4]
36 ALUMINIUM · 1-2/2013

ALUMINIUM SMELTING INDUSTRY
Fig. 7: Basic flow
chart for seawater
neutralisation of
red mud [4]
Fig. 6: Tube digestion [3]
It goes without saying that the aim of every
refinery is to become a low-cost producer, and
so must examine the major factors influencing
the first-quartile costs:
• Proximity to the bauxite mine
• Proximity to a deepwater harbour
• Low energy cost
• Low soda cost
• Low energy, caustic and lime
consumptions.
The first four factors depend on the location
selected as well as on available infrastructure.
The final factor depends on the bauxite mineralogy
and on selection of the technology
to be applied. Fig. 4 shows the bauxite entering
the grinding step at ambient temperature,
where it is then mixed with the spent liquor.
The ground suspension is heated to its digestion
temperature, which is determined by the
bauxite’s composition: gibbsitic bauxites need
low temperatures, while boemitic bauxites require
higher temperatures. The digested slurry
is then rapidly cooled and the green liquor
(alumina-rich solution) is separated from the
red mud. In the same figure, heat recovery is
maximised so as to minimise the addition of
live steam needed to bring the fresh slurry to
the required digestion temperature. A similar
principle can be seen when the incoming green
liquor is indirectly cooled with outgoing spent
liquor prior to precipitating alumina tri-hydrate
in the next stage. The hydrate is then fed
to the calcination stage. The figure also makes
it easy to distinguish between the white and
red sides of an alumina refinery production
site.
venture with Hatch – HOT (Hatch
Outotec) – can supply the entire
digestion tool box. The joint venture focuses
on designing and developing integrated tube
digestion and evaporation solutions using single-stream
heating in jacketed pipe technology.
This allows you to efficiently recover the
heat in the digested slurry. Fig. 6 shows the
slurry as it is heated to the digestion temperature
and then held for a time in tube reactors
to meet the reaction requirements. Next, the
slurry is flash cooled in stages to near- ambient
pressure, while using the heat from vapour to
the pre-heat incoming slurry in counterflow.
The water vapour transfers its heat to the
slurry as it condenses on the outside shell of
the jacketed pipes.
Red mud disposal: sea
water neutralisation
The residue from the Bayer process – more
commonly known as red mud – still has a
high alkaline content and must be neutralised.
Fig. 7 illustrates the basic flow
chart for neutralisation by magnesium in the
sea water. The mud / seawater mixture is held
in a reactor so that the caustic is chemically
neutralised. The hydrotalcite-rich mud and
magnesium-deficient seawater are then decanted
using a conventional clarifier.
The supernatant magnesium-deficient seawater
with the correct permits is now suitable
for environmental discharge.
The small facility shown in Fig. 8 can treat
the entire rate of red mud production from
a refinery producing four million tonnes of
product per year to environmentally acceptable
levels. The magnesium actively reacts
with the liquor phase components of red mud;
namely aluminum and hydroxide ions. During
the neutralisation process, the dissolved
magnesium levels drop from approx. 1,200
mg/l to around 300 mg/l and the aluminum
level drops to less than 5 mg/l. These net reductions
of magnesium and aluminum are the
Digestion and evaporation
The appropriate equipment for digestion must
be selected based on the kinetics of the digestion
reactions, bauxite type and target heat
recovery. Available technology for the digestion
process includes autoclaves and tube
digestors, which are selected according to
throughput, number and size. Outotec’s joint
Fig. 8: Neutralisation facility [4]
36 ALUMINIUM · 1-2/2013

ALUMINIUM SMELTING INDUSTRY
result of their precipitation as insoluble salts,
forming hydrotalcite as a product.
Calcination
The average energy consumption in the calcination
processes for an alumina refinery
globally exceeds 3,100 kJ/kg of alumina.
Outotec calcination technology has reduced
this figure to about 2,800 kJ/kg of alumina. In
fact, Outotec was recognised with an honourable
mention from the German energy agency
Dena in 2010. Additionally, Outotec can provide
numerous references for its calcination
technology.
Cyclones are an integral component of a
circulating fluidised bed (CFB) calciner and a
key element for efficient heat recovery with a
minimal impact on product quality. The typical
CFB calciner layout includes five cyclones,
each customised to the prevailing process conditions.
The cyclone’s geometry is critical its
performance in terms of separation efficiency
and particle breakage, and thus by extension,
for the overall performance of the calciner.
References
[1] F. Habashi : Bayer’s Process for Alumina Production:
A Historical Perspective, Bull. Hist. Chem.
17/18 (1995), p. 15-19
[2] B. Haneman, A. Wang: Optimising Flash Tank
Design for the Alumina Industry. 9 th Alumina Quality
Workshop (2012) p 127-131
[3] A. Wang, B. Haneman, C. Coleman: Pressure
Surge Mitigation at High Temperature Tube Digestion
Facility of Yarwun Alumina Refinery. 9 th Alumina
Quality Workshop (2012) p 132-137
[4] A. Scarsella, T. Leong, B. Henriksson: A Novel
and Environmentally Friendly Process for the Treatment
of Bayer Process Residue. 9 th Alumina Quality
Workshop (2012) p 171-175
Authors
Michael Missalla heads the Light Metals/Fluidised
Beds business line at Outotec. He has designed
several processes for a variety of metallurgical applications.
His PhD topic was ‘Calculation method
for highly loaded cyclones’. He also has experience
in chemical plant operations, process engineering,
R&D, as well as in training and development.
Alessio Scarsella heads the Alumina Refinery group
at Outotec Germany and has extensive experience
in combustion and alumina refining. He has an MBA
from Deakin University and a PhD in chemical engineering
from the University of Adelaide in fluid
mechanics and combustion. Dr. Scarsella has held
process and senior project leading positions in the
alumina industry, where he developed fundamental
and operational expertise in refining alumina from
bauxite. He has also executed major greenfield refinery
projects.
Andreas Koschnick is Outotec’s director for Solution
Sales Latin America. He holds a degree in industrial
engineering and began his career with Lurgi
in project management for the Leuna petrochemical
refinery, which was the largest industrial project in
Europe. As a former general manager of a construction
and engineering company in Brazil, he was responsible
for the implementation of major industrial
projects in the energy and metallurgical sector.
Fives Solios – 30 years of experience in fume desulphurisation
A. Courau, Solios Environnement
Formerly Procedair, Solios Environnement
has supplied turn-key plants for
fume desulphurisation dedicated to many
different industrial applications,
such as diesel motor production,
paper fabrication, sulphuric acid
production, anode baking furnaces,
electrolysis reduction gases,
or waste incineration. Today, Solios
Environnement’s know-how
in desulphurisation processes
mainly applies to electrolysis pot
gases or to anode baking furnace
fumes of primary aluminium
smelters.
Relying on its long-standing experience,
Fives Solios is now a privileged
partner for the design of SO 2
scrubbers. Indeed, after studying all
parameters of a project and evaluating
all available technologies, Solios
Environnement is able to propose
tailor-made solutions in which its
efficient SO 2 units combine various
processes and meet perfectly its customers’
needs.
While projects that are located
near the sea can benefit from using
seawater in wet scrubbers, various
other solutions are available in other
geographic locations. This article reviews all
solutions already considered and exploited for
SO 2 treatment without seawater.
Like many existing technologies, Fives Solios’s
desulphurisation treatments commonly use a
calcium reagent (limestone, lime, lime milk),
Application Process Technical data available
Methionine production for
animal food industry (France)
Desulphurisation on two
diesel engines of 5 MW with
heavy fuel oil (Spain)
Desulphurisation on two coalfired
stoker-type boilers
(Virginia, USA)
Aluminium electrolysis
potline (USA)
Waste incineration
(England)
Desulphurisation on six diesel
engines of 12,5 MW with
heavy fuel oil (Philippines)
Paper wastes
incineration (Australia)
Black liquor furnace on ammonium
bisulphate process
(France)
Table: Characteristics of various references
Wet-scrubber (packing)
Reagent: caustic soda
Semi-wet scrubber
Reagent: lime milk
Enhanced all dry-scrubber
Reagent: lime
Wet scrubber (pulverisation)
Reagent: sodium carbonate
(Na 2 CO 3 )
Dry scrubber
Reagent: lime
With Conditioning towers
Wet-scrubber (pulverisation)
Reagent: caustic soda
Enhanced all dry-scrubber
Reagent: lime and
activated carbon
Wet-scrubber (pulverisation)
Reagent: ammonium
bisulfite
78,000 Nm 3 /h at 320 °C
Max inlet value: 3,000 mg SO 2 / Nm 3
Outlet guaranteed value: 300 mg SO 2 / Nm 3
Measured values: 30-200 mg SO 2 / Nm 3
2 x 33,300 Nm 3 /h at 190 °C
Efficiency DeSO x : > 91%
30,000 Nm 3 /h at 250 °C
Efficiency DeSO x : 92%
637,000 Nm 3 /h at 65-93 °C
Inlet concentration: 370 mg SO 2 / Nm 3
Outlet concentration: 15 mg SO 2 / Nm 3
4 x 125,000 Nm 3 /h at 165 °C
Inlet value: 400 mg SO 2 / Nm 3
Outlet guaranteed value: 50 mg SO 2 / Nm 3
2 x 215,000 Nm 3 /h at 380 °C
Efficiency DeSO x : > 70%
90 000 Nm 3 /h at 175 °C
Max inlet value: 1,260 mg/Nm 3
Outlet guaranteed value: 85 mg/Nm 3
Measured values: 26 mg/Nm 3
Efficiency DeSO x : 98%
143,000 Nm 3 /h at 185 °C
Inlet value: 10,000 ppm (28 g SO 2 / Nm 3 )
Outlet values: 200-400 ppm (560-1,120 mg SO 2 /Nm 3 )
Efficiency DeSO x : 96%
38 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
© Fives Solios
Fig. 1: Enhanced all-dry scrubbing process
Fig. 2: Semi-wet scrubbing process
based on the following chemical reaction:
Ca(OH) 2 + SO 2 → CaSO 3 + H 2 O.
Other compounds such as ammonium bisulfite
or activated carbon (which has a valuable
adsorption capacity) can also be used.
SO 2 treatment processes can be classified
into four main families :
Dry scrubbing: Fives Solios’s all-dry scrubbing
process uses the Venturi reactor coupled
with a pulse jet fabric filter. The vertical reactor
provides intimate contact of gas with a solid
reagent. Reagent recirculation maximises
pollutant elimination, and therefore reduces
spikes at the stack. Acid gas removal is
achieved in the filter by reaction in the filter
cake with the unspent reagent. This process is
operationally simple, easy to maintain and a
low energy consumption.
Enhanced all-dry scrubbing: The addition
of a conditioning drum to the dry scrubbing
process enables the reagent to be moisturised
before being injected into the reactor. Water
evaporation cools the flue gas, creating ideal
conditions for SO 2 removal – ideal reaction
temperature, lowest reagent surface temperature
and more humidity at the point of reaction
– which results in an increased surface
area for chemical adsorption. This process was
developed by Procedair in the 1980s, and it
is particularly suitable for high efficiency in
SO 2 removal.
Semi-wet scrubbing: Fives Solios’s semiwet
scrubbing process treats acid gases in a
spray dryer coupled with a pulse jet fabric filter.
The reagent (e. g. lime milk) is dispersed
into fine droplets to extend its contact area
with SO 2 . Desulphurisation is controlled by
the reagent flow, while the water flow enables
temperature control of the fumes. This process
allows rapid response to variations of inlet
pollutant levels and can so control high acid
gas concentrations.
Wet scrubbing: The reagent is dissolved
and put into contact with SO 2 either by pulverisation
into the gas stream or by spraying
water on packing, which has a shape which
ensures high contact area between liquid and
gas. Pulverisation scrubbing can reach higher
efficiency than packing scrubbing in a dusty
atmosphere. Packing generally requires to be
protected from dust; this is achieved by locating
the scrubber downstream of the filter.
Solios Environnement has successfully applied
these solutions; some references to various
projects are listed in the table.
Author
Fig. 3: Pictures of wet scrubbers (methionine production – catalyst regeneration)
Alix Courau is a process engineer at Solios Environnement,
located at St. Germain en Laye, France.
ALUMINIUM · 1-2/2013 39

ALUMINIUM SMELTING INDUSTRY
History of intensive mixing for carbon paste
B. Hohl, Eirich
Carbon paste is used in many different
fields of the heavy industries, for instance,
as anode or cathode blocks for primary
aluminium smelting, as graphite electrodes
for electric arc furnaces, as carbon bricks
for refractory linings, as Soederberg electrodes
for reduction furnaces, etc.
Over many decades, slowly running
batch mixers have been the only useful
aggregates for the preparation of such
products. For anode paste a continuous
preparation process became established
later which was based on one or two continuous
kneaders arranged downstream.
In the seventies of the last century, the
intensive mixer started on a triumphal
march through this industry. Starting
with individual machines for continuous
remixing and cooling of anode paste as
well as batchwise preparation of various
carbon bodies, the intensive mixer constantly
opened up new fields of application
in the carbon sector. Due to its special
benefits, such as high efficiency and
an attractive cost/performance ratio, the
intensive mixer can be found everywhere
in the carbon industry today.
This paper describes the most important
characteristics and applications, from
the beginnings until today.
Anodes for primary aluminium smelting
The world’s production of primary aluminium
reached approximately 44 million tonnes
in 2012, of which about 90% (39.6m t) were
produced in modern factories with so-called
prebaked anodes. The remaining 4.4 million
tonnes come from older works with Soederberg
technology. The requirement for anode
paste is therefore about 21.7 million tonnes
for prebaked anodes and 2.5 million tonnes
for Soederberg anodes.
Due to the high throughput rates together
with the constant formulas, continuous preparation
systems are used almost exclusively for
carbon anode paste preparation. More than
every second prebaked anode is produced
from partially or completely intensively prepared
paste (Eirich remixer-cooler, resp.
Eirich Mixing Cascade EMC). So, the use of
intensive mixers for the preparation of anode
paste has become state-of-the-art in the primary
aluminium industry.
Remixing and cooling of anode paste
Already in the 1970s, individual intensive
mixers were used as continuously operating
coolers for anode paste. In the Netherlands
and in Bahrain for instance, the breakthrough
of this technology began around 1990, followed
by two more machines in France and
Australia. Preceding this were extensive
test series at the Pechiney works in Sabart
(France). At that time, the customer was looking
for a paste cooler of high performance and
efficiency. With the continuously operating
Eirich intensive mixer, Pechiney found a machine
which not only coped reliably with this
task definition but additionally achieved excellent
homogenisation of the paste. By direct
addition of cooling water and its immediate
evaporation, the mixer achieved paste cooling
capacities never reached before.
On top of that is the effect of a more or less
‘cost-free’ homogeniser: the relatively long retention
time of 4-5 minutes, with the intensive
mixing effect and the additionally introduced
mixing energy of approx. 4 kWh/t, together
generate a considerably improved paste quality
compared to single-step preparation [2].
All these factors are the reason that in
the last 15 years hardly any single-step paste
preparation lines were built. In the same period,
numerous existing plants were retrofitted
with Eirich intensive remixer-coolers. The
installation of an additional machine into an
existing building often posed a great challenge
to the engineers. In the end, they always
found a solution to integrate the machine.
The effect of the Eirich cooler becomes
especially apparent when retrofitting into existing
lines, because here the improvement in
preparation quality is easy to prove.
Advantages
• Thanks to the cooler operating in a second
mixing stage, the hot mixing temperature
is freely adjustable independent of the
forming temperature
• Long retention time and intensive energy
input provide excellent mixing of the
paste
• Thus, essentially more stable paste quality;
parameter variations are reduced to less
than 50% of previous scatter range
• Agglomerate-free paste with constant
temperature
• Additional mixing energy raises paste
quality
• Higher green and baked anode density
improve anode strength
• Lower electric resistivity of the anode
improves electrolysis efficiency
• Clearly reduced porosity and optimised
pore structure improve anode life
• Lower chemical reactivity reduces anode
burn
• Possibility of increasing the performance
of the complete preparation system to a
certain extent.
High-performance remixer-coolers have been
installed recently, for instance at Alcoa Mosjoen
/ Norway, Qingtongxia/China and Emal
1+2 / Abu Dhabi.
All-intensive preparation of anode paste
The successful use of the intensive mixing
principle for paste cooling was the initiation
for the development of the Eirich Mixing Cascade
(EMC). Two series-connected intensive
mixers perform both hot mixing of coke and
binder pitch, plus subsequent remixing and
cooling. The special advantages of the Eirich
intensive mixer, such as low capex and opex,
short standstill periods on the occasion of
wear-related repairs, long retention time, com-
Fig 1: Eirich intensive mixing principle
Fig 2: Paste quality improvement thanks to the
second mixing level
© Eirich
40 ALUMINIUM · 1-2/2013

ALUMINIUM SMELTING INDUSTRY
History of intensive mixing for carbon paste
B. Hohl, Eirich
Carbon paste is used in many different
fields of the heavy industries, for instance,
as anode or cathode blocks for primary
aluminium smelting, as graphite electrodes
for electric arc furnaces, as carbon bricks
for refractory linings, as Soederberg electrodes
for reduction furnaces, etc.
Over many decades, slowly running
batch mixers have been the only useful
aggregates for the preparation of such
products. For anode paste a continuous
preparation process became established
later which was based on one or two continuous
kneaders arranged downstream.
In the seventies of the last century, the
intensive mixer started on a triumphal
march through this industry. Starting
with individual machines for continuous
remixing and cooling of anode paste as
well as batchwise preparation of various
carbon bodies, the intensive mixer constantly
opened up new fields of application
in the carbon sector. Due to its special
benefits, such as high efficiency and
an attractive cost/performance ratio, the
intensive mixer can be found everywhere
in the carbon industry today.
This paper describes the most important
characteristics and applications, from
the beginnings until today.
Anodes for primary aluminium smelting
The world’s production of primary aluminium
reached approximately 44 million tonnes
in 2012, of which about 90% (39.6m t) were
produced in modern factories with so-called
prebaked anodes. The remaining 4.4 million
tonnes come from older works with Soederberg
technology. The requirement for anode
paste is therefore about 21.7 million tonnes
for prebaked anodes and 2.5 million tonnes
for Soederberg anodes.
Due to the high throughput rates together
with the constant formulas, continuous preparation
systems are used almost exclusively for
carbon anode paste preparation. More than
every second prebaked anode is produced
from partially or completely intensively prepared
paste (Eirich remixer-cooler, resp.
Eirich Mixing Cascade EMC). So, the use of
intensive mixers for the preparation of anode
paste has become state-of-the-art in the primary
aluminium industry.
Remixing and cooling of anode paste
Already in the 1970s, individual intensive
mixers were used as continuously operating
coolers for anode paste. In the Netherlands
and in Bahrain for instance, the breakthrough
of this technology began around 1990, followed
by two more machines in France and
Australia. Preceding this were extensive
test series at the Pechiney works in Sabart
(France). At that time, the customer was looking
for a paste cooler of high performance and
efficiency. With the continuously operating
Eirich intensive mixer, Pechiney found a machine
which not only coped reliably with this
task definition but additionally achieved excellent
homogenisation of the paste. By direct
addition of cooling water and its immediate
evaporation, the mixer achieved paste cooling
capacities never reached before.
On top of that is the effect of a more or less
‘cost-free’ homogeniser: the relatively long retention
time of 4-5 minutes, with the intensive
mixing effect and the additionally introduced
mixing energy of approx. 4 kWh/t, together
generate a considerably improved paste quality
compared to single-step preparation [2].
All these factors are the reason that in
the last 15 years hardly any single-step paste
preparation lines were built. In the same period,
numerous existing plants were retrofitted
with Eirich intensive remixer-coolers. The
installation of an additional machine into an
existing building often posed a great challenge
to the engineers. In the end, they always
found a solution to integrate the machine.
The effect of the Eirich cooler becomes
especially apparent when retrofitting into existing
lines, because here the improvement in
preparation quality is easy to prove.
Advantages
• Thanks to the cooler operating in a second
mixing stage, the hot mixing temperature
is freely adjustable independent of the
forming temperature
• Long retention time and intensive energy
input provide excellent mixing of the
paste
• Thus, essentially more stable paste quality;
parameter variations are reduced to less
than 50% of previous scatter range
• Agglomerate-free paste with constant
temperature
• Additional mixing energy raises paste
quality
• Higher green and baked anode density
improve anode strength
• Lower electric resistivity of the anode
improves electrolysis efficiency
• Clearly reduced porosity and optimised
pore structure improve anode life
• Lower chemical reactivity reduces anode
burn
• Possibility of increasing the performance
of the complete preparation system to a
certain extent.
High-performance remixer-coolers have been
installed recently, for instance at Alcoa Mosjoen
/ Norway, Qingtongxia/China and Emal
1+2 / Abu Dhabi.
All-intensive preparation of anode paste
The successful use of the intensive mixing
principle for paste cooling was the initiation
for the development of the Eirich Mixing Cascade
(EMC). Two series-connected intensive
mixers perform both hot mixing of coke and
binder pitch, plus subsequent remixing and
cooling. The special advantages of the Eirich
intensive mixer, such as low capex and opex,
short standstill periods on the occasion of
wear-related repairs, long retention time, com-
Fig 1: Eirich intensive mixing principle
Fig 2: Paste quality improvement thanks to the
second mixing level
© Eirich
40 ALUMINIUM · 1-2/2013

ALUMINIUM SMELTING INDUSTRY
Anode paste with
high coarse and fine porosity
(continuous kneader)
Fig. 3: Green paste porosity as an indicator of mixing efficiency [1]
Anode paste with low porosity
and evenly coated coke particles
(continuous kneader + Eirich mixing cooler)
products is performed entirely batchwise. Especially
the so-called Ultra High Power (UHP)
qualities for graphite electrodes with large diameters
require an optimally prepared press
body. The very fact that up to three months
elapse between paste mixing and the quality
control of the final product, shows the high
cost of uncertain quality in such a process;
with the mixer being one of the key elements.
A lot of manufacturers are using Eirich highperformance
compact systems because they
need this reliable quality.
Optimisation of the three
important process steps
pensation of short-term variations in paste
composition, especially efficient and thus
moderate energy input, etc. come into their
own. On top of that, the machines are available
for a wide range of throughput rates, so
that even most modern smelters with more
than 600,000 tonnes a year of aluminium production
can be supplied from an anode plant
with just one single preparation line.
After the triumphant start of a pilot system
in a Swiss aluminium smelter, and following
comprehensive tests in Norway, it took about
ten years to commercialise this new idea successfully.
After launching a comparatively small plant
in Cameroon in 1998 [8, 9], the breakthrough
occurred in 2003 with the sale of three plants
to several customers in China [3] In the meantime
the EMC has gained ground in India as
well as in the Persian Gulf. At the Qatalum
greenfield smelter the magical limit of 60 t/h
was achieved in one single line for the first
time.
The concentration on only one preparation
line, even for extremely large anode factories,
is based on economic reasons, which require
a system with maximum reliability and high
availability, but in parallel with short downtimes
for maintenance work. Thanks to decades
of experience, an in-house production of
high quality standards, and a worldwide service
organisation, the EMC systems reach the
same performance as the well-known Eirich
remixer-coolers. Meanwhile, there are 14
EMC lines under construction or in operation.
Carbon products for other
metallurgical purposes
Intensive mixers have been successfully used
for manufacturing graphite electrodes for
electric arc furnaces, cathode blocks for primary
aluminium smelting [4] and carbon blocks
for linings of blast furnaces.
Based on the given task definition, the
paste preparation for these high-quality final
In the mid-1980s, Eirich was able for the first
time to replace a series of conventional batch
mixers of an Austrian graphite electrode manufacturer
by one single Eirich high-performance
mixer. The new batch preparation system
used the following principles:
• Separation of dry substance heating and
mixing process
• Application of a direct electric coke heater
of high performance
Fig. 4: Conventional two-step paste preparation Fig. 5: Eirich Mixing Cascade EMC Fig. 6: 35 t/h paste plant at Aostar/China [3]
42 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
Fig. 7: 36 t/h paste plant at Sohar/Oman [5] Fig. 8: 60 t/h paste plant at Qatalum [6]
• Application of an intensive mixer-cooler
with only 15 minutes batch processing
time
• Storage of the prepared paste in a special
silo (table feeder) to make the mixing
process independent from the press
operation.
This allowed the customer to replace numerous
conventional mixing systems by one single
Eirich line. This not only reduced the maintenance
effort by about a third, but also significantly
improved the mixing effect itself compared
to the existing sigma blade kneaders.
Advantages
• Fully electric coke heating equals the most
elegant solution on the market
• Rapid and accurate adjustment of the coke
temperature
• No HTF heating system required i.e. no
risk of fire, self-ignition, leakage, etc.
• Mixing energy input easily adjustable via
tool speed, tool shape and mixing time
• Rapid homogenisation in the intensive
mixer
• Significantly increased mixing quality
• Reduction in pitch consumption of 2-5%
• Simple machine design
• Wear and spare parts easily exchangeable
• Short maintenance standstill periods
• Insensitivity to varying operating
conditions
• One Eirich mixer may replace 8-12
conventional batchwise operated machines
• Thus, productivity increases in green
production of graphite electrodes are up
to 200%
• Investment and maintenance costs up to
30% lower
• High and freely selectable temperature
level of the preparation process, thanks
to direct electric heating and evaporative
cooling
• Compact tower system close to the press.
Conclusion
Thanks to its specific benefits, intensive mixing
has become proven technology in the carbon
paste preparation sector. Further technical
and commercial growth potential is assured.
The high efficiency at low investment and
operating costs make the Eirich intensive mixer
the means of choice also in the future.
References
[1] P. Stokka., Green paste porosity as an indicator
of mixing efficiency, Light Metals (1997), pp. 565-
568
[2] B. Hohl and L. Gocnik, L. Installation of an anode
paste cooling system at Slovalco, Light Metals
(2002), pp. 583-586
[3] B. Hohl, and Y. L. Wang, Experience Report –
Aostar Aluminium Co. Ltd China, Anode paste
preparation by means of a continuously operated
intensive mixing cascade, Light Metals (2006), pp.
583-587
[4] B. Hohl and V. V. Burjak, High-performance
preparation plant for cathode paste, Light
Sample C13, 10 min. Sigma mixing, 19%
Sample C11, 10 min. Eirich mixing, 19%
pitch, high fines, green density 1.646 kg/m 3 pitch, high fines, green density 1.685 kg/m 3
Fig. 9: Eirich high-performance compact system
for batchwise preparation of carbon paste
Fig. 10: Overview of the green samples mixed with a Sigma or with an Eirich mixer, magnification 160x,
polarised light
ALUMINIUM · 1-2/2013 43

ALUMINIUM SMELTING INDUSTRY
Metals (2008), pp. 997-1000
[5] M. Gendre et al., From technology development
to successful start-up and operations of Sohar:
The potential of the Bi-Eirich mixing line, Light
Metals (2010), pp. 963-968
[6] C. Bouché, S. Bhajun and B. Somnard, 60 tph
single line green anode plant commissioned at Qatalum,
Light Metals (2012), pp. 1153-1157
[7] M. Tkacet al., Effects of variation in production
methods on porosity development during anode
baking, 12 th Arabal Conference, 2006
[8] J.-C. Thomas, New concept for a modern paste
plant, 7 th Australasian Aluminium Smelting Technology
Conf. and Workshops, Melbourne, 2001
[9] C. Dreyer, C. Ndoumou and J.-L. Faudou, Reconstruction
of the mixing line for anode paste
production at Alucam, Light Metals (1998), pp. 705-
710
Others
This paper was presented at the ICSOBA Conference
in Belèm-Brazil, 2012
Author
Dipl.-Ing. Berthold Hohl is manager Carbon Technology
of Maschinenfabrik Gustav Eirich GmbH &
Co KG, based in Hardheim, Germany.
HMR’s automated stud repair line
I. Dal Porto, HMR Hydeq
The consumption of yoke studs is huge in
aluminium smelters. Today most of the
plants carry out the repair process manually.
The operation consists of removing
the damaged anode yoke from the overhead
conveyor, transport to the repair
shop, cutting off damaged studs with a
cutting torch, making a seam, adjusting
and welding of new parts – all these operations
are carried out manually. This
traditional manual repair cannot be costeffective
and cannot ensure a high quality
standard, since it involves handling and
transportation of the anode yoke and it
relies on the ability of a human operator
both for welding and for the cut, which
usually employs flame cutting. Flame cutting
results in damage to the surface which
is then needed for welding, whereas it is
very important to reduce the electrical
resistance of the welded joint. Poor quality
cut surfaces can significantly affect the
overall current efficiency of the electrolytic
process and hence production costs.
Automated stud repair line
HMR’s Automated Stud Repair Line (ASRL)
repairs anode yokes by replacing worn-out
studs with the new studs whilst anode yoke
and rod is still on the powered and free conveyor
in the rodding shop. The repair line is
fully automatic and requires only one operator.
The operation starts by testing of every anode
stud on the anode yoke in accordance with
the wear-and-tear specification set up by the
customer. Anode studs with wear and tear
above the acceptable limits are diverted on a
bypass to the ASRL for replacing. The powered
and free conveyors bring the anode rod
forward, first to the cleaning station, then to
the cutting station, where a saw cuts the exhausted
stud from the yoke, and finally into
the welding station, where fully programmable
welding robots perform a perfect weld.
After the replacement of worn anode studs,
the anode yoke with rod returns to the rodding
shop.
During the process of cleaning the studs to
remove bath, rust, oxide scale, etc., some dust
© HMR
Automated Stud Repair Line (ASRL) installed in Årdal, Norway, with sawing station on the right. Data from the measuring station is transferred to the sawing
station, which performs cutting automatically in accordance with the given information.
44 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
is released. Also during the welding process,
welding gas appears. In order to effectively
contain these impurities, a special cyclone filter
has been installed on the ASRL.
The advantages of HMR’s ASRL are:
• The line is completely automated and
requires just one supervising operator
• The process is efficient and very safe for
the floor personnel
• It reduces repair down-time to the
minimum
• There is no need to remove the anode
rods from the conveyor during stud
replacement
- Fewer anode rods are needed in the plant
(estimation 2-4%)
• Studs are replaced exactly according to
the procedure set up by the customer.
Procedure, line of action
HMR’s ASRL brings the studs distinctively to the same condition as on the anode yoke
Measuring station: All complete anode yokes
and rods are transported on the power and
free conveyer to HMR’s ASRL measuring station.
Each anode stud is checked against the
wear and tear limit set by the customer. Anode
studs with an acceptable wear-and-tear level
are returned to the plant. A bypass on power
and free conveyer brings anode studs with
wear and tear above the limit to the ASRL
for processing. The measurement station collects
historical data which later can be used for
statistical purposes.
Cleaning station: The HMR’s ASRL system
sends a signal to the robot-operated cleaning
device and indicates which stud is to be
cleaned. In front of the cleaning station there
is a conveyor block up. The robot with chain
centrifugal blast cleaning device starts to clean
DUBAL

ALUMINIUM SMELTING INDUSTRY
The specimens show the homogeneous welding
attainable and how tight the two parts are pressed
together. This improves the electric conductivity,
and it transfers heat better then than other joints
available on the market today.
studs, the anode yoke and rod is directed to
the automatic welding station. If the welding
station is occupied, the anode yokes and rod
wait at the intermediate storage zone. While
one robot handles the new stud, checks and
prepares it for a correct replacement and welding,
the other two robots execute the welding
operation simultaneously from both sides.
Then the already repaired anode yoke and
rod is returned into the system for rodding.
Safety system: The whole of HMR’s ASRL
is surrounded by a safety fence. Each robot
station has an additional safety fence. If anyone
opens a door in the fences, the system
stops robot movements momentarily. A separate,
moveable safety catch is placed around
the chain centrifugal blast cleaning station.
Samples of the stud bar cut by the saw. The quality
of the cut is very good and can be systematically
tested.
the saw cutting / welding area.
Saw: Thereafter the anode yoke and rod is
transported to the automatic saw station. Data
from the measuring station is transferred to
the cutting station, which performs cutting according
to the given information.
Welding station: After removal of a stud or
The photo shows two sliced part cut in the exact same cut
before welding. Second cut 10 mm below welding.
Performance, capacity and quality
HMR’s ASRL brings the studs distinctively to
the same condition as on a new anode yoke.
The operation provided by ASRL ensures in
a low electrical resistance of the joint thanks
to optimised cutting and welding procedures
developed by HMR and executed
reliably by the automated robotic
line.
The system has a repeatability
of < 0,1 mm (NB. depending on
anode rod condition) and a productive
capacity of ≤ 6 min. (NB.
depends on groove weld design,
number of studs per anode rod
and on conveyor speed). The
welding time is about four minutes
per stud.
It is quite important that the
cutting and welding area is kept
clean of bath, rust and iron scale contamination.
That is why a chain centrifugal blast cleaning
is a part of the ASRL system. This device prevents
bath, rust and iron scale from interfering
with welding, and it prolongs the life of saw
blades (40% alumina content in bath causes
rapid wear of saw blades). This cleaning allows
up to 800-1,000 studs cut to be obtained from
recommended saw blades.
However, one must bear in mind that the
quality of weld provided by ASRL depends
also upon external conditions. The most important
of these is that joint surfaces must be
clean and accurately machined. The studs cut
by the saw have a bright steel surface, which
is preferred for welding.
Author
Italo Dal Porto is senior engineer at HMR Hydeq
AS, based in Årdal, Norway.
Channel-type versus coreless induction furnaces
W. Spitz and C. Eckenbach, Marx GmbH & Co. KG
The company Marx gives an overview of
the different types of induction heating
units for melting, holding and holding/
casting furnaces. This paper focuses on
coreless inductors and on their advantages
over channel type inductors when
it comes to holding /casting of special
aluminium alloys. It illustrates and explains
this comparison for the case of a
holding/casting furnace in an aluminium
semi-fabrication plant in Europe which
was modified from a channel-type furnace
to a furnace with coreless inductor
technology. The paper gives technical
information comparing in detail the new
benefits, such as an increased service life
of the furnace of up to three years with
the crucible inductor. Specifically, this revamp
and upgrade of a 28 tonnes holding
and casting furnace with a power of 200
kW converted it to 40 tonnes and 450
kW, as demonstrated by construction and
field results.
Basically two different kinds of induction furnaces
are used for melting, holding and cast-
ing of metals: the channel-type induction furnace
and the coreless type induction furnace.
The channel-type induction furnace consists
of a refractory lined furnace body made
of steel to which one or several channel-type
inductors are flanged for heating the metal.
Due to effects like thermal conductivity and
buoyancy of the hot melt, in most cases the
channel-type inductor is flanged at the bottom
of the channel type furnace body. This results
in the typical design of a small to mediumsized
channel-type melting furnace like that
shown in Fig. 1.
46 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
Depending on the function of the furnace
in the production line other furnace body
designs may be appropriate, placing the channel
inductor in other positions. Channel-type
induction furnaces are used for copper and
copper alloy melting, as the copper is sensitive
to oxygen pick-up from the air at a turbulent
surface. Channel-type furnaces offer a smooth
bath surface, but still provide a sufficient turbulence
inside the melt to mix it and ensure
uniform chemical composition and temperature.
These are also the preferred type of
furnace for holding and casting of copper and
copper alloys (Fig. 2).
Another application for the channel inductor
is the holding of iron melts in huge storage
furnaces or holding / casting furnaces with
flanged forehearth, these being used in automatic
high-speed sand mould casting lines.
Channel-type furnaces have a much higher
electrical efficiency than coreless furnaces,
but when it comes to iron and steel melting
(high power density required) and frequent
alloy change, or the need to empty the furnace
regularly, the coreless furnace is the preferred
choice as melting for holding / casting
furnaces.
A third version of induction heating is a
so called ‘coreless inductor’. Coreless inductors
were already being used at the beginning
of the 1980s for heating holding furnaces in
the aluminium and copper casting industries,
typically for holding furnaces in continuous
casting lines. Such inductors consume more
energy than a channel-type inductor, but they
offer much longer lifetime and they allow easy
emptying the holding furnace on a regular basis
(Fig. 3).
Marx has gained an extensive experience
in modifying existing holding furnaces from
being heated by channel-type inductors to
being heated by coreless inductors. Such a
refurbishment and modification can increase
holding capacity, precision and power efficiency.
Changing the old conventional tap
switch power cabinet for a more economical
IGBT transistor converter cabinet also allows
a precise holding / casting temperature regulation
of the melt.
Such a furnace refurbishment will be illustrated
and explained using the example of a
28-tonne holding furnace at a prominent semifabricator
plant in the European aluminium
slab casting industry. This customer has been
operating eleven units with 20- to 30-tonne
holding furnaces, these being fed with liquid
metal by gas heated melting furnaces, which
supply the liquid metal by tilting into a semicontinuous
vertical casting line (Fig. 4).
The holding furnaces had been equipped
Fig. 1: Different types of induction furnaces – channel-type furnace
Fig. 2: Channel inductor – Aluminium
Holding /casting furnace
Coreless (crucible) inductor
Fig. 3: Different types of induction furnaces – furnace heated by coreless inductor
© Marx
ALUMINIUM · 1-2/2013 47

ALUMINIUM SMELTING INDUSTRY
3D-Visualisation
Fig. 4: Channel inductor, 28-tonne capacity Crucible inductor, 40-tonne capacity
with 200 kW channel-type inductors, but these
required weekly cleaning due to clogging of
the channels. Cleaning represents in significant
production downtimes as well as difficult and
time-consuming maintenance. In addition, the
furnaces needed five to six inductor changes
per year at one holding furnace, resulting in
additional maintenance costs and production
downtimes.
Converting an existing furnace involves
first collecting the furnace’s structural data. It
is useful and recommendable to visualise this
structure in a 3D image. Then we must decide
whether the furnace volume will remain unchanged
or whether the furnace casing should
be enlarged. For this purpose, we must subject
the unit needs to static and dynamic functional
testing and check the complete movement (tilting,
driving) devices and power input. Calculations
have to prove whether these components
must be replaced by more powerful ones.
On the construction site itself, the disconnection
of the old lower furnace body structure
is prepared and carried out. The welding
area is being mechanically and technically prepared
and the new substructure is positioned
on the contact surface and then welded onto
the furnace (Figs 5 and 6).
The new furnace substructure supports
the receiving structure for the crucible induc-
Fig. 7: 40-tonne holding and casting furnace, ready
for production
tor that is installed later on. After successful
welding and structural support, the furnace is
ready to undergo welding analysis and, after
approval, needs to be prepared for a new lining.
Constructional conditions, such as the furnace
pit, are also checked in terms of spatial geometry.
The necessary clearance spaces for more
expansive tilting movements may require
structural changes; this however is normally
not the case (Fig. 7).
In terms of cost saving and production increase,
such conversion is amortised in less
than one year. For operating personnel, handling
becomes much easier. So far, Gautschi
has retrofitted or has prepared for retrofitting
some 30 such furnace plants. It is nearly always
possible to use the existing furnace ves-
Fig. 5: Separation of existing substructure
Fig. 6: Mounting prefabricated new substructure
For 50 years, the Marx group in Germany
with its approximately 100 employees has
been working in the furnace industry. The
company’s activities include planning and
manufacturing of induction furnace plants,
engineering, development, remanufacture,
modernisation and retrofitting of induction
furnace plants, service and customer support.
The company has therefore gained extensive
experience in working on almost all types of
induction furnaces. Nearly every type of furnace
has been serviced, repaired, retrofitted
or modernised in its facilities. Its German sites
in Iserlohn, Hennigsdorf, Donauwörth and in
Youngstown, Ohio/USA provide well-aimed
proximity to their customers in Europe and
the United States.
48 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
Comparison over the year
Furnace with channel inductor
Furnace with coreless inductor
Cleaning cycles
52 cleaning cycles
no cleaning cycles
3 man-days each (1,248 h)
52 production downtimes due to cleaning
no production downtime due to cleaning
2 x 24 h each (2,496 h)
Inductor change
At least 5 inductor changes / shutdowns for repair
10 man-days each (400 h)
5 production downtimes
5 x 24h each (120 h)
At least 5 repair deployments
€10,000/piece each → €50,000
5 levelling processes and conditioning work on
rectangular flange
5 x 3 h (15 h)
Table: Comparison over the year
⅓ – 1 vessel change / shutdowns for repair
(1-3 man days → 8-24 h / 3 staff)
⅓ – 1 production downtimes
10-30 h
⅓ – 1 repair deployment
€10,000/piece each → €3,300-10,000
Refractories
⅓ – 1 levelling process and conditioning work
on round flange
1-3 h
furnace is surprisingly overwhelmingly clear
in favour of the crucible furnace (see Table):
As already mentioned, the modification
period can be used to change the old conventional-style
power supply against a more
efficient new converter power supply. Using
an infinitely variable power supply via transistor
converter in IGBT technology provides
for automated and visualised control of the
holding and casting process and, at the same
time, allows for monitoring the condition of
the crucible inductor itself.
It is clearly worthwhile to examine existing
furnaces and to retrofit them with modern
technology. This keeps melting and heating
technology one step ahead of the market.
Authors
sels, to shorten them at the bottom and to fix
a new substructure, thereby completing the
refit within quite a short time, with good preparation
in approximately four weeks. The
coreless inductor is simply bolted on to the
lower furnace body. If it wears out, it can be
changed within a time frame of 24 to 30 hours
maximum from pouring the furnace vessel
empty to its restart. The cost-benefit equation
in relation to channel furnace versus crucible
Dipl.-Wirt. Ing. (FH) Christian Eckenbach is managing
director of Marx GmbH & Co. KG, based in
Iserlohn, Germany.
Dipl-Ing. W. Spitz is sales manager for Induction
Furnaces at Marx GmbH & Co. KG.
Alcoa starts up potlining facility at Fjardaál Iceland smelter
Alcoa reports that a new potlining facility
is now in operation following its formal
launch last year at the company’s Fjardaál
smelter in Reydarfjördur Iceland. The
startup of the new plant marks the overall
completion of the integrated smelter on
which work initially began in 2004.
The cost of the new facility amounts to some
USD36 million, Alcoa says. Work started
in 2010, and overall construction has taken
about 18 months with Canadian engineering
company Hatch heading up the construction
in collaboration with Icelandic firm HRV Engineering.
Around 100 people worked on the
construction at the peak of the project. Following
a bidding process, VHE in Iceland was
chosen to operate the new potlining facility
in accordance with Alcoa’s stringent demands,
in terms of environmental and safety issues.
VHE has hired around 60 people to work on
potlining and pot repairs, and these operations
will be located partly in the new Alcoa potlining
facility and partly in VHE’s own facility
situated on the smelter site.
The new construction consists of three
buildings: a spent pot lining facility; a dedicated
potlining workshop, and an administration
block.
Spent pot lining, also known as SPL, consists
of the cathodic block (carbon) and insulation
(refractory lining materials) of aluminium
smelting pots that have reached the end of
their service life. The potlining area is a stateof-the-art
facility, purpose-designed and
equipped with latest plant and process technologies
and also ideal conditions for lining
new pots for the
smelter operation.
Alcoa presents
some key figures
that reflect the operating
performance
of the new
pot relining facility
since its opening
last year:
Over 40 pots
have been relined
and the facility
has the capacity to
reline around 100
pots per year.
An average of New potlining workshop
90 tonnes of materials
(refractory bricks, cathodes, paste and
mortar) are used to line each pot; and interestingly
the busy cathode transport crane which
traverses between the potroom and the relining
facility covers some 6 km each week.
Alcoa emphasises that many new jobs have
been created by the project overall, culminating
in the opening of the potlining facility, and
that increased business and revenues are also
being generated for the Icelandic economy.
The launch of the smelter in Reydarfjördur,
the company claims, has proved to be pivotal
for East Iceland: the number of residents has
increased by 1,000 since Alcoa’s aluminium
plant started operations.
Ken Stanford, contributing editor
© Alcoa
ALUMINIUM · 1-2/2013 49

The entire steelmaking process chain from a single source.

