METHOD FOR RECOVERING SODIUM AND SULFUR COMPONENTS FROM COPPER SULFIDE SLAG

摘要

PROBLEM TO BE SOLVED: To provide a method for recovering Na and S from a copper sulfide slag at high recovery rate as compounds reusable as a flux.SOLUTION: The method includes: adjusting the grain size of the copper sulfide slag solidified from its molten state so that the fraction of the grain size of 5-20 mm is ≥50 mass%; immersing granular copper sulfide slag into water to extract Na and S in the slag; and maintaining the pH of the aqueous solution to ≥9 to recover the Na and S components from the solution. It is possible to maintain S in the slag in a negative divalent state by immersing the slag having a prescribed grain size into water or the like without pulverizing the slag, and further is possible to prevent the vaporization of S to stably keep the negative divalent S in the aqueous solution by maintaining the pH of the solution to ≥9. Thereby, Na and S can be recovered at a high recovery rate as the compound reusable as the flux.