FUSED MAGNESIA-BASED REFRACTORIES
WITH IMPROVED HEAT RESISTANCE
V. V. Slovikovskii
and A. V. Gulyaeva
Translated from Novye Ogneupory, No. 3, pp. 50 – 51, June, 2014.
Original article submitted September 21, 2013.
The introduction of various additions into fused magnesia-based refractories is studied in order to make these
products more heat-resistant and reduce the cost of producing high-performance refractories. The study re
sults are used to attempt to improve the heat-resistance of refractories through the addition of Cr
the formation of ferrochromium during the refining operation lowers the refractories’ service temperature. The
optimum addition turns out to be 5 – 15% unfired magnesite MgCO
. Refractory products with improved heat
resistance can be effectively used in the linings of high-temperature equipment employed in ferrous and non
ferrous metallurgy, including fluidized-bed furnaces, Kivtset-TsS furnaces, horizontal converters, ore-roasting
furnaces, vertical converters, and electric furnaces used in ferrous metallurgy.
Keywords: heat resistance, periclase, elastic modulus, abrasion resistance, unfired magnesite, annular
The production of refractories in Russia is declining. Ac-
cording to data compiled by the association “Ogneupor-
prom” (comprised of six specialized plants and the refractory
plants at the Magnitogorsk Metallurgical Combine and
Nizhniy Tagil Metallurgical Combine) and by the Russian
Federal State Statistics Service, the output of refractories at
factories in Russia has dropped 55% since 2011. More than
1.5 billion rubles are lost each year by Russian refractory
companies due to imports. Such a situation could make the
country’s metallurgical industry and the military-industrial
complex completely dependent on the importation of
refractories . The development of technologies for making
durable refractory products that can compete with imports is
vitally important. This applies especially to refractories for
making the linings of high-temperature equipment designed
on the basis of the latest technologies — equipment such as
fluidized-bed furnaces, Kivtset-TsS furnaces, horizontal con
verters, and electric furnaces.
We conducted studies of a wide range of properties of
different high-durability refractory products when exposed to
the slags of fluidized-bed furnaces. Both traditional methods
and new methods were used in the studies (Table 1) . The
composition of the slag, %: SiO
39.5; CaO 11.0; FeO 18.5;
10.0; Cu 3.8; S 1.8.
An analysis of the properties of the refractory products
shows that they rank in the following increasing order based
on their resistance to slag: PKhSS, KhP, PKhS, MKhS,
MP-91. It was determined that the elastic modulus E of
MP-91 fused refractories increased sharply (by a factor of
1.5 – 2) compared to the same indices of sintered specimens
of similar composition. This indicates that the fused
refractories may have a low resistance to heat when used in
elements of the lining that are subject to thermal shocks. The
decrease in heat-resistance values (see Table 1) yields the se
ries PKhS, KhP, MKhS, PKhPP, MP-91. Thus, refractories
based on electrofused periclase (MP-91) have very good
chemico-physical properties except for heat resistance.
In the course of examining the feasibility of improving
the heat resistance of MP-91 products by introducing an ad
dition of Cr
, it was determined that the ferrochromium
obtained during the refining operation lowers the service
temperature of the refractory.
It was later proposed that unfired magnesite MgCO
used to improve the heat resistance of MP-91 products made
by the technology that was developed and introduced at the
OAO “Magnezit.” The specimens that were prepared for cor
responding testing were made by the following method.
Electrofused periclase of the 3 – 1-mm fraction was mixed
Refractories and Industrial Ceramics Vol. 55, No. 3, September, 2014
1083-4877/14/05503-0248 © 2014 Springer Science+Business Media New York
Ural Federal University, Ekaterinburg, Russia.