ALUMINIUM SMELTING INDUSTRY
Gautschi Engineering – An industry profile
O. Moos, Gautschi Engineering
Gautschi Engineering GmbH is one of
the world’s leading suppliers of casthouse
and heat treatment technology for the
aluminium industry since 1922. The wide
product range includes all necessary control
and automation equipment, and its
reliability and efficiency has been a major
contribution to the success of the company
over all those years. Gautschi has been
a supplier to all the
large aluminium
producers as well
as to many smaller,
independent companies
around the
world.
From the start, the
company has worked
to gain a thorough understanding
of its customers’
needs so that
together with them it
can develop comprehensive
solutions to
meet all their requirements.
This naturally
applied especially to
the beginning of its
operation, when the
commercial production
of aluminium had
just been established.
Gautschi’s head office
location in Switzerland certainly contributed
to the success in the aluminium industry, as
the first commercially operated smelter was
located just a few kilometres away. In addition,
the first aluminium cold rolling mill was
established in a neighbouring town.
As most components required to operate
the equipment were then not easily available,
Gautschi invested heavily in developing its
own technologies. In the early times, even
fuel and air line components were fabricated
in-house. For a period of time, Gautschi produced
part of the insulation material in its own
factory. Hydraulic equipment from valves to
cylinders was supplied by Gautschi. In addition,
the control systems are designed and
programmed in-house up to this day. Furthermore,
we still use our own design for blowers,
fans and burners (cold air, hot air and regenerative).
Nowadays, most components for combustion,
hydraulic, pneumatic and electric systems
are sourced from leading suppliers. However,
the profound experience from the past allows
Gautschi to understand basic principles
when designing the equipment supplied, and
to judge what components are most suitable
for a specific application.
Its history and wide product range allows
a system supplier such as Gautschi to offer all
Round top charged melting furnace with a melting capacity of 30 tonnes per hour
necessary expertise not only for a specific piece
of equipment, but also for its auxiliary components
and for equipment/processes adjacent
to the equipment within the whole working
area. For example, a casting machine can only
produce a certain quality if the casting process
already meets specific requirements.
Liquid metal furnaces
For many years, liquid metal furnaces for
standard applications were seen just as a necessity
in an aluminium casthouse. Main efforts
were put into the design of casting machines
(the heart of the casthouse) and the heat
treatment facilities. But in the second half of
the last century, the dramatic increase in energy
cost together with stringent environmental
requirements, and the demand for top quality
products, drove furnace suppliers and users
to take a new look at their furnaces. Nowadays
you can choose from numerous designs for liquid
metal furnaces according to the differing
requirements of modern casthouses.
Gautschi supplies a wide range of different
liquid metal furnaces with capacities between
10 to 140+ tonnes. Melting rates above 40 t/h
have been achieved in remelt facilities.
As mentioned above, Gautschi started to
develop its own technologies early on. This
was on the one
hand because certain
technologies
were not available
on the market, and
on the other hand,
because the available
technologies are
not always suitable
for specific applications.
Over the many
decades in operation,
the company developed
a wide range
of burners with a capacity
between 500
to 9,500 kW. These
burners either work
with cold air, or
with hot air (using a
central recuperator)
or they are regenerative,
with a heat
© Gautschi Engineering
exchanger module
directly attached to the burner head. In addition,
the burners can operate with different
fuels according to the customer’s needs.
Gautschi is especially proud having a regenerative
combustion system at hand (the Varega
Regenerative Combustion System), bringing
the thermal energy consumption down to
rates as low as 465 kWh th /t Al . Naturally, this
depends on a lot of factors, starting with good
house keeping practices (what kind of charging
material is available and how is separated and
stored), and including the kind of furnace used
as well as the level of maintenance done on
the equipment. In addition to being the most
efficient combustion system on the market,
the Gautschi Varega Regenerative Combustion
System requires minimal maintenance.
Other systems on the market require costly
maintenance at intervals of a few weeks to a
couple of months. For example, the ceramic
balls in the regenerator must be removed and
52 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
washed, and damaged balls must be replaced.
Gautschi’s systems offers maintenance cycles
of more than 12 months between the regenerator
cleaning. In addition, our system uses
honeycomb modules, of which only a small
proportion (generally only the top layer) must
be replaced during the maintenance, so keeping
cost to an absolute minimum.
In order to meet customers’ requirements,
we offer reverberatory melting and holding
furnaces, round top charged melting furnaces,
tower melting furnaces, and oval shaped holding
furnaces in its portfolio. However, due to
its huge technical data base, Gautschi is also
in a position to meet any special requirements
customers might have for a specific application.
Gautschi can be seen as the leading supplier
of round top charged melting furnace technology,
having supplied many such furnaces in the
course of its history. It is not uncommon for
such a furnace to remain in operation for 50+
years. Capital well invested!
This type of furnace is normally used in
larger remelt facilities (e.g. rolling mills) to
optimise the production capacities. A typical
installation might have a 120-tonne casting
line consisting of one RTC melting furnace,
one holding furnace and one VDC casting
machine for rolling slabs and produce more
than 140,000 tonnes a year. Output depends
not only on the melting furnace but also on
the material used to charge the furnace, and
on the size or format changes of the rolling
slabs.
Besides having expertise both for the liquid
metal furnaces and for its auxiliary equipment,
the company also supplies complete casting
lines, from the melting furnace up to the casting
machine. Complete lines have the advantage
that all battery limits / communication
interfaces are designed and supplied by one
company.
Casting systems
Gautschi’s casting machines are known for
their accurate and robust design as well as
for their high level of automation. The Gautschi
family of casting machines produce high
quality products such as rolling slabs, extrusion
billets, forging stock and foundry ingots
around the globe.
Vertical DC casting machines have been on
our agenda for more than six decades. These
machines have been constantly developed
over the years, and they feature Gautschi’s
Airglide mould technology for billets. Just
recently a newly developed billet mould gas
control system for a vertical DC casting machine
has been successfully commissioned at
one of our long-term partners.
This mould system offers a superb pit recovery,
with billets showing excellent surface
qualities while having minimised shell and
segregations zones. Compared to similar systems
available, the Gautschi Airglide mould
technology requires very low maintenance.
This mould system is mainly used for billet
diameters between 5 to 10”. However,
moulds as small as 2” and as large as 16” have
been supplied to different customers. All commonly
used alloys can be processed.
Gautschi has been one of the pioneers in
the design of horizontal DC machines to cast
billets and ingots, a technology which is still
commonly referred to as the Gautschi-Ugine
casting process. High versatility combined
GLAMA Maschinenbau GmbH
Hornstraße 19 D- 45964 Gladbeck / Germany
phone + 49 (0) 2043 9738 0 fax + 49 (0) 2043 9738 50 email: info@glama.de
web: www.glama.de

ALUMINIUM SMELTING INDUSTRY
with the low investment costs makes this
technology ideal for small scale production of
foundry ingot, forging rod or extrusion billet.
The technology is especially useful when producing
rods/billets of smaller diameters (normally
less than 3”) as no undesired bending
effects can occur, as opposed to such risks in
a vertical casting process. On the other hand,
casting larger diameters (normally more than
8”) can result in segregation zones within the
billet, because heavier alloying elements tend
to sink to the bottom of the billet.
Recently, Gautschi has designed the so
called smart caster. This casting system is designed
to offer very low investment costs and
short lead times. It is basically shop-assembled
and shipped in one unit. Thus it does not
need extensive installation on site, and this
further minimises time and cost. It is designed
as a dual strand standard caster for rod and
billet in a diameter range of 2 to 6”.
Both the primary and the secondary aluminium
industry have always counted on
Gautschi for the supply of reliable ingot casting
and stacking machines.
A wide variety of production lines allow
the production of ingots from 6 to 23 kg, with
a maximum output of 28 t/h. The latest development
in this field is an improved, partially
submerged pouring system. A plug and spout
system, in combination with a casting wheel,
successfully avoids turbulence and reduces
the generation of oxides.
Automatic speed control has been a standard
feature of Gautschi casting lines for years.
It ensures excellent weight consistency of the
ingots (which is necessary to ensure compact
stacks). Variation in the metal level of the feed
launder is compensated by the speed control
system, which ensures uniform filling of the
moulds.
Heavy-duty industrial robots have been
used in Gautschi ingot stacking lines for over
ten years. They can build rigid ingot stacks
weighing between 500 and 1,000 kg, depending
on customer requirements. Recent installations
have been equipped with a special sensor
measuring the distance between the ingot
layer in the robots handling system and the
previous layer of the stack. This allows the robot
release the ingots at a minimal fall height,
which increases the integrity of the stacks.
Heat treatment technology
The pre-heating and annealing processes are
some of the major steps in the production of
aluminium products, and they are of critical
importance for the quality of the final product.
Based on its long tradition of engineering,
Gautschi designs and supplies the full range
of equipment in the field of heat treatment.
These includes single and multi coil furnaces,
chamber homogenising furnaces as well as
pit type furnaces. Gautschi is also one of the
leading suppliers of pusher type furnaces,
having been involved in this technology for
more than 60 years.
This success is based on continuous product
development to improve productivity, temperature
uniformity and energy efficiency. As a
result, all components are carefully evaluated
and chosen to perfectly match each other. This
applies to the combustion systems, air guidance
and nozzle systems, recirculation fans,
insulation materials and temperature control.
It also applies to the complete handling system,
allowing short cycle times.
In 2007, Gautschi designed a new ingot
travel car for pusher type furnaces. As commonly
done, several pusher furnaces are installed
at the entry side of a hot rolling mill.
The ingot travel car allows for the installation
of some of the handling systems which often
serve more than one furnace. This car needs
just one unit for the up-ender and rail bridges
on the entry side, as well as single extraction
Gautschi pusher furnace
54 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
device, rail bridges and down-ender on the
exit side to serve several existing pusher-type
furnaces.
Just recently, the company has been awarded
the contract to revamp one of its pushertype
furnaces which had been supplied in the
mid-1950s. This long life underlines the high
quality, robustness, durability and reliability
of Gautschi equipment. We will supply a new
state-of-the-art combustion system for heavy
oil firing on this furnace. The furnace will also
get a new insulation lining in order to further
enhance its efficiency, allowing it to continue
production well into its second half century.
Besides the modernisation of older installation
to meet low-energy requirements, Gautschi
will continue with its efforts to further
improve all aspects of productivity and energy
consumption. This is the driving force behind
design enhancements and improvements in
the operation of these furnaces. We stay in
contact with our customers to work together
on practical solutions to create the most suitable
and efficient equipment for the heat treatment
in the aluminium industry.
Controls and automation
Throughout its history, Gautschi’s Controls
and Automation department has always been
one of the backbones of the company. Not
only are all the switchgear and control devices
designed in-house, but also the software
is written by competent team members. The
optimised hardware and software engineering
is only possible by constant training of all
members of the department.
Industrial robot in the process of creating an ingot
stack
Gautschi Airglide mould
It is common practice for personnel from our
Controls and Automation department to be
present during commissioning and start-up of
the equipment. This helps them to understand
and also optimise required processes, and in
cooperation with the customer to optimise the
process steps.
In a global environment, Gautschi can offer
other international brands besides its own
standard control systems based on Siemens
PLCs. Alternatives include Allen-Bradley,
Télémécanique and others to meet specific
customer requirements.
To facilitate the human-machine interface,
Gautschi uses software packages such as In-
Touch Wonderware, WinCC and WinCCflexible,
but can also accommodate special
requests by customers if desired.
In recent years, Gautschi is focussing especially
on the development and implementation
of control systems up to level 2 (and/or 3),
and works in cooperation with its customers
on the development of ERP systems.
Besides an optimised control system to
operate equipment supplied by Gautschi,
preventative maintenance programmes are
becoming a standard feature. This begins with
timers running and telling the operator to take
a specific action (e.g. to lubricate a gear box
motor, change hydraulic fluid, filters) In addition,
preventative maintenance can be incorporated
into equipment supplied by Gautschi,
so allowing customers to determine the ‘right’
time to maintain or exchange components.
This applies, for example, to vibration detectors
mounted on blower bearings. A warning
will appear on the HMI once elevated vibrations
are detected, allowing the customer to
react before a catastrophic failure of the bearing
occurs.
Furthermore, modern HMI systems allow
the service personnel to find specific information
about components used on the equipment.
The system stores key data (such as location
of instruments and sensors, component numbers,
spare part references) to facilitate spare
part handling by customers.
A state-of-the-art remote service centre
rounds up Gautschi support for its customers.
If required and desired, a remote service connection
links the equipment installed with
Gautschi headquarters in Switzerland, enabling
the Gautschi experts to consult its customers
on aspects of furnace operation / function
and maintenance.
Summary
Gautschi has been a reliable partner and expert
advisor for high quality facilities for the
aluminium industry for more than 90 years.
As a global supplier of complete melt shop
and heat treatment facilities, the company has
decades of experience and a worldwide network
of qualified experts. These ensure high
production efficiency and long-term success
thanks to Swiss precision engineering.
We assemble a thorough understanding of
our customers’ needs so as to develop together
comprehensive solutions to meet all requirements.
Product developments cover both current
and future market requirements. With
worldwide professional services Gautschi
guarantees the long-term operation of the facilities
it supplies. The customers profit from
the operator friendliness, easy servicing, long
service life, high quality and resource / energy
saving technology of the products.
Author
Dr. Oliver Moos is managing director of Gautschi
Engineering GmbH, based in Tägerwilen, Switzerland.
Electrical control system
ALUMINIUM · 1-2/2013 55

ALUMINIUM SMELTING INDUSTRY
Advanced technology from Brochot –
A proven solution for anode slot cutting
P. Dunabin, Brochot
The French-based company Brochot is a
well-established supplier of production
process equipment to the non-ferrous
metals industry. The company is represented
on a worldwide basis with offices
in Canada, China, Russia and the Middle-East
and with three workshops in
Quebec, France and China. The company’s
portfolio is extensive and increasing,
in particular with the addition of recent
equipment supply to the copper and
zinc industries by the Brochot Hydromet
division. However, Brochot’s principal
activity remains the design, development,
manufacturing and supply of equipment
for the primary aluminium sector. In this
sector the company is well known for the
supply of individual machines as well as
for complete turnkey projects for anode
rodding shops and anode handling installations.
A recent successful installation is an anode
slot cutting machine at the Nalco plant in Angul,
India. This machine is part of Brochot’s
on-going development of anode slot cutting
concept which seeks to improve and adapt
the design to the varying criteria of individual
smelter sites. Brochot continues to invest in
development of new and revised designs for
its slot cutting machine, and future orders will
incorporate a number of improvements to improve
cycle times and to adapt to client slotting
requirements.
Advantages of slotted anodes
The use of slotted anodes is now well established
in aluminium smelter potlines. The slotting
of anodes is known to give improvements
in pot efficiency by reducing the formation of
bubble films (which create higher electrical
resistance), by reducing anode cracking and
by allowing increased pot currents. The cost
of aluminium production depends critically on
the cost of energy used in the reduction process,
and so efficiency gains from slotted anodes
have a direct cost benefit.
Studies have shown that the gases (mostly
carbon dioxide and carbon monoxide) generated
by the reduction process form mainly on
the underside of the anode block, where they
build up of a layer of gas which increases the
Brochot anode slot cutting machine during workshop testing
cell resistance. The distance and time for a gas
bubble to escape from the underside of the
anode are determining factors of the thickness
of the bubble layer: basically, the shorter the
escape distance the lower will be the extra
resistance created by the gas layer. As anode
sizes grow, so the problem of the gas layer increases.
Thus the slots in the anode, for as long
as they exist, stimulate the shorter escape path
for gas bubbles formed on the underside of a
smaller anode.
Slot configurations
Anode slotting arrangements have existed
in two configurations – lengthwise slots and
transverse slots. These slots can be formed
in two ways: either by moulding during the
formation of green anodes, or by machining
the slots in baked anodes. It is accepted that
the longitudinal slot configuration delivers the
greatest benefit, and the Brochot slot cutting
machine produces slots in this direction.
The use of moulded slots has a number of
disadvantages compared to machined slots.
Slot forming plates introduced in green anode
moulds can affect the paste distribution and
compaction around the slots. The slots are
wider than machined slots, and they can become
clogged with packing coke at the anode
baking stage. The wider slots also reduce the
overall mass of carbon, consequently reducing
the life of an anode. Slots make the green
anodes more fragile and so increase rejection
rates during the green anode forming, cooling
and transportation stages. These problems are
exacerbated with increases in the slot depth,
although deeper slots would be potentially
useful to maintain their function through a
greater part of the anode life.
Machine installation and construction
The Brochot slot cutting machine is intended
to be used as an integral part of the anode handling
system. The machine is integrated into
the anode conveying lines, receiving anodes
from the baked anode storage areas, and cutting
the slots in them before they proceed to
the anode rodding shop. At Nalco the Brochot
machine was integrated as a retrofit into the
existing conveyor line just before feeding the
anode rodding station. The machine installation
was adapted to the existing slope of the
conveyor, and the design also allows the possibility
of configuring it for a ‘pass through’
process without slotting. Space restrictions in
this plant do not allow the use of a separate
by-pass conveyor.
The basic elements of the machine are: a
© Brochot
56 ALUMINIUM · 1-2/2013

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Anode slot cutting in progress
Brochot slot cutting machine during installation at Nalco
strong, rigid frame which supports an anode
transport carriage and anode lifts; a powerful
gearmotor which directly drives the shaft
mounted cutting tool discs; entry and exit roller
conveyors; and a fully enveloping enclosure
to retain carbon dust within the machine
whilst assuring operator safety.
Slot parameters
The machine delivered to Nalco can cut a variety
of slot configurations including horizontal
slot depth, as well as sloped slots up to 450
mm deep. In this machine the slot cutting unit
is in a fixed mounting configuration. Brochot,
as mentioned below, can deliver other slots
Brochot slot cutting unit
dimension as well. This simple and robust
solution is well adapted to the client’s needs.
Brochot can also offer machine configurations
with mobile slot cutting unit mountings, where
the cutting discs can be raised or lowered.
The position of the slots in the anode is normally
predefined by the client, but nevertheless
the distance between the slots may be
modified by changing the disc mounting spacers.
To help the gas bubbles to leave the slots
more quickly, the slot depth is often inclined.
This parameter can be quickly and easily
changed in the Brochot machine by adding or
removing spacers on the anode support pads
of the transport carriage. This operation inclines
the anode relative to the machine chassis,
so that the depth of cut is greater at one
end of the anode than at the other.
We emphasise that Brochot is manufacturing
in-house its own blade which is designed
for the specific application of each customer.
The stability of the slot cutting discs is very
important for reliable operation of the slot
cutting machine. Disc diameters for deep slots
become very large compared to the disc thickness.
One of the objectives of slot cutting is to
create a significantly narrower slot than in a
moulded anode. The disc stability is related
to its thickness, materials,
detail design and
fixing arrangements.
Any deformation of
the cutting discs will
cause premature wear
to cutting tools, with
localised tool heating,
and will create slots
that are wider than
desired. The design of
the Brochot disc ensures
excellent shape
stability despite the
mechanical loads and the thermal variations
caused by cutting anodes which are still hot,
particularly in their cores. For Nalco Brochot
has produced tooling which produces an 11.5
mm wide inclined slot with two slots per anode.
Brochot can also offer machines with slot
depth up to 450 mm with small slot widths.
Brochot offers a fully automated process
machine adapted to the products defined by
a particular smelter or anode production unit.
Within the limitations of the machine size
determined at the outset, the machine can be
adapted to accommodate changes in slot dimensions
(depth, length, slope, fully traversing
or partially traversing slots, distance between
slots) when production parameters change.
Tooling life
Operating costs of slot cutting machines depend
largely on the life of the cutting tools.
Brochot has worked over a number of years
to choose and refine the specification of the
cutting tools in order to achieve long life and
reliability. A single set of tool tips can reliably
achieve a life of 40,000 anodes (Customer reports
having achieved 45,000 anodes), and by
indexing the tool tips, the life of the tools can
be doubled. The Brochot tooling design uses
special tool holders carrying diamond tip tools
which are mounted alternately on either side
of our tool carrying discs. Brochot supplies the
complete machine and tooling package with
after-sales service, giving full support for supply
of consumables and replacement parts.
In any slotting operation the rigid mounting
of the anode is essential to avoid problems
of vibration during the machining operation.
The Brochot machine has a rigid anode transfer
carriage equipped with strong pneumatic
anode clamps. A motorised roller conveyor
delivers the anodes to the machine and places
above an anode lift. The lift raises the anode,
allowing the transfer carriage to position itself
around the anode. The lift retracts, lowering
the anode onto the anode support pads, and
then the carriage anode clamps fix the anode
securely in place. The carrier advances the anode
so that the discs cut the slots in the anode
as the carriage advances. After exiting the cutting
zone, the anode clamps release the anode
and the exit lift lowers it onto the outlet roller
conveyor. During this stage, the next cutting
anode is loaded and lifted, ready for the re-
ALUMINIUM · 1-2/2013 57

ALUMINIUM SMELTING INDUSTRY
turn of the anode carriage. The slot inclination
and the orientation of the slot are determined
by the height of the anode support pads, the
anode being inclined in the carriage during the
slotting operation.
The quality of the cutting operation and the
control of vibration are well understood by
Brochot, allowing reliable calculation of the
optimum for disc rotation speed and anode
advance. This ensures good prediction of slotting
cycle times in new projects, which is essential
for correct sizing of equipment in new
and existing installations.
Dust control
One drawback of slot cutting in baked anodes
is that the process creates carbon dust. To control
the dust, Brochot supplies a complete dust
extraction and filtration system along with the
slot cutting machine, and works together with
its clients to create the best package for the
site installation. A fully enclosing housing supplied
with the machine provides dust control
and safety protection. The housing is in two
parts, which are retractable to allow maintenance
access into the machine. The lower part
of the machine forms a dust collection hopper
which feeds a screw conveyor. During cutting,
the larger carbon particles fall into the hopper
from where a screw conveyor extracts them to
a collection bin. Periodically this bin is emptied
to the carbon recycling system.
Ongoing
developments
Capitalising on our experience
at Nalco and
at other sites, current
design developments at
Brochot focus on providing
cost optimised
designs with higher capacity,
so reducing cycle
times, whilst simultaneously
increasing the
depth of slot. New designs
optimise the use
of the cutting unit (discs
and drive system) to allow
multiple anode slotting
with a single cutting
unit. Other improvements
include: new dust
collection and extraction systems, tool life
optimisation, and automation of pass-through
systems to facilitate anode transfer without
slotting. The reliability of the equipment is of
primary importance, since downtime of the
slot cutting machine can quickly interrupt
supply to the rodding shop. The current Brochot
slot cutting ma-chine delivers a reliable
performance at around 45 anodes/hour, depending
on anode dimensions. The next generation
of equipment will maintain current
reliability levels while increasing this to a rate
Brochot anode transport carriage
of around 60 anodes/hour.
Backed up by its commercial and engineering
resources across several continents, Brochot
is already replying to client requests for
the next generation of slot cutting machines
and intends to remain a leading player in this
market.
Author
Philip Dunabin is manager of Brochot’s engineering
department, based in Tremblay en France.
Diffusion and convection of alumina
in the bath of a Hall-Héroult cell
R. von Kaenel and J. Antille, Kan-nak
The alumina concentration in the bath
plays a fundamental role in cell operation.
Local depletion may lead to
an anode effect. This paper presents a
mathematical model describing the alumina
convection-diffusion process in the
bath coupled to the cell magneto-hydrodynamic
(MHD), and discusses the relative
importance of the velocity field and
the alumina diffusion coefficient on the
alumina concentration in the bath.
The aluminium industry is continuously increasing
the productivity of electrolysis cells
by increasing the line current. In order to keep
an acceptable anode current density, smelters
then almost systematically increase the anode
length. This reduces the central channel
width (distance between the anodes along the
centre line of the cell) and the side channel
width (distance between the anodes to the side
lining). The channel geometry, Lorentz force
fields and bubbles have an important impact
on the bath velocity field.
In order to keep an acceptable energy input
when increasing the current, the anode to
cathode distance (ACD) is reduced as much
as possible before reaching the magneto-hydrodynamic
(MHD) instability constraints.
This further reduces the active bath volume.
Thus the increased current imposes an increase
of alumina feeding rate simultaneously
with a reduction of bath volume. Therefore,
the question of dissolution, diffusion and
alumina transport becomes an important element
for avoiding underfeeding, which would
lead to more frequent anode effects (AE).
Alumina dissolution is a very complex phenomena
in which the bath chemical composition,
bath temperature, alumina temperature
and alumina properties play an important role
[1-3].
In this paper we assume that the dissolution
is instantaneous when the alumina reaches
the bath surface, and so we concentrate
this study on the diffusion and transport by
stirring processes. The purpose of the study
is to optimise the feeding quantities (feeding
frequency) as well as the number and location
of alumina feeders so as to minimise the
number of AE and to avoid sludge.
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Theory
The theory is described in a more detailed
manner in reference [4]. Let us briefly mention
that the alumina distribution in the bath
is determined by the following partial differential
equation:
c: Alumina concentration in the bath
D: Alumina diffusion coefficient
u: Bath velocity field generated by MHD
Lorentz force and by the release of bubbles
If we consider fluctuations around the stationary
state:
(2)
The velocity field is generated by Lorentz
force field and by the bubbles. When the
number of bubbles produced, per m 2 and per
second, is too large, we cannot use a numerical
approach describing the motion of each
bubble separately.
There are essentially two standard ways to
overcome this difficulty. The first consists of
performing some kind of averaging over the
equations and over the corresponding fields.
The second bypasses the averaging and directly
postulates the flow equations for each
phase.
One of the main difficulties encountered
when performing an averaging process is related
to the possible jumps that fields can suffer
at the boundaries between the two phases.
One way to overcome this problem consists
in extending the domain of definition of each
motion equation to the domain occupied by
the two phases. This is achieved by multiplying
each equation by the characteristic function
corresponding to its domain of definition.
Derivatives are then performed in the sense
of distributions which allows us to keep track
of these discontinuities in the averaging process.
Whatever choice we make, the resulting
equations will contain terms which reflect
the interaction between the two phases. The
exact shapes of these terms are not known;
they have to be defined through constitutive
equations.
(3)
Taking into account the first law of Fick, eq.
3 becomes: in Fig. 3. From the two figures, the alumina
concentration field appears as only slightly
modified by the velocity field. However, when
An estimation shows that D turb is of the order
of 0.2 m 2 /s.
Industrial cell
(4)
The problem has been solved for a 180 kA cell
using two point feeders. On the feeders, the
alumina concentration is set to 5% of the bath
weight. When presenting a stationary solution,
this assumes continuous feeding. But we can
easily analyse the
impact of dump
feeding. Fig. 1 corresponds
to the
stationary alumina
distribution,
when the velocity
is neglected. The
concentration is
shown under the
anodes. The two
feeder locations
appear clearly in
the figure. The
asymmetry of the
diffusion pattern
reflects the larger
channel width at
the feeders. A difference
of close
to 2.5% alumina
concentration can
be observed at
the surface of the
anodes. The vertical
variation of
alumina is 0.5%
under the feeders,
but it is negligible
away from
the feeders.
Fig. 2 shows
the velocity field
generated by
the bubbles and
Lorentz force in
this particular
cell.
The impact of
the velocity field
on the stationary
solution of the
alumina concentration
is shown
considering the concentration evolution, the
time needed for reaching the stationary state
is reduced by a factor 2 when the velocity field
is acting. Therefore the velocity field plays an
important role in the feeding process (alumina
dumps).
To highlight the role of the velocity field,
Fig. 4 shows the difference between the alumina
concentration field due only to the diffusion
compared with that in presence of the
velocity field. The greatest differences are observed
at the ends of the cell, due essentially
to the MHD effects. High negative values re-
Fig. 1: Alumina concentration at the anode surface assuming no velocity field
Fig. 2: Velocity field in the bath of the cell
Fig. 3: Alumina concentration at the anode surface in presence of the velocity field
Fig. 4: Alumina concentration variation due to the velocity field
© Kan-nak
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ALUMINIUM SMELTING INDUSTRY
veal large differences in alumina concentration.
The velocity field helps to homogenise
the alumina concentration.
The above results depend strongly on the
alumina diffusion coefficient that was considered
to be 0.5 m 2 /s from the Reynolds
stress tensor. When the diffusion coefficient
is reduced, the velocity field becomes more
important. Fig. 5 shows how reducing the
diffusion coefficient impacts on the lowest
local alumina concentration in the bath. The
velocity field becomes more important, but
the global alumina concentration distribution
remains mainly defined by the diffusion
coefficient. Bubbles and Lorentz force field
act to produce much the same effect as an increase
in the alumina diffusion coefficient.
They play a key role due to the much faster diffusion
(the feeding in a cell is not continuous).
Although the maximum difference of alumina
concentration in the bath is clearly dependent
on the diffusion
coefficient,
the distribution itself
is not affected
in its shape.
Obviously, a
higher alumina diffusion
coefficient
leads to a lower
difference of concentration
in the
bath. Conversely,
greater distances
from the feeders
lead to higher differences
in concentration.
Moreover,
the situation
must be analysed
as function of time
and of the mass of
alumina fed at each
dump. The software allows us to determine
the highest difference of alumina concentration
in the bath for any type of cell design and
feeding strategy. It also considers the current
load in the cell, since Faraday’s law is satisfied
at the anode and cathode.
Fig. 5: Lowest alumina concentration function of the alumina diffusion coefficient
Example: mobile gas treatment system and
furnace covers with gas exhaust
Conclusions
A model for the velocity field in presence of
MHD and bubbles has been developed. The
velocity field is used to determine the evolution
of the alumina concentration using a nonstationary
convection-diffusion model. This
equation takes into account the feeding and
the Faraday law at the anodes and cathode.
The application to an existing cell with two
point feeders demonstrates the following:
• The local alumina concentration can vary
by up to 2-5% (depends on the bath composition)
• The pattern of
the alumina distribution
is not significantly
affected
by the velocity
field, but is mainly
Revamping solutions determined by the
diffusion process
and tailor made • The velocity
reduces the time
aluminium melting
needed to reach
and holding furnaces the stationary
state for the alumina
concentration
by a factor
of two when compared
to diffusion
only, and it therefore plays an important role
in the cell
• It would be of great interest to perform
measurements to validate the macroscopic
alumina diffusion coefficient
References
[1] O. Kobbeltvedt, S. Rolseth and J. Thonstad:
The dissolution behaviour of alumina in cryolite
bath on a laboratory scale and in point fed
industrial cells. Department of Electrochemistry,
Norwegian Institute of Technology, Trondheim,
Norway
[2] R. G. Haverkamp. PhD Thesis, University
of Auckland (1992).
[3] O. Kobbeltvedt, S. Rolseth and J. Thonstad:
On the Mechanisms of Alumina Dissolution
with relevance to Point Feeding Aluminium
Cell, Light Metals, TMS, 1996, pp.421-427
[4] R. von Kaenel, J. Antille, M. V.Romerio and
O. Besson, Impact of magnetohydrodynamic
and bubble driving forces on the alumina
concentration in the bath of a Hall-Héroult
cell, to be published in Light Metals, TMS,
2013.
Acknowledgement
The authors would like to thank Prof. Olivier
Besson from University of Neuchâtel and Prof.
Michel Romerio from The Swiss Institute of
Technology who developed the theory and
software.
Authors
René von Kaenel received his diploma of physicist
from The Swiss Federal Institute of Technology
Lausanne (EPFL) with a specialisation in plasma
physics before working for ICL in London and
specialising in computer science. In 1981 he joined
Alusuisse and became the head of the modelling
activities for smelting technology. In 2000, he received
the title of Electrolysis director in the new
Alcan organisation and further supervised Alcan’s
modelling activities. Since 1981 he has participated
in many smelter modernisation projects all over the
world, leading to large productivity increases. He
has published many articles on electrolysis cells,
casting processes and inert anode technology. In
2004 he created Kan-nak Ltd., a specialised company
for the optimisation of processes, in particular
of the Hall-Héroult process.
Dr. Jacques Antille obtained a degree in Physics at
the University of Lausanne in 1978 and his PhD at
the European Centre of Nuclear Research (CERN)
in 1984. Soon after he joined Alusuisse Technology
and Management Ltd and worked on modelling
projects of the Hall-Héroult process and casting
processes. In 2004 he joined Kan-nak S.A. where he
leads the magnetohydrodynamic studies to optimise
the electrolysis process as well as all measurement
techniques.
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Power upgrade of Isal Potlines 1-3
B. Jonsson, RTA; M. Wiestner, ABB
The most challenging and advanced
power upgrade ever has been realised in
an aluminium smelter. In 2012 Rio Tinto
Alcan Iceland (Isal) accepted delivery
from ABB Switzerland of four new rectiformers
which now feed from a new 220
kV AIS step down substation all three
potlines at Isal. The project history and
technical challenges will be described.
In the period 1959 to 1971 the Government of
Iceland was keen to develop power intensive
industry to utilise the hydro power resources
of Iceland, of which at least 30 TWh/a are considered
economically harnessable and not of
major conservation value.
In the early 1960s contacts between Alusuisse
and the Ministry of Industry soon
became formal negotiations, which in 1966
concluded with a master agreement on the
engineering and construction of the facilities in
Straumsvik for the production of aluminium.
A power contract was also concluded between
the National Power Co., Landsvirkjun, and
the Icelandic Aluminium Co. Ltd (Isal), a sole
subsidiary of Alusuisse.
The Isal Smelter was constructed in several
steps, from part of Potline 1 inaugurated in
mid-1969 to Potline 3 entering into operation
by mid-1997.
In the middle of the 1980s the electrolysis
pots of both elder potrooms were replaced by
a then recently developed new type, so called
cradle pots, which had more thermal expansion
capability than their predecessors. The
purpose of this development by Alusuisse was
to raise the current intensity of the potlines
from then 104 kA to some 120 kA, which is
the rated current for each of the rectifier stations
A and B for the Potlines 1 and 2, to which
totally eight rectifier units are assigned. Rectifier
unit B4 was modified to serve as a booster
rectifier for test purposes and connected to 20
pots in Potline 2 for current tests up to 20 kA
around 1990. By the middle of the 1990s, the
rated current, 120 kA, was already achieved
for 320 pots in Potlines 1 and 2.
Back then, Alusuisse looked for further
investments and pursued the option of a new
potline with identical pots but with bigger and
magnetically optimised DC-busbars. The rated
current intensity of Potline 3 is 135 kA with
four rectifier units. In 2000 the filter system
for rectifier C was extended to enable current
intensity above 140 kA and in 2004 the fifth
RTA Isal at Straumsvik, Iceland
rectifier was added to maintain (n-1) operability
of the rectifiers.
By 2004, the current intensity in Potlines
1 and 2 had reached 125 kA. Then the filter
system for rectifier B, whose reactive power
demand is higher than that of A, was extended
and the current intensity raised gradually to its
present value of 133 kA.
The present value of the current intensity in
Potline 3 is 168 kA, and since November 2011
there is a 20 kA, 100 V DC, booster rectifier
operated to achieve 181 kA on ten test pots
in Potline 3.
The substation and rectifier equipment serving
Potline 1 is from the Swiss company Oerlikon,
and that for Potline 2 is from the Swiss
company BBC. Both companies are predecessors
to ABB, a consortium composed of the
Swedish Asea and the Swiss BBC. ABB was
in 1995 the successful bidder for the power
system in the substation extension and new
Rectifier Station C for Potline 3 in Straumsvik.
There are three different current control
systems for the potlines of Isal. Rectifier A
comprises diodes, rectifier transformers and
regulating transformers with On-Load Tap
Changers (OLTCs) from Maschinenfabrik
Reinhausen (MR) in Regensburg, Bavaria, extremely
reliable equipment. The Potline 1 current
fluctuates, but is kept constant with an accuracy
of ± 0,1 kA within a 24 hours interval.
Rectifier B comprises diodes, rectifier
transformers with saturable reactors of voltage
range ± 30 V DC, and regulating transformers
with OLTCs from MR. This equipment provides
for constant current control for Potline
2. Rectifier C comprises thyristors and rectifier
transformers with constant current control
and fast load-shedding capability, and with a
very big range of load gradients for Potline 3.
Each rectifier station has its own current
control system with their pros and cons. In Potline
1 the current is fluctuating. The control
algorithm optimises the number of steps so as
to simultaneously minimise both the number
of diverter switch operations and the longterm
current deviation from the setpoint.
Rectifier stations B and C provide for constant
current with regulating transformers.
These are rectifier transformers with saturable
reactors and diode rectifiers in B, respectively
rectifier transformers and thyristor rectifiers
in C. Each system has its advantages and disadvantages,
but the superior controllability
of a thyristor rectifier is unquestionable. This
is advantageous to achieve quick and modulated
load shedding. On the other hand, this
feature is not useful for multiphase voltage
dips deeper than 50%, because we then need
to release the thyristors from the grid to avoid
wrong triggering damage to the thyristors. In
an island grid like the Icelandic one, such dips
tend to occur about once a year.
The introduction of programmable logic
controllers at Isal in 1990 gave rise to optimised
potline current control and to enhanced
open circuit protection. This has supported
the search for higher current and energy effi-
© ABB
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ALUMINIUM SMELTING INDUSTRY
Largest transformer in Iceland
220 kV AIS (Air Insulated Substation)
ciency, as well as for fewer anode effects, thus
reducing the release of greenhouse gases. The
merit of Isal in this context is high on a world
wide scale.
The modern control technique has also
served to enhance safety in the potrooms.
Huge power will be concentrated in a pot in
which the potline circuit is broken at high current.
Such an event is catastrophic to personnel
in the vicinity, to the superstructure of the
pot and to equipment in the vicinity. In 1991,
Isal, supported by an entrepreneurial mechanical
engineer and software expert from Berkeley
University, Hafliði Loftsson, started data
collection to develop a protective algorithm
in an empirical manner. This software development
proved itself soon successful in Potroom
1, in which arc prediction and protection
has avoided any arc flash across pots since its
introduction.
This scheme was then adapted to the different
dynamic of Potroom 2, and soon after
start-up of Potroom 3, it was adapted to the
much more dynamic control characteristic of
Potroom 3. This protection scheme has to be
adopted by the parallel operating old and new
rectifiers.
132 kV GIS (Gas Insulated Switchgear) operated at 60 kV
Scope background
On 19 June 2006 ferroresonance struck the
voltage measurement transformers on the
secondary busbar of the stepdown transformers
for Rectifier Station C, feeding Potline 3.
Subharmonic oscillations occurred between
the inductances of these VTs and the capacitances
of the 33 kV cables feeding the five
rectifier transformers. This caused excessive
voltage across the VTs and huge overloading.
Floating power systems are prone to this phenomenon
under raised voltage conditions, as
was the case here at midnight during midsummer.
What triggered the ferroresonance was a
change in the active and reactive load, when
Potline 3 was being taken to zero current due
to a certain pot-tending need.
Voltage measurement on the delta busbar
of the fixed ratio 220/33 kV, 51 MVA, Single
Phase Stepdown transformers serves mainly to
provide a reference signal to the gate control
of the thyristors. When this input measurement
disappeared, the rectifiers became inoperable,
which resulted in freezing of the pots.
In spite of successful cold restarting of the
160 frozen pots in the period 16 July through
31 August 2006, this
event cost at least
USD30 million. Therefore
Isal undertook a
number of minor improvements
from June
2006 to January 2007
to avoid a reoccurrence
of this rare phenomenon.
However
the major risk mitigation
still remained to
be realised.
In December 2006
the then owner of Isal,
Alcan, carried out a
due diligence analysis on site Straumsvik with
experts of Isal to evaluate the power supply
availability to the three potlines. This Hazop
Risk Analysis revealed severe weaknesses in
the design of the main power supply, when
confronted by a number of common mode
failure scenarios. It was obvious that these
weaknessess could only be corrected by major
strengthening of the power system.
The concept chosen in a specification made
by Isal and Alesa, an engineering company of
Alcan and now of Rio Tinto Alcan (RTA), was
to design a new 220 kV bay feeding 2 x 75 kA,
900 V DC, swing rectifier units of thyristors,
thus virtually bypassing the existing power
supply system. The swing rectifiers can be operated
in parallel with each of the rectifier stations
A, B and C, serving all three potlines. The
rated power capability of this enhanced reliability
system is 200 MVA on the 220 kV side
and 150 kA, 900 V on the DC side. The normal
operating voltage of the potlines is only 720
V DC, while the high voltage capability allows
for restarting a potline on the verge of freezing,
e.g. after a grid failure, as there is then no
reserve power supply for the Isal smelter.
In March 2007 a referendum was held in
the nearby municipality of Hafnarfjördur, a
few kilometres from the existing smelter in
which the public rejected a new smelter for
Isal. Then Isal proposed a plan B of enlarged
production capability of the existing smelter
from 190 to 230 kt/a with a potential for
further creep. This was approved by the new
owner, RTA.
The concept is to add a stepdown transformer,
200 MVA, and two thyristor rectifiers,
75 kA, 900 V DC, dedicated to Potlines 1 and
2 for the creep concept. The idea is to continue
operation of the four old rectifier units
for each of the Potlines 1 and 2 as the most
valuable part of this equipment has a remaining
lifetime of some 30 years. Then normal
62 ALUMINIUM · 1-2/2013

