METHOD FOR PURIFYING SILICON

PROBLEM TO BE SOLVED: To provide a method for purifying silicon in which a high purity silicon raw material is recovered from silicon powder containing an abrasive grain component. SOLUTION: The method for purifying silicon comprises a melting step of heating silicon powder generated by machining using abrasive grains in a crucible under an inert gas atmosphere to the melting point of silicon or higher to obtain molten silicon, a solidifying step of solidifying the molten silicon by unidirectional solidification from the lower part of the crucible to the upper part thereof to obtain a silicon block, and a removing step of removing the lower region and the upper region of the silicon block in the crucible with a physical method selected from cutting, polishing, and blasting or a chemical method selected from acid dissolution and alkali dissolution. COPYRIGHT: (C)2010,JPO&INPIT