| 摘要 |
PURPOSE:To efficiently produce the title high-quality fine powder useful for a high-temp. material and a wear-resistant material with a simple process by reducing and nitriding or carbonizing the secondary flock of amorphous fine powder wherein specified SiO2 or SiO and C source are coexistent under the fluidized-bed conditions. CONSTITUTION:An org. silicon compd. (e.g., tetraethoxysilane) is thermally decomposed in the high-temp. region by a CVD process or hydrolyzed in the presence of carbon to obtain the secondary flock of amorphous fine powder having several tens -100 mu particle size wherein SiO2 or SiO and a C source are coexistent in 2.5-10 molar ratio of C/Si in the submicron-order primary particles. The secondary flock is then supplied into an externally heated fluidized-bed reaction vessel from its upper inlet, a nonoxidizing gas such as N2 is introduced from a lower gas-inlet fitted below a perforated plate provided with a heat-resistant sheet material having air holes at 1.0-10 cm/sec linear velocity to form a fluidized bed, and reduction nitriding or carbonization is carried out at 1,200-1,850 deg.C to obtain the title fine powder. |