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operation will constitute four old units at some
112 kA and a new unit at some 74 kA (in total
186 kA) in Potlines 1 and 2. This can also be
accomplished in (n-1) operation.
Two out of three plant power transformers
were upgraded from 15 to 30 MVA. One of
them was needed to cope with higher load of
the gas treatment centres for the pot fumes,
and the upgrade to cope with an electric furnace
in the casthouse to homogenise extrusion
billets. Billets are a new product type of Isal,
replacing the hot rolling slabs.
The feeder of the plant power transformer
supplying auxiliaries of Potline 3 was relocated
from 33 kV busbars to the new 60 kV
GIS-busbars. The latter are equipped with
sectionalisers enabling load transfer between
stepdowns on each 220 kV line without affecting
the potline operation, which is a step
forward for Isal. The reason for preferring GIS
to AIS was lack of land at the seaside of the
substation.
The benefit of the feeder relocation is not
only for higher reliability of the power supply.
It also means that the 15 MW power formerly
allocated for plant power can now be
transferred to the rectifier station, thus yielding
180-185 kA permissible current intensity
from rectifier station C, instead of 168 kA
previously.
The new power contract with the National
Power Co. and the transmission agreement
with the TSO, Landsnet, is for delivery of 425
MW at power factor over at least 0,98 for a
calendar month. In addition to this high reactive
power compensation, the TSO also requested
thorough filtering of harmonics, keeping
each voltage harmonic under 1,0% and the
total voltage distortion factor below 1,5% at
the Isal 220 kV intake.
This demanded a sophisticated engineering
of 2x85 MVA filters connected to the 60 kV
busbars.
Immediately useful
Overhaul of transformers and rectifiers was
postponed under the IPU Construction Period
to avoid a crowded construction area and to
reduce production loss and disturbances to
the electrolysis. This would have inflicted
considerable losses to Isal, as it was not possible
to weld busbars on full potline current
intensity. This is the main explanation for the
higher than expected fault rate of equipment
under the commissioning period. One regulating
transformer failed in each of the rectifier
stations A and B, and then, at short notice,
the new rectifier sections A5 and B5 had to
be temporarily put into operation in order to
keep full potline current,
133 kA. The transformers
tap changers were
repaired on site.
While leakage in a
rectifier transformer in
station B was being repaired,
the damping
units for one of the
rectifiers B took fire.
Then only two old units
were available for Potline
2. This would not
have been a sustainable
situation for this
potline, i.e. its current
intensity would have been 80 kA only out
of 133 kAm or 60%. The electrolyte temperature
would have approached its freezing
point while repair of the damping unit
took place. It is likely that some pots would
have been lost, and the operational stability
and efficiency of others would have been
adversely affected. The electrolysis costs and
lost revenue due to such a serious situation can
be estimated to USD1,5 million. As new units
were made available to the Isal operation by
ABB, full current intensity could be kept in the
potline during this critical situation.
All this delayed the hot commissioning
and disturbed the schedule of ABB; however,
ABB, its subcontractors and Isal gained valuable
experience.
Spooky damage to control equipment like
coils and control valves was observed during
this period. We identified the origin by analysing
the voltage quality on the 60 kV busbar
feeding the new plant power transformer,
which supplies the auxiliary voltage to the new
system, S, and the existing system C. With
new rectifier units in operation without any
filter ON, the voltage contains a lot of harmonics
with Total Voltage Distortion Factor,
TVDF = 10. It was therefore decided to modify
the control concept of the filters. Instead
of being switched on when the reactive power
demand is about 30 MVAr, the first part of
the filter is switched on after switching on
the first rectifier transformer, but before it is
loaded. With the filter of the third harmonic
on, the voltage is a true sinus curve, and the
voltage quality is even higher when switching
on the filter for the fifth and eleventh harmonic
as the first part.
Conclusion
The fruitful cooperation between ABB Switzerland
and Isal has now lasted for about 45
years from the engineering of the power and
Busbar system with FOCS (Fibre Optic Current Sensor)
control system for Potline 1 in Straumsvik
until the commissioning of the 4 x 75 kA rectifier
units and their power supplies in autumn
2012. This cooperation has been beneficial to
both parties.
Icelandic companies have never played so
big a role in realisation of an ABB project in
Straumsvik as in the IPU Project. Orkuvirki
has erected all the equipment and has engineered
and assembled a number of switchgear
and controlgear units. Staki has developed the
software of the master controller of each potline
as well as the software of the supermaster
and of the SCADA. All this has been accomplished
in good relationship with the owner of
the systems, Isal, which has been closely consulted
at each stage and made contributions to
the technical developments as well.
The technical infrastructure delivered to
Isal is in accordance with the technical specification
made jointly by Alesa, an engineering
company of RTA in Zürich, Switzerland, and
Isal, prior to the bidding process of the IPU
project.
The power and control system of the substation
of Isal is a state-of-the-art solution for
the complicated task of extending a power
distribution system of an over 40 years old
aluminium smelter in full production. This was
accomplished without any injury and without
any major damage to the smelter’s equipment.
Isal looks ahead to a prosperous future of
an ever increasing production capacity, higher
productivity and improved reliability of power
supply to the electrolysis pot lines and to the
plant as a whole.
Authors
Bjarni Jonsson is leader of Electrical Services of
Rio Tinto Alcan, based at Icelandic Aluminium Ltd,
Straumsvik, Iceland.
Max Wiestner is manager of the business group Primary
Aluminium which is part of the ABB Global
Product Group, based in Dättwil, Switzerland.
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ALUMINIUM SMELTING INDUSTRY
Applying computational thermodynamics
to industrial aluminium alloys
P. Mason and H.-L. Chen, Thermo-Calc Software
Even more than GPS and Google Earth
have changed our view and navigation of
the world, so computational thermodynamics
is changing the way metallurgists
see what goes on inside alloys during solidification
and heat treatment. This tool
gives us new and more detailed views of
the phase diagrams of almost all the commercial
aluminium alloys. But it also lets
us explore the phases in new alloys which
have never yet been made. Thus we can
now study phases in virtual alloys without
using real materials or laboratory instruments
and equipment. Compared with
actually casting and heat treating alloys
for metallurgical studies, and then preparing
and interpreting the samples, computational
thermodynamics represents huge
savings in time and expense.
Computational thermodynamics has been
used in the aluminium industry for more
than two decades in order to understand and
model the behaviour of existing alloys, to accelerate
the development of new alloys, and
also to give insight into improvements in the
areas of process optimisation and the simulation
of casting and heat treatment. During this
time, the CALPHAD (CALculation of PHAse
Diagrams) approach [1] and related software
packages and databases have made significant
contributions in this area.
This trend has gained added momentum in
recent years with the publication by the National
Academies report on Integrated Computational
Materials Engineering (ICME) in
2008 [2], and with the announcement by President
Obama of the Materials Genome Initiative
(MGI) in June 2011 [3]. ICME is an
emerging discipline that can accelerate materials
development and unify design and manufacturing.
To quote from Wikipedia: “Integrated
Computational Materials Engineering
(ICME) is an approach to design products, the
materials that comprise them, and their associated
materials processing methods by
linking materials models at multiple length
scales.” This is similarly linked to the goals of
the MGI which aims to double the speed with
which new materials are developed, manufactured
and bought to market, thus increasing
innovation and competitiveness while also reducing
cost and time.
Computational thermodynamics is a foundational
component of ICME since it fundamentally
links the phases that form, and hence
their microstructure, to the chemical composition
of an alloy, and also the temperature
variation that a material may be subjected
to. It is also essentially the driving force for
many of the phase transformation reactions
that take place during materials processing.
The CALPHAD approach
CALPHAD technique uses all available thermochemical
information, both thermodynamic
and phase equilibria data, to fit model parameters
used to describe the Gibbs energy
of individual crystallographic phases. The objective
is to obtain a consistent set of model
parameters that can describe the thermodynamic
properties of the system in a realistic
way. The Gibbs energy of each phase is described
by an appropriate
thermodynamic model
which depends on its
physical and chemical
properties, for example,
crystallography, type of
bonding, order-disorder
transitions, and magnetic
properties. These Gibbs
energy functions, which
take into consideration
chemical composition and
temperature dependence,
are obtained by the critical
evaluation of binary
and ternary system and
then through the use of
software, such as Thermo-
Calc, multicomponent
calculations can be made
for alloys of industrial
importance, based on the
constraints of compositon,
temperature and pressure for the system as a
whole.
Additionally, the CALPHAD method can
also be extended to model atomic mobilities
and diffusivities in a similar way. By combining
the thermodynamic and mobility databases,
it is possible to simulate kinetic reactions
during solidification and subsequent heat
treatment processes by using other software
such as DICTRA and TC-PRISMA. These are
respectively computer programs for simulating
diffusion-controlled phase transformations
and for simulating multi-particle precipitation
kinetics in multicomponent alloy systems.
Through the use of such simulations it is
possible to optimise alloy compositions and
to predict optimal solidification processes and
solution heat treatment temperature ranges all
this without performing many time-consuming
and costly practical experiments.
Thermodynamic and kinetic databases
The quality of the predictions depends
strongly on the quality of the thermodynamic
and atomic mobility databases that are used.
TCAL1 is a new thermodynamic database developed
by Thermo-Calc Software which contains
all the important Al-based alloy phases
within a 26-element framework [Al, Cu, Fe,
Fig. 1: Equilibrium solidification and Scheil solidification simulations of alloy
AA7075, compared with experimental results from Bäckerud et al [8]
Mg, Mn, Ni, Si, Zn, B, C, Cr, Ge, Sn, Sr, Ti, V,
Zr, Ag, Ca, H, Hf, K, La, Li, Na, Sc]. This includes
in total 346 solution and intermetallic
phases are included. Developed using the
CALPHAD approach, TCAL1 is based on
critical evaluations of binary, ternary and even
higher order systems which enable making
predictions for multicomponent systems and
alloys of industrial importance. A hybrid ap-
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proach of experiments, first-principles calculations and CALPHAD
modelling have been used to obtain thermodynamic descriptions
of the constituent binary and ternary systems. In total, 147 of the
binary systems in this 26-element framework have been assessed to
their full range of composition. TCAL1 also contains assessments of
58 ternaries in the Al-Cu-Fe-Mg-Mn-Ni-Si-Zn system. In addition,
twelve quaternaries and one quinary system have been assessed.
MOBAL2 is a kinetic database containing mobility data for the
liquid and fcc phases in Al-based alloys within a 23-element framework
[Al, Cu, Fe, Mg, Mn, Ni, Si, Zn, Cr, Ge, Sn, Sr, Ti, V, Zr, Ag,
Ca, Hf, K, La, Li, Na, Sc]. For the FCC phase, the database contains
assessed impurity diffusion data in Al for all included elements. It
also includes complete and critical assessments in some important
binary systems. As for liquid, there are also assessed data for diffusion
in liquid Al for Al, Cr, Cu, Fe, Ge, Mg, Mn, Ni, Si, Ti, V, and
Zn.
The TCAL1 and MOBAL2 databases are the result of a longterm
collaboration with academia that has involved extensive experimental
work, as well as critical assessments of the published
literature. Both databases have also been validated where possible
against higher order systems, such as data published for industrial
alloys. Such validation highlights the key systems which are the
basis of many of the commercial aluminium alloys to which care of
special practical importance. Take for example, the AA-7000 series
alloys, which are high strength, high toughness alloys often used in
high performance applications such as aircraft, aerospace and competitive
sporting equipment: these alloys are based around the Al-
Cu-Mg-Zn system. In spite of the addition of other minor elements
like Mn and Si etc., the main hardening elements Zn, Mg and Cu
play a dominant role in the formation of the main precipitate phases
such as C14 (MgZn 2 , the η phase), S (Al 2 CuMg) and T (which is
stable in the Al-Cu-Mg, Al-Mg-Zn and Al-Cu-Mg-Zn ternary systems).
In some cases, the formation of the Al 7 Cu 2 Fe phase may also
be important. These phases dominate the balance of the properties,
and their amounts are closely related to the composition and to the
heat treatment conditions. In TCAL1, the thermodynamic description
of the Al-Zn-Mg-Cu-Fe core system has been systematically
refined and validated in order to give more accurate predictions
for these commercial Al-based alloys. More specifically, crucial corrections
or modifications have been made for the following related
ternary systems: Al-Cu-Fe, Al-Cu-Mg, Al-Cu-Zn, and Al-Mg-Zn.
tion during solidification. For example Onda et al [5] investigated the
solidification of alloy AC2A. The authors noted: “Prediction of the
solidification model by thermodynamic calculations is useful from a
practical point of view.”
However, equilibrium thermodynamic calculations, while useful, do
not consider the dynamic effects of time. DICTRA is a software tool
used for detailed simulations of diffusion-controlled phase transformations
for multi-component alloys where time diffusion is a parameter.
Example applications include the simulation of microsegregation during
solidification, heat treatment, growth and dissolution of precipitates,
and coarsening. Senaneuch et al [6], for example, used DICTRA to
look at diffusion modelling in brazed aluminium alloy components;
and Samaras et al [7] simulated the evolution of the as-cast microstructure
during the homogenisation heat treatment of alloy AA6061.
In the latter paper, the alloy microsegregation, which results after casting,
was calculated with the Scheil module using Thermo-Calc, and
the microstructure evolution during homogenisation was then simulated
with DICTRA. The composition profiles of the alloying elements,
and the volume fraction of the secondary phases, were calculated as
a function of homogenisation time. Comparison with experimental
work concluded: “The model reproduces the homogenisation kinetics
reasonably, and it is capable for the prediction of the homogenisation
heat treatment completion times.”
Two examples in the areas of casting and heat treatment using
Thermo-Calc in conjunction with TCAL1 are illustrated below.
Molten Metal Level Control
Thermodynamic and kinetic simulations
Predictions for multicomponent systems are useful, since they show
what phases could form at different temperatures during processing
and operation, for different alloy compositions, both under equilibrium
and under non-equilibrium conditions. Phase diagrams make
it possible to see how an element is influencing the phase stabilities
and solubilities of different elements at varying temperatures. For
example, Thermo-Calc can be used to predict second phase particles
that are formed during casting, homogenisation, downstream rolling
and annealing. Gupta et al [4] performed such a study to validate
calculations of phase stability made using Thermo-Calc against
experimental observations for automotive alloy AA6111, which is
a commercial body sheet alloy. The paper concluded: “The type of
particles, and the temperature regime in which they are formed,
are consistent with the predictions made by the Thermo-Calc software.”
The Scheil model in Thermo-Calc can also be used to predict
non-equilibrium solidification behaviour and micro-segrega-
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ALUMINIUM SMELTING INDUSTRY
Casting and solidification
For fabricating aluminium alloys, it is useful
to understanding solidification during casting
and to predict the phases that are likely
to precipitate during cooling. A Scheil solidification
calculation of the alloy AA7075 was
performed by using the real alloy composition
(Al, 0.11 Si, 0.28 Fe, 1.36 Cu, 2.49 Mg, 0.19
Fig. 2: Calculated isothermal section of the Al-Cu-Mg-Zn quaternary
system at 600 °C and 6 wt.% Zn compared with experimental work of
Strawbridge [10]
Cr, 5.72 Zn, wt.%). The calculation predicts
that Al 45 Cr 7 solidifies primarily before the
formation of (Al) although it had not been
experimentally observed. Considering that it
is probably the only Cr-bearing phase in this
alloy, its formation would be almost certain.
Due to its small amount, however, its formation
can hardly be observed in the DTA trace
or in the solidified microstructures. The formation
of (Al) was followed by the Al 13 Fe 4 ,
Mg 2 Si, T and V (MgZn 2 ) phases, which agrees
well with the experimental results. Imposed
on the diagram shown in Fig. 1 (see previous
page) are the accumulated solid phase fractions
at different temperatures, which have
been evaluated from the experimental DTA
trace obtained by Bäckerud et al [8]. It should
be noted that DTA can only allow a qualitative
evaluation. Nevertheless, it is suggested by
the comparison that the real solidification significantly
deviates from the equilibrium solidifi-cation,
but can be reasonably approximated
by a Scheil solidification simulation.
Heat treatment
The controlled heat treatment of aluminium
alloys allows the metallurgist to optimise, control
and generate a reproducible and predictable
change in the microstructure of the alloy.
This serves to influence properties such as
strength, ductility, fracture toughness, thermal
stability, residual stress, dimensional stability
and resistance to corrosion and stress corrosion
cracking [9]. The main heat treatment
procedures for aluminium alloys are homogenisation
and annealing, as
well as precipitation hardening,
which involves the
three steps of solution heat
treatment, quenching and
aging. Computational modelling
tools, such as those
described here, can give
insight into each of these
stages. For example, the purpose
of solution heat treatment
of aluminium alloys is
to put the maximum practical
amount of the hardening
solutes, such as Cu, Mg, Si,
Zn or other elements, into a
state of solid solution in the
Al matrix. Multicomponent
phase diagrams calculated
using Thermo-Calc can aid
this type of analysis without
the need to perform timeconsuming
experiments.
The 7000-series alloys
are heat-treatable wrought aluminium alloys,
and it is useful to perform equilibrium calculations
at solution treating temperatures and
at aging temperatures in order to predict the
phase formations in these alloys. As an example,
Fig. 2 shows a calculated isothermal section
of the Al-Cu-Mg-Zn quaternary system
at the typical solution treating temperature of
460 °C, and at a Zn content of 6 wt.%; the calculation
was in very good agreement with the
experimental data from Strawbridge et al [10].
This diagram can be used to generally account
for the phase constitution at the solution temperature
for a number of 7000 series alloys,
e. g. AA7010, AA7050, AA7075, AA7175,
AA7475 and AA7178, etc. Andreatta [11] reported
that Al7Cu 2 Fe and Al 23 CuFe 4 are the
most abundant of the intermetallics in AA7075
and AA7475, together with traces of Mg 2 Si,
Al 6 Fe, S, T and Al 12 (Fe,Mn) 3 Si, after being
solution treated. In such cases, it is necessary
to perform equilibrium calculations using real
alloy compositions by including other minor
elements. Because of the high Fe content, the
calculation using TCAL1 shows that Al 7 Cu 2 Fe
forms in alloy AA7075 with an amount up to
1%, and Al 13 Fe 4 coexists in a small amount.
However, for alloy AA7475, Al 7 Cu 2 Fe is calculated
to be the only main intermetallic.
Summary
The materials community is increasingly using
computational modelling tools, and is applying
them more widely to material design and process
optimisation. For more than two decades,
CALPHAD- based software and databases
have been employed within the aluminium
industry and they have served to improve
the understanding of existing alloys, to accelerate
the development of new alloys and
also to model and understand better materials
processing routes. The quality of the predictions
depends on the quality of the thermodynamic
and kinetic databases that they use.
Some examples have been given here to illustrate
how these tools are being used within the
aluminium industry in the areas of casting and
solidification as well as heat treatment.
References
[1] N. Saunders, A.P. Miodownik, Calphad (Calculations
of Phase Diagrams): A Comprehensive
guide, Pergamon Materials Series, vol. 1, ed. R.W.
Cahn (Oxford, OX: Elsevier Science Ltd, 1998).
[2] National Research Council, Integrated Computational
Materials Engineering: A Transformational
Discipline for Improved Competitiveness and National
Security. Washington, DC: The National
Academies Press, 2008.
[3] http://www.whitehouse.gov/sites/default/files/
microsites/ostp/materials_genome_initiative-final.
pdf
[4] A.K. Gupta et al., 2006, Materials Science Forum,
519-521, 177
[5] H. Onda et al., 2007, Materials Science Forum,
561-565, 1967
[6] J. Senaneuch et al., 2002, Materials Science Forum,
396-402, 1697
[7] S.N. Samaras, G.N. Haidemenopoulos, 2007,
Journal of Materials Processing Technology, 63-73,
194
[8] L. Bäckerud, G.C. Chai, J. Tamminen, Solidification
Characteristics of Aluminium Alloys, Vol. 1 and
2. Sweden (1990)
[9] H. Moller, 2011, Heat Treatment of Al-7Si-Mg
casting alloys, Aluminium International Today, 16-
18, Vol 23, No 6
[10] D.J. Strawbridge, W. Hume-Rothery, A.T.
Little, The constitution of aluminium-copper-magnesium-zinc
alloys at 460 °C. J. Inst. Metals (London)
74 (1947) 191-225
[11] F. Andreatta, Local electrochemical behaviour
of 7xxx aluminium alloys, PhD thesis, 2004
Authors
Paul Mason is president of Thermo-Calc Software
Inc., based in McMurray, PA, USA.
Hai-Lin Chen is with Thermo-Calc Software AB,
based in Stockholm, Sweden.
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ECL – A privileged equipment supplier
to the primary aluminium industry
A.-G. Hequet, ECL
Created in 1947 and based in Ronchin, a
suburb of Lille, ECL entered the aluminium
business in 1955. In 1962 it commissioned
the world’s first pot tending machine. By
the 1970s the company concentrated mainly
on the aluminium industry and has become
a key partner of most smelters around the
world. It is now part of the Rio Tinto Alcan
group and its products are used in the
reduction, carbon and casthouse areas of
the smelter. The product range includes
pot tending machines, cranes and transfer
equipment for the potlines, as well as a wide
range of products and services for the carbon
sector. These include green and baked
anode handling equipment and specialised
cranes, complete anode rodding shop,
and metal and bath handling systems.
The involvement of ECL does not end with
the conception, production, erection and commissioning
of its products. The company offers
a wide range of supporting services including
training, technical assistance, spare parts, on-site
maintenance management, equipment audits,
refurbishment and upgrades. The machines are
adaptable to all the potline technologies used in
today’s smelters.
To better serve its customers around the world
on a 24/7 basis, ECL has a network of seven subsidiaries
around the world.
Solutions for all sectors
of the aluminium smelter
© ECL
ECL Pot Tending Machine
Reduction: Pot equipment is a significant part
of what ECL offers to the reduction sector, with
more than 15,000 pots equipped by the company
worldwide. However, ECL’s flagship product is
doubtless the Pot Tending Machine (PTM). Adaptable
to all the reduction technologies, each crane
is designed to each smelter’s specification. The
ECL PTM is still evolving: safer, more efficient,
more reliable and more compact, while also being
cheaper to commission and to operate.
The potline offer also includes anode beam
raising mechanisms, anode jacking frames, crust
breaking and feeding devices, J hooks and fixings,
anode clamps and sealing jaws.
Carbon: ECL offers equipment for the whole
carbon sector, from single machines to turnkey
rodding shops for all types of anodes, including
the building. The company also delivers furnace
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ALUMINIUM SMELTING INDUSTRY
tending assembly and fully automated anode
handling shops: green and baked anode handling
cranes, transfer cranes, conveyors, cooling
tunnel and anode hole cleaning machine.
Services: As mentioned above, ECL provides
an exhaustive range of services, either
from the main base in Ronchin, France, or
through its subsidiaries.
Innovation: ECL is also a driving force
when it comes to innovation. The ECL R&D
department is constantly working on new
ways to make aluminium production safer,
easier, more productive, and to make sure
the equipment meets the ever increasing environmental
and safety requirements. 30,000
hours are dedicated yearly to R&D. Research
focuses on HSE innovations, equipment cost
reduction, operational cost reduction, and on
automated equipment, through a combination
of theory, experiment and computational
simulation.
Recent technological advance – the
‘New Concept Furnace Tending Assembly’
Since ECL commissioned the first anode baking
Furnace Tending Assembly (FTA) in 1963
in Slatina, Romania, the designs and tasks of
ECL Furnace Tending Assembly
this machine have evolved. For the first time
in the industry’s history, ECL has performed
a total rethink of the FTA, based on:
• A modular structure providing higher per-
formance in terms of: safety, shorter commissioning
time, productivity, quality as
well as operational cost savings
• A streamlined architecture, giving significant
weight and height reductions
• The possibility to have one or two grabs
and / or one or two filling pipes on the
crane
• Better, faster and more efficient coke suction
flow rates, speed of movement of the
tools
• An evolutionary design greatly improving
maintenance access and costs and ergonomics.
Consequently, the ECL New Concept FTA is
lighter and more compact and has improved
performance. Its new design has been conceived
to make human intervention easier and
safer: operators benefit from an ergonomic
cabin and from easy access for maintenance.
The ECL New Concept FTA is based on
a modular structure that offers several advantages
over conventional designs. First, it
is lighter than a regular crane. As the FTA
is the main piece of equipment supported by
the anode baking furnace building’s rails, this
weight reduction has a direct impact on the
design and cost.
The modular concept leads to
a simplification of the FTA’s overall
structure. Each of the crane’s
constituent elements and the links
between them (pneumatic, electric
and optical) have gone through a
total rethink that makes them individual
modules rather than imbricated
elements. The result is a
crane that is faster to commission
and easier to maintain. Furthermore,
the FTA tools dedicated to
work on the pits have been located
differently, which greatly improves
the operator’s view. Consequently
he can more accurately control the
tools’ movements and can reduce
damage to the tools and flue wall.
The modularity of the cranes
also allows flexibility in implementing
upgrades. A second grab
and or a second filling pipe can be
installed on a machine to match
any later increase in anode production.
Whereas the design of
all FTAs is made according to the
customer’s requirements, the ECL
New Concept FTA, ensures that it
keeps room for later improvement and development.
In such a harsh environment of heat, gas,
and dust, it is essential to prioritise environment,
health and safety for the smelter but
above all for the operators. The ECL R&D
department focused especially on providing
an ergonomic cabin, and they paid special
attention to air quality and temperature control,
visibility, safety and reliability.
To minimise the safety risks (falling, pinching,
crushing, suffocation) ECL equipped its
crane with safety features:
• A retractable step ladder with guardrail
provides to access the crane
• An emergency evacuation access is available
whatever the position of the main
trolley, in case of a power cut or damage
to tools in the furnace
• Many more emergency stop push buttons
surround the workplace
• Relocating floodlights improves lighting
and avoids shadows
• Stairs instead of ladders between the different
platforms on the crane provide a
much easier way to transport a maintenance
tool box.
The cabin has been also subject to many changes
and turned into a shell around the operator.
The cabin is more spacious: its size increased
by 75%, which brings many advantages. The
operator benefits from a 70% wider window
area, thereby bringing a brighter environment
and better visibility. With a 10 metres visibility
under the cabin, the operator is now able to
see into the bottom of the pit, which greatly
eases the operation of coke filling and sucking.
Now two to three people can fit in the cabin
at the same time, providing good conditions
for training and management purposes.
Seats have been rethought and are now
motorised, enabling cross travel movements
to facilitate and ensure seat position accuracy
perfectly in front of the tools. The seat includes
height adjustment as well as air and mechanical
suspension, arm support and body fixation
for greater ease and flexibility. As an option,
cameras can be installed on the suction pipe
to improve the overall operator’s safety observation
without back bending. The operator
can also adapt the control units (joystick) according
to his morphology.
All these features facilitate the driving of
the FTA and considerably reduce fatigue of
the driver.
Easier maintenance, safer and cheaper
By redesigning its FTA, ECL has greatly improved
the operator’s working environment,
but has also facilitated maintenance work, for
which access was difficult to some key areas.
The New Concept FTA is now equipped with
several onboard platforms which include:
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• A complete upper platform gives full access
to the grab hoist unit, to the top of
the storage hopper (sucking pipe elbow),
and to the top of the filter hopper to
perform filter bags changing
• A maintenance platform provides access
to the valve situated between the cyclone
and the filter hopper, and to the valve used
to control the de-dusting sucking during
the pit filling phase
• A platform is situated at the top of the
sucking pipe
• The 25-tonne hoist is now directly accessible
from a platform above the main
trolley
• A platform links the top of the FTA girder
to the long travel maintenance platform
• Lifting points and lifting rails installed directly
on the crane facilitate the dismantling
of heavy components not directly
accessible (moto-reducer, air condition
unit, hoist unit).
No effort has been spared in ensuring safety
of both the operator and the maintenance
staff. The large number of on-board platforms
makes obsolete any external mobile platform
which was often unavailable when needed,
and always cumbersome.
A New Concept FTA combining
reliability and greater performance
A double filling pipe: The new architecture of
the FTA is based on a double filling pipe assembly;
these pipes can be used individually
or simultaneously. Compared with a conventional
FTA (1 filling pipe, 1 grab and 1 sucking
pipe) this system of double filling pipe
increases by almost 10% the FTA utilisation
rate and therefore productivity. The utilisation
rate is carefully computed by ECL engineers
to match the customer’s production needs,
while keeping a capacity back-up of at least
25%. This approach ensures that the FTA is
not oversized (therefore not over-priced) and
reliably meets the anode production requirement.
ECL engineers also worked to make the
filling pipe more resistant to shocks, to variations
of coke temperature, and to the risks
of pipe blocking and falling. The pipe has
therefore become wider and shorter. Reducing
the pressure drop and consequently the
abrasion and maintenance costs for the suction
circuit. Stronger bumpers
have been installed. The
nozzle of the filling pipe has
been modified in order to ease
conical flow and to decrease
the time of filling. Regarding
the flexible de-dusting pipe located
on the filling pipe, it has
been replaced by an outside
mechanical pipe. This solution
eliminates all risk of friction between
lifting cable and de-dusting
system as well as any risk of
tearing the de-dusting pipe.
A powerful sucking pipe,
from 65 to 110 m 3 /h: this new
capacity of the sucking pipe
set up in the FTA almost doubles the suction
rate. Moreover, the sucking pipe is equipped
with a new shock absorption system, so avoiding
the risk of crushing the pipes.
Towards a fully automated FTA: What
about a crane in a few years time operating
on its own in this harsh environment? The
FTA is already equipped with some automatic
sequences, such as automatic positioning
over the pits, to assist the operator in his daily
tasks. The ECL R&D department is never at
rest, and is always looking for more automation
processes to include in the FTA.
ECL Training Academy
Training in a simulator
ECL has recently launched a customised training
programme dedicated to operators and
maintenance technicians. This programme is a
unique opportunity to improve skills, capabilities
and knowledge on crane operations and
maintenance of ECL equipment sub-assemblies
(hydraulic, pneumatic, mechanical and
electrical). The programme consists of five full
days of training session right on the doorstep
of our customers.
Two special technical containers allow
trainees to practice right after theory. The
first container is equipped with a multipurpose
driving crane simulator. In it trainees can
improve their accuracy and rapidity, and
can reach a suitable level of dexterity both
through PTM and FTA driving exercises. The
programme grades trainees after each exercise
in the simulator. Thus the trainer and the
trainee have a global view of the progress
achieved and of what competences still need
improvement.
In the second technical container the
trainees can practice on real devices (compressors,
etc.). Training is crucial for success, and
is fruitful for both employers and employees
of a smelter. When well trained, the operator
will become more efficient, productive and
a valuable asset to the smelter, needing less
supervision. This will lead to fewer accidents,
less equipment damage and consequently
costs, better productivity and better quality.
Technicians and operators from different
smelters can share their experience and learn
from each other’s know-how.
A first session was organised in Dubai in
2011 to meet with ECL customers from the
Middle East, and a second session in Canada
in 2012.
Here is the reality: produce more, faster,
at a lower cost and in a safer way. ECL is
constantly innovating, and both The New
Concept FTA and the ECL Training Academy
greatly help to achieve all this.
Author
Anne-Gaëlle Hequet is External Communication
manager at ECL, based in Ronchin, France.
Suppliers Directory – for your benefit
On pages 100 to 113, leading equipment suppliers to the aluminium industry present
their product portfolios and ranges of services. Take advantage of this useful information.
ALUMINIUM · 1-2/2013 69

