Lack silicon carbide is produced at high temperature in an electric resistance type furnace with quartz sand and petroleum coke as its main raw materials. Its hardness is between fused alumina and synthetic diamond. The mechanical intensity of it is higher than fused alumina. It is brittle and sharp and has electrical and heat conductivity in some degree. The abrasives made of it are suitable for working on cast iron, non-ferrous metal, rock, leather, rubber, etc. It is also broadly used as refractory material and metallurgical additive.