射频感应等离子体制备球形氧化铝的工艺研究

Preparation procedure for spherical alumina by RF induction plasma

采用射频(RF)感应等离子体对颗粒形状不规则的氧化铝粉作球化处理,当氧化铝以极短暂时间快速穿越射频等离子体炬时,颗粒因受热而熔化成液滴,快速冷却,形成球形固态颗粒。应用单因素法讨论射频等离子体制备球形氧化铝的工艺参数,研究了制备过程中相关的中气流量、抽风负压、送粉速度和分散方式等主要工艺参数对球形氧化铝粉的影响。用电子扫描显微镜(SEM)观测评估球化效果,测定松装密度和振实密度。

This article studies the preparation of spherical alumina with irregular shape powder by radio frequency （RF） in- duction plasma. The single factor method is adopted to discuss parameters of spherical alumina prepared by RF plasma process. Studies on the impact on spherical alumina powder of gas flow, negative pressure ventilation, powder feed rate and dispersion methods and other major preparation process parameters are made. Scanning electron microscope （SEM） is used to observe and assess the effect of spheroidization on the bulk density and tapped density. When the alumina is getting through the RF plasma torch in very short time, the particles are heated and melt into droplets. After rapid cooling, spherical solid particles form.