| 摘要 |
PURPOSE:To refine a large amt. of free C-contg. metal carbide fine powder with high recovery efficiency in a short time by charging the powder from a lower portion of a fluidized bed of heat resistant particles fluidized with an oxidizing gas and combustion-removing the free C while raising the powder. CONSTITUTION:Free C-contg. metal carbide powder such as silicon carbide powder with an average particle size of 200mu or less fed with raw material constant vol. feeder 9 is air-conveyed 10 and charged 4 into fluidized bed 1 of heat resistant particles in hermetically sealed container 2 through gas dispersion plate 3. While the powder is rising in bed 1, the free C is burned at 800-1100 deg.C, and the combustion gas is floated and scattered in bed 1 together with the powder, which is then separated, discharged 6 from the top of bed 1, and collected with collecting means 7. As the heat resistant particles silica with an average particle size of 150- 500mu or the like is used. The superficial standard gas velocity of an oxidizing gas such as air is pref. adjusted to 5-100cm/sec, and the static height of the bed to 0.2-3.0m. |
