black silicon carbide three kinds of law

Synthesis
There are H&X brown aluminum oxide nitridation of silicon powder, silicon dioxide and silicon tetrachloride reduction method. In large-scale industrial production, silica reduction method is more valued by the people. Reduction of silica silica powder 100 parts (by weight, hereinafter the same), mixed with 35 parts of carbon black, 100 parts of urea resin, and then 800 parts of water, 0.1 parts of aluminum oxide (as used in nuclear reactor), 1 part of oxalic acid H&X silica sand supplier parts of ammonium and nonionic surfactants (as a dispersant), for strong stirring, and aqueous ammonia was added with stirring to adjust the Ph of 9.0. Good slurry was spray-dried material, the resultant was dried in an electric furnace in a nitrogen atmosphere for 3 h at 1480 ℃ reduction nitridation reaction. Then restore the reaction product in. 720 ℃, the air carried off the carbon treatment, to obtain silicon nitride powder products.