REFRACTORIES IN HEAT UNITS
WEAR-RESISTANT CEMENT-FREE REFRACTORY MIXES
V. I. Sizov
and L. A. Karpets
Translated from Novye Ogneupory, No. 8, pp. 9 – 12, August, 2005.
Original article submitted April 19, 2005.
Development results for refractory mixes based on fused corundum, spinel, and quartz glass and intended for
use in the ferrous and nonferrous metallurgy (induction and channel-type furnaces, mixers for iron and alumi
num casting technologies) are reported. Unlike the conventional mixes, the newly designed mixes can be used
to prepare dry mixtures and cement-free castables. Results of industrial tests are given.
The ever-increasing requirements placed on the thermal
resistance of the refractory lining of heat-powered units ne-
cessitate a new approach to the manufacture of refractory
mixes and components that would allow the quality of the
end product to be raised to a higher level. Much effort has
been spent to outline the major areas of research in improv-
ing refractories and to gain an insight into the mechanism of
wear of the refractory lining. In particular, concrete steps
were taken to develop equipments for finely dispersed pow
ders that would enable obtaining dense refractory materials
and thus reducing their in-service wear rate. Another impor
tant concern was to increase the activity of sintering of the
refractory and to achieve its better compactability during
molding. Finally, the efforts were focused on selecting
“active” components that might be helpful in solving these
The experience gained in the use of refractory mixes for
the lining of iron and aluminum-melting units, both at home
and abroad, showed fused corundum, spinel, and quartz glass
as promising candidates for that purpose. Based on some ex
pertise in this area, primary attention was directed to further
development of the refractory mixes traditionally used in the
iron and aluminum-making industries.
When using white electrofused corundum for making a
monolithic layer, for example, for the lining of soaking fur
naces), low-melting sintering aids and refractory clay are
normally employed for that purpose. Mixes of this type are
well established in the manufacturing methods and currently
are widely used in the foundry work.
However, as follows from the experience gained, this
variant is not necessarily always the best one, considering
that, based on white corundum, the lining can be achieved
only by the use of a ramming technique. The as-received
ramming mixtures are normally supplied in a moistened
state; their shelf life is rather short (3 – 4 months), they are
prone to freeze-caking in the winter time and require special
conditions for their storage or additional pre-treatment prior
to use (when freeze-caked). Furthermore, they are not suit
able for making the lining by the dry vibromolding tech
nique, widely recognized to be energy- and cost-saving.
Another technique aimed at reducing the infiltration of
molten metal and slag into the lining is the introduction of al
loying additives (dopants) into the molten material that
would allow one to control the composition of the refractory
and create a glassy phase on the working (hot) surface of the
refractory and thus set a barrier to infiltration.
The controlled introduction of dopants, for example, into
corundum, makes it possible to obtained a material with tai
lored performance parameters suited for service under speci
fied operating conditions.
The strict control of granular composition and introduc
tion of narrow fractions of a Ti-containing corundum powder
made it possible to prepare fine-grained mixes which pro
vided a minimum of molten iron infiltration into the lining.
Despite the relatively high porosity, the pore diameter usu
Refractories and Industrial Ceramics Vol. 47, No. 1, 2006
1083-4877/06/4701-0001 © 2006 Springer Science+Business Media, Inc.
East Research Institute for Refractories (VOSTIO), Ekaterinburg,
Russia; Dinur Joint-Stock Co., Pervouralsk, Sverdlovsk Region,