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

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, tungsten, and molybdenum;
• comprising:
• (a) transferring said molybdenum, tungsten, and vanadium metal values from said pregnant liquor into a first organic solution by means of a first organic liquid extractant comprising a quaternary ammonium compound;
• (b) stripping said first organic solution with a first aqueous ammonium bicarbonate stripping solution to form an aqueous solution containing said molybdenum, tungsten, and vanadium metal values;
• (c) transferring nickel metal values from said pregnant liquor into a second organic solution by means of an organic nickel extractant comprising an oxime;
• (d) reducing cobalt metal values in said pregnant liquor to divalent cobalt;
• (e) transferring cobalt metal values from said pregnant liquor into a third organic solution by means of an organic cobalt extractant selected from the group consisting of dioximes, hydroxy-oximes, and beta-diketone;
• and
• (f) stripping each of said second and third organic solutions with aqueous stripping solutions to form a cobalt-containing aqueous solution and a nickel-containing aqueous solution.