Removal of boron from metallurgical grade silicon by
electromagnetic induction slag melting
electromagnetic induction slag melting
(1. School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China;
2. Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education,
Dalian University of Technology, Dalian 116024, China)
2. Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education,
Dalian University of Technology, Dalian 116024, China)
Abstract: A new purification process was developed to remove impurities in metallurgical grade silicon (MG-Si) by electromagnetic induction slag melting (EISM). Vacuum melting furnace was used to purify boron in different slag systems. The results show that the removal effect in SiO2-CaO-Al2O3 systems is better than that in other slag systems by EISM. The boron content in MG-Si is successfully reduced from 1.5×10−5 to 0.2×10−5 during EISM at 1 823 K for 2 h. Meanwhile, Al, Ca and Mg elements in MG-Si are also well removed and their removal efficiencies reach 85.0%, 50.2% and 66.7%, respectively, which indicates that EISM is very effective to remove boron and metal impurities in silicon.
Key words: metallurgical grade silicon; slag system; partition ratio