UNROASTED THERMAL INSULATING REFRACTORY MATERIALS
BASED ON HIGH-ALUMINA CEMENT AND PHOSPHATE BINDERS
A. N. Abyzov,
V. M. Rytvin,
V. A. Abyzov,
V. A. Perepelitsyn,
and V. G. Grigor’ev
Translated from Novye Ogneupory, No. 8, pp. 49 – 52, August, 2011.
Original article submitted April 1, 2011.
Results from the development and studies of thermal insulating refractory materials based on fillers and bind
ers produced from the aluminothermic production slag are considered. The properties of the newly created
materials are presented.
Keywords: thermal insulating refractory materials, high-alumina cement, aluminothermic slag, phosphate
binder, refractory properties
One of the paths towards increasing the operating effi-
ciency of thermal power plants used for different purposes
lies in the use of high-refractory thermal insulating materials
in the lining of the plants. Refractory articles produced in
small batches and fabricated with the use of combustible ad-
ditives or a foaming method are mainly used for this purpose.
Depending on composition, the articles will have an apparent
density from 0.4 to 1.3 g/cm
and maximum service tempera-
ture from 1150 to 1550°C. The articles are produced by
means of a complex energy-intensive technology that in-
volves a high rate of expenditure of thermal energy for dry
ing and high-temperature roasting. These drawbacks are
lacking in the case of thermal insulating refractory materials
(cellular heat-resistant concrete) fabricated according to an
aerated concrete or foam-concrete technology on a base of
different binders, such as alumina and high-alumina cement,
liquid glass, and phosphate bonding materials (orthophos
phoric acid, phosphate binders). The technology used for the
production of these materials is simpler, the materials do not
have to be roasted, and large-dimensional articles, including
those of complex shape, may be fabricated, and in addition
cast-in-place linings may be created [1 – 3]. Unroasted ther
mal insulating refractory materials produced by the aerated
concrete technology are the most common in Russia.
The properties of heat-resistant aerated concrete are de
termined predominantly by the type of binder and finely
ground additives (fillers) used in the production of the con
crete. Cellular concrete based on high-alumina cement and
phosphate binders exhibit the highest service temperatures
(up to 1500°C) .
Cement obtained by means of sintering from pure oxides
as well as cements from clinkers produced from slag gener-
ated in aluminothermic smelting of chromium metal and
ferrotitanium from the Kluchevsk Ferro-alloys Plant (from
clinkers KVTs 65, KVTs 70, and KVTs 75) are used in Rus-
sia in the development of heat-resistant aerated concrete
based on high-alumina cement. The principal minerals in these
types of cement are aluminomagnesia spinel (CA
), and alkali-containing alumina (Na
Moreover, chromous corundum is present in chromium metal
slag and perovskite CaO·TiO
in ferro-titanium cinder slag.
A composition of heat-resistant aerated concrete with
service temperature 1300°C was developed as a result of
studies performed at the Scientific Research Institute of Re
inforced Concrete and the Moscow Institute of Railway
Transport Engineers. The composition is based on high-alu
mina cement generated in aluminothermic production with
finely ground additive of chamotte. With grinding powder of
white synthetic corundum and an additive consisting of a
mixture of white synthetic corundum grinding powder and
alumina used as the additive, a thermal insulating refractory
material with service temperature 1400°C is obtained.
Porification (de-densification) of the mixture is achieved
through the use of the reaction produced in the interaction of
aluminum powder with calcium oxide hydrate [4 – 6]. Where
the shrinkage of a thermal insulating refractory material in
duced by heating to a given temperature, as determined by a
standard technique, is less than 2%, this temperature is
Refractories and Industrial Ceramics Vol. 52, No. 4, November, 2011
1083-4877/11/05204-0303 © 2011 Springer Science+Business Media, Inc.
OOO Klyuchev Concentration Plant, Dvurechensik, Sverdlovsk
Southern Ural State University, Chelyabinsk, Russia.
OAL UK Russian Special Alloys, Yekaterinburg, Russia.