MINI-TECHNOLOGY FOR OBTAINING ALUMINOUS CEMENT
V. M. Ufimtsev,
A. A. Gulyaev,
and V. A. Kamenskikh
Translated from Novye Ogneupory, No. 8, pp. 35 – 38, August, 2012.
Original article submitted April 1, 2012.
This article examines the feasibility of producing aluminous cement based on highly dispersed raw materials
by using reverberatory electric furnaces with capacities ranging from 1.2 to 4.6 tons/day. A technology is de
veloped for low-temperature solid-phase sintering and tests are performed on the resulting product. Recom
mendations are given on selecting and minimizing the cost of the necessary production equipment. An alterna
tive sintering-based technology is also proposed, this technology involving the kiln roasting of aluminous ce
ment in a discrete-continuous regime.
Key words: aluminous cement, microcalcite, dust from the electrostatic precipitators of alumina calcination
furnaces, solid-phase sintering, reverberatory furnace, sinter roasting.
Aluminous cement is commonly made by melting in
electric-arc furnaces, and blast furnaces are also used for this
purpose. The melting technologies that are used are generally
very energy-intensive because there is no regenerative com-
ponent. This type of cement is also obtained by sintering ,
and it can also be produced by sinter roasting; sinter roasting
has been successfully used to obtain aluminous cement based
on limestone-bauxite mixtures . Positive results from the
sinter roasting such mixtures were obtained previously by H.
Wendeborn, who was one of the pioneers of modern agglom
eration technology .
Of the sintering-based technologies, the best-known
technology is that which involves roasting in tunnel furnaces.
This method is similar to the technology which employs
semi-dry pressing to obtain ceramic brick. Use of the latter
for cement production makes it possible to employ the same
equipment. In the simplest variant that is used to make
high-aluminate refractory cements, the heat treatment is con
tinued only until complete bonding of the lime. Here, the for
mation of the clinker (complete bonding of the alumina) is
completed during use of the refractory. This approach makes
it possible to lower the temperature used to roast the clinker
by 200 – 300°C, since the process of bonding the lime is
dominated by solid-phase sintering. In addition to reducing
the amount of heat consumed, the given approach reduces
energy costs incurred in crushing the binder by 67% due to
the low density of the roasted product .
We attempted to develop a technology for making
aluminous cement that would be profitable for relatively low
volumes of production. The development work was founded
on the latest achievements in the field of refractories based
on aluminous cements and the advent of compact and effi-
cient high-temperature heating equipment — reverberatory
electric furnaces. The use of industrial waste products in the
production process should also help lower the cost of making
The main factor that accounts for the efficiency of
solid-phase sintering is obviously the large and balanced spe
cific surface of the original components. Here, the term “bal
anced” means that this index should be of the same order of
magnitude for all of the components of the mixture, while the
specific surface of each particular component should also
ideally be inversely proportional to its concentration in the
The term “solid-phase sintering” merits special discus
sion, since it seems somewhat self-contradictory. In our opin
ion, this combination of words accurately characterizes the
specifics of the given process because it is governed by the
limitingly small volume of the liquid phase that participates
in mass exchange. We hold that the heat-related shrinkage of
the product which takes place during solid phase sintering
should be viewed as reliable indirect proof that the liquid
phase participates in the sintering operation. In other words,
in the present case the term “solid-phase” signifies the abso
lute dominance of diffusion processes and the local character
of the microscopic liquid-phase sources in a three-dimen
Refractories and Industrial Ceramics Vol. 53, No. 4, November, 2012
1083-4877/12/05304-0250 © 2012 Springer Science+Business Media New York
Ural Federal University, Ekaterinburg, Russia.