A THERMOSTABLE FORSTERITE REFRACTORY DEVELOPED
ON A MODEL OF HEAT CONDUCTION AND THERMAL FAILURE
OF THE REFRACTORY LINING
N. N. Grishin
and O. A. Belogurova
Translated from Novye Ogneupory, No. 5, pp. 32 – 35, May, 2006.
Original article submitted January 23, 2006.
A model of heat conduction and thermal stability for ceramics and refractory is proposed and forsterite-based
materials with high thermal stability are developed. A relationship between the heat conductivity and the den
sity of a material for practical use is proposed.
Advances in the industrial-scale production of refrac-
tories from magnesian silicate raw materials are hampered
by a major shortcoming of forsterite materials ¾ low stabi-
lity against sharp drops in temperature (low thermal stabi-
lity). In practice, the thermostability of refractories is nor-
mally assessed by solving appropriate criterial equations in
which the heat conductivity plays a key role. Precisely the
heat conductivity is a pivotal factor in the interaction be-
tween heat flow and refractory lining. The lack of an ade-
quate theoretical model of heat transfer in the lining, and of
refractory thermostability criteria, has been a limitation in
developing new materials.
In this work, we establish major system parameters that
define conditions for heat conduction and thermal failure of
refractory lining conceived of in terms of nonequilibrium
thermodynamics. Based on a theoretical model, a technology
for manufacture of thermally stable forsterite refractories is
For deformable solids subjected to thermodynamically
reversible processes, a small change in internal energy E is
equivalent to the difference between the acquired heat per
unit volume and the work done by internal stress forces :
dE = TdS + s
where T is the temperature, S is the entropy, s
is the stress
tensor for the i-component of the force acting on the surface
is the strain tensor that determines the change in
unit length in the strained body.
At failure, the system is not in equilibrium, but its unit
mass elements may be conceived of as persisting in a state of
local equilibrium. For the conditions of nonequilibrium
strain and local equilibrium, Eq. (1) is written as
where t is the time.
The law of conservation of energy in open systems in
volved in a nonequilibrium process in the absence of diffu
sion flows and chemical and isomorphic transformation
takes the form :
where dq is the elementary heat; P: is the pressure tensor;
r is the density; grad v is the neighboring layer velocity gra
dient of the strained body.
The derivative of entropy with respect to time for a
nonequilibrium process under similar conditions is defined
by the equation
is the heat flow.
Refractories and Industrial Ceramics Vol. 47, No. 3, 2006
1083-4877/06/4703-0168 © 2006 Springer Science+Business Media, Inc.
I. V. Tananaev Institute for Chemistry and Technology of Rare
Elements and Raw Minerals, Kola Research Center, Russian
Academy of Sciences, Apatity, Murmansk Region, Russia.