SCIENTIFIC RESEARCH AND DEVELOPMENT
STUDY OF THE STRUCTURE AND PROPERTIES OF GRAPHITES
FOR REFRACTORY PRODUCTION. PART 2. PROPERTIES OF PERICLASE-
AND CORUNDUM-GRAPHITE REFRACTORIES WITH INTRODUCTION
INTO THEIR COMPOSITION OF GRAPHITE FROM DIFFERENT
I. D. Kashcheev,
K. G. Zemlyanoi,
and S. A. Pomortsev
Translated from Novye Ogneupory, No. 1, pp. 17 – 21, January 2016.
Original article submitted August 17, 2015.
Results are provided for a study of the effect of different graphites GÉ-1 and GCh (Russian Federation), Falke
94100 and Falke 9280 (Brazil), +592 (PRC), +595 (Madagascar), and FLS 897 (Norway) on physicochemical
properties of periclase- and corundum-graphite refractories. It is shown that the type of graphite affects charge
properties even in the preparation stage, and object physicochemical properties.
Keywords: periclase, corundum, graphite, strength, porosity, oxidation resistance.
The main properties ensuring the life of carbon-contain-
ing refractories in metallurgical units are open porosity (ap-
parent density), ultimate strength in compression (bending),
and oxidation resistance. The chemical resistance of car
bon-containing refractories is provided by the carbon com
ponent of a charge, only carbon is removed (it burns off, dis
solves in metal/slag, consumed in carbide formation), and re
fractory corrosion resistance decreases rapidly . The resis
tance of a decarburized layer may be improved as a result of
purity of the starting oxide material, i.e., the purer refractory
powders used, the better is lining resistance , and also due
to an increase in sintering capacity of the mineral phase dur
ing operation. The main factor affecting corrosion resistance
of carbon-containing refractories is decarburization resis
Natural flaky graphite is used most as a carbon-contain
ing material, since it is more oxidation resistant as a result of
its ordered crystal structure . The greatest chemical resis
tance to oxygen is exhibited by natural graphite, although it
has low mechanical strength. Crystalline graphite exhibits al-
most no absorption capacity, whereas in finely-ground/finely-
crystalline (it is often called amorphous) graphite the phe-
nomenon of absorption becomes marked. Simultaneously
with a reduction in grain /crystal size there is an increase in
graphite chemical activity. Therefore for engineering tasks it
is desirable to separate finely-dispersed graphite in a special
form of carbon, i.e., amorphous.
For graphite materials, with which work is normally car
ried out, a dispersed structure is superimposed on substance
crystal structure. This distorts the main graphite properties
and gives it new properties that cannot be directly introduced
into its molecular structure. Therefore, apart from the main
graphite properties, generally it is necessary to consider its
dispersed condition. Attention should be drawn to the fact
that during extraction of graphite from natural graphite-con
taining rocks flotation is the most effective concentration
method. Flotation reagents used are SAS that are a good wet
ting agent for a graphite flake surface, and soda, water glass,
lime and other electrolytes are used for depressing foam.
Therefore after graphite extraction by flotation it is necessary
to clean it from SAS and added dispersants, which cannot al
ways be removed entirely, and remain at the surface of
graphite plates enriching it in alkali and alkaline-earth cat
Refractories and Industrial Ceramics Vol. 57, No. 1, May, 2016
1083-4877/16/05701-0022 © 2016 Springer Science+Business Media New York
Part 1 published in Novye Ogneupory No. 11 (2015).
FGAOU VPO Ural Federal University, Ekaterinburg, Russia.
OOO Ogneupor, Magnitogorsk, Russia.