Process for the production of refined metallurgical silicon

摘要

Silicon platelets essentially free of iron are precipitated from a solution of metallurgical grade silicon in molten aluminum and are melted in contact with silica slag to produce a refined metallurgical silicon (RMS). By directionally solidifying the refined silicon-slag melt, a directionally solidified refined metallurgical silicon (DS/RMS) is separated from a region of solidified melt having a high concentration of impurities rejected by the silicon as it solidifies. The resulting RMS and DS/RMS materials are low-cost, multigrained products having a substantially higher impurity content than in conventional high purity semiconductor grade silicon while, at the same time, have suitable properties for desirable solar cell and other silicon applications.