STEEL + TECHNOLOGY 01/2020 EXTRACT

38 | STEEL TECHNOLOGY
Steelmaking
Thermochemical erosion of ladle well fillers
during steel production
In 2016 the authors’ findings on temperature distribution and oxygen partial pressures in the well block of steel
ladles in an EAF steel plant in northern Spain were published [1]. Fuelled by these observations, further
experiments were conducted to examine the thermophysical properties of ladle well fillers and intensively
research their sintering behaviour and the consequential development of mechanical strength. To verify their
conclusions and gain new information on the thermochemical interactions between ladle well fillers and steel,
Purmetall and Forschungsgemeinschaft Feuerfest realized a follow up project together with Georgsmarienhütte,
wherein live trials and laboratory experiments lead to new insights.
During steel production, ladle well fillers
are exposed to a wide range of
conditions, depending on the process
route, the applied treatments and the
chemical composition of the produced
steel grade. Free opening ladle wells are
essential for the efficient production of
high-quality steel grades. To verify the theories
resulting from their ongoing research
efforts [1], Purmetall GmbH Co. KG conducted
industrial trials with Georgsmarienhütte
GmbH in the EAF steel plant in
Georgsmarienhütte, Germany, to examine
the behaviour and thermochemical erosion
of an applied mass of ladle well filler in
contact with liquid steel during routine production.
As a supplier for the automotive industry,
Georgsmarienhütte steel works produce
roughly three quarter million tons of
steel rounds in its eponymous hometown.
The steel mill is equipped with a 140 t DC
EAF, two ladle furnaces, a purging stand,
wire injector and a vacuum degassing facility.
The finished, high quality steel grades
are then shaped via a six-strand billet caster
or ingot casting.
Industrial trials
At Georgsmarienhütte, steel ladles are
equipped with two slide gate systems,
one main operating well block, inner nozzle
and slide gate and one backup system.
The main slide gate is used during routine
production at the continuous caster. Well
block and casting channel are cleaned and
ladle well filler is added to the casting
channel. After the following treatment of
the produced steel grade, the main slide
gate system opens and the ladle well filler
flows into the tundish, enabling a free
opening of the steel ladle. Since the ladle
well filler from the main slide gate system
is hereby lost, only the backup system
allows trials which examine the applied
mass of ladle well filler after steel production.
For these trials, the backup system
that is not routinely opened during regular
production was cleaned from both, ladle
top and bottom before addition of ca. 50
Figure 1. GMH process route (Picture: Purmetall)
Figure 2. Slide gates seen from the ladle
bottom (Picture: Purmetall)
Dipl.-Ing. Marc Andre Bombeck, M.Eng. Malte Janssen, Purmetall GmbH & Co. KG, Oberhausen, Germany; Dr.- Ing.
Thomas Deinet, Forschungsgemeinschaft Feuerfest e.V., Höhr-Grenzhausen, Germany; Dr. rer. nat. Amin El Gammal,
Georgsmarienhütte GmbH, Georgsmarienhütte, Germany – Contact: janssen@purmetall.de
STEEL + TECHNOLOGY 2 (2020) No. 1