Indexed by:期刊论文

Date of Publication:2011-06-01

Journal:RARE METALS

Included Journals:Scopus、SCIE、EI

Volume:30

Issue:3

Page Number:274-277

ISSN No.:1001-0521

Key Words:electron beam melting; silicon; evaporation; impurities; removal efficiency

Abstract:The purification of metallurgical-grade silicon (MG-Si) has been investigated during electron beam melting (EBM) process. The results show that the phosphorus, calcium and aluminum contents decrease significantly after melting, and magnesium is partially removed. However, no significant change in content for boron and iron has been found. Langmuir's equation and Henry law were used to derive the removal efficiency for each impurity element. The free surface temperature was estimated by the Hertz-Knudsen-Langmuir equation and silicon's vapor pressure equation. Good agreement was found between measured and calculated impurities' removal efficiency for phosphorus, calcium and aluminum, magnesium, boron and iron. The deviation between the two results was also analyzed in depth.