| 摘要 |
PURPOSE:A powder of silicon is placed on the beds of heat-resistant fiber sheets and nitrided in a gas containing nitrogen at elevated temperatures to give fine particles of alpha-Si3N4 with reduced impurities. CONSTITUTION:The beds are made of a fiber sheet of high heat resistance and a silicon powder or a mixture thereof with Si3N4 is placed on them, then nitridization is effected in a gas containing nitrogen at elevated temperatures over 1,100 deg.C. The high heat-resistant fibers are, e.g., of carbon, Si3N4 or SiC. The powder is placed, e.g., on the beds of high heat-resistant fiber sheets which are piled up in several layers, in a thickness of about 10mm.. Thus, the reaction heat emitted on the reaction is readily dissipated from both top and bottom surfaces to enable easy maintenance of temperature not exceeding the upper limit, 1,350 deg.C, without control of the nitrogen partial pressure.
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