Vacuum distillation refining of metallurgical grade silicon (Ⅰ)——Thermodynamics on removal of phosphorus frommetallurgical grade silicon
来源期刊:中国有色金属学报(英文版)2007年增刊第1期(Part ⅡB)
论文作者:魏奎先 马文会 戴永年 杨斌 刘大春 汪镜福
文章页码:1022 - 1025
Key words:metallurgical grade silicon; solar grade silicon; refining; vacuum distillation; thermodynamics; phosphorus removal
Abstract: The removal of impurity phosphorus from metallurgical grade silicon is one of the major problems on purification of metallurgical grade silicon for solar grade silicon preparation. The thermodynamics on vacuum refining process of the metallurgical grade silicon was studied via separation coefficient of impurity phosphorus in the metallurgical grade silicon and vapor-liquid equilibrium composition diagram of Si-P binary alloy at different temperatures. The behaviors of impurity phosphorus in the vacuum distillation process were examined. The results show that the vacuum distillation should be taken to obtain silicon with less than 10-7 P, and the impurity phosphorus is volatilized easily by vacuum distillation in thermodynamics. Phosphorus is distilled from the molten silicon and concentrated in vapor phase.
基金信息:the National Natural Science Foundation of China
Sustentation Project of Science and Technology of China
the Doctorial Programs Foundation of Ministry of Education of China