SCRUBBING OF AMMONIA FROM LIQUID ION EXCHANGE REAGENTS

摘要

A process for scrubbing extracted ammonia from oximes. The process is particularly adaptable as a secondary scrub, prior to acid stripping, in a process in which metals are recovered from ammoniacal leach liquors by solvent extraction. The present process eliminates the pH rise of the aqueous scrub liquor associated with acid scrubbing of ammonia from oximes into which ammonia has been extracted. Extractable metal sulfates are utilized in an aqueous scrub solution at a pH <7. The net result is an exchange of ammonia on the oxime for copper or nickel in the scrub solution with resulting loading of copper or nickel by the oxime and the formation of ammonium sulfate in the aqueous scrub solution with no change in the pH of the aqueous scrub solution.