SPECIALIZED SPINELLIDE-PERICLASE REFRACTORIES
S. A. Suvorov,
P. V. Plyukhin,
and M. A. Golovin
Translated from Novye Ogneupory, No. 9, pp. 30 – 33, September, 2004.
Original article submitted June 22, 2004.
Specialized carbon-doped spinellide-periclase refractories developed for the bottom lining of a ladle furnace
are described. Large-sized PShUP 1-1-grade refractory blocks have been used for the “impingement” zone
which made it possible to reduce the conventional wear rate of 6.21 mm per heat to 2.55 – 2.95 mm in the im
pingement” zone and to 1.09 – 1.66 mm in the hot layer of the bottom lining.
Improving quality and cutting production costs has been
and continues to be an issue of never-abating concern for all
metallurgical and steelmaking plants. The use of high-alu-
mina and corundum-based castables for the refractory lining
of steel ladles requires, as is commonly believed, a lesser
amount of labor and materials for construction, maintenance,
and repair work. However, not infrequently, much less atten-
tion is paid to the eventual contamination of steel billets with
by-products of degradation of the alumina-based lining ma-
terial. The loss of weight of the lining during the period of
time prior to the first reconditioning repair may amount to
5 – 10 tons depending on the ladle capacity and the residual
lining thickness according to the accepted norms at a particu
lar plant. The occurrence of nonmetallic inclusions degrades
the quality of the product, and their removal incurs additional
costs. Practice has shown that the removal of alumina prod
ucts into slag, even under well-established processing condi
tions (sophisticated refining, vacuum degassing, and argon
blowing), is not always efficient. Residual contaminating in
clusions, entrained into the molten steel, decrease its fluidity
and, with time, become deposited to foul the metal-conduct
ing path (holding nozzle, nonswirl nozzle, etc.). The crust
material, composed mainly of alumina products, is removed
hydrodynamically into the molten metal and, consequently,
into the cast billet.
The use of spinellide-periclase refractories as an alterna
tive to corundum and high-alumina castables reduces the risk
of contamination to a minimum and makes the technological
process more cost-effective. Carbon-doped spindled-peri-
clase refractories have been developed [1, 2] with due ac-
count taken of the factors responsible for the eventual break-
down of the steel ladle lining. Of special concern were pro-
perties important for the effective service of refractories:
chemical stability, low heat conductivity, resistance to infil-
tration, and high thermomechanical strength.
Infiltration of metal and slag into the refractory renders it
less resistant to spalling and wear. The capillary impregna-
tion of a refractory is controlled by a number of conditions
such as phase composition, porosity, wettability, and temper
ature. With the pore diameter increasing from 10 to 50 mm,
the infiltration depth increases by a factor of 3 or even more.
Therefore coarse-grained and finely dispersed refractory
components were taken in a proportion that made it possible
to form a microscopic structure that prohibited easy penetra
tion of the melt into the bulk of the refractory. Mercury
porosimetry was used to determine the pore size distribution
(Fig. 1). Pores of size 3 – 15 mm were predominant in the
Newly developed doping additives were used to mini
mize chemical degradation and heat losses and to increase
the heat resistance of the hot layer of the lining. Figure 2
shows the microstructure of a refractory viewed under a
Philips XL-30 scanning electron microscope.
A pilot batch of periclase-spinel refractories with tailored
phase composition, microstructure, and physicomechanical
properties (designed in conformance with TT 200-303–2003
Technical Regulations) was produced at the Kombinat
Magnezit JSC. The refractory was labeled under the grade
Refractories and Industrial Ceramics Vol. 45, No. 6, 2004
1083-4877/04/4506-0431 © 2004 Springer Science+Business Media, Inc.
St. Petersburg Technological Institute (Technical University), St.
Petersburg, Russia; Magnezit Trading House Joint-Stock Co.,
Satka, Chelyabinsk Region, Russia.