Process and an apparatus for producing silicon carbide consisting mainly of beta-type crystal

摘要

A process and an apparatus for producing silicon carbide consisting mainly of beta -type crystal are disclosed. The fine silicon carbide consisting mainly of beta -type crystal is produced by charging the starting material of silica and carbon with a mole ratio of C/SiO2 of 3.2-5.0 into a top portion of a vertical-type reaction vessel having a preheating zone, a heating zone and a cooling zone in this order, descending the starting material by gravity through the reaction vessel, heating the starting material in the heating zone at a temperature of 1,600 DEG -2,100 DEG C. by electrically indirect heating in horizontal direction to effect the formation of SiC, cooling the resulting reaction product in the cooling zone under a non-oxidizing atmosphere, and recovering the cooled product from the bottom portion of the reaction vessel to obtain a product having a composition ratio by weight of silicon carbide, silica and free carbon which lies within the area represented by the area ABCD shown in FIG. 1 of the accompanying drawings.