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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.
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