ALUMINIUM SMELTING INDUSTRY
Novel gas cleaning
for anode baking
furnace
B. Herrlander, Alstom Power
In November 2011 Alstom started the
novel gas cleaning plant for the anode
baking furnace at Alcoa Mosjøen, Norway.
This Fume Treatment Centre (FTC)
comprises a new gas cooling principle that
replaces the conventional conditioning
tower with a heat exchanger. The AHEX
heat exchanger has the dual purpose of
cooling the flue gas while it simultaneously
works as a reactor for capturing tar
and HF on alumina. The heat exchanger
is integrated into the filter, which thus
constitutes a very compact FTC design.
The novel FTC concept
Even though improved state-of-the-art firing
technologies on today’s open anode baking
furnaces have significantly reduced the
emissions, there is still a need for further gas
cleaning to meet regulations. The main furnace
emissions are compounds in the flue gas such
as PAH (Polycyclic Aromatic Hydrocarbons),
HF, SO 2 and carbon particles. HF emissions
originate from the recycled butts used in the
anode production and PAH from the green
anode material. A number of PAHs are known
for their carcinogenic, mutagenic and
teratogenic properties. These include
benz[a]anthracene*, chrysene*,
benzo[b, j, k]fluoranthene*,
benzo[a]-pyrene*,
The integrated Alstom AHEX FTC
The Årdal DDS
benzo[ghi]perylene, dibenz(a,h)anthracene*
and indeno(1,2,3-cd)-pyrene* (*classified by
the US EPA as probable human carcinogens).
Some of these compounds are subject to
emission limits set by government authorities.
These are typically expressed as subsets of the
various PAHs such as PAH-16 and OSPAR
11, which are subsets including 16 or 11 different
PAHs. The abatement of PAH is temperature-dependent
in such a way that the
removal efficiency increases by lowering the
flue gas temperature.
The novel FTC with AHEX solves a number
of problematic issues related to the traditional
conditioning tower filter combination. The
conditioning tower evaporative cooling principle
increases the flue gas moisture content,
typically by some 6-7%, to reach the acceptable
operation temperature levels around
100-110 °C. However, a drawback of this
method is that the increased moisture content
may cause corrosion in the conditioning tower
and hydrolysis of the bag polyester material
in the fabric filter.
By contrast, the gas cooled in the
AHEX avoids this humidity increase, and
thus prevents the above problems. Now, as
the temperature is lowered in the AHEX, various
tars (including PAH) start to condense.
In order to prevent these from fouling the
AHEX tubes, we inject alumina upstream.
This measure ensures there is a controlled
condensation of tar on the alumina. The alumina
also adsorbs HF and to some extent SO 2 .
Since the tar will end up on the alumina for
the potlines, there is no need for disposal of
hazardous material. Conventional conditioning
tower cooling may occasionally cause
wet bottom with tar-rich effluents, and it will
inevitably result in tar deposits in the ducts
connecting to the filters, from where it must
be removed and safely disposed of as hazardous
material. With AHEX no such ducts are
required as AHEX is integrated in the fabric
filter unit.
This novel FTC with AHEX is built on Alstom’s
DDS (Distributed Dedicated Scrubber)
concept. The DDS is based on the well-proven
Abart dry scrubbing technology, which features
a two-stage counter-current gas cleaning
process. It was designed for greenfield as
well as for retrofit / modernisation projects, for
applications where space is limited, or where
the customer needs to minimise the resources
used for site installation / erection. The DDS
invention has been granted patents in all major
aluminium producing countries. The DDS
integrates fresh alumina storage, and it is
equipped with an internal alumina handling
system powered by one high pressure fan.
Enriched alumina from the DDS is distributed
back to the pots via Alstom’s Alfeed
system. There is one exhaust fan per filter
compartment, which operates on medium
voltage (440 V). This allows full flexibility for
tuning the DDS for optimal performance. The
DDS is supplied in modules, which makes it
easy to transport and install. The DDS can
be fully shop-manufactured, as the size of a
DDS compartment meets road transportation
requirements. Shop fabrication ensures a uniformly
high quality of work. Several DDS can
© Alstom Power
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be erected simultaneously and independently.
The DDS system may integrate a SO 2 scrubber
on the top, which enables it to comply
with more stringent emission limit values. The
available reagent choice is between an alkaline
solution or seawater. This DDS / SO 2 technology
will be in operation around the middle of
2013 at a smelter in Europe.
The AHEX is integrated to the DDS, upstream
of the filter stage. The hot gas, containing
the condensable fumes, is cooled inside
multiple water-cooled steel tubes in the
AHEX, where it enters the cooling tubes from
the top. The fumes are mixed with alumina
in the plenum upstream of the tubes inlets.
The hot fumes include condensable tar components,
which during the gas cooling condense
on the alumina surface. Simultaneously HF
and to some extent SO 2 is adsorbed. Due to
the efficient mixing of alumina and gas inside
the heat exchanger tubes, the AHEX FTC absorbs
more than 95% of the HF and tar on
the alumina. The efficient collection of tar
aerosols on the alumina particles reduces the
risk of tar depositing on the heat exchanger
surfaces. In addition the injected abrasive
alumina particles will clean the surfaces of
possible deposits, as demonstrated in the earlier
trials in the ME, which were the basis for
this patented design.
Control or elimination of fouling of heat
exchanger surfaces has been the main driver
behind Alstom’s development of this new fire
tube heat exchanger. Alstom has long-term
experience with fire tube heat exchangers on
similar or more difficult flue gases, such as
from Fe/Si- and Si-metal furnaces. Over the
last three years this technology has also been
proven for potgas in full-size demonstration
units (EHEX, MHEX, IHEX) at Alcoa Mosjøen
in Norway.
The adsorption process is enhanced by the
even gas / particle distribution, relatively long
retention time and short mixing length within
the confined space of the multiple parallel
tubes. The dry process of the novel AHEX
FTC, allows the gas to be cooled to temperatures
below 105 °C, possibly even below 80
°C. This allows for further condensation of
PAH and improved cleaning efficiency. After
leaving the heat exchanger the cooled gas enters
directly into the dry scrubber, where the
main part of the injected alumina is separated
into the filter hopper and re-circulated directly
back to the heat exchanger inlet. Primary
alumina is injected into the filter compartment
and collects on the bags in a final polishing
stage to adsorb any trace components of
tar fumes and HF. Through an overflow device
in the filter hopper the re-circulated or spent
alumina leaves the system to be sent to the
pots. The new AHEX FTC can efficiently handle
a larger variation of the flue gas flow than
today’s systems. There is no need to re-circulate
the gas, as is common for the conditioning
tower-based FTC.
The heat energy recovered in the AHEX
may be used or disposed to the environment.
One example of efficient use is in district heating,
another to use it for seawater desalination.
Electricity production is also possible by
deploying an Organic Rankine Cycle (ORC)
machine. For the AHEX plant at Mosjøen, the
hot water will be used for both district heating
and for driving an ORC for electricity production.
During the cold season, an extension
from the plant’s (and thus also the town’s) district
heating system to the AHEX is planned.
Validation of the AHEX FTC concept
The full scale AHEX concept is demonstrated
at the existing Alcoa Mosjøen FTC, which Alstom
delivered. This includes six filter compartments
downstream of the conditioning
tower. One compartment is retrofitted with
the AHEX heat exchanger. Thus the gas bypasses
the existing conditioning tower and
flows directly into the top of the heat exchanger
and further on to one filter compartment,
which operates on gas from the heat exchanger
only. This compartment is therefore
conveniently benchmarked with the other
five compartments which run on flue gas from
the conditioning tower. The measurements on
the gas from these compartments are references
in the full-scale validation of the AHEX
performance. The ingoing water temperature
to the AHEX is usually 60 °C and the outgoing
is 80-90 °C. The inlet gas temperature
normally varies between 160 and 190 °C and
the corresponding outlet gas temperature
reads 90-100 °C.
The heat recovered in the AHEX heats up
the 50% glycol water mixture to about 90 °C.
This fluid flows in a closed loop between the
AHEX and the heat delivering heat exchanger.
Here it is normally cooled down to about 60
°C. The heat flow is calculated from measuring
the fluid mass flow and corresponding temperatures
in and out of the AHEX, deploying
a specific heat value of approx. 3,300 kJ/kgK
for the heat transfer fluid. The heat transferred
to the fluid is in the range of 0.8 to 1 MW.
This indicates a total heat recovery potential
of about 5 MW for the complete anode bake
plant at Alcoa Mosjøen.
A 50% higher gas flow is estimated to flow
through the AHEX compartment, compared
to the remaining compartments. The reason
for the higher gas flow to the AHEX compartment
is the lower pressure drop across the
AHEX compared to the conditioning tower.
The gas flow is estimated within ± 10% accuracy
assuming a gas specific heat value
The installed full scale demo AHEX FTC at Alcoa
Mosjøen
of about 0,37 Wh/Nm 3 . This is based on the
fact that the heat absorbed in the fluid will
be equal to the heat recovered from the gas
(neglecting the small heat loss to the environment).
The total gas flow to the remaining
compartments is measured in a venturi duct.
To validate that there is no excessive dust
deposits on the AHEX tubes, a heat transfer
coefficient is calculated from the measured
data and divided by a theoretically calculated
heat transfer coefficient from the literature.
The stable quota curve indicates that the heat
transfer coefficient is
not degrading due to
e. g. excessive dust de-
Schematic diagram of AHEX, the combined heat
exchanger and tar condensation system
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ALUMINIUM SMELTING INDUSTRY
posits. Even if there are some fluctuations in
the measured pressure drop, it is evident that
the pressure drop is not increasing over time.
This is also verified by several visual inspections
of the heat exchanger surfaces. It demonstrates
that the heat exchanger is clean and
not fouled by tar residue.
Extractive PAH samples from the flue gas
were collected with standard methods from
the inlet to the conditioning tower and from
the AHEX compartment outlet, as well as from
the outlet of the other compartments. These
measurements let us calculate the removal efficiency.
During the measurements the outlet gas
temperature from the AHEX was raised so as
to be identical to that of conditioning tower
outlet, so as to simplify the comparison of the
AHEX concept with a conventional filter compartment.
The measured removal efficiency of
the AHEX can therefore be considered conservative,
since it would collect more PAH on
an AHEX FTC, when operated at the lower
gas temperatures typical for AHEX. An external
laboratory analysed the samples for the
different PAH compounds (gas chromatography
– mass spectrometry method).
It is evident that the AHEX compartment
has similar or better removal efficiency compared
to the reference compartment. Overall
the removal efficiency for the PAH-16 gas
compounds was 18% higher for the AHEX
compartment. As the gas flow through the
AHEX compartment is in the order of 50%
higher compared with the reference compartment,
the AHEX compartment collects about
70% more PAH (kg/h) than the reference
compartment. A visual inspection of the enriched
alumina from the AHEX compartment
revealed it to have a much darker colour compared
with alumina from the reference compartment.
As the primary alumina flow to all
of the compartments is identical, this supports
the higher collection efficiency. HF emissions
from the filter compartments were measured
by portable HF analyser. It showed that the
HF emission from the AHEX compartment
is significantly lower than from the reference
compartment. For further details see [1].
Conclusion
A novel Fume Treatment Centre (FTC) concept
has been developed. The core of this concept
is the integrated heat exchanger reactor
which simultaneously combines cooling the
flue gas with adsorbing PAH, condensed tars
and HF on alumina. This novel FTC concept
is a further development of the Alstom’s DDS
(Decentralised Dedicated Scrubber) technology.
This new AHEX concept integrated into
the filter eliminates the need for a conditioning
tower with water injection. All the operational
challenges related to the conditioning
tower (corrosion, tar deposits, bag hydrolysis)
are reduced or eliminated. The fumes flow directly
into the filter without the need for a
duct from the conditioning tower to the filter.
The AHEX concept allows cooling the gas to
below 100 °C without the risk of corrosion of
the duct and the filter. The improved cooling
of the gas will allow for even higher removal
efficiency. The AHEX offers recovery of approx.
1 MW th heat per compartment.
The concept has been validated on a full
scale demo-plant at Alcoa Mosjøen, which has
been in operation since November 2011. The
performance of the compartment with AHEX
has been compared with another compartment
running on a conditioning tower at the
same gas temperature. The emission measurements
show that the AHEX has a much higher
emissions removal efficiency compared to the
compartment with conditioning tower. This
higher efficiency is achieved even though the
AHEX compartment handles 50% more gas
compared with the compartment downstream
of the conditioning tower.
The novel AHEX FTC is more compact
compared with a conditioning tower cooled
FTC, and it allows for improved removal efficiency,
thus reducing emission of carcinogenic
tars and gaseous fluorides. It recovers
heat which when used reduces the smelter’s
carbon footprint. It eliminates handling of carcinogenic
residues from tar drop outs in conditioning
towers and ducts, and it adds ‘renewable’
energy to the smelter. It secures lower
operational and capital costs compared with
the conventional conditioning tower-cooled
FTC. AHEX is flexible, it allows integration
in existing FTCs, and it will add many benefits
both to greenfield and brownfield smelter
projects.
References
[1] A. Sorhuus, S. Ose and G. Wedde, AHEX-
A New, Combined Waste Heat Recovery and
Emission Control System for Anode Bake Furnaces,
TMS 2013, San Antonio, Texas, USA.
Author
Bo Herrlander is global marketing manager Industry
& Power of Alstom Power, based in Växjö,
Sweden.
GNA cathode block sealing process
T. Phenix, GNA alutech
GNA alutech inc. of Montreal, Canada,
is recognised as a leader in the supply of
cathode sealing equipment and of control
systems to primary aluminium smelters
worldwide. Having worked for some
29 years with major aluminium smelters
around the globe, the company has
improved the cathode sealing process
with equipment designs that are more
productive yet more efficient. The equipment
is also diverse, being easily adaptable
to seal blocks and bars from various
smelter technology providers and brought
together in a single production line. We
have provided systems for different potroom
technology suppliers, including AP
30, 35, 37 and 40, Hydro, Montecatini,
Sumitomo and others.
Cathode blocks are among the materials necessary
to line a typical reduction cell. These
blocks vary in dimensions and configuration,
and must be mated to steel bars before being
installed in the cells. For many years,
this cathode assembly process was typically
done by hand using rudimentary tools and
basic handling equipment. Now that has all
changed, and different approaches with various
levels of mechanisation and automation
have been developed to streamline this process.
They make it more efficient and improve
the electrical conductivity and the lifetime of
the fin-ished product, the cathode bar and
block assembly.
System overview
Today’s cathode block sealing system groups
together a number of machines and heating
sources to clean and heat the steel bars as
well as to heat the carbon-graphite blocks
prior to reaching the point of assembly. At
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SPECIAL
ALUMINIUM SMELTING INDUSTRY
this stage, operators are involved to continue
the process, and they usually perform a quick
check of the block and bar temperatures prior
to pouring the sealing medium, which typically
iron during the mating procedure.
The GNA steel bar furnaces are typically
heated using SCR controlled electrical elements
to achieve the required temperature.
Electrical energy for the various motions and
movements is regulated through a comprehensive
electrical control scheme with an operating
programme containing several hundred
I/O’s. Feedback and data are continually available
to the operators and to the smelter Scada
system to create a data base, to do trending
and to manage inventories.
© GNA
Block oven and feed conveyor
consists of molten iron from a local induction
furnace. In addition to this mating and sealing
process using the molten iron, operators must
feed the system with the basic raw materials
that include the blocks and steel bars. Following
that, where the initial cooling process is
completed they remove the final assemblies
to a dedicated storage area.
The assembly tolerances are specified and
need to be within a few millimetres. Also, the
correct temperatures are critical to the success
of the sealing process, with minimal temperature
variation across the blocks and bars, not
only as they exit their respective heaters, but
also just prior to the pouring of the molten
Motor control centre
This is also the case for the block ovens; however,
recirculation fans are also incorporated
into the latter to ensure adequate heat transfer
to meet the production cycle time requirements.
Specific design strategies are used in
zoning the heating equipment to achieve and
main-tain optimum temperatures, while also
consuming as little energy as possible. The
PLC program strategy regulates energy usage
for heating, and it also controls all system
movements in order to respect the temperature
variance which is specific to the applicable
bar-block combination.
A GNA cathode assembly line can store
enough materials to meet the requirements
for several hours of production,
thereby freeing up the operator
for other tasks.
In the cathode assembly line,
the material handling requirements
are multi-dimensional with
the bars flowing through the assembly
chain, changing direction,
being shot-blasted to clean the
surface of rust and mill scale,
and then heated. In parallel, the
blocks are heated to their respective
temperature and are then
automatically assembled with the
bars using an automated crane and
special handling system of GNA
design and fabrication; all under
the watchful eye of an operator.
System performance and reliability
Here is where the repeatability and reliability
pay off. The mechanical system and its controls
must continually produce block and bar
assemblies within the specified tolerances
and temperature limits. This is vital so that
primary producers can prepare and store the
multitude of cathode blocks required for a new
smelter start up or for on-going pot maintenance.
Rejects are both costly and time-consuming.
New smelters typically start producing
sealed cathode blocks one year prior to
actual potroom construction. They often work
two shifts per day, six or seven days a week
to meet their cathode block sealing target so
as to guarantee start-up of the smelter and
the production of molten metal.
The quality and precision of the block assembly
is particularly important as the cell
amperage is ever-increasing, causing more aggressive
service conditions. This can affect the
cathode service life, emphasising the benefits
of a reliable quality. Also, the costs associated
with pot ‘patching’ or ‘relining’ due to premature
failure of the pot lining are a significant
part of the costs of producing aluminium.
Managed by a logical, user-friendly control
system, and supported by a knowledgeable
staff with a stock of critical spare parts, the
GNA system will return many years of quality
operation to the smelter for their sealed cathode
requirements. Having demonstrated proven
reliability for more than 20 years, GNA
consistently strives to refine and improve their
equipment to meet the client’s most stringent
requirements and expectations.
Illustrated in the diagram (next page) are
the cathode block oven, the bar furnace and
the assembly area. There a gantry crane automatically
retrieves the hot bars and aligns
and positions them in the hot block during the
mating process.
Client relations
For each client, GNA analyses his specific
needs and produces a system overview to
determine the guaranteed performance for a
particular assembly line. We design and adapt
our systems for both greenfield and brown-
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ALUMINIUM SMELTING INDUSTRY
the resulting findings to our design, and this
is a major part of our continual improvement
process. Guards and fences are used to protect
personnel from moving machinery that starts
automatically. Electronic aids are also strategically
located that will stop any piece of
equipment or the complete system, should a
specific area be breached.
Operator comfort is also in the forefront,
with noise abatement equipment and dust
collection provided for specific components
of the system.
Sustainability, the final word
Schematic diagram of cathode block oven, bar furnace and assembly area
field sites, providing detailed layout and foundation
drawings. These drawings include the
utility requirements necessary for the client to
construct or modify a building to install the
new equipment.
In the course of our engineering study,
the assembly line production target is only
one aspect of the project. The system design,
which incorporates several pieces of material
handling equipment as well as heating systems,
hydraulic and pneumatic systems, is all
engineered to exacting standards that reflect
the smelter’s immediate and long-term objectives.
Typically, a single master control station is
located so as to provide the operator with a
clear view of where the bars and blocks are
assembled and sealed in the critical mating
and sealing process.
Safety
As stated above, system reliability is of primary
importance, but not more important
than safety and ergonomics for the operators.
The GNA cathode sealing system is the
result of many years’ experience in designing
and building such equipment for aluminium
smelters, and this is reflected in the safety
aspect of day-to-day operations. Having performed
risk analysis studies on cathode systems
for several clients, we routinely apply
To ensure optimum performance and the
ongoing production capability of the GNA
assembly line, comprehensive manuals and
training are provided, both for the system
operators as well as the maintenance personnel.
The training consists of classroom sessions
and also a hands-on experience directly
on the assembly line. Continuous technical
support and spare parts are made available
to the client long after we have left their site,
thus ensuring the plant can maintain a stable
supply of sealed cathode block assemblies for
the life of the smelter.
Author
Ted Phenix is CEO of GNA alutech inc, based in
Saint-Laurent, Quebec, Canada.v
Slotting anodes and recycling carbon
Slots cut in the bottom surface of the
anodes are an effective way to evacuate
the gas continuously formed during
the aluminium reduction process, thus
reducing the accumulation of gas bubbles
underneath the anodes. Major benefits
commonly achieved by the use of slots in
the anodes are the reduced cell resistance
and the improved cell stability. Depth of
slot is important to ensure these benefits
last for the entire anode life (full life
slot); slot shapes are important to achieve
other benefits in the pots management
thanks to the control of the gas exit direction
and related area of influence. T. T.
Tomorrow Technology, based in Italy
close to the city of Padua, has achieved
particular knowledge in anodes cutting
and slotting technology. Internal R & D
as well as long experience in the design
and manufacture of dedicated equipment
for anodes cutting and slotting, as well as
for the carbon area, have been the basis
to develop the patented Automatic Slots
Cutting Machine.
The most recent of the anodes slotting machines
manufactured by T. T. is incorporated
in the automatic anodes slotting line delivered
to Trimet Aluminium in Hamburg, Germany,
which is now in operation to feed the slotted
anodes to the potrooms. This line manages in
fully automatic mode to cut one or two slots
in the bottom of two completely different
anodes types. The line in Hamburg has been
supplied with a dedicated carbon material
recovery system and aspiration and filtration
unit, which allow 100% recycling of carbon
material produced while slots are cut. The accurate
value of recycling rate is at 99,995%,
far above the expectations of the customer.
An air filtration unit was designed to meet
the severe requirements of the local authorities.
Noise reduction, capture of all the dust
and carbon material emissions and discharges
together with the proprietary design of critical
parts of the line to reduce pollution impacts
contribute to have the highest environmental
protection while the anodes are slotted.
Recycling of the carbon material recovered
from the slotted anodes is achieved through
collecting, transporting, sizing, buffering and
returning to the raw material silos the carbon
material which is reprocessed in the mixer to
form new anodes. Recycling benefits to the
smelter and the environment are: reduced
amount of raw materials used to produce
anodes, reduced wastes, conserving natural
resources, and saving money.
The equipment manufactured by the company
is furthermore particularly designed to
minimise operator exposure to any potential
hazards during operation as well as during
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© T.T. Tomorrow Technology
Two slots being cut simultaneously
maintenance, resulting in a healthy and safe
working environment for the operators.
The slots cutting machine is supplied with
a sound and dust proof cabin, complete with
complementary items as hydraulic power unit,
electrical panel / MCC with necessary controls
and HMI for the friendly operations. The ability
to access the machine control and software
at any time from anywhere via special programs
is a huge advantage that T. T. Tomorrow
Technology customers value highly.
The fact that both planned maintenance
and unplanned machine downtime costs are
expensive is well known to T. T., whose design
and construction criteria for this reason are:
• Simplicity of design
• Robust construction
• Reliable operation
• Easy and low cost operation and maintenance
• Safety operation and maintenance.
While the slots cut in the baked anodes have
proved to solve a lot of the problems suffered
when slots are formed by the conventional
way in the vibrocompactor (last but not least
the lack of homogeneity in the anode due to
the blades in the forming press preventing
uniform material distribution and forming
pressure) the slots cut with the technology
proposed by T. T. have reached the target of
depth required to ensure that the benefit of
the slots last for the full anode life. The economic
and production benefits that are so
achieved in the potroom management are
bigger than those achieved with the deeper of
the shorter slots that can be produced with
conventional methods in the green anodes.
With T. T.’s anodes slotting machines the
depth and the inclination of the slots can be
furthermore managed and adjusted at any
time during production: the slot configuration
and the slot shape are therefore flexible. Another
big and important advantage is the possibility
to cut interrupted
slots, which allow to control
the gas flow direction
toward the centre of the
pots.
Particularly the automatic
slots cutting machines
are manufactured
to perform three profiles
of slots:
• Straight slots (passing
thought the anode at the
same depth); the actual
slot depth is anyway adjustable
(pre-selectable)
from the operator panel
• Inclined slots: starting
from a pre-selectable slot
depth, ending to a smaller
one with a constant inclination;
the value of the inclination
angle is anyway
adjustable (pre-selectable)
from the operator panel
• Interrupted slots:
where while slots are cut
the blades are quickly
removed from the slots
before reaching the end
of the anode; position where the blades are
removed from the slot is selectable from operator
panel.
T. T. Tomorrow Technology has recently
been awarded of a new contract for a highly
customised automatic anodes slotting machine
by a major aluminium smelter in Australia.
Construction is in progress; and its commissioning
is scheduled for the beginning of the
second half of 2013.
Other projects for automatic anodes slotting
machines, says T. T., are under discussion
with smelters around the world, which
are positively evaluating the capability of the
slotting machine to cut one or two deep
longitudinal slots in the bottom surface of the
baked anodes even of different dimensions,
whether they are to be cut with straight slot/
slots or with (variable) slope or interrupted
before the end of the anode.
The carbon material recovery system and
the combined air filtration, developed by T. T.
and reaching almost 100% recovery and recycling
rate, is complementary to the anodes
slotting machine. Energy savings, increased
productivity, reduced greenhouse gas emissions,
money saving for raw material purchase
and prevention of pollution caused by
the recycling of process wastes are key factors
matching the short-term ROI of the anodes
slotting equipment.
View of an air filtration and carbon recycling system
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ALUMINIUM SMELTING INDUSTRY
Testing a new ‘STARprobe’
M. Dupuis, GeniSim; J.-P. Gagné, Stas
In addition to the two main tasks an aluminium
reduction cell controller has to perform,
namely to keep both the dissolved alumina
concentration in the bath and the anode cathode
distance (ACD) under tight control [1],
modern cell controllers are also in charge of
keeping the bath ratio (or excess AlF 3 ) concentration
under control.
This task has proven to be quite challenging
despite the fact that, at first glance at least, it
looks quite straightforward. Fluoride evolves
out of the cell in the off-gas; a big fraction of
that fluoride is captured by the fresh alumina
in the scrubber and returns to the cell as part of
the secondary alumina feed to it. The part that
does not return to the cell must be compensated
by direct AlF 3 feeding in order to maintain
a constant bath ratio in the cell. The cell
controller performs that task using feedback
control algorithms based on regular measurements
performed by cell operators.
Recently Alcoa has develop a revolutionary
new technology to measure bath ratio in the
potroom almost as quickly as you can measure
bath temperature [2, 3]. Furthermore, in
addition to the excess AlF 3 concentration, the
new STARprobe also measure the bath temperature,
the dissolved alumina concentration,
and the cell superheat. That last information
can be used as part of the cell control logic, as
previously presented in [4] for example.
GeniSim’s Dyna/Marc dynamic aluminium
reduction cell simulator has been used to model
and evaluate the efficiency of the traditional
combined bath sample/XRD analysis and bath
temperature measurement bath ratio control
logic, and to compare it with a new control
algorithm based on STARprobes excess AlF 3
concentration and superheat measurements.
Taking into consideration the neutralisation
of some of the fluoride absorbed by the fresh
alumina in the scrubber by the sodium already
present in it, we can assume that the equivalent
of 3.6 kg/hr of AlF 3 is fed back to the cell
by the secondary alumina (on average or at
the nominal 100% alumina feeding rate). This
leaves 1.1 kg/hr of AlF 3 that must be directly
fed using a point breaker feeder (PBF) under
the supervision of the cell controller.
However, this hourly dose is only about
0.14% of the excess AlF 3 in the bath, since
the cell contains close to eight tonnes of bath
and hence about 800 kg of excess AlF 3 . This
means that if the direct AlF 3 feed were to be
completely stopped for some reason, it would
take about 72 hours for the excess AlF 3 concentration
to drop by 1 to 9%. In view of this
relatively slow response time of the cell, it
should be quite easy to keep the excess AlF 3
concentration under tight control. But such
control is clearly lacking in the great majority
of smelters, so some other factors must be
complicating things.
How daily operations influence the bath
ratio: In the above mass balance calculation,
about 75% of the AlF 3 is fed back to the cell
as part of the alumina feeding. However, in
Fig. 1: Daily excess AlF 3 concentration variation modelled without control and any mass imbalance as
generated by Dyna/Marc cell simulator
© GeniSim
Performing the AlF 3 mass balance
Using a 300 kA cell as an example, the fluoride
mass balance can be performed as follows.
Fluoride evolved out of the cell at a rate
dictated by many factors, like the bath ratio
and temperature and the state of the anode
cover [5]. In the current example, the fluoride
evolution rate is calculated to be 33.6 kg F/t
Al with the cell conditions selected, namely
10% excess AlF 3 , 970 °C, and a good anode
cover. For a 300 kA cell producing 94.7 kg
Al / hr, this represents the equivalent of 4.7 kg
of AlF 3 that evolves out of the cell and hence
must be replaced each hour.
Fig. 2: 20 days excess AlF 3 concentration variation modelled without control and any mass imbalance
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Fig. 3: Corresponding 20 days of excess AlF 3 concentration sampling results
modelled assuming no bath sampling noise
Fig. 4: Corresponding 20 days of excess AlF 3 concentration sampling results
modelled assuming 0.5% standard deviation white sampling noise
modern continuous tracking control logic, the
alumina is never fed constantly at the nominal
100% rate to the cell. As a result, the excess
AlF 3 concentration swings up and down
according to the alumina feeding cycle. The
direct AlF 3 additions are also performed in
discrete events, for example 2 kg every 110
minutes, in order to average 1.1 kg/hr. Those
discrete additions also influence the short term
variation of the excess AlF 3 concentration.
As well as the irregular AlF 3 addition, several
thermal events also affect the AlF 3 evolution,
such as the bath temperature, but more
importantly the ledge thickness variation: as
ledge is mostly pure cryolite, ledge formation
concentrates the excess AlF 3 in the molten
bath. Ledge formation occurs after anode
change events, for example. Fig. 1 shows the
calculated daily variation of the concentration
of AlF 3 in the modeled bath in the absence of
control additions and of any AlF 3 mass imbalance.
The standard deviation on the average
value is about 0.1%.
Sampling frequency and delayed XRD results:
The next factor complicating things is the
long delay in evaluating the bath chemistry
through manual interventions. The traditional
way of proceeding requires manual bath sampling,
manual processing of the bath samples,
at best semi-automatic analysis of the bath
samples by a XRD instrument, and manual
input of the results in a database accessible to
cell controllers. Considering the cost of a XRD
analysis, it is typical to take bath sample every
second day and to get results at 8 to 24 hours
after the actual bath sampling.
Fig. 2 shows the calculated variation of
the AlF 3 for a period of 20 days, again in a
model without control additions or any mass
imbalance. Fig. 3 shows the results of the bath
Fig. 5: Simulation of the process without perturbation; top without control, bottom with feedback control,
10% target concentration (XRD results, once per day, 1 day delay, 0.5 kg/hr% proportional band and
-0.1 kg/hr°C proportional band)
sampling performed once a day, always at the
same time of the day. The delay between taking
the sample and receiving the results of the
analysis is clearly not an issue when the concentration
is drifting very slowly. Yet any delay
in the feedback response can cause instability,
depending on the controller setup.
So far, despite the daily events ‘process
noise’, the sparse sampling frequency, and the
delay in getting the sampling analysis results,
should make it easy to stabilise the bath ratio.
So there is no obvious explanation for why it
is so difficult to control the bath ratio.
Bath sampling noise problem: But a new
problem affecting bath ratio control has recently
been identified: it is the bath sampling noise
due to the bath composition being far from homogeneous
[6]. The standard deviation of that
bath sampling noise has been evaluated to be
around 0.5%, which is five times greater than
the process noise generated by daily events.
That bath sampling noise, contrary to the daily
events noise, is completely unpredictable. Fig.
4 shows the simulated results of bath sampling
performed on the 20 days period presented in
Fig. 2, but when 0.5% white noise is added to
the noise-free results presented in Fig. 3. The
fluctuations are about seven times greater.
Simulated process response using standard
control without any process perturbation:
Now, we want to test a typical control logic
where both the delayed XRD analysis from
bath samples and measured bath temperature
are used to correct the direct AlF 3 feeding
rate as it is commonly done in the industry
these days. The proportional band was set
to 0.5 kg/hr% for the 24 hours delayed bath
XRD analysis results, and to -0.1 kg/hr °C for
the bath temperature measurement. The bath
sampling and the temperature measurement
for the model are done simultaneously every
24 hours.
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ALUMINIUM SMELTING INDUSTRY
A bath sampling noise having a standard deviation
of 0.5% has been added to the XRD
analysis results following observation recently
reported [6]. For the temperature measurement,
a bath sampling noise having a standard
deviation of 2.5 °C has been added as reported
in [6].
Fig. 5 presents the modeled results in the
dynamic cell simulator for a period of 100
days. The top graph presents the results obtained
without any control and in the absence
of process perturbation. The initial bump is
an indication that the steady state conditions
used as initial transient conditions are not
100% representative of the long term pseudo
steady state conditions.
The bottom graph presents the results obtained
with feedback control active. Unfortunately,
it is not as good as the results without
control. This shows that the bath sampling
noise, combined with the 24 delay in the bath
sampling analysis result, is destabilising this
feedback control loop.
Simulated process response using standard
control with a significant process perturbation:
In order to more seriously test the stability
of the feedback control loop, we added a
major perturbation to the simulation. On day
14, we simulated removal of about half of the
cover material from the anodes. This increases
the anode panel heat loss by about 30 kW
from 230 to 260 kW. As we can see in Fig. 6,
as a natural response, the cell must reduce its
cathode heat loss by the same amount. It does
this by reducing its superheat by about 1 °C
and by increasing its ledge thickness by about
5 cm. This extra ledge formation concentrates
the excess AlF 3 in the molten bath by about
2%, where it remains close to 12% if the direct
AlF 3 additions remain unchanged.
This is clearly a case where some feedback
control is required. Fig. 7 presents the model
results obtained using the standard control described
above. After the change of superheat,
the 970 °C temperature target is no longer
compatible with the 10% excess AlF 3 target.
Combined with the 1 day offset between the
AlF 3 feedback and the temperature feedback,
this generates a cyclic response characteristic
of somewhat unstable feedback control. This
type of oscillation with a wave length of about
20 days and an amplitude of about 2.5% is
very often seen in real smelters. Those undesired
oscillations occur despite careful selection
of the values of the proportional constants
in an unsuccessful attempt to avoid feedback
loop instabilities.
The new STARprobe
Fig. 6: Simulation of 100 days natural response (no control) to a significant reduction of the anode cover
material thickness resulting in an increase of the anode panel heat loss by 30 kW
Fig. 7: Simulation of the process with a significant perturbation; feedback control, 10% target concentration
(XRD results, once per day, 1 day delay, 0.5 kg/hr% proportional band and -0.1 kg/hr°C proportional
band)
The STARprobe is a portable device that takes
real-time measurements of bath properties
in electrolysis cells, such as Superheat, Temperature,
Alumina concentration and bath
Ratio or acidity (STAR). This synchronicity of
measurements is a most important step forward
in improving the control and efficiency
of electrolysis cells. It unites the conventional
processes of temperature measurement and
bath sampling analysis into one online measurement.
This simplifies and greatly shortens
the process and time delay from measurement/sampling
to pot control decision. The
pot control decision can therefore be based
on the real-time cell conditions rather than on
conditions from few hours ago, or even from
as long as 24 hours ago.
This integrated real-time measurement system
consists of four major components:
• Reusable probe tip
• Portable stand to fit various pot
configurations
• Electronics for data acquisition and
analysis, and wireless communications
for data transfer
• Tablet PC with programs to perform all
necessary tasks during measurements.
Considering the great advantages of the STARprobe,
Alcoa has decided to share the technology
with the rest of the aluminium industry
starting from 2012. In this regard, Alcoa has
just appointed STAS, a well recognised leader
in the aluminium industry, to commercialise
the new STARprobe analysing system.
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Simulated process response of STARprobe
to a significant process perturbation: Exactly
the same major perturbation was used to test
the efficiency of the feedback control loop
using STARprobe measurements. The same
day measurement frequency is used and the
same 0.5 kg/hr% proportional constant for the
AlF 3 feedback loop. Obviously in this case
however, the measurement results are available
without delay. In addition, the measured
superheat was also used to activate a separate
feedback loop which adjusts the target cell
resistance based on the offset between the target
and the measured superheat.
The measured superheat is also affected
by a very significant bath sampling noise. That
bath sampling noise was estimated to have a
standard deviation of about 2 °C in [6], so we
added a 2 °C standard deviation white sampling
noise to the simulation.
The obtained results are shown in Fig. 8.
In this case the response to the perturbation
is slower than in the previous case, because
there is no longer a correction based on the
temperature offset, and because a ± 1 °C deadband
was imposed on the superheat target in
order to inhibit wrong responses to the noise
in the superheat measurements. Yet after a 25
days transient response to the perturbation,
the excess AlF 3 concentration goes back to
its target value and remains on target without
oscillations after that.
Fig. 9 shows the evolution of the target cell
resistance. After a delay of 6 days, a 0.01 μΩ
correction to the target cell resistance was
applied each day for 15 days giving a total
0.15 μΩ correction. This 0.15 μΩ ‘permanent’
correction ensures that the superheat remains
within the 3.5 to 5.5 °C range, despite the
fact that the anode panel now dissipates an
extra 30 kW of heat loss.
Conclusions
This study demonstrates the value of using a
dynamic cell simulator to optimise existing
cell controller algorithms and to test new ones
without putting real cells at risk. The Dyna/
Marc cell simulator used in this study is available
to the whole aluminium industry through
GeniSim Inc. Version 14 supports adding the
simulated bath sampling noise at the level
seen in the AlF 3 measurements. The model can
also use STARprobe measurements instead of
bath samples/XRD analysis to perform bath
ratio control.
The revolutionary new STARprobe measurement
tool makes possible a new control
logic scheme based on independent control
of the excess AlF 3 and of the cell superheat.
Modelling proves this to be superior to the
standard single feedback control loop, which
uses two target variables (namely the excess
AlF 3 and the operating temperature) to control
a single control action, namely the direct
AlF 3 additions.
The STARprobe developed by Alcoa [2,
3] is now available to the whole aluminium
industry through STAS (http://www.stas.com/
en/starprobetm.html).
Fig. 8: Simulation of the process with a significant perturbation; feedback control, 10% target concentration
(STARprobe measurements once per day, 0.5 kg/hr% proportional band and daily 0.1 μΩ target resistance
correction due to superheat offset from target)
Fig. 9: Evolution of the cell target resistance (there is a 0.4 μΩ change of target resistance each day during
the anode change event)
References
[1] M. Dupuis, Testing cell controller algorithms
using a dynamic cell simulator, ALUMINIUM 88
(2012)1-2, 50-55.
[2] X. Wang, B. Hosler and G. Tarcy, Alcoa STARprobe
TM , Light Metals, (2011), pp 483-489
[3] X. Wang, G. Tarcy, E. Batista, and G. Wood, Active
pot control using Alcoa STARprobe TM , Light
Metals, (2011), pp 491-496
[4] T. Rieck, M. Iffert, P.White, R. Rodrigo and R.
Kelchtermans, Increased Current Efficiency and Reduced
Energy Consumption at the Trimet Smelter
Essen using 9 Box Matrix Control, Light Metals,
(2003), pp 449-456.
[5] W. Haupin and H. Kvande, Mathematical Model
of Fluoride Evolution from Hall-Héroult Cells,
Proceedings from the International Jomar Thonstad
Symposium, ed. by A. Solheim and G. M. Haarberg,
Trondheim, Norway, October 16-18, (2002),
53-65.
[6] M. Dupuis, P. Bouchard and J. P. Gagné, Measuring
bath properties using the STARprobe TM , 19 th
International ICSOBA Symposium (2012), to be
published.
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ALUMINIUM SMELTING INDUSTRY
Author
Dr. Marc Dupuis is a consultant specialised in the
applications of mathematical modelling for the
aluminium industry since 1994, the year when he
founded his own consulting company GeniSim Inc.
(www.genisim.com). Before that, he graduated with
a Ph.D. in chemical engineering from Laval University
in Quebec City in 1984, and then worked ten
years as a research engineer for Alcan International.
His main research interests are the development of
mathematical models of the Hall-Héroult cell, dealing
with the thermo-electric, thermo-mechanic,
electro-magnetic and hydrodynamic aspects of the
problem. He was also involved in the design of experimental
high amperage cells, and in the retrofit
of many existing cell technologies.
Jean-Pierre Gagné is specialist for elecrolysis
products of Stas, based in Chicoutimi, Canada. Stas
designs and manufactures equipment for the primary
and secondary aluminium industry.
Carbothermic reduction – An alternative aluminium production process
H. Kvande, NTNU
About twenty years ago the present author
co-authored a paper [1] with the title Carbothermal
production of aluminium –
technically possible, but today economically
impossible? Since then significant
resources have been spent on the study of
this process and much experimental work
has been done. So, it is time to ask again if
such a carbothermic process for production
of aluminium really is still economically
impossible. The present paper reviews the
published literature of the last two decades
to try to evaluate the current status of carbothermic
aluminium production.
The standard industrial aluminium electrolysis
process (Hall-Héroult) has several weaknesses,
as we know: very high capital investment,
a complex anode change operation,
high energy consumption, pollution of the environment
and emissions of greenhouse gases.
That is why the search for alternative methods
for production of aluminium will probably
never stop. In 2000 Alcoa announced that it
had started to develop a process based on carbothermic
reduction of alumina. Since then
little published information has emerged
about the progress of Alcoa’s work. This is
quite understandable in view of the importance
which a successful result would have.
So let us here first take a look at the present
status of carbothermic aluminium production.
Carbothermic production
of aluminium – its history
The idea of carbothermic reduction of alumina
to aluminium is indeed an old dream.
Aluminium-copper alloys with about 15% Al
were produced industrially already in 1886
[2], the same year as the present industrial
electrolysis process was invented. In the 1920s
Al-Si alloys with 40-60% Al were produced
in Germany, and about 10,000 tonnes of
these alloys were produced annually in the
period up to 1945.
The first attempt to produce pure aluminium
by carbothermic reduction of alumina was
performed around 1955. Pechiney worked
on the process from 1955 to 1967, but terminated
the programme for technical reasons.
Reynolds worked on an electric arc furnace to
produce aluminium from 1971 to 1984. Alcan
acquired information from Pechiney and continued
their research, but stopped in the early
1980s. Alcoa tried to develop the process to
produce Al-Si alloys from 1977 to 1982.
However, in 1998 Alcoa started the carbothermic
production project again, together
with Elkem R&D in Norway. They changed
their focus from an open arc furnace (with high
generation of volatile aluminium-containing
gases) to a submerged arc process. Elkem
already had a long experience with modern
silicon furnace technology, and so came up
with the idea for a new type of high-temperature
electric reduction reactor tailor-made for
carbothermic production of aluminium. Alcoa
had a good understanding of the fundamental
chemistry and a long experience with carbothermic
production of aluminium from the
work in the 1960s until the 1980s. Together
Alcoa and Elkem then agreed to try this again.
Carbothermic aluminium production:
the three main steps in the process
As the name says, the purpose of the carbothermic
method is to use carbon and heat to
reduce alumina to aluminium, according to
the overall reaction:
Al 2 O 3(s) + 3 C (s) + heat = 2 Al (l) + 3 CO (g)
The reaction proceeds close to and above
2 000 °C, and it produces CO as the primary
gas. The gaseous by-product is therefore different
from that of the Hall-Héroult process,
which produces CO 2 .
The carbothermic process can be divided
into three steps, as shown in the flow chart:
• Production of a slag, which contains a
molten mixture of alumina and aluminium
carbide
• Production of a molten aluminiumcarbon-(carbide)-alloy
• Production of pure aluminium (refining)
from the aluminium-carbon-(carbide)-
containing alloy.
The two most difficult steps here are steps 2
and 3; the production of the molten aluminium
alloy and the subsequent refining of this
alloy. In addition the process needs a gas
scrubber to collect the aluminium-containing
gases that evaporate from the furnace at
these high temperatures. This is an engineering
challenge. The main reactions are:
Overall carbothermic reduction:
Al 2 O 3 (l) + 3 C (s) = 2 Al (l) + 3 CO (g) E ° theoretical
= 7.9 kWh/kg Al
Stage 1 (T > 1 900 °C):
2 Al 2 O 3 (s) + 9 C (s) => (Al 4 C 3 + Al 2 O 3 ) (slag)
+ 6 CO (g)
Stage 2 (T > 2 000 °C):
(Al 4 C 3 + Al 2 O 3 ) (slag) => (6 Al as metal alloy
with Al 4 C 3 ) + 3 CO (g)
The latter two chemical equations are not
stoichiometrically correct here, because both
the slag and metal phases will have varying
compositions. The molten aluminium phase
will always contain some dissolved carbon,
and therefore it can be considered chemically
as an Al-C alloy. There are two molten phases
here and they will not mix. The molten alloy
has the lower density and will float on top of
the molten slag phase.
The carbothermic reduction process produces
poisonous CO, which has to be captured.
If the CO were later burnt as fuel it would
produce CO 2 . To avoid releasing this greenhouse
gas this should then either be used as a
chemical or captured and stored (CCS).
Information published after year 2000
Here is a list of expected potential gains from
carbothermic aluminium production, as published
by Alcoa in 2000 [3]:
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© Kvande
• Lower production costs by 25%, and reduced
capital costs by 50%. This may give
lower total cost by up to 35%.
• Less need for workforce.
• Lower electrical energy consumption by
more than 30%. About 10.0 kWh/kg Al is
expected and about 8.5 kWh/kg Al can be obtained
with energy recovery from the gases.
The theoretical minimum energy consumption
for this reaction is 7.9 kWh/kg Al, so the
energy efficiency will be much higher than for
the existing electrolysis process, where typically
about 50% of the energy now is lost as
heat given off to the surroundings.
• Better environmental protection. There
will be no gaseous fluoride emissions by vaporisation
from the electrolyte, and of course
no emissions of perfluorocarbon gases (CF 4 ),
which now are formed during anode effects in
the electrolysis cells. The process will eliminate
volatile organic carbon-containing fumes
(PAH) from tar used in the anode production
step, and there will be no solid waste from
spent pot lining (SPL).
In 2003 Bruno et al. [4, 5] gave an excellent
overview of Alcoa’s work so far on carbothermic
aluminium production. Later Bruno
[6] documented the non-proprietary R&D
work conducted on the Aluminium Carbothermic
Technology (ACT) project from the
contract inception on 1 July 2000 to its termination
at the end of 2004. The objective of the
programme was to demonstrate the technical
and economic feasibility of a new carbothermic
process for producing commercial grade
aluminium, designated by Alcoa as the Advanced
Reactor Process (ARP).
In connection with Alcoa’s attempt to buy
Alcan in 2007, some interesting information
was published [7]. This confirmed that research
on carbothermic reduction of alumina
was underway in Norway. More interestingly
here, Alcoa wrote that it was then planning to
move from a pilot scale of 1.5 MW to an 8.0
MW scale-up, and suggested this might later
be developed in Québec when the furnaces
could reach that stage. The plan to move the
carbothermic work away from Norway was
probably a consequence of the attempt to buy
Alcan.
Furthermore, working with Elkem AS
in Norway, Alcoa had so far invested more
than USD37 million on this project. The annual
budget for this research was at that time
USD14.8 million, with a 35-person development
team [7]. This information clearly shows
that Alcoa was using significant effort, money
and resources on the project. The target then
was industrial aluminium production by this
process in 2020.
Flow chart of the aluminum carbothermic technology – advanced reactor process concept of Alcoa and Elkem
Alcoa and Elkem continued to hold joint ownership
in the carbothermic process technology
that was being developed. It claimed that the
carbothermic process technology holds the
potential to produce aluminium at a lower
cost, driven by reduced conversion costs, lower
energy requirements and lower emissions,
and that it also promises a lower capital cost
than traditional aluminium smelting. The technology
was claimed also to hold potential for
significant cost improvement in the production
of other metals. These are very similar to the
claims that were published in 2000 [3].
In an article in the Norwegian technical
journal Teknisk Ukeblad [8] in 2008 Alcoa
and Elkem Research confirmed that they had
worked on this process for nearly ten years.
Here are some of the statements given in this
article:
• “We can produce aluminium with 30%
lower energy” (from 13 down towards 9 kWh/
kg Al).
• “We have developed good adaptive regulation
algorithms that can control the process
very accurately.”
• “We think that we have solved several of
the big challenges in the carbothermic process.
The main challenge is to develop process
equipment that can withstand these high temperatures
(above 2 000 °C). Today’s situation
is that there are still a couple of problems that
remain to be solved.”
• “If successful, the world’s first carbothermic
aluminium plant can be in operation in
Norway before 2020.”
The most recent publication on
carbothermic aluminium production
At the 2012 TMS Annual Meeting, a paper
[9] was presented which contained a lot of
interesting information about the progress of
this work. It claimed that the cooperation between
Alcoa and Elkem has been highly successful
and that process development has advanced.
Several test campaigns had been done
at Elkem’s research facility in Kristiansand.
In 2011 Alcoa decided to continue the development
of the carbothermic process on its
own and established the Alcoa Norway Carbothermic
group. The test reactor with auxiliary
systems was then moved to the Alcoa Lista
aluminium smelter in Southern Norway.
While the initial process had used separate
compartments for the two stages of the process
(first production of the molten alumina-carbide
slag and then the molten aluminium-carbon
alloy), the current concept uses a single
reactor compartment to continuously produce
aluminium.
The process generates significant amounts
of aluminium-containing vapours. This has always
been a major challenge with this process,
and much effort has gone into dealing with
this issue. Vapour recovery concepts continue
to be major development areas. The condensation
of the vapours needs control to keep
the off-gas port open so that the off-gas generated
in the process, i. e. CO (g) , can leave the
reactor. This has led to the development of
advanced cooled off-gas pipes [9].
The technical achievements together with
improved process understanding have now
resulted in a reactor design that is able to
continuously operate the process for several
weeks at the time. Each tap then generates
several hundred kilograms of metal, so that a
campaign thus yields many tonnes [9].
So what are the main technological and engineering
problems that remain to be solved?
The authors [9] claim that the process now
faces only few challenges. They mention spe-
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ALUMINIUM SMELTING INDUSTRY
cifically: determination of optimal furnace
shape, electrode configuration, and operating
conditions for a scaled-up reactor. They
also need to find the optimal operating conditions.
The plans are now to continue working
towards establishing a commercial plant for
producing carbothermic aluminium.
Concluding remarks
The carbothermic reduction technology for
production of aluminium has previously been
considered to have a high risk for failure, although
it is now seemingly closer than ever to
commercialisation.
If successful, then for cost, energy and environmental
reasons this technology would
probably have to be licensed to other aluminium
producers.
Very few, if any, other aluminium producers
can compete with Alcoa in this field
of technology, and so the rest of the world’s
aluminium producers will have to wait and see
what happens.
References
[1]. H. Kvande, R. Huglen and K. Grjotheim, Carbothermal
production of aluminium – Technically
possible, but today economically impossible?, Proceedings
of the International Symposium arranged
in honour of Professor Ketil Motzfeldt, edited by
H. Kvande, NTH, Trondheim, Norway, 1991, pp.
75-102.
[2]. P. T. Stroup, Carbothermic smelting of aluminium.
The 1964 Extractive Metallurgy Lecture,
Trans. Met. Soc. AIME, 230 (1964), pp. 356-372.
[3]. Aluminum Carbothermic Technology Advanced
Reactor Process (ACT-ARP), Office of Industrial
Technologies, Energy Efficiency and Renewable
Energy, US Department of Energy, Washington,
D.C. 20585, IT, Oct. 2000.
[4]. M. J. Bruno, Aluminum Carbothermic Technology
Comparison to Hall-Héroult Process, Light
Metals 2003, Edited by P. N. Crepeau, TMS (The
Minerals, Metals & Materials Society), 2003, pp.
395-400.
[5]. K. Johansen, J. A. Aune, M. Bruno and A. Schei,
Aluminum Carbothermic Technology Alcoa - Elkem
Advanced Reactor Process, Light Metals 2003, Edited
by P. N. Crepeau, TMS, 2003, pp. 401-406.
[6]. M. J. Bruno, Aluminum Carbothermic Technology,
Final Technical Progress Report for the Period
2000 July through 2004 December, Submitted to
US Department of Energy on 31 Dec. 2004.
[7]. Information given in a press release: Alcoa
sends letter to Alcan board outlining commitments
to Québec will meet requirements of agreement
between Alcan and Québec government, Montréal,
Québec and New York, New York, 17 May 2007.
[8]. Article in Teknisk Ukeblad (Technical Weekly
Magazine), No. 16, May 2008 (in Norwegian).
[9]. C. V. White, Ø. Mikkelsen and D. Roha, Status
of the Alcoa Carbothermic Aluminum Project,
International Smelting Technology Symposium (Incorporating
the 6 th Advances in Sulfide Smelting
Symposium), Edited by J. P. Downey, T. P. Battle
and J. F. White, TMS, 2012, pp. 81-88.
Author
Dr. Halvor Kvande recently retired from his position
as chief engineer at Norsk Hydro in Oslo, Norway,
where he worked for 32 years. From 2009 to
2011 he was Professor and Qatalum chair in the
department of Chemical Engineering at Qatar University
in Doha, Qatar. He is presently Professor at
the Norwegian University of Science and Technology
(NTNU) in Trondheim, Norway.
Recycling of smelter materials through
rotary crushing and material separation
D. J. Roth and B. Best, GPS Global Solutions
There are many areas in the aluminium
smelter operation that can benefit from
efficient recycling of materials through
low-cost, simple rotary processing operations.
Didion International Inc. has the
most widely developed uses and applications
for rotary crushing and separation
systems, being especially suited to recycling
and recovery of dissimilar materials
that are often mechanically bonded
together. This technology developed in
the foundry industry in the early 1970s,
initially to separate metal castings from
the sand mould pieces in which they were
cast. These hot, heavy castings required
the development of a very durable machine.
The continued improvement of the
Didion RT/RS Tumblers has made mechanical
processing of mixed materials a
very cost-effective and low-maintenance
alternative to other processing systems.
© GPS
Fig. 1: Model RT 84-2100 Didion scrubber, crusher and separator
These flexible systems can perform surface
scrubbing, crushing, screening and sizing in
one single piece of equipment. The Didion
systems take up far less space than conventional
crushing and screening process facilities,
while at the same time requiring less maintenance
and manpower to operate. The RT/RS
Tumbler systems significantly improve the
aluminium industry’s potential impact on the
environment by this basic approach to processing
bath, carbon, thimble, dross and salt cake.
The RT/RS Tumbler is a single processing
unit that can perform multiple processing
steps within one piece of equipment. This is
achieved through the
patented double liner
configurations. The
system requires very
low levels of manpower.
The equipment was
originally designed for
automotive foundry
production applications
and was required
to run 24 hours a day,
seven days a week with
minimal maintenance.
This operating philosophy
makes the Didion
systems perfect for primary
aluminium smelters, whose focus is on
making aluminium and not on problems with
ancillary equipment.
There are four basic features of the Didion
RT Rotary Processing Systems: first, their ability
to process very large pieces of feed, up to
1,750 mm blocks, in the same processing step
as fines separation; second, their ability to
crush with controlled fines generation; third,
their ability to ‘scrub’ a surface, so removing
82 ALUMINIUM · 1-2/2013

