摘要
湿法提纯作为冶金法路线制备太阳能级硅前处理工序,可去除大部分铁铝等碱金属及硼杂质,提高最终产品收率。实验考察了湿法除硼过程主要工艺因素:浸出剂浓度、温度、时间、搅拌等对产品纯度的影响,采用SEM对产品进行表征。当工艺条件为c(HNO3)=6.5 mol/L,c(H2SO4)=6 mol/L,温度120℃、时间4 h,处理后产品中杂质质量分数为3.574×10-6,湿法过程单元的去除率为44.58%。实验结果为高等级太阳能级硅制备工业化开发大幅度降低成本提供了技术基础。
As a pre-treatment process for preparing solar-grade silicon（SG-Si）,the hydrometallurgical route can remove not only most of alkali metal like iron and aluminum but also boron impurity in metallurgical-grade silicon（MG-Si） to raise the final product yield.The factors such as the concentration of leaching agent,temperature,time and stirring were researched in the process of removing boron,and the samples were characterized by ICP,SEM,etc.The result shows that when MG-Si powder is leached at appropriate conditions of c（HNO3）=6.5 mol/L,c（H2SO4）=6 mol/L,reaction temperature 120 ℃,reaction time 4 h,the final boron impurities mass fraction after treatment can be reduced to 3.574×10^-6,and the removal rate of boron impurity in MG-Si powder is 44.58%.The experimental results provide the technical reference for reducing the cost of industrialized development of SG-Si preparation.
出处
《化学工程》
CAS
CSCD
北大核心
2010年第11期68-71,76,共5页
Chemical Engineering(China)
关键词
太阳能硅
冶金级硅
湿法冶金
除硼
solar-grade silicon
metallurgical-grade silicon
hydrometallurgy
boron removal
