REFRACTORIES IN HEAT UNITS
UPGRADE OF REFRACTORY LINING OF TEEMING LADLES
S. N. Prosvirov,
D. A. Kalinin,
and M. E. Savkin
Translated from Novye Ogneupory, No. 7, pp. 18 – 19, July, 2007.
Original article submitted March 13, 2007.
A gradual upgrade of refractory lining of 160-ton teeming ladles, the disadvantages of the previous lining
schemes, and methods for their elimination are described. The implementation of developed techniques has
increased the resistance of teeming ladle lining by 60% (from 50 to 80 heats) and the consumption of refrac
tory in the working layer of lining has decreased by 35.7% (from 4.79 to 3.08 kg/t of steel.
The electric steel-melting plant at the Oskolskii Electro-
metallurgical Works (OEMW) has four 150-ton electric arc
furnaces DSP-150 for steel melting, two plants for integrated
steel refining, two plants for circulation degassing of steel,
and four machines for continuous bar casting (MCBC) with
bar sections 150 ´ 150 and 170 ´ 170 mm
The capacity of teeming ladles is 160 tons, the capacity
of tundish ladles is 25 and 28 tons. The main service condi-
tions of teeming ladles are as follows: the ladle lining tem-
perature before steel tapping is 850 – 1000°C, the tempera-
ture of steel tapped from the furnace is 1650 – 1750°C, the
time between steel tapping and the beginning of casting
120 – 300 min, the refining time on the plant for integrated
refining of steel (PIRS) is 95 min (including 25 min electric
current treatment and 70 min argon blow); the share of heats
treated on the PIRS is 60%, degassing time is 20 – 25 min;
the share of heats with degassing is 33%; the basicity of slag
in the ladle is 1.5 – 2.5; the duration of casting on MCBC
Nos.1–4is70–90minandMCBT No. 6 — 45 min.
Metal refining on the PIRS creates rather stringent condi
tions for the service of refractories in teeming ladle lining.
The time the metal stays in the ladle becomes longer in view
of the necessity to complete the processes of deoxidization,
alloying, and full averaging of metal with respect to its
chemical composition and temperature. The intense mixing
of metal and slag in the ladle using bottom blow intensifies
the aggressive medium effect on the refractory lining.
Due to an insufficient transmitting capacity of the PIRS,
40% of metal is tapped from the furnace at a temperature of
1700 – 1750°C, which also increases the wear rate of the
working layer of the teeming ladle lining.
After the periclase-carbon lining in teeming ladles was
introduced in 1995, its upgrade occurred in four stages.
Stage 1. The walls and the slag belt were lined with
SU-products. The average resistance of ladle lining was
50 heats, the refractory consumption per 1 ton of steel was
4.79 kg. The main disadvantages were a low construction
strength of the brickwork and the possibility of its destruc-
tion after more than 50% of the refractory thickness had been
worn. To eliminate these disadvantages we changed to pro-
ducts of the P-format.
Stage 2. The walls and the slag belt were lined by P-for
mat products. The average resistance of the ladle lining in
creased by 15 heats, i.e., to 65 heats, the refractory consump
tion per ton of steel decreased by 16% and amounted to
4.02 kg. In the service of lining made of P-format
refractories from various suppliers we observed a nonuni
form wear of lining along the ladle height and along its pe
rimeter and insufficient resistance of its reinforcing chamotte
layer during the transit of metal. To raise the efficiency of
periclase-carbon refractories, the thickness of the walls and
the slag belt brickwork was differentiated, making the baffle
wall, the blow unit zone, and the slag belt zone thicker; the
reinforcing layer of the lining was strengthened by means of
replacing chamotte by mullite-corundum. At the same time,
refractories from different suppliers were tested.
As a result of the adopted measures, the resistance of
lining grew on the average by 8.8 heats and reached 73.8
heats, the refractory consumption per ton of steel decreased
by 14% and amounted to 3.44 kg (based on the service of
Stage 3. The use of an additional layer made of a special
buffer mixture between the working and the reinforcing lining
Refractories and Industrial Ceramics Vol. 48, No. 3, 2007
1083-4877/07/4803-0161 © 2007 Springer Science+Business Media, Inc.
Oskolskii Eletcrometallurgical Works, Russia.