Adding the alkaline medicine to the heavy metal which utilizes the acetic acid - nitric acid - phosphoric acid mixed acid

摘要

PROBLEM TO BE SOLVED: To provide a heavy-metal fixing agent utilizing effectively an acetic acid-nitric acid-phosphoric acid system mixed acid waste liquid which is exhausted from liquid crystal manufacturing processes, semiconductor manufacturing processes, silicon wafer manufacturing processes and so on.;SOLUTION: This heavy-metal fixing agent is formed by adding an alkali agent to an acetic acid-nitric acid-phosphoric acid mixed acid waste liquid. The method for manufacturing this heavy-metal fixing agent comprises adding and dispersing the acetic acid-nitric acid-phosphoric acid mixed acid waste liquid into the alkali agent. The addition of the alkali agent to the acetic acid-nitric acid-phosphoric acid mixed acid waste liquid solves a problem of the corrosion on a kneader or reaction vessel caused by a strong acidity of the mixed acid waste liquid as well as solves a problem of the occurrence of acetic acid gas and of the odor resulting therefrom by making the acetic acid in the mixed acid waste liquid to acetic ions, and enables an effective utilization as a heavy-metal fixing agent utilizing a heavy-metal fixing ability of phosphoric acid in the mixed acid waste liquid.;COPYRIGHT: (C)2010,JPO&INPIT