Effect of Sodium-Based Slag Treatment on the Distribution of Impurities in Metallurgical Grade Silicon

Abstract:

The distribution of impurities in metallurgical grade silicon before and after slag treatment was investigated for the purpose of upgrading metallurgical grade to solar grade silicon. It was found that metal impurities co-deposited with silicon and formed different intermetallics in the precipitated phase, and these intermetallics such as Si-Fe, Si-Ni, Si-Ti-V and Si-Ca-Al-Fe were substituted by Si-Fe-Ti-V after treatment of Na2CO3-SiO2 slag. Non-metallic impurities B and P were nearly homogeneous distribution in metallurgical grade silicon before and after slag treatment. Moreover, a particular analysis of the microstructure of slag has been carried out, it was determined that metal impurities Al and Ca could easily migrate from silicon to slag phase in the refining process.

• Periodical: Advanced Materials Research (Volumes 690-693)
• Pages: 949-953
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.690-693.949
• Online since: May 2013
• Authors: Ming Fang, Cheng Hao Lu, Hui Xian Lai, Liu Qing Huang, Juan Chen, Jin Tang Li, Wen Hui Ma, K.X. Wei, Zhi Lin Sheng, Jian Ning Shen, Xue Tao Luo
• Keywords: Distribution, Impurity, Metallurgical Grade Silicon, Sodium-Based Slag, Solar Grade Silicon

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