INCREASING THE ENDURANCE OF THE CONVERTER LINING
A. B. Yur’ev,
V. P. Komshukov,
Yu. A. Marakulin,
and A. P. Presnyakov
Translated from Novye Ogneupory, No. 6, June, 2004, pp.7–10.
Original article submitted March 25, 2004.
A brief review of the expertise in increasing the endurance of the lining for converters gained at the West Sibe
ria Iron and Steel Works (WSISW) is given. Within three years after the WSISW oxygen converter shop has
been put in service, the lining endurance could be improved to 728 heats (1.8 times the design endurance). A
flame gunning technology has been developed, which made it possible to achieve an endurance of 1300 heats
(at a maximum of 2500 heats). A technology for repairing the converter lining by applying a slag coating
(scull) in the stream of an inert gas has been developed. The combined effect of these two technologies made it
possible, in 2003, to achieve an average endurance of 2476 heats (at a maximum of 4500 heats).
At the West Siberia Iron and Steel Works (WSISW) over
the 36-year service time, a wealth of expertise in developing
advanced refractory materials for the lining of oxygen con-
verters has been gained. Converter shops, with their arsenal
of 5 converters, were, figuratively speaking, a test site for
new steel-making technologies and new refractory materials.
Programs targeted at the introduction of resource-saving
steel-making technologies and advanced refractories for the
converter lining have been developed at the WSISW.
Development of a high-resistant refractory typically in
volves three steps: (i) development of a steel-making tech
nology and design of new kinds of lining; (ii) introduction of
the flame gunning technique; (iii) use of advanced refractory
materials and introduction of new steel-making technologies
and techniques for converter repair.
At step 1, the central issue was optimization of steel-
making operational parameters. Three-nozzle tuyeres were
replaced by four-nozzle ones, the heat time was reduced, the
converter’s idle time was minimized, etc. Much attention
was given to improving the lime quality. Adding lime with
70% (or higher) CaO within the first 3 minutes at the blasting
onset made it possible to obtain high-quality slags with a
bacisity of 4 – 4.2; in the final slag, the FeO concentration
was 11 – 12%.
Considerable attention was given to improving resin-
bonded refractories by modifying the mixture composition
and updating the pressure molding technique. Using a pro
cessed coal tar with a high coking value (42 – 44%) and a
high mixing temperature (up to 100 – 120°C), holding time
of up to 5 sec at a maximum molding pressure made it possi-
ble to increase the compressive strength of the refractory ma-
terial up to 60 MPa; the residual carbon in refractory mate-
rials was 4 – 5%, which made it possible to increase thermal
endurance of the converter lining by further 100 – 150 heats.
The additional measures taken: improved properties of
the resin-bonded refractories, differentiated (zonal) brick-
work pattern, improved processing converter regime —
made it possible to increase the service life of the lining from
375 heats (1968 – 1969) to 728 heats (1971). Ultimately, the
specific refractory consumption could be reduced from 3.1 to
2.63 kg/ton steel.
Under laboratory conditions, a technology for production
of resin-bonded refractories containing additions of 12 –
15% graphite or kish graphite (a graphite produced from the
steel-making waste kish) was developed in which the mix
ture was treated by sonication. Later, a commercial-scale
production of refractories based on this technology was orga
nized. The concentration of residual graphite in the refrac
tory material was 9%, and thermal endurance of the lining
prepared from this material was 852 heats.
At this step, a mathematical model was used to describe
the effect of process parameters on the thermal endurance of
the lining. An effective tool for evaluating the effect of ser
vice conditions on endurance characteristics is a multiple
correlation and regression analysis. Material used for the sta
tistical processing were data on resin-bonded refractories,
process parameters, and the lining endurance available from
various manufacturers (a total of 48).
Refractories and Industrial Ceramics Vol. 45, No. 5, 2004
1083-4877/04/4505-0309 © 2004 Springer Science + Business Media, Inc.
West Siberia Iron and Steel Works Joint-Stock Co., Russia.