Abstract: A novel class of extractants and a method of using the extractants in the hydrometallurgical recovery of nickel and cobalt metal. The extractants comprise a water immiscible organic solvent system containing solubilized mercaptide anions. In an important embodiment of the invention, the mercaptide ions are generated by adding a mercaptan to a mixed water immiscible solvent comprising a basic compound such as an amine, preferably a tertiary amine, and a polar component such as an alcohol, whereby the mercaptan undergoes acid dissociation.The extractants are used by being contacted with cobalt, nickel, or cobalt and nickel containing aqueous solutions. On mixing, the cobalt and/or nickel values are taken up by the organic as cobalt or nickel mercaptides. These may then be stripped of cobalt and nickel by treatment with an aqueous alkaline solution and carbon monoxide.

Abstract: A novel process for recovering nickel metal from aqueous ammoniacal nickel solutions such as leach liquors at or close to ambient temperatures and pressures. The process comprises contacting the nickel solution with carbonyl ferrate ions such as HFe(CO).sub.4.sup.- or Fe(CO).sub.4.sup.-- in the presence of carbon monoxide to produce nickel carbonyl. The nickel carbonyl is collected as a gas, concentrated, and decomposed to produce nickel metal and carbon monoxide. The carbonyl ferrate ions may conveniently be produced by subjecting an iron pentacarbonyl solution to an aqueous alkaline solution containing potassium hydroxide or the like. The nickel depleted ammoniacal liquor is purged of iron resulting from the nickel carbonylation treatment by oxidizing the ferrous values to iron oxide and may thereafter be recycled to solubilize additional nickel values.

Abstract: A novel process for extracting, concentrating, and isolating nickel and cobalt from aqueous solution thereof. A cobalt and/or nickel bearing solution is contacted with an extractant comprising a substantially water immiscible organic solvent containing solubilized mercaptide anion to form water insoluble cobalt and nickel mercaptides in the organic phase. The organic phase is then separated from the raffinate and contacted with an alkaline solution and carbon monoxide to produce nickel and cobalt carbonyl compounds. Typically, the nickel carbonyl produced is gaseous Ni(CO).sub.4 which may be easily isolated by known methods from other components in the off-gas stream. Pure nickel metal is then obtained from the nickel tetracarbonyl by known methods. The cobalt carbonyl compound produced is typically water soluble carbonyl cobaltate ion, Co(CO).sub.4.sup.-, which may be oxidized to form water insoluble cobalt carbonyl compounds.

Abstract: A process for winning copper from acidic aqueous solutions which employs hydrogen to drive the reaction. The copper bearing liquor is treated with an organic phase comprising a quinolic reductant and a nitrile solubilized in a water immiscible solvent. Components of the two phases react to produce a nitrile ligand stabilized cuprous solution and an organic solution containing oxidized quinolic compound. After separation, the organic phase containing the spent quinolic is regenerated by hydrogenation. The cuprous ion solution is flash distilled to drive off the nitrile and to produce equimolar quantities of copper metal and cupric ions by disproportionation. The nitrile may be reabsorbed into the organic phase for reuse.

Abstract: Copper is recovered from solutions containing cupric ammoniacal complexes by reducing copper in the complexes to the cuprous state and thereafter precipitating the copper as cuprous acetylide by passing acetylene through the solution. After the cuprous acetylide is separated from the solution and washed thoroughly, it is reacted with acetonitrile and an acid to form acetylene and a cuprous-acetonitrile complex: Cu(CH.sub.3 CN).sub.2.sup.+. The solution containing this complex is then flash distilled to remove the acetonitrile and to disproportionate unstable cuprous ions into copper metal and cupric ions. Following the disproportionation, the components are separated and copper metal is collected. SUBACKGROUND OF THE INVENTIONThis invention relates to the recovery of copper from ammoniacal solution which may also contain nickel, cobalt, and other ions. In practicing the invention, very pure copper metal is obtained without the need to employ ion exchangers, acid stripping, electrowinning, or electrorefining.

Abstract: Copper values are recovered from an acidic solution of solubilized cupric ions by the reduction of cupric copper to cuprous copper with hydrogen gas in the presence of a solid hydrogenation catalyst and in the presence of a cuprous ion stabilizing ligand. Catalyst poisoning by precipitation of copper metal on the surface of the catalyst during the reduction is avoided by controlling the ratio of Cu.sup.+/ligand/Cu.sup.+.sup.+ and by terminating the hydrogenation before copper metal precipitates on the catalyst. The solution containing the cuprous ions is separated from the solid catalyst and the cuprous ions are then disproportionated to produce copper metal and cupric ions.The removal of the last amounts of cupric ions from solutions, after several stages of reduction and disproportionation is achieved by allowing the cupric ions to precipitate on the catalyst as copper metal.