Removal of Impurities from Metallurgical Grade Silicon During Ga-Si Solvent Refining

详细信息    查看全文

• 作者：Jingwei Li ; Boyuan Ban ; Yanlei Li ; Xiaolong Bai ; Taotao Zhang ; Jian Chen
• 关键词：Ga ; Si alloy ; Metallurgical grade silicon ; Solvent refining ; Impurities
• 刊名：SILICON
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：9
• 期：1
• 页码：77-83
• 全文大小：1,769 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Inorganic Chemistry
  Materials Science
  Organic Chemistry
  Polymer Sciences
  Biomedical Engineering
  Nanotechnology
  
• 出版者：Springer Netherlands
• ISSN：1876-9918
• 卷排序：9

文摘

Purification of metallurgical grade silicon (MG-Si), using gallium as the impurity getter has been investigated. The technique involves growing Si dendrites from an alloy of MG-Si with Ga, followed by their separation by acid leaching. The morphologies of impurity phases in the MG-Si and the Ga-Si alloy were investigated during the solvent refining process. Effective segregation ratios of B and P in the Ga-Si system were calculated. Most metallic impurities formed silicides, such as Si-Fe-Ga-Mn or Si-Fe-Ga impurity phases, which segregated to the grain boundaries of Si or into the Ga phase during the Ga-Si solvent refining process. After purification, the refined Si is plate-like with < 111 > crystallographic orientation, and the removal fraction of B and P was 83.28 % and 14.84 % respectively when the Si proportion was 25 % in the Ga-Si alloy. The segregation ratios of B and P were determined to be 0.15 and 0.83 when the solid fraction of Si was 0.25. The effective removal of B and P by a solidification refining process with a Ga-Si melt is clarified.