| 摘要 |
PURPOSE:To simply and surely obtain a high alpha-type highly pure silicon nitride powder. CONSTITUTION:The method for producing silicon nitride powder having an alpha-form content of >=90wt.% by directly reacting metallic silicon powder with nitrogen in the presence of calcium oxide comprises using metallic silicon powder having an metal impurity content of 5-20mum, an oxygen content of 0.1-0.4wt.% and an average particle diameter of 5-20mum as the metallic silicon powder and further adding calcium oxide in an amount of 0.2-0.7 pts.wt. per 100 pts.wt. of the metallic silicon powder. |
