Some properties of refractories based on clinkers with various concentrations of calcium oxide

Abstract

The All-Union Institute of Refractories has developed the technology for producing periclase--lime clinkers based on natural raw materials: dolomite and magnesite [I].Some of the properties of these refractories prepared from clinkers with a CaO concentration of 2-60% have been studied.* The clinkers were prepared by firing briquettes made from raw powdered dolomite and magnesite at 1600~The chemical composition of these materials is given in Table I. The apparent density of the magnesite clinkers with I0, 20, or 40% CaO and the dolomite clinker was, respectively, 3.29, 3.33, 3.32, 3.24, and 3.24 g/cm 3.The specimens of refractory were made from a batch of the following grain composition [2]:40% fractions from 2-0.5 mm; 25% from 0.5-0.06 mm; and 35% <0.06 mm.As the bonding material, we used a "solid" carboniferous resin and paraffin as the temporary bonding in the preparation of the fired specimens.Before the study of their properties, the unfired specimens were heat-treated at higher temperatures in a nonoxidizing medium at 400~As the resistance of the resin-impregnated fired refractories during service are significantly higher than that of the unimpregnated, some of the specimens fired at 1700~ were impregnated with carboniferous pitch preceded by vacuum treatment [3].