微波酸碱处理微纳米碳化硅粉体杂质去除工艺研究

Impurity Removal Technology of Micro Nano Silicon Carbide Powder by Microwave Acid/Alkali Method

利用微波消解技术和酸碱化学介质对微纳米碳化硅粉体中Fe_2O_3,Si,SiO_2去除工艺进行了研究。正交试验结果表明:微波功率4 k W,微波频率2450 MHz时,反应温度90℃,盐酸浓度3 mol·L^(-1),反应时间10 min,液固比4∶1,Fe_2O_3去除率达到97.4%;反应温度90℃,氢氧化钠浓度180 g·L^(-1),反应时间10 min,液固比3∶1,Si的去除率达到97.31%,SiO_2达到97.26%;除杂后SiC粉体的纯度达到98.1%;通过碳化硅粉体形貌分析,除杂后SiC粉体表面附着物质明显减少,较除杂前更加光滑。

The removal process of Fe2O3 , Si and SiO2 in micro nano silicon carbide powder was investigated by microwave digestion technology and acid and alkali chemical medium. The orthogonal test results show microwave power 4 kW, microwave frequency 2450 MHz, when the reaction temperature 90 ℃ , and the concentration of hydrochloric acid 3 mol ·L^-1,reaction time 10 min, and liquid to solid ratio 4： 1,the removal effect is better, Fe2O3 removal rate reach 97.4% . The reaction temperature 90 ℃ , the concentration of sodium hydroxide 180 g · L^-1, the reaction time 10 min, liquid to solid ratio 3 ： 1, removal of Si and SiO2 the better effect, the removal rate of Si reached 97. 31% and SiO2 reached 97.26% . The purity of SiC powder was 98. 1% after removal of impurity. The morphology analysis of silicon carbide powder by SEM shows that the surface attachment of SiC powder was significantly reduced after removal of impurities, which was more smooth than before removal of impurities.