PRODUCTION OF ULTRAFINE POWDER OF SILICON CARBIDE

摘要

PURPOSE:Silica, carbon and a carbonaceous binder are mixed in a specific manner and granulated and the resultant starting material is introduced into the reactor where heat is applied to effect the reaction leading to SiC, thus producing ultrafine particles of silicon carbide suitable for producing sintered silicon carbide products. CONSTITUTION:A carbon powder of 1-1,000m2/g specific surface area and a carbonaceous binder are mixed using a liquid dispersant and, when necessary, a surface active agent, then the mixture is mixed with silica and a carbonaceous binder and granulated. The resultant granular starting material is charged from the hopper 19 on the reactor 6 having the preheating zone 2, the heating zone 3 and the cooling zone 4 where the particles fall down with their own weight to the heating zone 3 where they are heated with the graphite heater 8 so that they are kept at 1,500-2,000 deg.C to effect the reaction into SiC. The reaction product comes down to the cooling zone 4 where they are cooled in a nonoxidative atmosphere and discharged whereby the objective ultrafine particles of silicon carbide are obtained.