SiO2-CaO-MnO熔渣氧化精炼除硼提纯多晶硅的研究  

Study on Purification of Polysilicon by SiO2-CaO-MnO Molten Slag Oxidation Refining and Boron Removal

作　　者：马璐明 鲁俊 张彦辉 李亚琼[1] 张立峰[1] MA Luming;LU Jun;ZHANG Yanhui;LI Yaqiong;ZHANG Lifeng(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学冶金与生态工程学院

出　　处：《热加工工艺》2019年第17期30-33,37,共5页Hot Working Technology

基　　金：国家自然科学基金项目(51604023);中央高校基本科研业务费项目(FRF-BD-18-010A,FRF-TP-18-029A1)

摘　　要：熔渣精炼是制备太阳能级多晶硅过程中最为成熟和广泛应用的除硼手段。为了去除硼杂质,本文选用SiO2-CaO-MnO熔渣进行熔渣精炼研究,并考察了熔渣的光学碱度与除硼效果的关系。结果表明,经精炼后,渣硅分界明显,精炼硅易于分离,精炼硅存在Si-Ca、Si-Mn金属间析出相,且析出相中富集B、P等杂质;随着熔渣中MnO含量的增加,硅中的B含量先降低后升高,当MnO含量为5%时,硅原料中B含量从23.91×10^-6wt降低到4.40×10^-6wt,去除效率达到81.60%。Slag refining is the most mature and widely used boron removal method for the preparation of solar grade polysilicon.In order to remove boron impurities, SiO2-CaO-MnO slag was selected for refining research.And the relationship between the optical basicity of slag and boron removal effect was examined.The results show that the boundary between slag and silicon is obvious after the refining, and the refined silicon is easy to separate.There are Si-Ca and Si-Mn intermetallic precipitated phases in the refined silicon, and the impurities such as B and P are enriched in the precipitated phase.With the increase ofMnO content in slag, B content in silicon decreases firstly and then increases.When theMnO content is 5%, the boron content in the silicon raw material is reduced from 23.91×10^-6wt to 4.40×10^-6wt and the removal efficiency reaches 81.60%.

关 键 词：熔渣精炼 除硼 多晶硅 光学碱度 

分 类 号：TG250.2[金属学及工艺—铸造]