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摘要

PROBLEM TO BE SOLVED: To provide a method of treating waste liquid containing silicon particles discharged from a polishing or cutting process of silicon wafer in a semiconductor manufacturing; and to provide a safe and economical method of collecting silicon from waste liquid containing silicon particles.;SOLUTION: This method comprises steps of: adding a component inactivating the surface of silicon particles to waste liquid containing silicon particles; making the waste liquid alkaline of pH 8 or more; and treating the waste liquid allowable for discharging. In this method, after the waste liquid is subjected to alkaline treatment, silicon is collected from the waste liquid before hydrogen gas is generated from the waste liquid.;COPYRIGHT: (C)2007,JPO&INPIT