SPECIAL
ALUMINIUM SMELTING INDUSTRY
Fig. 2: Primary crushing chamber
Fig. 3: Typical large blocks
materials that are foreign to the base structure,
and allowing for valuable base structure
materials to be recycled and reused; fourth,
their ability to classify several sizes of material
from bag house dust to 1,750 mm in the same
single piece of equipment.
Summary of primary plant applications
for the RT tumbler processing system:
• Rotary bath crusher and size separator in
a single process, with the ability to remove
the tramp aluminium from this electrolyte
in the same step
• Carbon reclaimer and cleaner, to scrub
the bath off used carbon blocks before
crushing, recycling and then crushing them
to the required size, all this in the same
piece of equipment
• Removal of carbon and bath from cast
Fig. 4: Autogenous section with impact zone cast
liners
thimbles in the anode rodding shop,
thereby saving consumables and floor
space compared with traditional shot
belts methods
• Separation of metallics from oxides and
salts in dross and salt cake processing,
significantly improving the environmental
impact by eliminating or reducing the
landfill residues
• burner balls
• Separation of spent pot liner material.
Crushing of large blocks of material
Handling large blocks of material can be particularly
difficult for most processing systems.
However, these must be reduced in size if they
are going to be recycled. Most systems either
use a primary jaw crusher or a mobile hydraulic
hammer / crusher for this first breaking
step. The RT systems handle this in the first
section of the drum, taking this time-consuming
and often dangerous manual labour step
out of the procedure.
The material is normally charged by end
loader into a large hooded vibratory feed
hopper that loads the drum. Large, cast steel
teeth lift the blocks and then crash them down
on hardened spikes for an impact and autogenous
milling step that can handle any material
used or produced in the smelter. For
example, solid aluminium sows can be inadvertently
charged into this section of the drum
when processing dross, and they will not cause
any damage to the Didion unit. Large uncrushable
pieces, such as large slabs of aluminium,
can be removed from the machine simply
by backing out the feeder and reversing the
rotation of the drum, discharging these large
pieces into a waiting tub. This practice causes
no damage to the equipment, as is often the
case with impacting systems.
This is a valuable feature in bath, pot cleanings
and dross processing applications. This
one piece of equipment is unique in being able
to handle these large pieces without significantly
disrupting the process flow.
Crushing with controlled fines generation
The impact action of the material falling
on the cast steel flights in the prebreaking
and autogenous
chambers, combined
with the action of the
muller roller, allows
for severe crushing,
while also immediately
removing the
fines; this is a key
process feature in achieving success. The key
technical challenge that the RT unit solves
is that it can both preserve the preferred
crushed material sizing that was chosen to
go through the liners, and also remove finer
materials that would form a cushioning bed,
so lowering the efficiency of autogenous impacting.
This characteristic becomes valuable when
processing recycled carbon anode pieces for
the downstream processes. Preselecting the
correct liner opening and screen size determines
the distinctiveness of materials, generating
appropriately sized fines for further
processing in the green carbon plant. This
normally multiple step process is simpler with
the RT/RS system.
The unique size control abilities of the RT
can reduce the large blocks to the exact fraction
sizes needed in recycling these materials.
The impact breaking action of the system on
the particles gives sharp fracture angles which
are preferred for the green carbon recycling
process.
The system’s impact crushing characteristics
also work for recycled bath processing, allowing
for product sizing and for the removal
of tramp ferrous metals and aluminium. The
RT system provides a uniform product to put
back on top of the pot cells.
‘Scrubbing’ surfaces remove materials
that are foreign to the base structure
The interior design of the Didion RT systems
can combine multiple sections to accomplish
a variety of processing goals. The scrubbing
or removal of foreign material from the base
material is a standard application for Didion
rotary equipment. In the original foundry applications
for the units, this served to remove
sand from the base casting.
There are three areas where this feature of
the systems have applications in the primary
aluminium plant: to remove bath from the
spent anodes, to remove of carbon
from the thimble
castings after
separa-
Fig. 5: Heavy duty rotary
separator / thimble cleaners
– RS
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ALUMINIUM SMELTING INDUSTRY
Fig. 6: Spent anode with bath
tion from the rod, and finally to remove metal
and oxides off alumina filter balls.
The system works by using the bits and
pieces of materials to clean each other, relying
on the size differences of individual pieces
of the material to clean even in the pockets
where small amount of bath or carbon may
be trapped.
To remove bath from the anodes, or carbon
from the thimbles, the standard practice
of shot blasting is inefficient and time consuming.
The steel shot is an expensive consumable
that risks being carried over to contaminate
other aspects of the process. Its cleaning efficiency
is not perfect, so that significant
amounts of sodium/bath can contaminate the
next phase of the process. These salt contaminants
typically cause problems with the refractories
in the carbon baking furnaces and in
the thimble casting furnaces. The RT/RS
processing technique prevents most of the
bath and carbon carry-over into the next part
of the production process, improving quality,
or event eliminating the furnace refractory
problems.
An additional unique application for the
rotary separator is the ‘cleaning’ of alumina
balls that are used in aluminium filter applications
and in regenerative burner applications.
These unique materials are an expensive
consumable in the aluminium casting facility
within the smelter. There is currently no
widely used method for cleaning and recycling
of the balls used in the aluminium filter
beds. They typically go out with the dross and
are destroyed to recover the small amounts
of aluminium attached to them. This aluminium,
although valuable, is worth less than the
high-cost alumina balls. These alumina balls
are also used in regenerative burner systems.
They typically are cleaned on a regular basis
by washing them with water in a separate
process, dissolving any contaminants that may
be stuck to the surface. The contaminated
waste water from the process must be dealt
with and is often a water discharge problem.
The RS processing of these balls produces a
clean, reusable ball, along with easily disposable
fines. This is a minor generation area of
waste, but when looking at overall recyclability,
reductions of landfill and reuse of materials,
every opportunity can be an important
gain for the environment.
Fig. 8: Spent balls from aluminium filter
Fig. 9: Rotary processed alumina balls
Fig. 7: Clean RS processed thimbles
Classify several sizes of material
in the same processing step
This equipment has the ability to simultaneously
separate up to eight different size fractions
in the same processing unit, from bag
house dust up to 1,750 mm blocks. It achieves
this with the appropriate selection of the
crushing chamber dam ring openings, liner
openings and screen sizes.
The numerous Didion patents for this
unique piece of equipment explain this very
significant trait of the RT & RS processing
units. There are significant advantages from
both a process view point and from a general
economics view point of being able to accomplish
many processing steps in one unit
has major advantages as seen from the viewpoints
both of technical process and of general
economics
The process advantages that are the key
bonus of this unit are that it can separate all
material sizes as follows:
• The ability to take almost
any size of initial
feed, the only restriction
being the selection
of the overall diameter
of the unit. Systems are
available in diameters
up to 4.5 metres. The
unique reversing feature
of the system, with
the units incorporating
the primary impact
chamber, allow for solid
Fig. 10: Particle size control
aluminium to be processed, cleaned and discharged
into tubs after retraction of the entry
feeder. Typical block size here is + 250 mm.
• The coarse and fine particle removal is the
next stag. This can be the key to recovering
the value of the materials in processing dross
and to the efficiency of the process with the
autogenous impact designs. The screens in this
area can have any opening size smaller than
the liner holes. This hooded area is designed
for two screens that allow for different opening
sizes in each panel. These screens can
quickly be removed and changed for other
sizes, for instance if downstream processes
need changed size fractions. A typical fines
screen selection will range from -10 mm to
+ 3 mm.
• An important option is the ability to select
recirculation or direct discharge from the machine
of the intermediate materials classified
by the liner holes, which guarantees processing
flexibility. In bath carbon processing it
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SPECIAL
ALUMINIUM SMELTING INDUSTRY
with a 200 kW drive motor, the smallest
with a 22 kW drive motor. Processing
cost per tonne will vary with the
size of the unit, with the largest unit
processing 20 tph at an operating cost
of USD0.75/t. This cost includes all
monthly maintenance, capital costs,
and a cast liner replacement after seven
years of operation. This processing
cost / tonne is exclusive of local labour
cost. Certainly, even with all labour included,
pro-cessing through these large
units is less than USD10/t.
Custom sizes, throughputs and
processing configurations are part of the
Didion philosophy of equipment design,
and variants can always be evaluated and
normally accomplished.
Fig. 11: Material flow diagram and fines separation – RT
Summary
can control the size and characteristics of the
particles moving forward to the next process
step. When processing materials that contain
metallic aluminium, this element allows for
high concentration of metallics that can be
either efficiently melted in-house or sold for
high metal contents. The liner holes / slot sizes
typically range from 10 to 50 mm.
• The autogenous milling section will reduce
friable materials down to the size of the liner
openings. No friable or metallic materials can
then exit the back end of the drum. These
materials will usually be in the size range of
-250 mm to +50 mm. They can be further sized
with a rotary classifier attached to the end of
the drum to sort them into three additional
cuts, depending on customer requirements.
• The air flow of the bag house system provides
the final product sizing possibilities. The
pollution control device normally removes
-0.5 mm materials. This fraction can be subdivided
by use of a cyclone separator before
the bag house.
All of these sizing steps occur inside the
Didion system to provide products that can
be recycled as they are, or else moved on
further for carbon re-use in the green carbon
plant, or bath to be reused in the potlines.
Dust emissions to the environment are strictly
controlled by the bag house / pollution control
system, which is either installed with the
unit or attached to the plant system.
General comments
The RT/RS systems can be designed such that
they can act as an aggressive crushing unit or
as a gentler ‘scrubbing’ unit. They can also be
designed to have both features in one unit.
This type of design flexibility is an advantage
when removing bath from the spent anodes
before crushing them to the appropriate size
in the same piece of equipment.
The installation space requirement for the
largest unit is an envelope of approx. 6 x 30
metres. This layout would assume product
discharge into tubs. Conveyors can be added
to the system for continuous removal of the
products. These conveyors can be set up in
many configurations for additional separation
steps, such as eddy current processing, magnetic
separation and / or product bulk bagging.
Stand-alone systems that are used for dross
or salt slag processing typically require two
people per shift to operate the entire system.
The systems are very reliable. They were designed
to be part of manufacturing lines in
high-production
automotive foundries
that run 24
hours a day, seven
days a week.
Any unscheduled
downtime is
unacceptable to
this industry. This
reliable performance
results from
using simple, dependable
parts
and extremely
heavy duty components.
Operational
costs are very
low. The largest
unit operates Fig. 12: RT system charging
The flexibility of the design configurations of
the Didion rotary processing equipment offers
many potential applications in the aluminium
smelter environment. These dynamic systems
can lower overall processing cost by reducing
manpower, maintenance and energy consumption
as well as reducing the plant area required
for the above-mentioned materials processing
practices. The additional benefits of better recyclability
of the dross and other aluminiumcontaining
materials will also reduce landfill
cost and reduce greenhouse gas emissions.
Authors
David J. Roth is president and Brian Best is product
manager of GPS Global Solutions, based at Downingtown,
PA., USA.
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ALUMINIUM SMELTING INDUSTRY
Meeting of the ISO Committee for analysis of
materials for primary aluminium in Switzerland
L. P. Lossius, Norsk Hydro; J.-C. Fischer, R&D Carbon
The Swiss standardisation authority SNV
and R&D Carbon Ltd hosted the 6 th Plenary
Meeting of ISO Technical Committee
226 ‘Materials for the production of
primary aluminium’ in Sierre early in October
2012. The participation was good,
with 16 delegates and eight of the twelve
P-member countries attending.
Highlights of the meeting were the progress on
four new alumina standards and the harmonisation
of three anode / cathode standards on
mechanical strength; details for each material
type below are given below.
Two new convenors were confirmed: Mr
Wu Lin of Do-Fluorides (China) for smelter
grade fluorides and Mr Jean-Claude Fischer
of R&D Carbon (Switzerland) for petroleum
coke.
The Technical Committee 226 is responsible
for 110 ISO standards on the sampling
and analysis of materials for the electrolytic
production of aluminium, covering the material
groups Smelter grade alumina, Smelter
grade fluorides, Pitch, Petroleum coke and
Carbon electrodes. The main work is maintenance
and development of standards, with a
dedicated work group (WG) for each material.
After the Sierre meeting, the Work Group
Convenors are:
• Nigel Turner of Koppers EU, UK; WG1 on
Pitch
• Professor Harald A. Øye of NTNU, Norway;
WG2 on Carbon electrodes
• Ray Brown of Alcoa, Australia; WG3 on
Smelter grade alumina
• Wu Lin of Do-Fluoride Chemicals Co., Ltd,
China; WG4 on Smelter grade fluorides
• Jean-Claude Fischer, R&D Carbon Ltd,
Switzerland; WG6 on Petroleum coke.
The Plenary Meeting reconfirmed 17 standards
and confirmed the development of 11
new standards. This makes a fairly large
number of standards, but current development
work mostly replaces out-of-date methods
with new and improved methods, and aims to
later withdraw the out-of-date standards.
For Smelter grade alumina there are four
standards in development, based on the muchused
Australian standards: elemental analysis
by XRF, bulk density, flow time, and α-alumina
content. In addition to the informal work
in WG3, the following ISO technical experts
are nominated for this work: Ray Brown (Alcoa
Australia, SA), Flor Campa (Alcoa, for
AENOR), Kjell Hamberg (Hydro, for SN) and
Josef Lovcican (Slovalco, for SUTN).
For Smelter grade fluorides the new standard
ISO 12926 for elemental analysis by XRF
From the tour of the R&D Carbon facilities in Sierre, from the left: Ray Brown (Alcoa, Convenor alumina),
in front Erwin Smits (Aluchemie), Petter Lossius (Hydro, Committee Chair), Nigel Turner (Koppers EU, Convenor
Pitch), Ma Cunzhen (SAC), Yu Yiru (JN Carbon), Xue Xujin (Do-Fluorides) and Jean-Claude Fischer
(R&D Carbon, Convenor Petroleum coke).
will be ready for publication in 2013. Work
is also on-going in the fluoride field to review
or replace several old fluoride methods; ISO
technical experts are Xujin Xue (Do-Fluorides,
for SAC); Wu Lin (Do-Fluorides, for SAC);
Oscar Pérez (Derivados del Flúor, for AENOR)
and L.P. Lossius (Hydro, for SN).
For Pitch, a critical issue today is the determination
of Quinoline insoluble. TC 226 expresses
high concern for the continued availability
of Quinoline because REACH regulations
could ban it, but Quinoline is vital and
critical to an important raw materials test. The
committee therefore recommends interested
organisations, if they are surveyed, to state
that they wish to retain Quinoline.
In the Solid carbon bodies the next published
standard will be the dynamic modulus
of elasticity by the resonance method, which
goes to the final vote this autumn. Work is also
on-going to harmonise existing standards, and
Andreas Schnittker (SGL Carbon, for DIN) has
harmonised the existing standards for 3-and
4-point flexural strength, as well as the crushing
strength standard; these will be republished
in 2013. ISO technical experts are Harald A.
Øye (NTNU, for SN), Jean-Claude Fischer
(R&D Carbon, for SNV), Erwin Smits (Aluchemie,
for NEN), Yu Yiru (JN Carbon, for SAC)
and Nigel Turner (Koppers EU, for BSI).
For Petroleum coke there is a revision to
specific electrical resistivity to add measurement
of the 1.4-1.0 mm fraction, harmonising
the sample preparation for the routine coke
analysis.
For information on the work in TC226,
please contact the Secretary Knut Aune at
kau@standard.no or the Committee Chair
Lorentz Petter Lossius, Hydro Aluminium,
Norway at lorentz.petter.lossius@hydro.com.
Stéphane Sauvage is the Technical Programme
manager for TC226 on behalf of the
ISO Central Secretariat, Geneva. Note that
the standards in the TC226 programme are
available in the ISO Store as a CD made specifically
for ‘Materials for the production of
primary aluminium’.
The Committee thanks R&D Carbon, Hydro
Aluminium and Sør-Norge Aluminium
for sponsoring the 2012 Plenary Meeting and
TC226. The plenary meetings are held every
18 months, and the next plenary meeting will
be hosted by DIN and SGL Carbon, in Wiesbaden,
Germany, on 8-9 May 2014. In September
2015, a plenary meeting will be hosted
by SAC and Do-Fluorides Chemicals, in China.
Authors
Dr.-Ing. Lorentz Petter Lossius is principal engineer
for primary metal technology at Norsk Hydro ASA,
based in Øvre Årdal, Norway.
Jean-Claude Fischer is director of R&D Carbon Ltd,
based in Chalais, Switzerland.
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INDUSTRY
Chips versus briquettes: How the aluminium
industry can effectively and efficiently recycle scrap
G. Tucholski, Ruf US
For the aluminium industry, there has
long been an issue of how to recycle,
transport and / or dispose of scrap metal
and swarf (machining chips). Many in the
aluminium industry recycle their scrap
aluminium in the form of chips. These
chips can provide additional revenue
through recycling. However, there are
some challenges with recycling aluminium
chips as chips are bulky and tend to be
difficult to transport. Also, it is difficult,
if not impossible, to remove the machining
coolant or lubricant, which leaves
manufacturers with wet and oily chips.
Recyclers often will not accept wet chips,
or will charge a fine.
Companies throughout Europe, and
now in North America, have discovered
a new way to process aluminium scrap:
briquetting. Briquetting offers an efficient
and effective way to recycle aluminium
scrap, and it also solves many of the common
problems that arise from recycling
aluminium in the form of chips. Briquettes
are consistent in shape, size and
weight, and so they are easy to stack and
transport, besides having other advantages
that will be addressed later in this
article.
What is briquetting?
At its most basic level, briquetting is a process
that compresses metal scrap and swarf
into compact, easy-to-manage round blocks
(briquettes) with densities and resale values
that rival those of massive metals. Briquet-
Aluminium briquette and chips
As the technology and performance of briquetting
have advanced, so
have the potential benefits that
it holds for the aluminium industry.
Briquetting boosts the
bottom lines by adding value
to the waste stream. There are
three main advantages of briquetting
for manufacturers:
The melting factor: The biggest
advantage of briquetting
aluminium is that briquettes
melt better than loose chips.
Comparing the same weight of briquettes
versus chips, briquettes will produce more
aluminium after being melted. Chips tend
to burn, whereas briquettes melt more like a
solid. This is the main reason smelters use briquettes
instead of chips – they are going to get
more metal out of their bath than if they were
using chips. When the process is complete,
more material is recovered with briquettes,
which means more revenue.
Removing coolant or oil: Through the briquetting
process, coolant or oil lubricant that
saturates aluminium drains out more easily.
This liquid can then either be recycled for adting
has been used for more than 50 years,
but its technology and benefits have evolved
greatly over the years. For example, old-style
briquetting machines were big, loud and had
high-maintenance costs.
Today, briquetting systems made by companies
like Ruf are just the opposite. Our briquetting
systems are engineered specifically
to run reliably and efficiently, and to deliver
the same or better production rates while using
less horsepower.
The benefits for the aluminium industry
ditional revenue and / or savings (especially
when it is mostly oil), or it can be disposed
of safely and more easily. There are two big
advantages to being able to remove the coolant
or oil:
First, it allows the manufacturer to do the
recycling in-house instead of having to go
through a third party, which reduces costs.
Second, when a manufacturer sells chips that
still have coolant and oil on them, the manufacturer
will be penalised. Transporting wet
chips also creates a potential problem – it is
Briquettes are consistent in shape, size and weight,
therefore easy to stack and transport
hazardous if the oil or coolant drips onto the
road during transport, so extra precautions
and steps must be taken. This penalty, along
with the liability of transporting wet chips, can
really add up.
Space, transportation and storage: When
dealing with chips, there have always been issues
with storage and transportation because
chips are loose, take up much more space
and cannot be stacked or contained neatly.
Briquetting solves all of these problems. Briquettes
are stackable, which makes them easy
© Ruf
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TECHNOLOGY
to transport and store.
Additionally, the density of
briquettes helps during transport.
Briquettes weigh about
120 pounds per cubic foot (about
2,000 kg/m 3 ) whereas chips weigh
only about 15 pounds per cubic
foot (about 250 kg/m 3 ). The cost
savings for transporting briquettes
alone tends to justify manufacturers’
purchase of a briquetter.
Briquetting in action: how
briquetting helps global
manufacturer of training
ammunition to squeeze
value from its scrap
Ultimate Training Munitions
(UTM) makes high-performance
training ammunition and safety
systems that allow armed forces
and law enforcement agencies in
the US and around the world to
conduct safe and effective Close
Quarter Battle (CQB) training
exercises. Headquartered in the
United Kingdom, UTM also has production
facilities in the United States as well as a global
sales network operating in 45 countries.
In UTM’s US factory, ten machines work
in 60,000 square feet of space to create training
ammunition, weapon conversion kits, and
safety system equipment. During production,
tonnes of turnings are created as the precision
munitions and system components are turned
and finished using a high-speed aluminium
turning processes. Because copious amounts
of oil are required to keep the aluminium lubricated
as it is turned, the turnings produced
are so saturated with oil that they are practically
worthless. This created a problem for
UTM because it was forced to dispose of these
oily, messy turnings as best it could – temporarily
storing them as waste in hoppers, where
oil could be partially drained before the turnings
were sold for next to nothing to scrap
processors.
Coming across Ruf Briquetting at an international
manufacturing technology trade
show, UTM’s plant manager saw the potential
for briquetting as a way to tackle his plant’s
chip disposal problem. After making a visit
to Ruf’s German production facility to gain
a ground-up understanding of its innovative
briquetting technology and systems, UTM began
working with Ruf’s team in the US. UTM’s
Ralf Wagner says that Ruf was a pleasure to
work with every step of the way, and was
willing to do “whatever it took” to help UTM
Ruf briquetter
find the right briquetting solution for its operations.
According to Wagner, this included briquetting
test batches of UTM’s scrap, and then
sending the briquettes to an independent lab
to test their moisture content to ensure that
Ruf’s technology would meet the company’s
needs. “Our moisture content threshold for
getting optimum return for our chips is 2%.
With Ruf briquettes, our chips contain only 1.1
to 1.8% moisture. This drastically improves
our chip resale revenues – by about 50 cents
per pound.”
Since deploying its Ruf briquetter, UTM
has grown scrap revenue by 250% and is also
able to filter and reuse the processing oil it
reclaims as the scrap is compressed during
the briquetting process. Wagner says that his
company’s Ruf briquetter paid for itself in
less than six months. Overall, the efficiency of
UTM’s operations has risen with streamlined
scrap processing, and because scrap drainage
hoppers are no longer needed, UTM was able
to save 20% of its valuable floor space. Its
factory is cleaner, and as a result its employees
are safer.
As illustrated by UTM’s results, briquetting
solves many potential problems and increases
revenue for manufacturers dealing with aluminium.
Briquettes melt at a higher yield than
chips. Chips are less dense and have a relatively
larger surface area, so that they tend to
burn or oxidise during the melting process.
Briquettes melt more like compact metal, so
the manufacturer sees a recycling price closer
to that of recycling compact aluminium.
Additionally, the coolant or oil recovery
during the briquetting process cuts costs. Wet
chips are too dangerous to mix with molten
metal. If a manufacturer is using oil as a lubricant,
the oil savings and recovery alone will
usually pay for a briquetter. Thirdly, briquetting
saves time and space for manufacturers,
while also making transportation easier and
more cost efficient.
As briquetting becomes more common
throughout North America and beyond, its
benefits to manufacturers will continue to
grow as well.
About Ruf
Located near Cleveland in North Olmstead,
Ohio, Ruf is the North American subsidiary
of Ruf GmbH & Co. KG in Germany – a global
pioneer of advanced briquetting systems
for more than 40 years. The quality and performance
of its briquetting systems are proven
worldwide with more than 3,000 machines
currently in operation.
Author
Greg Tucholski is with Ruf US, based in North Olmstead,
Ohio, USA.
88 ALUMINIUM · 1-2/2013

