Low-temperature purification process of metallurgical silicon

作     者：赵立新 王志 郭占成 李成义 ZHAO Li-xin;WANG Zhi;GUO Zhan-cheng;LI Cheng-yi

作者机构：中国科学院过程工程研究所湿法冶金清洁生产技术国家工程实验室北京100190 中国科学院研究生院北京100049 北京科技大学高效钢铁冶金国家重点实验室北京100083 中国矿业大学化学与环境工程学院北京100083 

出 版 物：《Transactions of Nonferrous Metals Society of China》 (中国有色金属学报（英文版）)

年 卷 期：2011年第21卷第5期

页      面：1185-1192页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：Project (2009BAB49B04) supported by National Key Technologies R&D Program  China 

主　　题：metal liquating method metallurgical purification process tin-silicon system solar grade silicon 

摘      要：The removal of B and P consumes most of heat energy in Si metallurgical purification process for solar-grade Si. Metal-liquating purification of metallurgical grade silicon （MG-Si）, also called Si-recrystallization from metal liquid, was a potential energy-saving method for the removal of B and P efficiently, since Si could be melted at lower temperature by alloying with metal. The selection criteria of metal-liquating system was elaborated, and Al, Sn and In were selected out as the optimum metallic mediums. For Sn-Si system, the segregation coefficient of B decreased to 0.038 at 1 500 K, which was much less than 0.8 at the melting point of Si. The mass fraction of B was diminished from 15×10^-6 to 0.1×10^-6 as MG-Si was purified by twice, while that of most metallic elements could be decreased to 0.1×10^-6 by purifying just once. During the metal-liquating process, the formation of compounds between impurity elements and Si was also an important route of impurity removal. Finally, one low-temperature metallurgical process based on metal-liquating method was proposed.