When from the foul solution which contains the hydrofluoric acid and the Kay hydrofluoric acid the Acid component from the foul solution which includes manner and its

摘要

PROBLEM TO BE SOLVED: To provide a method and an apparatus for separating/recovering recyclable hydrofluoric acid and silicofluoric acid efficiently from a waste liquid containing hydrofluoric acid and silicofluoric acid.;SOLUTION: The method comprises separating the solid in the waste liquid containing hydrofluoric acid and silicofluoric acid and then first concentrating the waste liquid by distillation, and recovering an aqueous solution containing mainly hydrofluoric acid and an aqueous solution containing mainly silicofluoric acid, respectively. Other materials are remained in the distillation pot residue. The aqueous solution containing hydrogen fluoride can be recycled as a chemical etching treatment liquid for glass after adjusting the concentration by adding hydrofluoric acid. The aqueous solution containing silicofluoric acid can be recycled as synthetic raw materials of silicofluoric acid and silicofluoride for sales on the market by converting the hydrofluoric acid to silicofluoric acid by adding silicon dioxide and further by adjusting the concentration to a given one by diluting it with water.;COPYRIGHT: (C)2008,JPO&INPIT