Study on Aluminum Reduction from Metallurgical Silicon Using Electron Beam Melting

Abstract

Metallurgical-grade silicon is purified by using electron beam melting (EBM) technology in this paper. The distribution of impurity aluminum in silicon is uneven in ingot preparation, which shows the enrichment trend that from the bottom to the top and from the edge to the centre of the ingot. The content of aluminum is low in marginally place of ingot, and is lower than the detection limit of ICP-AES (1×10-5%). The theoretical analysis on aluminum evaporation is conducted. The relation between volatilization of impurity aluminum and surface temperature of melting silicon and melting time is introduced from Langmuirs equation and Henry law, which indicates that the removal rate of aluminum increase with the rising of the temperature in melt surface and the expanding of the time, the experimental results are in accord with the calculated one.