The reuse modulo null potassium fluoride of valuable ones which are recovered by the valuable thing recovery modulo and its manner from the waste salt which contains

摘要

PROBLEM TO BE SOLVED: To provide a method for recovering and recycling sodium fluoride or acidic sodium fluoride that has high utility value in industry from a waste salt containing potassium fluoride.;SOLUTION: The method for recovering the valuables from the waste salt containing potassium fluoride is characterized by treating an aqueous solution of which the fluoride content is 1-20% with sodium chloride or an aqueous solution of sodium chloride to recover the crystal of sodium fluoride when the solution is neutral or alkaline or to recover the acidic sodium fluoride when the solution is strong acidic, as a relatively large crystal which has extremely good precipitation properties. The recovered sodium fluoride or acidic sodium fluoride can be recycled as industrial sodium fluoride or acidic sodium fluoride, or as a raw material of hydrogen fluoride preparation or of artificial cryolite preparation.;COPYRIGHT: (C)2005,JPO&NCIPI