MATERIAL COMPOSITION AND PROPERTIES
OF REFRACTORY BAUXITES
V. A. Perepelitsyn,
I. V. Kormina,
and P. A. Karpets
Translated from Novye Ogneupory, No. 8, pp. 66 – 73, August, 2005.
Original article submitted February 11, 2005.
Data on the chemical and mineral composition and properties of bauxite in Russia and across the globe are re
ported. The material composition is shown to be a central factor that controls high-temperature properties of
bauxites — refractoriness and melting point.
At present and in the near future, the main types of
refractories for ferrous metallurgy manufactured on a com-
mercial scale are oxide-carbon materials in the four-compo-
nent system MgO – Al
The primary physicochemical parameter that determines
the wear resistance of a refractory under heavy-duty operat-
ing conditions is energy density [1 – 3]. The energy density
, is the total amount of energy which is required
for complete destruction of a unit volume of material; it is
defined as the ratio of the energy of formation (Gibbs energy
) to the molar volume V:
The MgO – Al
– C system can provide a total
of seven refractory oxide compounds with melting points
from 2800 to 1710°C and a graphite with a sublimating tem
perature of 3800 – 4200°C. The energy density and melting
point of aluminum and magnesium-containing compounds
show no correlation with the melting point (Table 1).
Table 1 shows that alumina-containing compounds offer
a clear advantage over their chemical analogs of magnesian
composition in the calculated (theoretical) energy density,
despite the lower melting point of the corresponding simple
and complex oxides.
The high energy density of alumina-containing materials
bears direct relevance to their other properties of practical
importance such as enhanced resistance to the corrosive at-
tack by basic slags (except for high-calcium slags), inertness
in reducing liquid and gaseous media, low thermal expan-
sion, high strength and hardness, and other properties. Based
on densely sintered corundum, a unique heat-resistant mate-
rial — tabular alumina — has been developed for wide appli-
cation; currently, this material has no analog among high-
temperature magnesian refractories.
There are good reasons to believe that further progress in
the field will be achieved by increasing the use of corun
dum-containing high-alumina refractories at the expense of
Refractories and Industrial Ceramics Vol. 46, No. 5, 2005
1083-4877/05/4605-0352 © 2005 Springer Science+Business Media, Inc.
Dinur Joint-Stock Co., Pervouralsk, Sverdlovsk Region, Russia.
TABLE 1. Physicochemical Properties of Refractory Compounds
in the MgO – Al
– C System
3800 – 4200
CaO × 6Al
Periclase MgO 2800 50.9