REFRACTORIES IN HEATING UNITS
REFRACTORIES USED IN OAO SEVERSTAL’
A. B. Mal’tsev,
S. V. Efimov,
M. V. Toporkov,
D. E. Smirnov,
and A. A. Moiseev
Translated from Novye Ogneupory,No.7,pp.5–7,July 2008.
Original article submitted April 11, 2008.
A set of measures implemented in OAO Severstal’ converter production for improving the quality of
refractory materials used is described. The measures carried out make it possible to provide steel production at
the level of 9.5 million tons and steel smelting of a critical assortment (automobile steel, strips, and ship steel
of the highest strength categories).
Currently during steel production one of the main roles
providing productivity and product quality is played by
refractory materials used for lining the main steel smelting
units. In view of this under OAO Severstal’ converter pro-
duction (CP) conditions considerable attention is devoted to
the quality of refractory materials, technology for main-
taining them and the design of lining units. In order to
increase steel productivity in CP to 9.5 million tons it is
necessary to increase lining life for converters to 5000 melts,
which has been achieved with implementation of a set of
measures directed towards improving maintenance for
converter lining as a result of increasing the efficiency of
applying a slag lining, equipping converter mouths with
water and air cooling, and a reduction in FeO content in the
slag before tapping by 2% as a result of using improved tips
for blowing lances with tangential arrangement of nozzles.
Apart of requirements for increasing lining life there is
work for optimizing its design directed at a reduction in FeO
content in the converter slag. In one converter lining (project
Severstal’-4-1) a design was implemented for the bottom
with the possibility of blowing by a lance with a lower
position, that made it possible to achieve an average FeO
content in the slag in a converter campaign of 24.2%.
An important link in preparing high quality steel is
extra-furnace treatment: here special attention is devoted to
lining quality for the steel pouring ladle. With extra-furnace
treatment of steel, including treatment in metal finishing
units (MFU), steel vacuum treatment units (SVU) and also in
a ladle furnace unit (LFU), conditions are created for
increased erosion of the slag belt lining of the steel pouring
ladle. With introduction of a LFU in 2005, and with an
increase in the volume of production for vacuum treated steel
there is an increase in the duration of holding metal in the
ladle and the life of the lining of the steel pouring ladles
started to fall (Fig. 1). In order to maintain steel pouring ladle
lining life at the level of 95 – 105 melts work was carried out
for increasing the carbon content in the slag belt of the lining
from 12 to 16%.
In order to improve metal quality and purity effective
blowing of metal with argon is necessary during extra-
furnace treatment. In this connection in the CP an attempt
was made to introduce into operation a unit for testing
Refractories and Industrial Ceramics Vol. 49, No. 4, 2008
1083-4877/08/4904-0239 © 2008 Springer Science+Business Media, Inc.
OAO Severstal’, Russia.
Fig. 1. Change in steel pouring ladle lining life C, melts, proportion
of vacuum treatment metal Me
, %, proportion of metal treated in a
, %, and duration of holding metal in a ladle t, min, in
the period 2003 – 2007.