TECHNOLOGY
Bühler Lost-Core-
Technologie eröffnet
weites Anwendungsspektrum
Aktuelle Trends wie der Leichtbau in
der Automobilbranche oder der Druck,
immer bessere Produkte zu geringeren
Kosten zu produzieren, verlangen nach
kreativen Lösungen im Druckguss. Eine
innovative Antwort darauf ist die Lost-
Core-Technologie (Salzkerntechnik), die
vielfältige Anwendungen erlaubt. Auf
einem Symposium der Bühler AG Mitte
November in Uzwil, Schweiz, ließen sich
über hundert Entwickler und Anwender
aus aller Welt darüber ins Bild setzen.
Namentlich die Automobilindustrie ruft nach
Kostenreduktion, integralem Design (Verringerung
der Anzahl an Bauteilen) und höherer
Produktivität. Die Lost-Core-Technologie eröffnet
dazu vielfältige Möglichkeiten. Bei
diesem Verfahren werden gewisse Partien des
zu gießenden Bauteils mit einem Salzkern
ausgespart, der dann wieder ausgespült wird.
Auf diese Weise lassen sich Bauteile aus dem
Kokillen- und Sandguss substituieren; zugleich
kommen die Vorteile des Druckgießens
– Materialeinsparung, kürzere Zykluszeiten,
weniger Nachbearbeitung – voll zum Tragen.
Zusätzlich erlaubt Lost Core die Entwicklung
ganz neuer Bauteile. So kann die innere
Formgebung komplexer gestaltet werden. Die
Zusammenfassung mehrerer Bauteile zu einem
einzigen ermöglicht eine höhere Funktionsintegration
und die erhöhte Gestaltungsfreiheit
erlaubt ein komplett neues Teiledesign.
Am Anfang des Bühler Lost-Core-Verfahrens
steht das Teiledesign für die Salzkern-
applikation, gefolgt vom Form-, Aluminiumteil-
und Salzkern-Konzept. Das Verhalten
des flüssigen Salzes und des Aluminiums
in der Form sowie die Qualität des Bauteils
können heute mit Software simuliert werden.
Dadurch entfallen nachträgliche, kostentreibende
Anpassungen der Form. Bei der Herstellung
des Salzkerns, der die innere Formgebung
des Bauteils bestimmt, spielt die optimale
Salzlösung eine zentrale Rolle, um die
Stabilität des Kerns zu garantieren und die
anschließende Entkernung zu ermöglichen.
Produziert werden Salzkern und Aluminiumbauteil
auf einer Druckgießmaschine mit
Echtzeitregelung. Diese stellt sicher, dass der
Kern während des Umgießens nicht beschädigt
wird. Entfernt wird der Kern mit Wasserhochdruck.
Bühler verfügt über die Ausrüstung für
die erfolgreiche Anwendung der Lost-Core-
Technologie und kann den gesamten Prozess
von der ersten Idee bis zur Produktionsreife
unterstützen.
Gut besuchtes Symposium
Das große Interesse an der neuen Technologie
zeigte sich am gut besuchten Symposium
von Bühler Mitte November. Die über hundert
Teilnehmer, vor allem von Vertretern der
Automobilbranche und ihren Zulieferern,
konnten sich von den Vorteilen des Lost-Core-
Prozesses persönlich überzeugen. Zum besseren
Verständnis wurde ein konkretes Projekt
in allen Schritten simuliert. Auch der Wirtschaftlichkeitsaspekt
kam nicht zu kurz und
wurde von Andreas Hennings und Georg Habel
vom Gießereiunternehmen Bocar unterstrichen.
Als weiteren Höhepunkt konnten die
Teilnehmer die verschiedenen Prozessphasen
live miterleben. Prof. Dr. Lothar Kallien von
der Hochschule Aalen präsentierte ergänzend
die Ergebnisse eines 3D-Freiformflächenprojekts,
bei dem die Lost-Core-Technologie angewandt
wurde.
Bühler Lost Core technology
opens up a wide
range of applications
Current trends such as lightweight construction
in the automotive industry or
the pressure to manufacture increasingly
better products at lower cost require
creative die casting solutions. An innovative
answer to this is the ‘Lost Core’
technology (salt core technology), which
allows for a diverse range of applications.
More than 100 developers and users from
around the globe listened to these multifaceted
opportunities at a symposium in
mid-November at the Bühler headquarters
in Uzwil, Switzerland.
What the automotive industry is calling for is
cost reduction, integral design (reduction in the
number of components) and higher productivity.
The Lost Core technology opens up diverse
opportunities for this. With this technology
certain parts of the component to be cast are
recessed with a salt core which is then rinsed
out again. This allows to replace permanent
mould cast and sand cast components by die
castings, with the benefits of material savings,
shorter cycle times and reduced post-processing.
Lost Core also enables the development
of completely new components. The internal
shaping can comprise complex designs; the
combination of multiple components into one
single unit enables high function integration
and the increased design freedom allows for a
completely new component design.
The Bühler Lost Core process begins with
the component design for the salt core application,
followed by the mould, aluminium part
and salt core concepts. The behaviour of the
liquid salt and aluminium in the mould as well
as the quality of the component can be simulated
by software. This eliminates the need for
subsequent costly adaptations of the mould.
In the creation of the salt core which deter-
© Bühler
Fotos: a) Aluteil, b) Salzkern, c) Aluteil mit Kern
Photos: a) Aluminium component, b) Salt core, c) Component with salt core
ALUMINIUM · 1-2/2013 89

TECHNOLOGY
mines the internal shaping, the optimal salt
solution plays a crucial role in ensuring the
stability of the core while simultaneously enabling
its subsequent removal.
The salt core and the aluminium component
are produced on a die casting machine with
real-time control. This prevents damage to the
core during recasting. The core is removed by
pressurised water. Bühler has the necessary
know-how and equipment for the successful
application of Lost Core technology and is in
a position to support the complete process
from the initial idea to the production stage.
A well-attended symposium
The great interest in the new technology was
demonstrated by the well-attended Bühler
symposium in mid-November. A concrete
project was simulated over all stages to promote
better understanding. The economic
aspects were also discussed by Andreas Hennings
and Georg Habel from the Bocar die
casting company. The participants were also
able to experience the various process phases
live. Prof. Lothar Kallien from the University
of Aalen supplemented the programme by
presenting the results of a 3D free-form surface
project which was implemented using the
Lost Core technology.
GM welding innovation enables increased use of aluminium
In the USA, General Motors Research &
Development, headquartered in Warren,
Michigan, has developed what it claims
to be an industry-first aluminium welding
technology expected to enable more use
of the metal in future vehicles, in which
its lightweighting advantage can help
improve both fuel economy and driving
performance.
Essentially a novel development of resistance
spot welding, GM’s process innovation uses a
patented multi-ring domed electrode in joining
aluminium to aluminium, which overcomes
the unreliability of traditionally used smooth
tip electrodes. By using this process GM expects
to eliminate nearly 2 lb (0.907 kg) of rivets
from aluminium vehicle body parts such
as doors, bonnets and tailgates. GM already
uses this patented process on the bonnets of
the Cadillac CTS-V and the tailgate of the hybrid
versions of Chevrolet Tahoe and GMC
Yukon. The company says it plans to exploit
this technology more extensively starting in
2013.
“The ability to weld aluminium body structures
and closures in such
a robust fashion will give
GM a unique manufacturing
advantage,” said Jon
Lauckner, GM chief technology
officer and vice
president of Global R&D.
“This new technology
solves the long-standing
problem of spot welding
aluminium, which is how
all manufacturers have
welded steel parts together
for decades,” he adds. “It is
an important step forward
2013 GM Chevrolet Tahoe hybrid SUV: The two-mode power system is
state-of-the-art engineering, but the battery pack adds more than 300 lb
(136 kg) to the vehicle. Weight is a fuel economy killer – and to compensate,
the bonnet and tailgate are aluminium. The lighter-weight metal is
also used for the wheels, which are low mass, aero-efficient forged parts.
Concentric rings on the domed electrode tip shown on the right, are key
to the effectiveness of the aluminium resistance-welding technology.
GM’s patented process centres on three concepts: the electrode design,
the controls for the electrical current and the technology for dressing the
tip intermittently.
that will grow in importance as we increase the
amount of aluminium used in our cars, trucks
and crossovers over the next several years.”
Spot welding uses two opposing electrode
pincers to compress and fuse metal parts together,
using an electrical current to create
intense heat to form a weld. The basic process
is inexpensive, fast and reliable, but until now,
not sufficiently robust for use with aluminium
in the present manufacturing environment.
GM’s new welding technique is said to work
on sheet, extruded and cast
aluminium with the use of
a result of a proprietary
multi-ring, domed electrode
head that penetrates
the surface metal oxide to
produce a stronger weld.
Historically, carmakers
have used self-piercing rivets
to join aluminium body
parts, due to the variability
in production with conventional
resistance spot
welding. However, use of
rivets adds cost and riveting
guns have a limited
range of joint configurations.
In addition, end-oflife
recycling of aluminium
parts containing rivets is more complex.
“No other automaker is spot-welding aluminium
body structures to the extent to which
we are planning, and this technology will allow
us to do so at low cost,” according to Blair
Carlson, GM manufacturing systems research
lab group manager. Notably, he adds that the
company is to consider licensing the technology
for non-GM production in wider areas of
automotive, heavy truck, rail and aerospace
applications.
According to Ducker Worldwide, a Michigan-based
market research firm, aluminium
use in vehicles is expected to double by 2025,
reflecting the many advantages the metal offers
compared with steel. One kilogram of
aluminium can replace 2 kg of steel. Its corrosion-resistance
and excellent blend of strength
and low mass can help improve fuel economy
and performance. Further highlighting these
application benefits AluminumTransportation.org
adds that a 5 to 7% fuel saving can
be realised for every 10% weight reduction,
and substituting lightweight aluminium for a
heavier material is one way to achieve this
goal. Cars made lighter with aluminium also
can accelerate faster and brake quicker than
their heavier counterparts.
Ken Stanford, contributing editor
© General Motors
90 ALUMINIUM · 1-2/2013

APPLICATION
Aluminium: Tesla’s secret weapon in new Model S
USA Tesla Motors’ Model S electric
performance prestige saloon car, already
well underway shipping to buyers worldwide,
is one of the latest fine examples of
aluminium-intensive vehicle design and
construction.
The Palo Alto, California-based car manufacturer
announced three years ago that it
planned to build an aluminium-bodied saloon,
and the company scheduled a production run
of 5,000 cars for 2012, ramping up to 20,000
for this year. To date, Tesla had released only
its acclaimed ‘Roadster’, which combined an
extruded aluminium chassis with carbon fibre
composite body panels. Now notably, for the
larger Model S saloon, aluminium components
have been substituted for composites.
Tesla’s design director, Franz von
Holzhausen, explains: “For limited or lowvolume
production cars like the Roadster, carbon
fibre is a material to reduce weight, but
not a solution for higher-volume production
due to costs and manufacturing time. For
Model S, we are using aluminium for the body
panels and chassis, realising that it is as strong
as steel but lighter in weight, and has similar
manufacturing capabilities. Weight is the
enemy of fuel economy – and in the case of
Model S, battery life and lighter weight translate
directly to efficiency.”
Tesla has robustly emphasised that the
Model S is the first all-electric luxury saloon
to be built “from the ground up” – with the
aim of creating a vehicle with optimal rigidity,
light weight, aerodynamics, and interior
space: Tesla engineers fit the vehicle’s slimline
battery pack below the floor in a perfectly
flat array to provide the Model S with the under-car
airflow and aerodynamics more commonly
associated with a race vehicle – while
maximising the occupancy space above (the
vehicle can seat up to seven passengers).
Advertisement
The battery pack – a high-performance aluminium
structure in its own right – when married
to the state-of-the-art aluminium body
structure, according to Tesla engineers, becomes
three times stiffer.
Tesla Motors’ new aluminium intensive Model S saloon …
… pioneers performance, economy and safety
The body shell itself is aluminium space frame
architecture comprising castings, extrusions
and stampings. Cast cross members and aluminium
extrusions in the front-end crumple
zone, unhindered by the presence of a gasoline
engine, are designed to maximise impact
absorption in the event of a crash. (Model S is
engineered with the intent of achieving 2012
five-star NHTSA safety ratings.)
Tesla’s rear multilink suspension – unique
to the Model S – is made from lightweight
but exceptionally rigid extruded aluminium,
helping the vehicle to achieve sportscar-like
ride and handling performance, including acceleration
to 96 km/hr (60 mph) in a swift and
silent 4.4 sec.
Tesla Motors has purchased the former
NUMMI factory in Fremont, California, where
it will build the Model S sedan and future
Tesla vehicles. As recently as April 2010,
this factory was used by Toyota to produce
the Corolla and Tacoma vehicles using the
industry-leading Toyota production system.
It is claimed to be one of the largest, most advanced
and cleanest automotive production
plants in the world. The factory is located in
the city of Fremont near Northern California’s
Silicon Valley, very close to Tesla’s Palo Alto
headquarters. The company claims best-inclass
engineers can be recruited in the high
tech area and the short distance also ensures
a tight feedback loop between engineering,
manufacturing and other Tesla divisions.
Ken Stanford, contributing editor
© Tesla
ALUMINIUM · 1-2/2013 91

COMPANY NEWS WORLDWIDE
Aluminium smelting industry
© Dubal
Aluminium S.A. signs USD200m
contract with Glencore
Aluminium S.A., part of the Mytilineos group,
has signed a USD200m contract with Swissbased
multinational Glencore for the sale of
75,000 tonnes of aluminium billets and slabs.
These quantities will be exported to the European
and US markets from January 2013 to
June 2014.
This contract confirms the group’s strong
export orientation and stresses the important
role of the aluminium industry in Greece,
where it contributes more than 80% of the
added value of Greek finished products that
are exported abroad.
RTA evaluates offers for French smelter
Metal Bulletin reports that Rio Tinto Alcan
is evaluating several offers for its Saint-Jeande-Maurienne
aluminium smelter in the
French Alps as part of a process to find a buyer
for the plant. The smelter could close once
its energy contract expires in 2013 if a buyer
is not found. Production curtailments began
at Saint-Jean-de-Maurienne after the 2008
downturn.
Ma’aden Alcoa joint venture
celebrates first hot metal
On 12 December Ma’aden and Alcoa commissioned
the first of 720 pot cells at their
joint venture smelter at Ras al Khair in Saudi
Arabia. At the smelter ceremony, Ma’aden
president and CEO Khalid Al Mudaifer highlighted
the achievement of first hot metal
in only 25 months from the pouring of first
concrete: “Today we see the first aluminium
produced in Saudi Arabia and the launch of a
new industry,” he said.
Abdullah Busfar, chairman of the Ma’aden
Alcoa joint venture, commented: “It is just
29 months since the joint venture issued Bechtel
with a notice to proceed with construction.”
He congratulated Bechtel and its team
of 46 different sub-contracting companies
that employed the labour and expertise of
about 14,000 people from 25 different nationalities
to reach this milestone. “They have
worked almost 60 million hours with worldclass
safety performance. More than 700 Saudi
Arabian citizens have completed their initial
intensive training and are ready to take their
place as skilled operators within this smelter,”
he said.
Disinvestment of Nalco delayed
The Indian government has delayed the sale
of its 12.5% stake in National Aluminium
Co. (Nalco), saying that the company’s latest
quarterly financial performance did not reflect
its true financial position. The divestment will
now happen in the first quarter 2013. Further
talks about the Nalco disinvestment will take
place early in January.
The Indian government is offloading stakes
in metals companies Hindustan, such as Copper
Ltd, in Metals and Minerals Trading Corp.
of India Ltd and in Nalco in an effort to pump
revenue into its slowing economy.
Alba upgrade to improve productivity
Aluminium Bahrain (Alba) has upgraded its
Potline 5 from AP30 to AP36 technology.
The upgrade was made possible with the successful
installation of the first 1,600 mm long
anode in Potline 5. Alba’s production process
will receive further boost with additional
modifications from the reduction side on anode
reference gauges, PTA shovel size, simulations
on start-up pots, etc.
Alba produced 890,217 tonnes of primary
aluminium in 2012 – a production record on
the previous year (881,310 tonnes). The
record in metal production was achieved without
incurring any significant additional capital
expenditures, says CEO Tim Murray.
Bauxite and
alumina activities
CBG and Mubadala sign bauxite deal
Compagnie des Bauxites de Guinée (CBG),
one of the world’s largest bauxite explorers,
has signed a long-term supply agreement with
Abu Dhabi’s Mubadala Development Company.
CBG is 49% owned by the government
of Guinea and 51% by Halco Mining, a consortium
composed of Alcoa, Rio Tinto Alcan
and Dadco. The new agreement is expected
to boost Guinea’s GDP by about USD500m a
year and provide a significant increase in fiscal
revenues. Mubadala owns 50% of Emal, with
the remaining 50% owned by Dubal. Mubadala
revealed in Q2 2012 that it was performing
a feasibility study regarding the construction
of an alumina refinery.
Global Alumina acquires
BHP interest in Guinea project
Global Alumina, a corporation participating
in a joint venture to develop an alumina refinery,
mine and associated infrastructure in
the bauxite-rich region of the Republic of
Guinea, has announced that the joint venture
partners Dubal and MCD Industry Holding
(Mubadala) have waived their pre-emptive
rights to purchase their pro rata share of BHP
Billiton interests in the project. Therefore,
Global Alumina will acquire all of BHP’s one
third interest in the project, increasing its stake
in the project from 33.3 to 66.7%. The joint
venture wants to develop a 10m-tpy bauxite
mine, with a refinery that would have a capacity
of more than 3.3m tpy.
92 ALUMINIUM · 1-2/2013

COMPANY NEWS WORLDWIDE
Chalco plans to build
alumina plant in Indonesia
Aluminum Corp. of China plans to build an
alumina facility with a production capacity
of 1m tpy in Indonesia. A feasibility study is
under way; the earliest date for completion of
the plant will be 2014/15. This is what President
Luo Jianchuan said in an interview in
Aluminium semis
November. In August last year, Chalco signed
an agreement with PT Indonusa Dwitama
to form a joint venture destined to develop
Indonesia’s biggest bauxite mine. China
imports over 60% of its bauxite, of which
about 80% (2011: 36m t) comes from Indonesia.
However, bauxite imports from Indonesia
fell 55% in October from a year ago
to 1.1m tonnes.
fuel-efficient commercial truck, trailer and
bus wheels. This is the first wheel manufacturing
facility Alcoa has opened in China, adding
to the list of existing wheel facilities in North
America, Europe and Japan.
AWTP has had a presence in China since
2004, when it began selling wheels out of
Shanghai. Since then, the business has grown
to include an employee base in Guangzhou,
Beijing, Jinan and Suzhou. Through additions
to its distribution network earlier in 2012, Alcoa
has built a robust sales and service presence
capable of supporting all of China.
© Hydro
Ground-breaking ceremony
for aluminium rolling mill
In mid-December, Alcoa and Ma’aden broke
ground for the construction of expanded rolling
mill capabilities at Ras Al Khair. The new
capabilities will enable the facility to supply
aluminium automotive, building and construction
sheet, and foil stock to the Kingdom’s
developing new industry and other global
markets beginning in 2014.
Brazil world leader in
aluminium beverage can recycling
The Brazilian Aluminium Association
(Abal’)and the Brazilian Association of Cans
of High Recyclability (Abralatas) have reported
that the country has recycled 248,700
tonnes of aluminium beverage cans of a total
of 253,100 tonnes available on the market
in 2011. This corresponds to a recycling rate
of 98.3%, keeping Brazil ahead in the world
leadership since 2001.
The beverage can manufacturing industry
has been investing continuously to meet the
demand. In 2012, the industry increased its
production capacity from 21 to 23 billion units
a year (+9.5%); growth in the consumption of
cans is expected to rise 7%.
Alcoa will curtail Indiana
extrusion plant in 2013
Alcoa will lay off employees at its extrusion
plant in Auburn, Indiana, and curtail the facility
by the end of March due to weak market
conditions. The plant is part of Alcoa’s Wheel
and Transportation division, and produces
automotive components and extrusions. Cutting
costs has been cited as a priority for
Alcoa, as weak aluminium prices combined
with high energy costs have put pressure on
producers in recent years.
Alcoa opens aluminium wheel
facility in Suzhou, China
Alcoa Wheel and Transportation (AWTP) has
opened a production facility in Suzhou marking
an expansion that creates a full wheel
manufacturing, distribution, sales and service
network in China. This facility brings to China
Alcoa’s forged aluminium wheel technology
that manufactures lighter, stronger and more
On the move
Aleris has appointed Ralf Zimmermann senior
vice president and general manager of Rolled
Products Europe.
K. Alan Dick, executive vice president and
CEO of Aleris Global Recycling, is leaving the
company. In future, the company’s recycling
business will be led by Terrence J. Hogan,
senior vice president and general manager of
Recycling and Specification Alloys Americas,
and Russell Barr, vice president and general
manager of Recycling Europe.
Roeland Baan, executive vice president
and CEO of Global Rolled & Extruded Products
at Aleris, is new chairman of the European
Aluminium Association (EAA) for the period
2013-2015. He succeeds Tadeu Nardocci (Novelis).
Gerd Götz, formerly global head of Public
Affairs with Philips, has been appointed EAA’s
new director general. He succeeds Patrick de
Schrynmakers, who has left the association
after 12 years of commitment.
Eric Roegner, 42, has been named COO of
Alcoa Investment Castings, Forgings and Extrusions,
a new position. He has been president
of Alcoa Forgings and Extrusions since 2009
and has led Alcoa Defence since June 2012.
Marian Daniel Nastase has been appointed
Vimetco’s president of the board of
directors; Frank Mueller was appointed vicepresident
of the board of directors.
Eivind Kallevik has been appointed executive
vice-president and CFO of Norsk Hydro.
The appointment of Kallevik, currently head
of finance in Hydro’s Bauxite & Alumina
business area, will become effective from 15
February. He will replace Jørgen C. Arentz
Rostrup. Executive vice president of Extruded
Products, Hans-Joachim Kock, succeeds Mr
Kallevik as head of Finance in Hydro’s Bauxite
& Alumina business area.
ALUMINIUM · 1-2/2013 93

COMPANY NEWS WORLDWIDE
Suppliers
Danieli Fröhling supplies slitting and
trimming line to Novelis Nachterstedt
After having received orders for various Novelis
plants, e. g. in Brazil and Korea, Danieli
Fröhling has been granted another contract to
supply a slitting and trimming line, this time
to Novelis Nachterstedt, located in Saxony
Anhalt, Germany.
The Nachterstedt plant supplies customers
of industrial, packaging, building and automotive
applications in Europe. It is equipped
with the latest cold rolling technology and
features a robot workshop dedicated to the
laser-cutting of shaped body blanks for the
automotive industry.
The new edge trimming and slitting line will
handle material up to 3.5 mm thickness and
a strip width of 850 mm up to 2,250 mm.
Line speed is up to 800 m/min. The incoming
coil weight will be as much as 25 tonnes.
One of several highlights of this line is the
full automatic positioning slitting shear with
centre cut. Cutting width, cutting gap and cutting
depth adjustment will be positioned automatically
after input of incoming strip data
within seconds. The first coil is to be processed
on this line in early 2014.
Seco/Warwick acquires
Nespi International
Seco/Warwick GmbH, located in Stuttgart,
Germany, has acquired 100% of Nespi International,
Bedburg-Hau, Germany. Nespi is a
furnace engineering company specialised in
retrofits, repairs, service and spare parts supplies
for many types of furnaces. This is a further
step in the growth strategy of the Seco/
Warwick group, which is one of the major heat
processing equipment manufacturers worldwide.
The acquisition will strengthen Seco/
Warwick’s business, especially on the German
and Western European markets, such as
Austria, Switzerland and the Netherlands.
Group CEO Pawel Wyrzykowski stated:
“After our successful development in some
key world markets we would like to put emphasis
on our offer to our German speaking
customers now.” Nespi has been renamed
Seco/Warwick Service GmbH.
At the end of November Seco/Warwick
SA, Swiebodzin / Poland, dissolved the joint
venture with Winfor GbR, Stuttgart, that both
companies held in Seco/Warwick GmbH.
Seco/Warwick SA acquired the Winfor shares
in Seco/Warwick GmbH. The managing directors
Thomas Wingens and Karol Forycki left
Seco/Warwick GmbH on 30 November. Thomas
Kreuzaler has temporarily taken over
as managing director beside his other group
functions.
Novelis scrap melting
furnace under commissioning
In January 2013 commissioning of the new
melting furnace supplied by Hertwich Engineering,
Austria, was well in progress at Novelis
Italia SpA in Pieve, Italy.
This Ecomelt PS-80 multi-chamber furnace
is aimed to recycle clean and contaminated
aluminium scrap for a new casting line
at Pieve, as part of Novelis’ effort to raise the
recycling content in its various rolling operations
around the world from 34 to 80% by
2020. The Ecomelt PS-80 is designed for
processing 80 tonnes per day.
The Ecomelt furnaces operate particularly
economically when melting scraps which
contain combustible organic substances, so
reducing gas consumption to 400 kWh/t, significantly
below that of conventional melting
furnaces. That saves energy costs and lowers
the CO 2 emissions. In addition, the immersion
melting process reduces metal loss to below
3%. Hertwich Ecomelt furnaces combine high
flexibility in terms of scrap types with low
metal loss and low environmental impact.
The Ecomelt concept of scrap recycling will
be the central topic of a presentation to be
held at OEA Aluminium Recycling Congress
in Düsseldorf, Germany (25./26. February
2013).
Otto Junker and Can-Eng
Furnaces co-operate on services
The Otto Junker Group, Simmerath/Germany,
and Can-Eng Furnaces International Ltd, Niagara
Falls / Ontario, have recently signed an
agreement to co-operate on customers services.
The companies’ complimentary product
range will enhance each other’s ability to
service worldwide users of thermal processing
equipment. Global customers will find a complete
range of ferrous and non-ferrous melting,
pouring, process heating and heat treating
equipment for complex thermal processing
applications. To support customers, both Otto
Junker and Can-Eng would invite inquires
for either groups products be forwarded to
the nearest geographical sales office. Key
contacts are Tim Donofrio (vice president,
Standard and Aluminium Products, Can-Eng
Furnaces, tdonofrio@can-eng.com) and Jan
van Treek (sales manager Thermoprocessing
Plants, Otto Junker, jvt@otto-junker.de).
The Author
The author, Dipl.-Ing. R. P. Pawlek is founder
of TS+C, Technical Info Services and Consulting,
Sierre (Switzerland), a service for the primary
aluminium industry. He is also the publisher
of the standard works Alumina Refineries and
Producers of the World and Primary Aluminium
Smelters and Producers of the World. These
reference works are continually updated, and
contain useful technical and economic information
on all alumina refineries and primary
aluminium smelters of the world. They are
available as loose-leaf files and / or CD-ROMs
from Beuth-Verlag GmbH in Berlin.
Hertwich Ecomelt PS furnace
© Hertwich
94 ALUMINIUM · 1-2/2013

RESEARCH
Cathode wear in Hall-Héroult cells
K. Tschöpe, E. Skybakmoen, A. Solheim, SINTEF Materials and Chemistry; T. Grande, NTNU
Laboratory tests for cathode wear identify
some variables as important, and eliminate
others. These results are compared
with models and with industrial potline
experience.
Introduction
The research team Electrolysis in SINTEF
Materials and Chemistry offers a high level of
competence in the field of light metals production,
molten salt chemistry, and particularly,
the process of aluminium electrolysis. The
activities cover fundamental as well as applied
research in close collaboration with the
industry and NTNU (Norwegian University of
Science and Technology). This paper reviews
the recent activities in the Durable Materials
in Primary Aluminium Production (DuraMat)
project on cathode wear, a phenomenon that
is of great interest for all primary aluminium
producers.
The Hall-Héroult process has for more than
125 years been the only commercial method
for primary aluminium production. To date,
this process has survived the attempts to replace
it by alternative methods such as carbothermal
reduction, electrochemical reduction
of anhydrous aluminium chloride, and electrolysis
based on inert electrodes.
Tremendous scientific and technological
efforts have been made to improve the efficiency
of the process; e. g. the potline amperage
has been increased from 50 kA in 1940
to currently 400-500 kA [1]. Modern cells
may operate at specific energy consumptions
as low as 12.5 kWh/kg Al, and the current efficiency
is typically in the range of 92-96%.
Careful choice of new lining materials, and in
particular, the increase of the graphite content
in cathode blocks, is one of the factors that
made this possible. Anthracitic carbon has
been gradually replaced by the now state-ofthe-art
graphitised cathode blocks. While this
has allowed additional energy savings and
increased productivity through the increased
electrical conductivity, these benefits need to
be weighed against higher material costs and
lower wear resistance.
eventually leads to direct
contact between
the metal and the
collector bar. Consequently,
cathode wear
is usually the limiting
factor for the service
life of aluminium reduction
cells. The cross
sectional view of cathode
blocks often reveals
a W-shaped wear
pattern, and even a
WW-pattern has been
observed, as shown in
Fig. 1 [3]. Typical wear
rates are in the range
of 2-6 cm/year [4].
The cell service life is
a crucial economic
parameter, which
makes it important to
understand the wear
mechanism(s).
It is generally agreed
that formation, dissolution
and transport
of aluminium carbide are important factors
that influence the cathode wear. Aluminium
carbide can be formed chemically as well as
electrochemically, according to reaction (1)
Fig. 1: Visualisation of the wear profile. Cathode surface of a shutdown
cell after 2,088 days in operation (a); plotted image using the laser scanning
method, the blue colour corresponds to less wear and the red colour
indicates the highest wear (b); longitudinal wear profile of all 19 cathodes
showing the WW-shaped wear pattern (c) [3].
and (2), respectively. However, the underlying
mechanism(s) suggested are mainly based
on theoretical considerations and are still a
matter of discussion [5-10].
Characteristics of cathode wear
Wear is generally defined as net removal of
material from a surface [2]. Carbon blocks
wear excessively along their periphery, which
a) b)
Fig. 2: Schematic drawing of the experimental set-up with a quartz glass tube and position of the sample
(a) as well as the sample appearance and its exposed cross section after embedding and polishing (b)
ALUMINIUM · 1-2/2013 95

RESEARCH
4 Al (l) + 3 C (s) → Al 4 C 3(s) (1)
3 C (cathode) + 4 AlF 3 (diss) + 12 e - →
Al 4 C 3 (s) + 12 F - (diss) (2)
To improve the physical understanding and to
build competence concerning this branch of
materials performance, we need to combine
data from chemical and electrochemical experiments
with fundamental studies on diffusion
and thermodynamics, and with computer
modelling of transport processes. This paper
aims to give an insight to the wear mechanisms
of the carbon cathode by summarising the
procedures and some of the main results from
our experiments. A more detailed description
can be found in a series of publications in the
corresponding literature [11-18].
Fundamental studies
To understand the formation mechanism(s) of
aluminium carbide it is necessary to examine
a) b)
c) d)
possible influencing factors. As stated above,
the formation of aluminium carbide could be
of either chemical or electrochemical nature.
The simplest system to start with is molten aluminium
and carbon in direct contact (case 1)
using the so called Al-C diffusion couple test.
In the further course of the work, we intend
to include stepwise other parameters such as
presence of cryolite (case 2) and polarisation
(case 3), so as to build up an experiment that
mimics real potline conditions. The test setup
for case 1 and 2 experiments is shown in
Fig. 2. More detailed descriptions can be found
elsewhere [11, 12].
Case 1 experiments revealed that aluminium
carbide indeed forms by a purely chemical
reaction at the Al-C interface. Temperatures
above 1 100 °C were needed for carbide formation,
probably because the reaction was
impeded by a protective Al 2 O 3 layer initially
present at the aluminium surface due to exposure
to air. This oxide layer had to evaporate
and/or disintegrate mechanically by thermal
expansion to ensure appropriate contact between
aluminium and carbon, leading to the
formation of a dense layer of small Al 4 C 3 crystallites.
A possible reaction mechanism for the
first stage of carbide formation was discussed
[11]. Introduction of synthetic cryolite at the
Al-C interface changed the morphology of
the aluminium carbide layer to a more needle-like
structure, and reduced the reaction
temperature to 1 030 °C [12]. This confirms
that cryolite acts as a wetting agent by dissolving
the oxide layer [5, 7]. This is ongoing work,
and studies currently focus mainly on cases 2
(cryolite) and 3 (polarisation).
The authors used the case 1 set-up in a side
study to compare different types of carbon
materials and their influence on aluminium
carbide formation. Sample treatment, temperature,
duration, and argon pressure in the
glass tube were kept constant throughout
the experiments. Afterwards, the quartz tube
shown in Fig. 2a) was quenched in water and
the sample was removed. The spent samples
were embedded in epoxy and wet cut with
100 % ethanol in a precision diamond saw.
Afterwards, the samples were wet-ground and
polished using 100% ethanol as lubricant to
avoid reactions of the aluminium carbide in
the sample with the moisture in air.
Optical microscopy using a polarising filter
revealed the Al-C interface and aluminium
carbide formation. Some of the initial results
are presented in Fig. 3. As can be observed,
all types of carbon produced aluminium carbide
layers with similar appearance, which
leads to the preliminary conclusion that the
carbide formation is independent of the type
of carbon material. Even though the Al-C diffusion
tests are long-term tests and involved
only small amounts of carbide formation, the
authors would like to point out that this result
is in accordance with observations made during
the wear test studies, which will be described
in the following.
Experimental cathode
wear investigations
Fig. 3: Comparison of polished cross sections of different carbon materials: electrode graphite (a), graphitised
carbon of two different types (b, c) and vitreous carbon (d) after the experiments performed at
1 200 °C, 0.8 bar argon atmosphere and 10 days duration. The Al 4 C 3 layer is clearly visible at the aluminium
carbon interfaces as indicated in Fig. 2.
Several authors have described laboratory test
methods for studying the wear mechanism(s)
and to reveal the influence of different experimental
conditions on the wear rate [5,
13-16, 19-26]. Recent attempts have focused
on predicting the behaviour and performance
of commercial cathode materials in industrial
cells. Ranking or comparing cathode materials
requires defining a standardised test with
consistent test parameters. Several types of
laboratory set-ups to ‘accelerate’ the wear
have been tested. The most promising one is
96 ALUMINIUM · 1-2/2013

