电弧等离子体冶炼提纯工业硅(英文)

开发了一种把电弧等离子体冶炼和电磁感应搅拌熔体相联合的在高纯石墨坩埚内冶炼提纯工业硅的硅冶炼提纯技术.掺入到电弧等离子体工作气体流中的反应性气体在硅熔体液面处与杂质反应生成挥发性杂质化合物.工业硅中难去除的杂质是B,P和Al.用由水蒸气构成的反应性气体精炼熔融态工业硅来降低其中B和P的含量,随后定向凝固移除其他杂质.用此方法冶炼处理工业硅,其中的B,P,Al,Fe,Ti,Ca和Cu的含量从7.67,73,1931,2845,166,235和56mg/kg分别降低到5.85,29,202,676,36,89和9mg/kg.硅的纯度由原来的99.46%提纯高到99.93%.

Vacuum refining metallurgical grade silicon by arc plasma

An approach combining arc plasma and electromagnetic stirring of molten silicon has been developed to refine metallurgical grade silicon in a high purity graphite crucible. The addition of reactive gases to the arc plasma gas led to volatilization of impurities at the melt silicon surface. The most problematic impurities to remove from metallurgical grade silicon are B, P and Al. A simple process to remove B and P from metallurgical grade silicon by treatment with vapor steam was developed by refining metallurgical grade silicon in the molten state followed by directional solidification. Using commercially available metallurgical grade silicon as a starting material, it was reduced from 7 67 mg/kg to 5 85 mg/kg of B, from 73 mg/kg to 29 mg/kg of P, from 1 931 mg/kg to 202 mg/kg of Al, from 2 845 mg/kg to 676 mg/kg of Fe, from 166 mg/kg to 36 mg/kg of Ti, from 235 mg/kg to 89 mg/kg of Ca, from 56 mg/kg to 9 mg/kg of Cu by utilizing this approach. The purity of silicon refined increased from 99 46% of MG silicon to 99 93%.