| 摘要 |
PURPOSE: To produce a granulated material of a low-oxygen porous silicon, capable of efficiently producing silicon nitride having a highα-type content and good in reactivity with a slight variation by adding a carbon powder to a metallic silicon powder and granulating the resultant mixture. CONSTITUTION: A carbon powder having 20-500m<2> /g specific surface area in an amount of 0.3-5wt.% based on the total amount of a metallic silicon powder and an organic powder in an amount of 1-5wt.% based on the total amount of the metallic silicon powder are mixed with the metallic silicon powder having 4-10μm average particle diameter and the resultant mixture is then granulated and dried to provide a granulated material having 0.2-10mm grain diameter. The resultant granulated material is then treated in a temperature region of 1250-1400 deg.C in an inert atmosphere except nitrogen in a heating furnace for 0.5-5hr to afford a granulated material of the metallic silicon having 0.2-10mm average grain diameter. The granulated material of the metallic silicon has >=0.5m<2> /g specific surface area, <=0.4wt.% oxygen content, <1wt.% carbon content and >=1μm and <=2μm pore diameter mode. When the granulated material is used as a raw material to carry out nitriding reaction in a rotating furnace or a fluidized bed reactional furnace, silicon nitride having a highαtype content can efficiently be produced.
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