RESEARCH
based on the ‘inverted’ cell design by Patel et
al. and Sato at al. [23, 24] and is described here.
A schematic drawing of the setup is shown in
Fig. 4 a); more detailed descriptions have been
published elsewhere [13-15].
The present laboratory study kept all parameters
constant, and compared three different
commercial cathode materials. The test
proved that it can accelerate the observed
wear rate compared with the conditions in industrial
cells, and it provides reproducible results
for each material. Nevertheless, the wear
rate was in the same range for all three tested
cathode materials, showing that the wear is
not material dependent [15].
Hence, the same test set-up was used to
identify what actually influences the wear rate
[14, 16]. The surface morphology of the cathode
samples was changed by introducing slots.
By superimposing polished cross sections of
spent and virgin samples as depicted in Fig.
4b), we could directly visualise the worn area.
The results demonstrated the significant influence
of current density and of hydrodynamic
conditions. Increased speed of rotation increases
the mass transfer when the speed exceeds
the threshold where forced convection
dominates over natural convection. They also
showed that without polarisation there was no
indication of wear [16].
Thus our test cell cannot rank carbon cathode
materials under the presented standard
conditions, because the wear does not depend
on the type of material. Electric current is necessary
to initiate the aluminium carbide formation.
The test shows that a rotation speed of
50 rpm (equivalent to 8 cm/s, about the linear
speed of typical industrial metal pad and bath
movements) is too low to significantly increase
the dissolution rate of aluminium carbide. Increasing
the speed to 125 rpm (approx. 20 cm/
s in industry), however, significantly increased
the wear rate. Published data on similar test
cells stated that parameters like bath chemistry,
granulometry, current density, and physical
wear in general influence the wear rate [5,
14, 19, 25-26].
However, the question of why the industry
observes different wear rates for different
cathode qualities still remains. Usually,
the wear resistance of the cathode blocks is
ranked as follows: anthracitic > graphitic >
high density graphitised > graphitised. It is
to be noted that this ranking is made without
consideration of the conditions the different
materials are subjected to under operation.
Anthracitic materials normally operate with a
lower average current density and also with
a much more uniform current distribution, as
compared with graphitised cathode blocks.
a) b)
Fig. 4. Schematic drawing of the experimental set-up with a vertical rotating cathode (a). The dimension
of the graphite crucible (mm) is given in parentheses. 1 – Rotating cathode connecting rod, 2 – lid of
sintered alumina, 3 – thermocouple, 4 – Si 3 N 4 linings covering both ends, 5 a/b – cathode samples: two
surface morphologies: a) for ranking tests; b) for parameter studies, 6 – electrolyte, 7 – aluminium metal
(100 g), 8 – graphite crucible/anode, 9 – graphite support, 10 – anode lead. Subfigure (b) shows the sampling
position and preparation of worn cathode cross sections for both cathode types [13-16].
Our research has shown that the cathode
wear may not depend directly on the chemistry
of carbide formation and cathode quality
as such; rather, the wear rate is indirectly
affected, since the modern materials experience
higher current densities which enhance
the carbide formation and thus increase the
wear rate. In addition, higher rotation speeds
(physical wear component) above a threshold
speed promote mass transfer and dissolution
of aluminium carbide. This further increases
the wear rate by exposing more unreacted
cathode surface area to form aluminium carbide.
Therefore, industrial observations made
in cells operated under different conditions
might be misleading when compared to laboratory
tests, which are performed under standard
conditions [15].
Computational support
It needs to be pointed out that the reason for
the preferential wear along the periphery of
the cell is not well understood, and it seems
Fig. 5: Schematic representation of electrochemical formation and dissolution of aluminium carbide in a
pore [17, 18].
ALUMINIUM · 1-2/2013 97

PATENTE
obvious that more than one mechanism must
be involved. Solheim presented and discussed
three models concerning cathode wear [17].
Only one model, the so-called ‘carbon pump’-
hypothesis, provides a direct link between local
current densities at the cathode surface and
the wear rate [17, 18]. It is based on the assumption
that a solid aluminium carbide layer
covers the cathode surface during cell operation,
at least in spots or intermittently. This carbide
layer contains pores filled with electrolyte
which originates either from sludge or from a
bath film present between aluminium pad and
cathode. A possible pathway for the current is
then either through metal-filled areas/pores,
or more likely, around the carbide spots, leaving
a high local current density at the edges and
a smaller density above and below the centre
of the ‘islands’.
This current-shielding effect generates
a potential gradient along electrolyte-filled
pores, which might lead to electrochemical
crystallisation of Al 4 C 3 at the bottom of the
pore and dissolution of Al 4 C 3 at the top of the
pore. The scenario is sketched in Fig. 5 [18]
and can explain rapid wear leading to a W-
shaped cross-section of a used cathode. However,
other mechanisms exist that may increase
the wear rate; e.g. the metal flow velocity
and / or abrasion caused by the movement of
alumina particles. This has not yet been considered
in the modelling context described
here. More work is certainly needed to clarify
these issues. As a helpful tool, the commercial
FEM simulation software COMSOL Multiphysics
version 4.3 was used in the present
work in order to evaluate and support experimental
findings [14, 16, 18].
Conclusions
Laboratory tests indicate similar wear for all
tested carbon cathode grades under standardised
conditions, showing the independency on
the material type, but a strong effect of local
current density and metal flow velocity was
identified.
Acknowledgement
The present work was carried out in the competence-building
project ‘Durable Materials
in Primary Aluminium Production’ (KMB,
DuraMat), financed by the Research Council
of Norway, Hydro Primary Metal Technology,
Sør-Norge Aluminium, and Elkem Carbon.
The authors gratefully acknowledge permission
to publish the results.
References
[1] A. Tabereaux, JOM 52 (2000)2, pp. 23-29.
[2] H.A. Øye and B.J Welch, JOM 50(1998)2, pp.
18-23.
[3] E. Skybakmoen, S. Rørvik, A. Solheim, K. R.
Holm, P. Tiefenbach, and Ø. Østrem, Light Metals
2011, pp. 1061-1066.
[4] D. Lombard, T. Béhérégaray, B. Fève, and J. M.
Jolas, Light Metals 1998, pp. 653-658.
[5] M. Sørlie and H.A. Øye, Cathodes in Aluminum
Electrolysis, Düsseldorf, Germany: Aluminum Verlag,
2nd ed., 1994.
[6] M.A. Coulombe, M. Lebeuf, P. Chartrand, B. Allard
and G. Soucy, Light Metals 2010, pp. 811-816.
[7] R.C. Dorward, Met. Trans 4(1973), pp. 386-
388.
[8] P. Reny and S. Wilkening, Light Metals 2000,
pp. 399-404.
[9] J. Rødseth, B. Rasch, Ole Lund, and J. Thonstad,
Light Metals 2002, pp. 883-887.
[10] R. Ødegård, Å. Sterten, and J. Thonstad, Light
Metals 1987, pp. 295-302.
[11] B. Novak, K. Tschöpe, A.P. Ratvik and T.
Grande, Light Metals 2012, pp. 1343-1348.
[12] B. Novak, K. Tschöpe, A.P. Ratvik and T.
Grande, to be published in Light Metals 2013.
[13] K. Tschöpe, A. Støre, S. Rørvik, A. Solheim,
T. Grande, and A. P. Ratvik, Light Metals (COM)
2011, pp. 143-153
[14] K. Tschöpe, A. Støre, S. Rørvik, A. Solheim,
E. Skybakmoen, T. Grande, and A. P. Ratvik, Light
Metals 2012, pp. 1349-1354.
[15] K. Tschöpe, A. Støre, E. Skybakmoen, A. Solheim,
T. Grande, and A. P. Ratvik, to be published
in Light Metals 2013.
[16] K. Tschöpe, A. Støre, A. Solheim, E. Skybakmoen,
T. Grande and A.P. Ratvik, to be published
in JOM.
[17] A. Solheim, Loght Metals (COM ) 2011, pp.
135-142.
[18] A. Solheim and K. Tschöpe, to be published in
Light Metals 2013
[19] E. Skybakmoen, A. P. Ratvik, A. Solheim, S.
Rolseth, and H. Gudbrandsen, Light Metals 2007,
pp. 815-820.
[20] P. Rafiei, F. Hiltmann, M. Hyland, B. James, and
B. Welch, Light Metals 2001, pp. 747-752.
[21] P. Patel, M. Hyland, and F. Hiltmann, Light
Metals 2005, pp. 757-762.
[22] P. Patel, M. Hyland, and F. Hiltmann, Light
Metals 2006, pp. 633-638.
[23] Y. Sato, P. Patel, and P. Lavoie, Light Metals
2010, pp. 817-822.
[24] P. Patel. Y. Sato, and P. Lavoie, Light Metals
2011, pp. 1073-1078.
[25] K. Vasshaug, T. Foosnæs, G. M. Haarberg, A.
P. Ratvik, and E. Skybakmoen, Light Metals 2007,
pp. 821-826.
[26] K. Vasshaug, T. Foosnæs, G. M. Haarberg, A.
P. Ratvik, and E. Skybakmoen, Light Metals 2009,
pp. 1111-1115.
Authors
Dr. Kati Tschöpe is research scientist at the electrolysis
research team at SINTEF Materials and Chemistry
since 2012. She has been working on cathode
wear and degradation of bottom linings during her
PhD and Postdoc position at the Norwegian University
of Science and Technology (NTNU).
Egil Skybakmoen is research manager at the electrolysis
research team since 2004. He has 28 years
of experience within aluminium electrolysis and
his main fields of research have been fluoride bath
chemistry and lining materials.
Asbjørn Solheim, chief scientist, has conducted research
within aluminium electrolysis at SINTEF for
more than 30 years, particularly within bath chemistry
and modelling.
Dr. Tor Grande has been a professor at NTNU since
1997 and has a broad experience in materials science
and engineering with focus on both oxide and
none-oxide materials.
Patentblatt Oktober 2012
Fortsetzung aus ALUMINIUM 12/2012
Verfahren zum waagerechten Gießen und
Schneiden von Metallknüppeln. Novelis, Inc.,
Toronto, Ontario, CA. (B22D 11/126, EP 2 286
940, AT: 09.12.2004, EP-AT: 09.12.2004)
Gussaluminiumlegierung und Zylinderkopf
eines Verbrennungsmotors. Nippon Light Metal
Co. Ltd., Tokio, JP; Nissan Motor Co., Ltd., Yokohama-shi,
Kanagawa-ken, JP. (C22C 21/04, PS
60 2008 009 916, EP 2014780, AT: 04.07.2008,
EP-AT: 04.07.2008)
Verfahren zur Herstellung eines Titanschweißdrahtes.
Norsk Titanium Components AS, 0255
Oslo, NO. (C22C 14/00, EPA 2491155, WO
2011/049465, EP-AT: 21.10.2010, WO-AT:
21.10.2010)
Aluminiummaterial für eine Elektrode eines
elektrolytischen Kondensators, Verfahren zur
Herstellung von Elektrodenmaterial für einen
elektrolyt. Kondensator, Anodenmaterial für
einen elektrolyt. Aluminiumkondensator und
elektrolyt. Aluminiumkondensator. Showa
Denko K.K., Tokio, JP. (C22C 21/00, EP 1 841
892, WO 2006/068300, AT: 21.12.2005, EP-AT:
21.12.2005, WO-AT: 21.12.2005)
Aluminiumbandmaterial für lithographische
Druckplatten. Fujifilm Corp., Tokio, JP; Sumitomo
Light Metal Industries, Ltd., Tokio, JP. (C22B 9/02,
EP 2 284 288, AT: 24.07.2010, EP-AT: 24.07.2010)
Magnesiumlegierungsplatte und Verfahren
zur Herstellung derselben. Sumitomo Electric
Industries, Ltd., Osaka, JP. (B21B 3/00, PS 603 08
023, EP 1510265, WO 2003/103868, AT: 03.06.
2003, EP-AT: 03.06.2003, WO-AT: 03.06.2003)
Verfahren zum Druckgießen von gegliederten
Metallgussstücken. Trimet Aluminium AG,
45356 Essen, DE. (B22D 17/22, EP 2 008 740,
AT: 21.06.2008, EP-AT: 21.06.2008)
98 ALUMINIUM · 1-2/2013

PATENTE
Patentblatt November 2012
Feuerverzinkte Gussaluminiumlegierung mit
Al-Zn-Si-Mg-Re-Ti-Ni sowie Herstellungsverfahren
dafür. Jiangsu Linlong New Materials
Co., Ltd., Jiangsu 214183, CN. (C22C 21/02, EPA
2503017, WO 2011/079553, EP-AT: 31.03.2010,
WO-AT: 31.03.2010)
Zubereitung von Cu/Al-Katalysatoren. BASF
Catalysts LLC, Florham Park, N.J., US. (B01J23/
72, EP 0 888 185, WO 1997/034694, AT:
21.03.1997, EP-AT: 21.03.1997, WO-AT: 21.03.
1997)
Vorrichtung und Verfahren zur Entfernung
von Kaffeesatz aus speziellen Kaffeekapseln
aus Aluminium und zur Verkleinerung dieser
Kapseln. Franssen, Guy-Jacques-Marie, Spa, BE.
(A47J 31/06, PS 60 2008 010 418, EP 2146608,
WO 2008/139322, AT: 23.04.2008, EP-AT:
23.04.2008, WO-AT: 23.04.2008)
Vorrichtung zur Aufnahme von fester Debris
bei einer Elektrolysezelle zur Herstellung von
Aluminium. ECL, 59790 Ronchin, FR. (C25C
3/06, EPA 2510136, WO 2011/070245, EP-AT:
07.12.2010, WO-AT: 07.12.2010)
Alkaliresistenter Erdalkali-Aluminium-Wärmedämmstoff,
Verfahren zu seiner Herstellung
und seine Verwendung. Calsitherm Verwaltungs
Gmbh, 33175 Bad Lippspringe, DE. (C01F
7/16, EPA 2504280, WO 2011/063791, EP-AT:
24.11.2010, WO-AT: 24.11.2010)
Gelöteter Aluminium-Wärmeübertrager. Behr
GmbH & Co. KG, 70469 Stuttgart, DE. (F28F
19/06, EPA 2504656, WO 2011/064199, EP-AT:
23.11.2010, WO-AT: 23.11.2010)
Klebstoffe zum Verkleben von Polyurethan und
Aluminium. Hyundai Motor Co., Seoul, KR. (C09J
11/00, OS 10 2011 079 809, AT: 26.07.2011)
Verwendung einer Nickel-Chrom-Eisen-Aluminium-Legierung
mit guter Verarbeitbarkeit.
ThyssenKrupp VDM GmbH, 58791 Werdohl,
DE. (C22C 19/05, OS 10 2012 013 437, AT:
10.02.2012)
Aluminium-Kontrollarm und Verfahren zur
Herstellung desselben. Raufoss Technology
AS, Raufoss, NO. (B21D 11/00, OS 11 2005 002
470, WO 2006/046876, AT: 27.10.2005, WO-
AT: 27.10.2005)
Gefäß zur Speisenzubereitung aus Aluminium
oder Aluminiumguss mit Mengenskalierung
im Gefäßinneren. Elo-Stahlwaren Karl Grünewald
& Sohn GmbH & Co. KG, 55595 Spabrücken,
DE. (A47J 27/00, GM 20 2005 001 671,
AT: 03.02.2005)
Aluminium-Wärmetauscher. Willy Voit GmbH
& Co. KG Stanz- und Metallwerk, 66386 St. Ingbert,
DE. (F28F 9/02, GM 20 2006 013 389, AT:
31.08.2006)
Lager aus Aluminiumlegierung. Daido Metal
Co., Ltd., Nagoya, JP. (F16C 33/12, OS 10 2012
208 528, AT: 22.05.2012)
Verfahren zur Herstellung eines Aluminiumlötblechs.
Furukawa-Sky Aluminium Corp., Tokio,
JP. (B23K 35/28, PS 60 2006 025 498, EP
1795294, AT: 08.12.2006, EP-AT: 08.12.2006)
Erdbohrdrehbohrmeißel mit Meißelkörpern,
die Borkarbidteilchen in Aluminium oder Legierungsmatrixmaterialien
auf Aluminiumbasis
aufweisen sowie Verfahren zur Herstellung
derselben. Baker Hughes Inc., Houston, Tex., US.
(E21B10/42, PS 60 2007 018 509, EP 2079898,
WO 2008/042328, AT: 28.09.2007, EP-AT: 28.
09.2007, WO-AT: 28.09.2007)
Aluminiumlegierung für Druckguss und Herstellungsverfahren
für Gussstücke aus einer
Al-Legierung. Nippon Light Metal Co. Ltd., Tokio,
JP; Denso Corp., Kariya-city, Aichi-pref., JP.
(C22C 21/04, OS 10 2005 061 668, AT:
22.12.2005)
Wärmetauscher mit formschlüssig festgelegtem
Sammlerkasten. Mahle International
GmbH, 70376 Stuttgart, DE. (F28F 9/02, EPA
2507573, WO 2011/067247, EP-AT: 30.11.2010,
WO-AT: 30.11.2010)
Druckgusserzeugnis aus Aluminiumlegierung.
Aleris Aluminium Koblenz GmbH, 56070
Koblenz, DE. (22C 21/06, OS 601 26 529, EP
1138794, AT: 15.03.2001, EP-AT: 15.03.2001)
Vorrichtung zur Herstellung von Profilen oder
Blechformteilen aus Magnesium oder Magnesiumlegierungen.
TechMag AG, Baar, CH. (B21C
23/01, PS 101 56 034, AT: 15.11.2001)
System und Verfahren zum Herstellen von Mg-
Karosserieflächenelementen mit verbesserter
Korrosionsbeständigkeit. GM Global Technology
Operations LLC (n. d. Ges. d. Staates Delaware),
Detroit, Mich., US. (C21D 1/00, OS 10 2012 207
197, AT: 30.04.2012)
Legierungen der Serie 2000 mit Schadenstoleranzleistung
für Luft- und Raumfahrtanwendungen.
Alcoa Inc., Pittsburgh, Pa., US. (C22C
21/00, GM 20 2006 020 514, AT: 07.09.2006)
Verfahren zum Auswechseln einer verwendeten
Anode sowie Halter und System zur provisorischen
Aufbewahrung einer derartigen verwendeten
Anode. (C25C 3/06, EPA 2507413,
WO 2011/067477, EP-AT: 19.10.2010, WO-AT:
19.10.2010)
Sicherungsdrahtloser Verbindungsschutz mit
Drehschutz. Alcoa Inc., Pittsburgh, PA 15212-
5858, US. (F16L 19/00, EPA 2501975, WO
2011/062847, EP-AT: 12.11.2010, WO-AT:
12.11.2010)
Verbundprofil. Alcoa Aluminium Deutschland,
Inc., 58642 Iserlohn, DE. (E06B 3/263, GM 20
2006 021 120, AT: 08.12.2006)
Verfahren zur Herstellung eines Mg-Legierungsblechs
und Material für eine Mg-Legierungsspule.
Sumitomo Electric Industries, Ltd.,
Osaka 541-0041, JP. (B21B 3/00, EPA 2505274,
WO 2011/065248, EP-AT: 15.11.2010, WO-AT:
15.11.2010)
Vorrichtung zum Einpressen von Isolierstegen.
Alcoa Aluminium Deutschland, Inc., 58642 Iserlohn,
DE. (B23P 11/00, EP 2 366 489, AT:
15.03.2011, EP-AT: 15.03.2011)
Substrat mit einer Metallfolie zur Herstellung
von Photovoltaik-Zellen. Constellium Switzerland
AG, 8048 Zürich, CH. (H01L 31/039, EPA
2504862, WO 2011/063883, EP-AT: 02.11.
2010, WO-AT: 02.11.2010)
Verfahren zur Herstellung eines geformten
Karosseriebauteils für eine Fahrzeugkarosserie
aus einem Tailored Blank. Aleris Aluminium
Koblenz GmbH, 56070 Koblenz, DE; Audi AG,
85057 Ingolstadt, DE. (B62D 25/00, OS 10 2011
101 586, AT: 13.05.2011)
Verfahren zur Rückgewinnung von metallischem
beschichteten Schrott. Aleris Aluminium
Koblenz GmbH, 56070 Koblenz, DE. (C22B 21/
00, OS 602 24 657, EP 1386014, WO 2002/
101102, AT: 16.04.2002, EP-AT: 16.04.2002,
WO-AT: 16.04.2002)
Verfahren zur Herstellung einer Metallbandkante.
Hydro Aluminium Deutschland GmbH,
51149 Köln, DE. (B23P 9/00, PS 10 2009 026
235, AT: 23.07.2009)
Lamellenanordnung für Fassaden. Norsk Hydro
ASA, Oslo, NO. (E04F 10/08, PS 50 2007
008 323, EP 1816278, AT: 27.01.2007, EP-AT:
27.01.2007)
Schiebetür. Norsk Hydro ASA, Oslo, NO. (E06B
1/04, PS 60 2006 026 799, EP 1783312, AT:
31.10.2006, EP-AT: 31.10.2006)
Toleranzausgleichseinrichtung. WKW Erbslöh
Automotive GmbH, 42349 Wuppertal, DE. (B62
D 27/06, OS 10 2012 009 173, AT: 08.05.2012)
Aluminiumlegierung für Druckguss und Herstellungsverfahren
für Gussstücke aus einer Al-
Legierung. Nippon Light Metal Co. Ltd., Tokio,
JP; Denso Corp., Kariya-city, Aichi-pref., JP.
(C22C 21/04, OS 10 2005 061 668, AT: 22.12.
2005)
Fortsetzung in ALUMINIUM 3/2013
ALUMINIUM veröffentlicht unter dieser Rubrik
regelmäßig einen Überblick über wichtige,
den Werkstoff Aluminium betreffende Patente.
Die ausführlichen Patentblätter und auch
weiterführende Informationen dazu stehen
der Redaktion nicht zur Verfügung. Interessenten
können diese beziehen oder einsehen
bei der
Mitteldeutschen Informations-, Patent-,
Online-Service GmbH (mipo),
Julius-Ebeling-Str. 6,
D-06112 Halle an der Saale,
Tel. 0345/29398-0
Fax 0345/29398-40,
www.mipo.de
Die Gesellschaft bietet darüber hinaus weitere
Patent-Dienstleistungen an.
ALUMINIUM · 1-2/2013 99

LIEFERVERZEICHNIS
1
Smelting technology
Hüttentechnik
• Hydraulic presses for prebaked
anodes / Hydraulische Pressen zur
Herstellung von Anoden
1.1 Raw materials
Rohstoffe
1.2 Storage facilities for smelting
Lagermöglichkeiten in der Hütte
1.3 Anode production
Anodenherstellung
1.4 Anode rodding
Anodenschlägerei
1.4.1 Anode baking
Anodenbrennen
1.4.2 Anode clearing
Anodenschlägerei
1.2 Storage facilities for
smelting
Lagermöglichkeiten i.d. Hütte
FLSmidth MÖLLER GmbH
Haderslebener Straße 7
D-25421 Pinneberg
Telefon: 04101 788-0
Telefax: 04101 788-115
E-Mail: moeller@flsmidth.com
Internet: www.flsmidthmoeller.com
Kontakt: Herr Dipl.-Ing. Timo Letz
www.alu-web.de
• Bulk materials Handling
from Ship to Cell
Bulk materials Handling from Ship to Cell
www.coperion.com
mailto: info.cc-mh@coperion.com
1.4.3 Fixing of new anodes to the
anodes bars
Befestigen von neuen Anoden
an der Anodenstange
1.5 Casthouse (foundry)
Gießerei
1.6 Casting machines
Gießmaschinen
1.7 Current supply
Stromversorgung
1.8 Electrolysis cell (pot)
Elektrolyseofen
1.9 Potroom
Elektrolysehalle
1.10 Laboratory
Labor
1.11 Emptying the cathode shell
Ofenwannenentleeren
1.12 Cathode repair shop
Kathodenreparaturwerkstatt
1.13 Second-hand plant
Gebrauchtanlagen
1.14 Aluminium alloys
Aluminiumlegierungen
1.15 Storage and transport
Lager und Transport
1.16 Smelting manufactures
Hüttenerzeugnisse
• Unloading/Loading equipment
Entlade-/Beladeeinrichtungen
FLSmidth MÖLLER GmbH
www.flsmidthmoeller.com
see Storage facilities for smelting 1.2
ALUMINA AND PET COKE SHIPUNLOADERS
Contact: Andreas Haeuser, ha@neuero.de
1.3 Anode production
Anodenherstellung
Solios Carbone – France
www.fivesgroup.com
• Auto firing systems
Automatische Feuerungssysteme
LAEIS GmbH
Am Scheerleck 7, L-6868 Wecker, Luxembourg
Phone: +352 27612 0
Fax: +352 27612 109
E-Mail: info@laeis-gmbh.com
Internet: www.laeis-gmbh.com
Contact: Dr. Alfred Kaiser
• Anode Technology &
Mixing Equipment
Buss ChemTech AG, Switzerland
Phone: +4161 825 64 62
E-Mail: info@buss-ct.com
Internet: www.buss-ct.com
Hier könnte Ihr
Bezugsquellen-Eintrag stehen.
Rufen Sie an:
Tel. 0821 / 31 98 80-34
Dennis Ross
• Mixing Technology for
Anode pastes
Mischtechnologie für Anodenmassen
Buss AG
CH-4133 Pratteln
Phone: +41 61 825 66 00
E-Mail: info@busscorp.com
Internet: www.busscorp.com
1.4 Anode rodding
Anodenanschlägerei
• Removal of bath residues from
the surface of spent anodes
Entfernen der Badreste von der Ober -
fläche der verbrauchten Anoden
GLAMA Maschinenbau GmbH
Hornstraße 19
D-45964 Gladbeck
Telefon 02043 / 9738-0
Telefax 02043 / 9738-50
• Conveying systems bulk materials
Förderanlagen für Schüttgüter
(Hüttenaluminiumherstellung)
FLSmidth MÖLLER GmbH
Internet: www.flsmidthmoeller.com
see Storage facilities for smelting 1.2
RIEDHAMMER GmbH
D-90411 Nürnberg
Phone: +49 (0) 911 5218 0, Fax: -5218 231
E-Mail: thomas.janousch@riedhammer.de
Internet: www.riedhammer.de
• Rodding shop
www.brochot.fr
100

SUPPLIERS DIRECTORY
1.4.1 Anode baking
Anodenbrennen
• Open top and closed
type baking furnaces
Offene und geschlossene Ringöfen
RIEDHAMMER GmbH
D-90411 Nürnberg
Phone: +49 (0) 911 5218 0, Fax: -5218 231
E-Mail: thomas.janousch@riedhammer.de
Internet: www.riedhammer.de
Could not find your
„keywords“?
Please ask for our complete
„Supply sources for the
aluminium industry“.
E-Mail: anzeigen@giesel.de
1.5 Casthouse (foundry)
Gießerei
• Degassing, filtration and
grain refinement
Entgasung, Filtern, Kornfeinung
Drache Umwelttechnik
GmbH
Werner-v.-Siemens-Straße 9/24-26
D 65582 Diez/Lahn
Telefon 06432/607-0
Telefax 06432/607-52
Internet: www.drache-gmbh.de
Gautschi
Engineering GmbH
see Casting equipment 3.1
• Dross skimming of liquid metal
Abkrätzen des Flüssigmetalls
GLAMA Maschinenbau GmbH
see Anode rodding 1.4
• Furnace charging with
molten metal
Ofenbeschickung mit Flüssigmetall
GLAMA Maschinenbau GmbH
see Anode rodding 1.4
• Ingot Casting Line
• Metal treatment in the
holding furnace
Metallbehandlung in Halteöfen
Gautschi
Engineering GmbH
see Casting equipment 3.1
• Transfer to the casting furnace
Überführung in Gießofen
Gautschi
Engineering GmbH
see Casting equipment 3.1
GLAMA Maschinenbau GmbH
see Anode rodding 1.4
Drache Umwelttechnik
GmbH
Werner-v.-Siemens-Straße 9/24-26
D 65582 Diez/Lahn
Telefon 06432/607-0
Telefax 06432/607-52
Internet: www.drache-gmbh.de
• Transport of liquid metal
to the casthouse
Transport v. Flüssigmetall in Gießereien
GLAMA Maschinenbau GmbH
see Anode rodding 1.4
HERTWICH ENGINEERING GmbH
Maschinen und Industrieanlagen
Weinbergerstraße 6, A-5280 Braunau am Inn
Phone +437722/806-0
Fax +437722/806-122
E-Mail: info@hertwich.com
Internet: www.hertwich.com
INOTHERM INDUSTRIEOFEN-
UND WÄRMETECHNIK GMBH
Konstantinstraße 1a
D 41238 Mönchengladbach
Telefon +49 (02166) 987990
Telefax +49 (02166) 987996
E-Mail: info@inotherm-gmbh.de
Internet: www.inotherm-gmbh.de
see Equipment and accessories 3.1
Hampshire House, High Street, Kingswinford,
West Midlands DY6 8AW, UK
Tel.: +44 (0) 1384 279132
Fax: +44 (0) 1384 291211
E-Mail: sales@mechatherm.co.uk
www.mechatherm.com
Stopinc AG
Bösch 83 a
CH-6331 Hünenberg
Tel. +41/41-785 75 00
Fax +41/41-785 75 01
E-Mail: interstop@stopinc.ch
Internet: www.stopinc.ch
www.brochot.fr
• Melting/holding/casting furnaces
Schmelz-/Halte- und Gießöfen
Gautschi
Engineering GmbH
see Casting equipment 3.1
HERTWICH ENGINEERING GmbH
see Casthouse (foundry) 1.5
INSERTEC-INGENIERÍA Y SERVICIOS TÉCNICOS, S.A
Avenida Cervantes Nº6
48970 – Basauri – Bizkaia – Spain
Tel: +34 944 409 420
E-mail: Insertec@insertec.biz
Internet: www.insertec.biz
Sistem Teknik Endüstryel Firinlar LTD. STI.
TOSB – TAYSAD OSB 1.Cad. 14.Sok. No.: 3
Gebze, Kocaeli / Turkey
Tel.: +90 262 658 22 26
Fax: +90 262 658 22 38
E-Mail: info@sistemteknik.com
Internet: www.sistemteknik.com
Solios Thermal UK
www.fivesgroup.com
• Treatment of casthouse
off gases
Behandlung der Gießereiabgase
Gautschi
Engineering GmbH
see Casting equipment 3.1
1.6 Casting machines
Gießmaschinen
GAPCast
TM : the Swiss casting solution
see Casting machines and equipment 4.7
www.mechatherm.com
see Smelting technology 1.5
RIHS ENGINEERING SA
see Casting machines and equipment 4.7
• Pig casting machines (sow casters)
Masselgießmaschine (Sowcaster)
Gautschi
Engineering GmbH
see Casting equipment 3.1
101

LIEFERVERZEICHNIS
• Rolling and extrusion ingot
and T-bars
Formatgießerei (Walzbarren oder
Pressbolzen oder T-Barren)
Gautschi
Engineering GmbH
see Casting equipment 3.1
• Heat treatment of extrusion
ingot (homogenisation)
Formatebehandlung (homogenisieren)
Gautschi
Engineering GmbH
see Casting equipment 3.1
1.9 Potroom
Elektrolysehalle
T.T. Tomorrow Technology S.p.A.
Via dell’Artigianato 18
Due Carrare, Padova 35020, Italy
Telefon +39 049 912 8800
Telefax +39 049 912 8888
E-Mail: gmagarotto@tomorrowtechnology.it
Contact: Giovanni Magarotto
HERTWICH ENGINEERING GmbH
see Casthouse (foundry) 1.5
• Horizontal continuous casting
Horizontales Stranggießen
Gautschi
Engineering GmbH
see Casting equipment 3.1
HERTWICH ENGINEERING GmbH
see Casthouse (foundry) 1.5
• Scales / Waagen
Gautschi
Engineering GmbH
see Casting equipment 3.1
HERTWICH ENGINEERING GmbH
see Casthouse (foundry) 1.5
HERTWICH ENGINEERING GmbH
see Casthouse (foundry) 1.5
www.alu-web.de
• Vertical semi-continuous DC
casting / Vertikales Stranggießen
Gautschi
Engineering GmbH
see Casting equipment 3.1
Wagstaff, Inc.
3910 N. Flora Rd.
Spokane, WA 99216 USA
+1 509 922 1404 phone
+1 509 924 0241 fax
E-Mail: info@wagstaff.com
Internet: www.wagstaff.com
1.8 Electrolysis cell (pot)
Elektrolyseofen
• Bulk materials Handling
from Ship to Cell
Bulk materials Handling from Ship to Cell
• Anode changing machine
Anodenwechselmaschine
GLAMA Maschinenbau GmbH
see Anode rodding 1.4
• Anode transport equipment
Anoden Transporteinrichtungen
GLAMA Maschinenbau GmbH
see Anode rodding 1.4
• Crustbreakers / Krustenbrecher
GLAMA Maschinenbau GmbH
see Anode rodding 1.4
Could not find your
„keywords“?
Please ask for our complete
„Supply sources for the
aluminium industry“.
E-Mail: anzeigen@giesel.de
Hier könnte Ihr
Bezugsquellen-Eintrag stehen.
Rufen Sie an:
Tel. 0821 / 31 98 80-34
Dennis Ross
• Sawing / Sägen
Gautschi
Engineering GmbH
see Casting equipment 3.1
HERTWICH ENGINEERING GmbH
see Casthouse (foundry) 1.5
sermas@sermas.com
www.coperion.com
mailto: info.cc-mh@coperion.com
• Calcium silicate boards
Calciumsilikatplatten
Promat GmbH High Performance Insulation
Scheifenkamp 16, D-40878 Ratingen
Tel. +49 (0) 2102 / 493-0, Fax -493 115
verkauf3@promat.de, www.promat.de
• Exhaust gas treatment
Abgasbehandlung
Solios Environnement
www.fivesgroup.com
• Pot feeding systems
Beschickungseinrichtungen
für Elektrolysezellen
FLSmidth MÖLLER GmbH
www.flsmidthmoeller.com
see Storage facilities for smelting 1.2
• Dry absorption units for
electrolysis exhaust gases
Trockenabsorptionsanlage für
Elektrolyseofenabgase
Solios Environnement
www.fivesgroup.com
• Pot ramming Machine
www.brochot.fr
www.alu-web.de
• Tapping vehicles/Schöpffahrzeuge
GLAMA Maschinenbau GmbH
see Anode rodding 1.4
102

SUPPLIERS DIRECTORY
1.12 Cathode repair shop
Kathodenreparatur-
Werkstatt
• Cathode Sealing Bench
Eingießen von Kathodenbarren
Sermas Industrie
sermas@sermas.com
see Smelting technology 1.6
1.14 Aluminium Alloys
Aluminiumlegierungen
RHEINFELDEN ALLOYS GmbH & Co. KG
A member of ALUMINIUM RHEINFELDEN Group
Postfach 1703, 79607 Rheinfelden
Tel.: +49 7623 93-490
Fax: +49 7623 93-546
E-Mail: alloys@rheinfelden-alloys.eu
Internet: www.rheinfelden-alloys.eu
2
Extrusion
Strangpressen
2.1 Extrusion billet preparation
Pressbolzenbereitstellung
2.1.1 Extrusion billet production
Pressbolzenherstellung
2.2 Extrusion equipment
Strangpresseinrichtungen
2.3 Section handling
Profilhandling
2.1 Extrusion billet preparation
Pressbolzenbereitstellung
extrutec GmbH
Fritz-Reichle Ring 2
D-78315 Radolfzell
Tel. +49 7732 939 1390
Fax +49 7732 939 1399
E-Mail: info@extrutec-gmbh.de
Internet: www.extrutec-gmbh.de
1.15 Storage and transport
Lager und Transport
www.brochot.fr
SMS Siemag AG
see Rolling mill technology 3.0
Hier könnte Ihr
Bezugsquellen-Eintrag
stehen.
Rufen Sie an:
Tel. 0821 / 31 98 80-34
Dennis Ross
2.4 Heat treatment
Wärmebehandlung
2.5 Measurement and control
equipment
Mess- und Regeleinrichtungen
2.6 Die preparation and care
Werkzeugbereitstellung
und -pflege
2.7 Second-hand extrusion plant
Gebrauchte Strangpressanlagen
2.8 Consultancy, expert opinion
Beratung, Gutachten
2.9 Surface finishing of sections
Oberflächenveredlung
von Profilen
2.10 Machining of sections
Profilbearbeitung
2.11 Equipment and accessories
Ausrüstungen und Hilfsmittel
2.12 Services
Dienstleistungen
mfw-maschinenbau.com
Hier könnte Ihr
Bezugsquellen-Eintrag stehen.
Rufen Sie an:
Tel. 0821 / 31 98 80-34
Dennis Ross
• Billet heating furnaces
Öfen zur Bolzenerwärmung
INDUKTIONS-ANLAGEN + SERVICE GmbH & Co. KG
Am großen Teich 16+27
D-58640 Iserlohn
Tel. +49 (0) 2371 / 4346-0
Fax +49 (0) 2371 / 4346-43
E-Mail: verkauf@ias-gmbh.de
Internet: www.ias-gmbh.de
see Casthouse (foundry) 1.5
Could not find your
„keywords“?
Please ask for our complete
„Supply sources for the
aluminium industry“.
E-Mail: anzeigen@giesel.de
2.2 Extrusion equipment
Strangpresseinrichtungen
www.mechatherm.com
see Smelting technology 1.5
Oilgear Towler GmbH
Im Gotthelf 8
D 65795 Hattersheim
Tel. +49 (0) 6145 3770
Fax +49 (0) 6145 30770
E-Mail: info@oilgear.de
Internet: www.oilgear.de
www.alu-web.de
• Press control systems
Pressensteuersysteme
Oilgear Towler GmbH
see Extrusion Equipment 2.2
• Heating and control
equipment for intelligent
billet containers
Heizungs- und Kontrollausrüstung
für intelligente Blockaufnehmer
MARX GmbH & Co. KG
www.marx-gmbh.de
see Melt operations 4.13
103

