Hits:

Indexed by:Journal Papers

Date of Publication:2015-09-25

Journal:SEPARATION AND PURIFICATION TECHNOLOGY

Included Journals:SCIE、EI、Scopus

Volume:152

Page Number:32-36

ISSN No.:1383-5866

Key Words:Silicon; Purification; Electron beam melting; Directional solidification; Aluminum removal

Abstract:Aluminum is one of the main impurities in silicon, which can be separated and eliminated by electron beam melting. However, high removal efficiency can be obtained only by increasing melt temperature or extending refining time, resulting in high energy consumption. In this work, the directional solidification of silicon was achieved by electron beam with exponential decreasing power, considering that aluminum has both characteristics of segregation and evaporation. The distributions of aluminum show increasing trend from the bottom to the top of the electron beam melted silicon ingot, which is the same as that after traditional directional solidification. The removal efficiency is improved by the coupling of segregation and evaporation. Compared with traditional electron beam melting, the loss of silicon reduced by more than 52% and the energy consumption reduced by more than 54%. This method is more effective to remove aluminum from silicon with low energy consumption. (C) 2015 Elsevier B.V. All rights reserved.