Method of treating electrolytic solution of copper for purification and reuse thereof

摘要

There is disclosed an improved method of treating a spent electrolyte of copper from a cell for electrolytic refining of copper for the purpose of purification and reuse of the spent electrolyte. The process comprises the steps of: pretreating the spent electrolyte for removing copper therefrom until the copper content is greatly reduced but still remains at a level which is substantially higher than the total content of various metal ion impurities, preferably to a concentration of 10-13 g/l of Cu; blowing a hydrogen sulfide gas into the pretreated solution at a temperature of 40 DEG C. or higher until the redox potential of solution becomes a certain predetermined value to precipitate metal ions; filtering the treated solution to separate the residue available as a raw material for copper smelting from a filtrate which consists essentially of sulfuric acid; and returning the filtrate to the cell for electrolytic refining of copper.