LIEFERVERZEICHNIS
2.3 Section handling
Profilhandling
2.4 Heat treatment
Wärmebehandlung
CTI Systems S.A.
Z.I. Eselborn-Lentzweiler
12, op der Sang | L- 9779 Lentzweiler
Tel. +352 2685 2000 | Fax +352 2685 3000
cti@ctisystems.com | www.ctisystems.com
H+H HERRMANN + HIEBER GMBH
Rechbergstraße 46
D-73770 Denkendorf/Stuttgart
Tel. +49 711 93467-0, Fax +49 711 34609-11
E-Mail: info@herrmannhieber.de
Internet: www.herrmannhieber.de
Vollert Anlagenbau GmbH
Stadtseestraße 12, D-74189 Weinsberg
Tel. +49 7134 52 220 l Fax +49 7134 52 222
E-Mail intralogistik@vollert.de
Internet www.vollert.de
• Packaging equipment
Verpackungseinrichtungen
KASTO Maschinenbau GmbH & Co. KG
Industriestr. 14, D-77855 Achern
Tel.: +49 (0) 7841 61-0 / Fax: +49 (0) 7841 61 300
kasto@kasto.de / www.kasto.de
Hersteller von Band- und Kreissägemaschinen
sowie Langgut- und Blechlagersystemen
Nijverheidsweg 3
NL-7071 CH Ulft Netherlands
Tel.: +31 315 641352
Fax: +31 315 641852
E-Mail: info@unifour.nl
Internet: www.unifour.nl
Sales Contact: Paul Overmans
see Section handling 2.3
• Section transport equipment
Profiltransporteinrichtungen
• Stackers / Destackers
Stapler / Entstapler
BSN Thermprozesstechnik GmbH
Kammerbruchstraße 64
D-52152 Simmerath
Tel. 02473-9277-0 · Fax: 02473-9277-111
info@bsn-therm.de · www.bsn-therm.de
Ofenanlagen zum Wärmebehandeln von Aluminiumlegierungen,
Buntmetallen und Stählen
INSERTEC-INGENIERÍA Y SERVICIOS TÉCNICOS, S.A
Avenida Cervantes Nº6
48970 – Basauri – Bizkaia – Spain
Tel: +34 944 409 420
E-mail: Insertec@insertec.biz
Internet: www.insertec.biz
see Equipment and accessories 3.1
www.mechatherm.com
see Smelting technology 1.5
mfw-maschinenbau.com
• Section saws
Profilsägen
see Section handling 2.3
mfw-maschinenbau.com
• Section store equipment
Profil-Lagereinrichtungen
mfw-maschinenbau.com
• Transport equipment for
extruded sections
Transporteinrichtungen
für Profilabschnitte
www.ctisystems.com
see Section handling 2.3
mfw-maschinenbau.com
SECO/WARWICK EUROPE S.A.
ul. Šwierczewskiego 76
66-200 Šwiebodzin, POLAND
Tel: +48 68 38 19 800
E-mail: europe@secowarwick.com.pl
Internet: www.secowarwick.com
• Heat treatment furnaces
Wärmebehandlungsöfen
HOFMANN Wärmetechnik GmbH
Gewerbezeile 7
A - 4202 Helmonsödt
Tel. +43(0)7215/3601
E-Mail: office@hofmann-waermetechnik.at
Internet: www.hofmann-waermetechnik.at
INOTHERM INDUSTRIEOFEN-
UND WÄRMETECHNIK GMBH
see Casthouse (foundry) 1.5
• Homogenising furnaces
Homogenisieröfen
www.ctisystems.com
see Section handling 2.3
see Section handling 2.3
HERTWICH ENGINEERING GmbH
see Casthouse (foundry) 1.5
104

SUPPLIERS DIRECTORY
2.10 Machining of sections
Profilbearbeitung
• Billet saw
Bolzensägen
Sermas Industrie
sermas@sermas.com
see Smelting technology 1.6
• Ageing furnace for extrusions
Auslagerungsöfen für
Strangpressprofile
see Extrusion billet preparation 2.1
see Casthouse (foundry) 1.5
Hier könnte Ihr
Bezugsquellen-Eintrag
stehen.
Rufen Sie an:
Tel. 0821 / 31 98 80-34
Dennis Ross
2.11 Equipment and
accessories
Ausrüstungen und
Hilfsmittel
• Inductiv heating equipment
Induktiv beheizte
Erwärmungseinrichtungen
INDUKTIONS-ANLAGEN + SERVICE GmbH & Co. KG
Am großen Teich 16+27
D-58640 Iserlohn
Tel. +49 (0) 2371 / 4346-0
Fax +49 (0) 2371 / 4346-43
E-Mail: verkauf@ias-gmbh.de
Internet: www.ias-gmbh.de
see Casthouse (foundry) 1.5
Could not find your „keywords“?
Please ask for our complete
„Supply sources for the
aluminium industry“.
E-Mail: anzeigen@giesel.de
Nijverheidsweg 3
NL-7071 CH Ulft Netherlands
Tel.: +31 315 641352
Fax: +31 315 641852
E-Mail: info@unifour.nl
Internet: www.unifour.nl
Sales Contact: Paul Overmans
2.6 Die preparation and care
Werkzeugbereitstellung
und -pflege
• Die heating furnaces
Werkzeuganwärmöfen
schwartz GmbH
see Extrusion billet preparation 2.1
Nijverheidsweg 3
NL-7071 CH Ulft Netherlands
Tel.: +31 315 641352
Fax: +31 315 641852
E-Mail: info@unifour.nl
Internet: www.unifour.nl
Sales Contact: Paul Overmans
see Heat treatment 2.4
2.9 Surface finishing
of sections
Oberflächenveredlung
von Profilen
mfw-maschinenbau.com
3
Rolling mill technology
Walzwerktechnik
3.1 Casting equipment
Gießanlagen
3.2 Rolling bar machining
Walzbarrenbearbeitung
3.3 Rolling bar furnaces
Walzbarrenvorbereitung
3.4 Hot rolling equipment
Warmwalzanlagen
3.5 Strip casting units
and accessories
Bandgießanlagen
und Zubehör
3.6 Cold rolling equipment
Kaltwalzanlagen
3.0 Rolling mill technology
Walzwerktechnik
see Cold rolling units / complete plants 3.6
3.7 Thin strip / foil rolling plant
Feinband-/Folienwalzwerke
3.8 Auxiliary equipment
Nebeneinrichtungen
3.9 Adjustment devices
Adjustageeinrichtungen
3.10 Process technology /
Automation technology
Prozesstechnik /
Automatisierungstechnik
3.11 Coolant / lubricant preparation
Kühl-/Schmiermittel-Aufbereitung
3.12 Air extraction systems
Abluftsysteme
3.13 Fire extinguishing units
Feuerlöschanlagen
3.14 Storage and dispatch
Lagerung und Versand
3.15 Second-hand rolling equipment
Gebrauchtanlagen
3.16 Coil storage systems
Coil storage systems
3.17 Strip Processing Lines
Bandprozesslinien
3.18 Productions Management Sytems
Produktions Management Systeme
www.alu-web.de
105

LIEFERVERZEICHNIS
• Melting and holding furnaces
Schmelz- und Warmhalteöfen
• Annealing furnaces
Glühöfen
SMS Siemag Aktiengesellschaft
Eduard-Schloemann-Straße 4
40237 Düsseldorf, Germany
Telefon: +49 (0) 211 881-0
Telefax: +49 (0) 211 881-4902
E-Mail: communications@sms-siemag.com
Internet: www.sms-siemag.com
Geschäftsbereiche:
Warmflach- und Kaltwalzwerke
Wiesenstraße 30
57271 Hilchenbach-Dahlbruch, Germany
Telefon: +49 (0) 2733 29-0
Telefax: +49 (0) 2733 29-2852
Bandanlagen
Walder Straße 51-53
40724 Hilden, Germany
Telefon: +49 (0) 211 881-5100
Telefax: +49 (0) 211 881-5200
Elektrik + Automation
Ivo-Beucker-Straße 43
40237 Düsseldorf, Germany
Telefon: +49 (0) 211 881-5895
Telefax: +49 (0) 211 881-775895
Graf-Recke-Straße 82
40239 Düsseldorf, Germany
Telefon: +49 (0) 211 881-0
Telefax: +49 (0) 211 881-4902
3.1 Casting equipment
Gießanlagen
INSERTEC-INGENIERÍA Y SERVICIOS TÉCNICOS, S.A
Avenida Cervantes Nº6
48970 – Basauri – Bizkaia – Spain
Tel: +34 944 409 420
E-mail: Insertec@insertec.biz
Internet: www.insertec.biz
www.mechatherm.com
see Smelting technology 1.5
• Electromagnetic Stirrer
Elektromagnetische Rührer
Solios Thermal UK
www.fivesgroup.com
www.alu-web.de
• Filling level indicators and controls
Füllstandsanzeiger und -regler
Gautschi
Engineering GmbH
see Casting equipment 3.1
Wagstaff, Inc.
see Casting machines 1.6
Gautschi Engineering GmbH
Konstanzer Straße 37
CH 8274 Tägerwilen
Telefon +41 71 666 66 66
Telefax +41 71 666 66 77
E-Mail: info@gautschi.cc
Internet: www.gautschi.cc
Kontakt: Sales Departement
LOI Thermprocess GmbH
Am Lichtbogen 29
D-45141 Essen
Germany
Telefon +49 (0) 201 / 18 91-1
Telefax +49 (0) 201 / 18 91-321
E-Mail: info@loi-italimpianti.de
Internet: www.loi-italimpianti.com
Solios Thermal UK
www.fivesgroup.com
• Melt purification units
Schmelzereinigungsanlagen
Gautschi
Engineering GmbH
see Casting equipment 3.1
• Metal filters / Metallfilter
Gautschi
Engineering GmbH
see Casting equipment 3.1
www.alu-web.de
3.2 Rolling bar machining
Walzenbarrenbearbeitung
• Plate saw
Plattensägen
Sermas Industrie
sermas@sermas.com
see Smelting technology 1.6
• Slab saw
Barrensägen
Sermas Industrie
sermas@sermas.com
see Smelting technology 1.6
3.3 Rolling bar furnaces
Walzbarrenvorbereitung
BSN Thermprozesstechnik GmbH
see Heat Treatment 2.4
EBNER Industrieofenbau Ges.m.b.H.
Ebner-Platz 1, 4060 Leonding/Austria
Tel. +43 / 732 / 6868-0
E-Mail: sales@ebner.cc
Internet: www.ebner.cc
Gautschi
Engineering GmbH
see Casting equipment 3.1
schwartz GmbH
see Equipment and accessories 3.1
Solios Thermal UK
www.fivesgroup.com
• Bar heating furnaces
Barrenanwärmanlagen
see Heat treatment 2.4
EBNER Industrieofenbau Ges.m.b.H.
see Annealing furnaces 3.3
Gautschi
Engineering GmbH
see Casting equipment 3.1
• Homogenising furnaces
Homogenisieröfen
Gautschi
Engineering GmbH
see Casting equipment 3.1
HERTWICH ENGINEERING GmbH
see Casthouse (foundry) 1.5
schwartz GmbH
Solios Thermal UK
www.fivesgroup.com
see Heat treatment 2.4
www.alu-web.de
• Roller tracks
Rollengänge
Gautschi
Engineering GmbH
see Casting equipment 3.1
106

SUPPLIERS DIRECTORY
3.4 Hot rolling equipment
Warmwalzanlagen
• Hot rolling units /
complete plants
Warmwalzanlagen/Komplettanlagen
see Section handling 2.3
Achenbach Buschhütten GmbH & Co. KG
Siegener Str. 152, D-57223 Kreuztal
Tel. +49 (0) 2732/7990, info@achenbach.de
Internet: www.achenbach.de
see Cold rolling units / complete plants 3.6
• Coil transport systems
Bundtransportsysteme
www.ctisystems.com
see Section handling 2.3
see Section handling 2.3
Hier könnte Ihr
Bezugsquellen-Eintrag
stehen.
Rufen Sie an:
Tel. 0821 / 31 98 80-34
Dennis Ross
MINO S.p.A.
Via Torino, 1 – San Michele
15122 ALESSANDRIA – ITALY
Telefon: +39 0131 363636
Telefax: +39 0 131 3 61611
E-Mail: sales@mino.it
Internet: www.mino.it
Sales contact: Mr. Luciano Ceccopieri
SMS Siemag AG
see Rolling mill technology 3.0
3.6 Cold rolling equipment
Kaltwalzanlagen
Achenbach Buschhütten GmbH & Co. KG
Siegener Str. 152, D-57223 Kreuztal
Tel. +49 (0) 2732/7990, info@achenbach.de
Internet: www.achenbach.de
BSN Thermprozesstechnik GmbH
see Heat Treatment 2.4
• Coil annealing furnaces
Bundglühöfen
Gautschi
Engineering GmbH
see Casting equipment 3.1
• Cold rolling units /
complete plants
Kaltwalzanlagen/Komplettanlagen
MINO S.p.A.
Via Torino, 1 – San Michele
15122 ALESSANDRIA – ITALY
Telefon: +39 0131 363636
Telefax: +39 0 131 3 61611
E-Mail: sales@mino.it
Internet: www.mino.it
Sales contact: Mr. Luciano Ceccopieri
SMS Siemag AG
see Rolling mill technology 3.0
www.alu-web.de
• Drive systems / Antriebe
SMS Siemag AG
see Rolling mill technology 3.0
• Drive systems / Antriebe
SMS Siemag AG
see Rolling mill technology 3.0
• Rolling mill modernisation
Walzwerksmodernisierung
see Equipment and accessories 3.1
schwartz GmbH
see Heat treatment 2.4
www.alu-web.de
• Heating furnaces / Anwärmöfen
Gautschi
Engineering GmbH
see Casting equipment 3.1
• Process optimisation systems
Prozessoptimierungssysteme
Gautschi
Engineering GmbH
see Casting equipment 3.1
MINO S.p.A.
Via Torino, 1 – San Michele
15122 ALESSANDRIA – ITALY
Telefon: +39 0131 363636
Telefax: +39 0 131 3 61611
E-Mail: sales@mino.it
Internet: www.mino.it
Sales contact: Mr. Luciano Ceccopieri
SMS Siemag AG
see Rolling mill technology 3.0
• Spools / Haspel
SMS Siemag AG
see Rolling mill technology 3.0
• Coil transport systems
Bundtransportsysteme
www.ctisystems.com
see Section handling 2.3
H+H HERRMANN + HIEBER GMBH
Rechbergstraße 46
D-73770 Denkendorf/Stuttgart
Tel. +49 711 93467-0, Fax +49 711 34609-11
E-Mail: info@herrmannhieber.de
Internet: www.herrmannhieber.de
• Process simulation
Prozesssimulation
Gautschi
Engineering GmbH
see Casting equipment 3.1
SMS Siemag AG
see Rolling mill technology 3.0
• Roll exchange equipment
Walzenwechseleinrichtungen
SMS Siemag AG
see Rolling mill technology 3.0
107

LIEFERVERZEICHNIS
• Rolling mill modernization
Walzwerkmodernisierung
3.7 Thin strip /
foil rolling plant
Feinband-/Folienwalzwerke
• Rolling mill modernization
Walzwerkmodernisierung
Achenbach Buschhütten GmbH & Co. KG
Siegener Str. 152, D-57223 Kreuztal
Tel. +49 (0) 2732/7990, info@achenbach.de
Internet: www.achenbach.de
see Cold rolling units / complete plants 3.6
MINO S.p.A.
Via Torino, 1 – San Michele
15122 ALESSANDRIA – ITALY
Telefon: +39 0131 363636
Telefax: +39 0 131 3 61611
E-Mail: sales@mino.it
Internet: www.mino.it
Sales contact: Mr. Luciano Ceccopieri
• Slitting lines-CTL
Längs- und Querteilanlagen
see Cold rolling units / complete plants 3.6
• Strip shears/Bandscheren
see Cold rolling units / complete plants 3.6
SMS Siemag AG
see Rolling mill technology 3.0
• Trimming equipment
Besäumeinrichtungen
see Cold rolling units / complete plants 3.6
SMS Siemag AG
see Rolling mill technology 3.0
Hier könnte Ihr
Bezugs-
quellen-
Eintrag
stehen.
Rufen Sie an:
Tel. 0821 / 31 98 80-34
Dennis Ross
Achenbach Buschhütten GmbH & Co. KG
Siegener Str. 152, D-57223 Kreuztal
Tel. +49 (0) 2732/7990, info@achenbach.de
Internet: www.achenbach.de
see Cold rolling units / complete plants 3.6
• Coil annealing furnaces
Bundglühöfen
Gautschi
Engineering GmbH
see Casting equipment 3.1
see Equipment and accessories 3.1
schwartz GmbH
see Cold colling equipment 3.6
www.alu-web.de
• Heating furnaces
Anwärmöfen
Gautschi
Engineering GmbH
see Casting equipment 3.1
INOTHERM INDUSTRIEOFEN-
UND WÄRMETECHNIK GMBH
see Casthouse (foundry) 1.5
schwartz GmbH
see Heat treatment 2.4
• Thin strip / foil rolling mills /
complete plant
Feinband- / Folienwalzwerke /
Komplettanlagen
MINO S.p.A.
Via Torino, 1 – San Michele
15122 ALESSANDRIA – ITALY
Telefon: +39 0131 363636
Telefax: +39 0 131 3 61611
E-Mail: sales@mino.it
Internet: www.mino.it
Sales contact: Mr. Luciano Ceccopieri
SMS Siemag AG
see Rolling mill technology 3.0
Achenbach Buschhütten GmbH & Co. KG
Siegener Str. 152, D-57223 Kreuztal
Tel. +49 (0) 2732/7990, info@achenbach.de
Internet: www.achenbach.de
MINO S.p.A.
Via Torino, 1 – San Michele
15122 ALESSANDRIA – ITALY
Telefon: +39 0131 363636
Telefax: +39 0 131 3 61611
E-Mail: sales@mino.it
Internet: www.mino.it
Sales contact: Mr. Luciano Ceccopieri
3.10 Process technology /
Automation technology
Prozesstechnik /
Automatisierungstechnik
• Process control technology
Prozessleittechnik
SMS Siemag AG
see Rolling mill technology 3.0
Wagstaff, Inc.
see Casting machines 1.6
www.alu-web.de
• Strip flatness measurement
and control equipment
Bandplanheitsmess- und
-regeleinrichtungen
ABB Automation
Force Measurement
S-72159 Västeras, Sweden
Phone: +46 21 325 000
Fax: +46 21 340 005
E-Mail: pressductor@se.abb.com
Internet: www.abb.com/pressductor
Achenbach Buschhütten GmbH & Co. KG
Siegener Str. 152, D-57223 Kreuztal
Tel. +49 (0) 2732/7990, info@achenbach.de
Internet: www.achenbach.de
SMS Siemag AG
see Rolling mill technology 3.0
108

SUPPLIERS DIRECTORY
• Strip thickness measurement
and control equipment
Banddickenmess- und
-regeleinrichtungen
• Strip Width & Position
Measurement equipment
Bandbreiten- und
Bandlaufmesseinrichtungen
• Exhaust air purification
systems (active)
Abluft-Reinigungssysteme (aktiv)
ABB Automation
Force Measurement
S-72159 Västeras, Sweden
Phone: +46 21 325 000
Fax: +46 21 340 005
E-Mail: pressductor@se.abb.com
Internet: www.abb.com/pressductor
Achenbach Buschhütten GmbH & Co. KG
Siegener Str. 152, D-57223 Kreuztal
Tel. +49 (0) 2732/7990, info@achenbach.de
Internet: www.achenbach.de
SMS Siemag AG
see Rolling mill technology 3.0
Could not find your
„keywords“?
Please ask for our complete
„Supply sources for the
aluminium industry“.
E-Mail: anzeigen@giesel.de
• Strip Tension
Measurement equipment
Bandzugmesseinrichtungen
ABB Automation
Force Measurement
S-72159 Västeras, Sweden
Phone: +46 21 325 000
Fax: +46 21 340 005
E-Mail: pressductor@se.abb.com
Internet: www.abb.com/pressductor
3.11 Coolant / lubricant
preparation
Kühl-/Schmiermittel-
Aufbereitung
see Cold rolling units / complete plants 3.6
• Rolling oil recovery and
treatment units
Walzöl-Wiederaufbereitungsanlagen
SMS Siemag AG
see Rolling mill technology 3.0
• Filter for rolling oils and emulsions
Filter für Walzöle und Emulsionen
Achenbach Buschhütten GmbH & Co. KG
Siegener Str. 152, D-57223 Kreuztal
Tel. +49 (0) 2732/7990, info@achenbach.de
Internet: www.achenbach.de
Achenbach Buschhütten GmbH & Co. KG
Siegener Str. 152, D-57223 Kreuztal
Tel. +49 (0) 2732/7990, info@achenbach.de
Internet: www.achenbach.de
SMS Siemag AG
see Rolling mill technology 3.0
3.14 Storage and dispatch
Lagerung und Versand
SMS Siemag AG
see Rolling mill technology 3.0
3.16 Coil storage systems
Bundlagersysteme
www.ctisystems.com
see Section handling 2.3
H+H HERRMANN + HIEBER GMBH
Rechbergstraße 46
D-73770 Denkendorf/Stuttgart
Tel. +49 711 93467-0, Fax +49 711 34609-11
E-Mail: info@herrmannhieber.de
Internet: www.herrmannhieber.de
SMS Siemag AG
see Rolling mill technology 3.0
ABB Automation
Force Measurement
S-72159 Västeras, Sweden
Phone: +46 21 325 000
Fax: +46 21 340 005
E-Mail: pressductor@se.abb.com
Internet: www.abb.com/pressductor
www.alu-web.de
• Rolling oil rectification units
Walzölrektifikationsanlagen
see Section handling 2.3
3.17 Strip Processing Lines
Bandprozesslinien
• Roll Force Measurement equipment
Walzkraftmesseinrichtungen
ABB Automation
Force Measurement
S-72159 Västeras, Sweden
Phone: +46 21 325 000
Fax: +46 21 340 005
E-Mail: pressductor@se.abb.com
Internet: www.abb.com/pressductor
Achenbach Buschhütten GmbH & Co. KG
Siegener Str. 152, D-57223 Kreuztal
Tel. +49 (0) 2732/7990, info@achenbach.de
Internet: www.achenbach.de
SMS Siemag AG
see Rolling mill technology 3.0
3.12 Air extraction systems
Abluft-Systeme
see Cold rolling units / complete plants 3.6
REDEX
Zone Industrielle
F-45210 Ferrieres
Telefon +33 (2) 38 94 42 00
E-mail: info@redex-group.com
Internet: www.tension-leveling.com
• Anodizing Lines
Anodisier-Linien
SMS Siemag AG
see Rolling mill technology 3.0
109

LIEFERVERZEICHNIS
• Colour Coating Lines
Bandlackierlinien
www.bwg-online.com
see Strip Processing Lines 3.17
SMS Siemag AG
see Rolling mill technology 3.0
• Lithographic Sheet Lines
Lithografielinien
www.bwg-online.com
see Strip Processing Lines 3.17
see Cold rolling units / complete plants 3.6
• Stretch Levelling Lines
Streckrichtanlagen
www.bwg-online.com
see Strip Processing Lines 3.17
• Strip Annealing Lines
Bandglühlinien
www.bwg-online.com
see Strip Processing Lines 3.17
SMS Siemag AG
see Rolling mill technology 3.0
• Strip Processing Lines
Bandprozesslinien
BWG Bergwerk- und Walzwerk-
Maschinenbau GmbH
Mercatorstraße 74 – 78
D-47051 Duisburg
Tel.: +49 (0) 203-9929-0
Fax: +49 (0) 203-9929-400
E-Mail: bwg@bwg-online.de
Internet: www.bwg-online.com
3.18 Production
Management systems
Produktions Management
Systeme
PSI Metals Non Ferrous GmbH
Software Excellence in Metals
Carlo-Schmid-Str. 12, D-52146 Würselen
Tel.: +49 (0) 2405 4135-0
info@psimetals.de, www.psimetals.com
4 Foundry
Gießerei
4.1 Work protection and ergonomics
Arbeitsschutz und Ergonomie
4.2 Heat-resistant technology
Feuerfesttechnik
4.3 Conveyor and storage technology
Förder- und Lagertechnik
4.4 Mould and core production
Form- und Kernherstellung
4.5 Mould accessories and accessory
materials
Formzubehör, Hilfsmittel
4.2 Heat-resistent technology
Feuerfesttechnik
• Refractories / Feuerfeststoffe
Calderys Deutschland GmbH
In der Sohl 122
56564 Neuwied
E-mail: germany@calderys.com
Internet: www.calderys.de
INSERTEC-INGENIERÍA Y SERVICIOS TÉCNICOS, S.A
Avenida Cervantes Nº6
48970 – Basauri – Bizkaia – Spain
Tel: +34 944 409 420
E-mail: Insertec@insertec.biz
Internet: www.insertec.biz
Promat GmbH High Performance Insulation
Scheifenkamp 16, D-40878 Ratingen
Tel. +49 (0) 2102 / 493-0, Fax -493 115
verkauf3@promat.de, www.promat.de
www.alu-web.de
4.6 Foundry equipment
Gießereianlagen
4.7 Casting machines and equipment
Gießmaschinen
und Gießeinrichtungen
4.8 Handling technology
Handhabungstechnik
4.9 Construction and design
Konstruktion und Design
4.10 Measurement technology
and materials testing
Messtechnik und Materialprüfung
4.11 Metallic charge materials
Metallische Einsatzstoffe
4.12 Finishing of raw castings
Rohgussnachbehandlung
4.13 Melt operations
Schmelzbetrieb
4.14 Melt preparation
Schmelzvorbereitung
4.15 Melt treatment devices
Schmelzebehandlungseinrichtungen
4.16 Control and regulation technology
Steuerungs- und
Regelungstechnik
4.17 Environment protection
and disposal
Umweltschutz und Entsorgung
4.18 Dross recovery
Schlackenrückgewinnung
4.19 Cast parts
Gussteile
Refratechnik Steel GmbH
Schiessstrasse 58
40549 Düsseldorf / Germany
Phone +49 211 5858 0
Fax +49 211 5858 46
Internet: www.refra.com
4.3 Conveyor and storage
technology
Förder- und Lagertechnik
www.ctisystems.com
see Section handling 2.3
H+H HERRMANN + HIEBER GMBH
Rechbergstraße 46
D-73770 Denkendorf/Stuttgart
Tel. +49 711 93467-0, Fax +49 711 34609-11
E-Mail: info@herrmannhieber.de
Internet: www.herrmannhieber.de
110

SUPPLIERS DIRECTORY
• Fluxes
Flussmittel
see Section handling 2.3
4.5 Mold accessories and
accessory materials
Formzubehör, Hilfmittel
Solvay Fluor GmbH
Hans-Böckler-Allee 20
D-30173 Hannover
Telefon +49 (0) 511 / 857-0
Telefax +49 (0) 511 / 857-2146
Internet: www.solvay-fluor.de
4.7 Casting machines
and equipment
Gießereimaschinen
und Gießeinrichtungen
GAPCast
TM : the Swiss casting solution
Casting Technology / Automation
Tel.: +41 27 455 57 14
E-Mail: info@gap-engineering.ch
Internet: www.gap-engineering.ch
www.mechatherm.com
see Smelting technology 1.5
• Mould parting agents
Kokillentrennmittel
Schröder KG
Schmierstofftechnik
Postfach 1170
D-57251
Freudenberg
Tel. 02734/7071
Fax 02734/20784
www.schroeder-schmierstoffe.de
4.8 Handling technology
Handhabungstechnik
Hier könnte Ihr
Bezugsquellen-Eintrag
stehen.
Rufen Sie an:
Tel. 0821 / 31 98 80-34
Dennis Ross
4.6 Foundry equipment
Gießereianlagen
www.mechatherm.com
see Smelting technology 1.5
• Casting machines
Gießmaschinen
HERTWICH ENGINEERING GmbH
see Casthouse (foundry) 1.5
see Equipment and accessories 3.1
• Heat treatment furnaces
Wärmebehandlungsöfen
HOFMANN Wärmetechnik GmbH
Gewerbezeile 7
A - 4202 Helmonsödt
Tel. +43(0)7215/3601
E-Mail: office@hofmann-waermetechnik.at
Internet: www.hofmann-waermetechnik.at
see Casthouse (foundry) 1.5
Precimeter Control AB
Ostra Hamnen 7
SE-475 42 Hono / Sweden
Tel.: +46 31 764 5520, Fax: +46 31 764 5529
E-Mail: marketing@precimeter.com
Internet: www.precimeter.com
Sales contact: Jonatan Lindstrand
Competence in EMC and ASC casting
RIHS ENGINEERING SA
Tel.: +41 27 455 54 41
E-Mail: info@maschko.ch
Internet: www.maschko.ch
Wagstaff, Inc.
see Casting machines 1.6
Could not find your
„keywords“?
Please ask for our complete
„Supply sources for the
aluminium industry“.
E-Mail: anzeigen@giesel.de
• Continuous ingot casting
lines and aluminium rod lines
Kokillengieß- und Aluminiumdraht-Anlagen
Via Emilia Km 310
26858 Sordio-LO
Italy
Tel. +39.02.988492-1 . hq@properzi.it
Fax +39.02.9810358 . www.properzi.com
www.ctisystems.com
see Section handling 2.3
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diesem Format kostet
pro Ausgabe + Stichwort
110,00 € + MwSt.
Weitere Informationen unter
Tel. +49 (0) 821 / 31 98 80 - 0
4.10 Measurement technology
and materials testin
Messtechnik und
Materialprüfung
ratioTEC Prüfsysteme GmbH
In der Au 17
D-88515 Langenenslingen
Tel.: +49 (0)7376/9622-0
Fax: +49 (0)7376/9622-22
E-Mail: info@ratiotec.com
Internet: www.ratiotec.com
www.alu-web.de
4.11 Metallic charge
materials
Metallische Einsatzstoffe
• Recycling / Recycling
Chr. Otto Pape GmbH
Aluminiumgranulate
Berliner Allee 34
D-30855 Langenhagen
Tel:+49(0)511 786 32-0 Fax: -32
Internet: www.papemetals.com
E-Mail: info@papemetals.com
111

LIEFERVERZEICHNIS
4.13 Melt operations
Schmelzbetrieb
www.mechatherm.com
see Smelting technology 1.5
• Burner System
Brennertechnik
Büttgenbachstraße 14
D-40549 Düsseldorf/Germany
Tel.: +49 (0) 211 / 5 00 91-0
Fax: +49 (0) 211 / 5 00 91-14
E-Mail: info@bloomeng.de
Internet: www.bloomeng.de
see Extrusion 2.4.
Hier könnte Ihr
Bezugsquellen-Eintrag
stehen.
Rufen Sie an:
Tel. 0821 / 31 98 80-34
Dennis Ross
• Heat treatment furnaces
Wärmebehandlungsanlagen
Gautschi
Engineering GmbH
see Casting equipment 3.1
HERTWICH ENGINEERING GmbH
see Casthouse (foundry) 1.5
see Equipment and accessories 3.1
• Holding furnaces
Warmhalteöfen
Gautschi
Engineering GmbH
see Casting equipment 3.1
see Equipment and accessories 3.1
• Melting furnaces
Schmelzöfen
Gautschi
Engineering GmbH
see Casting equipment 3.1
HERTWICH ENGINEERING GmbH
see Casthouse (foundry) 1.5
see Equipment and accessories 3.1
MARX GmbH & Co. KG
Lilienthalstr. 6-18
D-58638 Iserhohn
Tel.: +49 (0) 2371 / 2105-0, Fax: -11
E-Mail: info@marx-gmbh.de
Internet: www.marx-gmbh.de
4.14 Melt preparation
Schmelzvorbereitung
• Degassing, filtration
Entgasung, Filtration
Drache Umwelttechnik
GmbH
Werner-v.-Siemens-Straße 9/24-26
D 65582 Diez/Lahn
Telefon 06432/607-0
Telefax 06432/607-52
Internet: http://www.drache-gmbh.de
4.15 Melt treatment devices
Schmelzbehandlungseinrichtungen
Metaullics Systems Europe B.V.
Ebweg 14
NL-2991 LT Barendrecht
Tel. +31-180/590890
Fax +31-180/551040
E-Mail: info@metaullics.nl
Internet: www.metaullics.com
4.17 Environment protection
and disposal
Umweltschutz und
Entsorgung
• Dust removal
Entstaubung
NEOTECHNIK GmbH
Entstaubungsanlagen
Postfach 110261, D-33662 Bielefeld
Tel. 05205/7503-0, Fax 05205/7503-77
info@neotechnik.com, www.neotechnik.com
4.18 Dross recovery
Schlackenrückgewinnung
ALTEK EUROPE LTD
Lakeside House, Burley Close
Chesterfield, Derbyshire. S40 2UB
UNITED KINGDOM
Tel: UK: +44 (0)1246 383737
Tel: USA: +1 484 713 0070
Internet: www.altek-al.com
5 Materials
and
Recycling
Werkstoffe
und Recycling
• Granulated aluminium
Aluminiumgranulate
Chr. Otto Pape GmbH
Aluminiumgranulate
Berliner Allee 34
D-30855 Langenhagen
Tel:+49(0)511 786 32-0 Fax: -32
Internet: www.papemetals.com
E-Mail: info@papemetals.com
6 Machining +
Application
Bearbeitung +
Anwendung
6.1 Equipment to produce
castplate
Ausrüstungen für
Gussplattenproduktion
• Slicing saw & Milling machines
Folienschneidmaschinen
Fräsmaschinen
Sermas Industrie
sermas@sermas.com
see Smelting technology 1.6
6.2 Semi products
Halbzeuge
• Wires / Drähte
DRAHTWERK ELISENTAL
W. Erdmann GmbH & Co.
Werdohler Str. 40, D-58809 Neuenrade
Postfach 12 60, D-58804 Neuenrade
Tel. +49(0)2392/697-0, Fax 49(0)2392/62044
E-Mail: info@elisental.de
Internet: www.elisental.de
112

SUPPLIERS DIRECTORY
6.3 Equipment for forging
and impact extrusion
Ausrüstung für Schmiedeund
Fließpresstechnik
• Hydraulic Presses
Hydraulische Pressen
LASCO Umformtechnik GmbH
Hahnweg 139, D-96450 Coburg
Tel. +49 (0) 9561 642-0
Fax +49 (0) 9561 642-333
E-Mail: lasco@lasco.de
Internet: www.lasco.com
www.alu-web.de
8 Literature
Literatur
• Technical literature
Fachliteratur
Taschenbuch des Metallhandels
Fundamentals of Extrusion Technology
Giesel Verlag GmbH
Hans-Böckler-Allee 9, 30173 Hannover
Tel. 0511 / 73 04-125 · Fax 0511 / 73 04-233
Internet: www.alu-bookshop.de
Could not find your „keywords“?
Please ask for our complete
„Supply sources for the
aluminium industry“.
E-Mail: anzeigen@giesel.de
• Technical journals
Fachzeitschriften
Giesel Verlag GmbH
Hans-Böckler-Allee 9, 30173 Hannover
Tel. 0511/8550-2638 · Fax 0511/8550-2405
GDMB-Informationsgesellschaft mbH
Paul-Ernst-Str.10, 38678 Clausthal-Zellerfeld
Telefon 05323-937 20, Fax -237, www.gdmb.de
International
ALUMINIUM
Journal
89. Jahrgang 1.1.2013
Verlag / Publishing house
Giesel Verlag GmbH
Post fach 5420, 30054 Hannover
Hans-Böckler-Allee 9, 30173 Hannover
Tel. +49(0)511 7304-0, Fax +49(0)511 7304-157
info@giesel.de, www.giesel-verlag.de
Postbank / postal cheque account Hannover,
BLZ / routing code: 25010030; Kto.-Nr. /
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Klaus Krause
Redaktion / Editorial office
Dipl.-Vw. Volker Karow
Chefredakteur, Editor in Chief
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Tel. +49(0)2225 8359643
Fax +49(0)2225 18458
vkarow@online.de
Dipl.-Ing. Rudolf P. Pawlek
Hüttenindustrie und Recycling
rudolf.pawlek@span.ch
Dipl.-Ing. Bernhard Rieth
Walzwerkstechnik und Bandverarbeitung
rollingmill-technology@t-online.de
Ken Stanford, Contributing Editor
kstanford2004@yahoo.co.uk
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Material Publication
Dennis Roß
Tel. +49(0)821 319880-34, d.ross@giesel.de
Anzeigenpreise / Advertisement rates
Preisliste Nr. 53 vom 1. Oktober 2012
Price list No. 53 from 1 Oct. 2012
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113

VORSCHAU / PREVIEW
IM NÄCHSTEN HEFT
Special: Die Aluminiumindustrie am Golf
Anlässlich der ALUMINIUM MIDDLE EAST 2013 vom
23. bis 25. April in Dubai berichten wir in unserem Special
über die Aluminiumindustrie in der Golf-Region – über die
dort ansässigen Unternehmen sowie über deren Ausrüstungspartner,
aktuelle Projekte und Marktentwicklungen.
IN THE NEXT ISSUE
Special: The aluminium industry in the Gulf region
In view of the ALUMINIUM MIDDLE EAST 2013 trade
fair in Dubai from 23 to 25 April we will be reporting on
the aluminium industry in the Gulf region – on the companies
located there and their equipment partners, current
projects and market developments.
Weitere Themen
• Energieoptimiert vom Aluminiumschrott zum
stranggepressten Halbzeug
• Tragbare Metallanalysatoren für Recyclingbetriebe
• Urban Mining – Rohstoffquelle der Zukunft
Research
• Einfluss der Biegeüberlagerung auf die Grenzform -
änderung von Aluminiumfeinblech
Other topics
• Energy optimised – from aluminium scrap to extruded
semi-finished products
• Portable metal analysers support recycling operations
• Low-energy air-cooled electromagnetic stirring systems
• Controlling high temperatures in smelting using
technical textiles
• Urban mining – raw material source for the future
Erscheinungstermin: 11. März 2013
Anzeigenschluss: 25. Februar 2013
Redaktionsschluss: 11. Februar 2013
Date of publication: 11 March 2013
Advertisement deadline: 25 February 2013
Editorial deadline: 11 February 2013
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