Recovery of cobalt, molybdenum, nickel and vanadium from an aqueous ammonia and ammonium salt solution by serial extraction of nickel and cobalt and coextracting molybdenum and vanadium

Claim 1

A process for separating the metal values in a pregnant liquor from an ammoniacal ammonium aqueous leach solution containing: (i) at least one metal value selected from the group consisting of cobalt and nickel; and (ii) at least one metal value selected from the group consisting of vanadium and molybdenum; comprising the steps of: (a) transferring nickel from said pregnant liquor into a first organic solution by means of a first organic liquid extractant comprising an oxime; (b) stripping said first organic solution with an aqueous stripping solution to form a nickel-containing aqueous solution; (c) reducing cobalt metal values in said pregnant liquor to divalent cobalt; (d) transferring cobalt metal values from said pregnant liquor into a second organic solution by means of an organic cobalt extractant selected from the group consisting of dioximes, hydroxy-oximes and beta-diketones; (e) stripping said second organic solution with an aqueous stripping solution to form a cobalt-containing aqueous solution; (f) transferring molybdenum and vanadium metal values from said pregnant liquor into a third organic solution by means of an organic extractant comprising a quaternary ammonium compound; and (g) stripping said third organic solution with an aqueous ammonium bicarbonate stripping solution to form an aqueous solution containing said molybdenum and vanadium metal values.