Influence of reactive alumina type on the properties of corundumspinel castables (review)

Abstract

In order to improve technology manufacture of high-quality refractory castables, have been executed review and analysis of some individual results on foreign studies aimed at researching the influence of reactive alumina’s type (in terms of specific surface area, particle size distribution, chemical purity) on properties of corundum-spinel castables of various compositions.
 It had been shown technological efficiency of corundum-spinel castables application:
 — composite material of E-SY288 brand in comparison with alumina of СL370 brand in terms of samples’s apparent porosity and cold modulus of rupture improving, regardless of the firing temperature;
 — alumina with the lower Na2O content (0.32 %) and particle size (d50 = 2.51 microns) in terms of samples’s permanent linear changes and cold modulus of rupture improving, fired at 1450 °C samples;
 — alumina with the minimum Na2O content (0.034 %) and the larger specific surface area (4.32 m2/g) in terms of mass’s flowability and samples’s apparent porosity, cold and hot modulus of rupture improving, regardless of the firing temperature;
 — alumina with the high Na2O content (0.11 %) and the smallest specific surface area (3.01 m2/g), but with a specific particle size distribution, in terms of samples’s cold crushing strength and cold modulus of rupture improving, regardless of the firing temperature, as well as alumina with the highest specific surface area (7.40 m2/g) in terms of samples’s abrasion resistance improving, alumina with an average specific surface area (4.68 m2/g) in terms of samples’s hot modulus of rupture (at temperatures of 1400 and 1500 °C) and thermal spalling resistance improving.