Liquid ion exchange process for the recovery of copper and nickel

Claim 2

A process for treating an ammoniacal leach liquor containing copper and nickel to separate the copper and nickel from the leach liquor and each other comprising the following steps: a. contacting the leach liquor with an organic extractant in a copper extraction circuit to extract copper and produce a copper loaded organic; b. contacting the copper depleted leach liquor of step (a) with an organic extractant in a nickel extraction circuit to extract nickel and produce a nickel loaded organic; c. stripping the nickel loaded organic extractant of step (b); d. recycling at least a portion of the organic stripped in step (c) containing unstripped nickel back to the copper extraction circuit, in the copper extraction circuit said unstripped nickel on the oganic being replaced by copper from the aqueous, said recycling step preventing the build up of copper on the organic in the nickel extraction circuit.

Claim 3

The process as set forth in claim 1 wherein the nickel is stripped in step (c) with a highly concentrated ammonium salt solution to yield a strip concentrate from which nickel or nickel oxide is recoverable without electrolytic treatment.

Claim 4

The process as set forth in claim 1 wherein the copper loaded organic extractant produced in step (a) is stripped of copper values to enable the copper to be recovered and wherein a portion of the organic extractant stripped of copper values is recycled to the nickel extraction circuit of step (b) to extract nickel.

Claim 7

A process for recovering copper and nickel from an aqueous ammoniacal leach liquor containing copper and nickel comprising the following steps: a. first extracting copper from the leach liquor in a copper extraction circuit with an organic extractant to leave a raffinate that is depleted in copper values and high in nickel values; b. thereafter extracting nickel from the raffinate of step (a) in a nickel extraction circuit; c. separately stripping the copper loaded organic produced in step (a) in a copper stripping circuit and the nickel loaded organic produced in step (b) in a nickel stripping circuit. d. thereafter introducing the stripped organic from the copper stripping circuit and the stripped organic from the nickel stripping circuit into a mix tank; e. mixing the organics from the copper and nickel stripping circuits in the mix tank; and, f. recycling a portion of the organic mixed in step (e) to the copper extraction circuit and recycling a portion of the organic mixed in step (e) to the nickel extraction circuit.

Claim 8

A process for recovering copper and nickel from an aqueous ammoniacal leach liquor containing copper and nickel comprising the following steps: a. first extracting copper from the leach liquor in a copper extraction circuit with an organic extractant to leave a raffinate that is depleted in copper values and high in nickel values; b. thereafter extracting nickel from the raffinate of step (a) in a nickel extraction circuit; c. separately stripping the copper loaded organic produced in step (a) in a copper stripping circuit and the nickel loaded organic produced in step (b) in a nickel stripping circuit. d. thereafter introducing the stripped organic from the copper stripping circuit and the stripped organic from the nickel stripping circuit into a mix tank; e. mixing the organics from the copper and nickel stripping circuits in the mix tank; and, f. recycling a portion of the organic mixed in step (e) to the copper extraction circuit and recycling a portion of the organic mixed in step (e) to the nickel extraction circuit.

Claim 9

A process for treating an ammoniacal leach liquor containing copper, nickel, cobalt and molybdenum values in which the ammonia content of the ammoniacal leach liquor is reduced to a level of 30 g/l or less prior to extracting nickel comprising the steps of: a. contacting the leach solution with an organic oxime to selectively extract copper from the leach solution; b. stripping copper from the copper loaded organic oxime of step (a) with an acid; c. subjecting the copper electrolyte produced in step (b) to electrowinning for the recovery of copper in the form of cathodes; d. contacting the copper depleted leach solution of step (a) which has an ammonia content of 30 g/l or less with an organic oxime to extract nickel; e. contacting the nickel loaded organic oxime produced in step (d) with a highly concentrated ammonium carbonate salt solution to strip a portion of the nickel loaded on the organic oxime; f. stripping ammonia from the strip solution of step (e) to precipitate nickel contained in the strip solution as a basic carbonate; g. recovering nickel from the precipitated carbonate of step (f); h. recycling the nickel stripped organic oxime of step (e) to step (a), to extract copper, the recycling of the nickel stripped organic oxime to the copper extraction circuit of step (a) preventing the build-up of copper in the organic oxime used for nickel extraction; and, recycling the organic stripped of copper in step (b) to step (d) to be used in extracting nickel.

Claim 10

A process for treating an ammoniacal leach liquor containing copper, nickel, cobalt and molybdenum values in which the ammonia content of the ammoniacal leach liquor is reduced to a level of 30 g/l or less prior to extracting nickel comprising the steps of: a. contacting the leach solution with an organic oxime to selectively extract copper from the leach solution; b. stripping copper from the copper loaded organic oxime of step (a) with an acid; c. subjecting the copper electrolyte produced in step (b) to electrowinning for the recovery of copper in the form of cathodes; d. contacting the copper depleted leach solution of step (a) which has an ammonia content of 30 g/l or less with an organic oxime to extract nickel; e. contacting the nickel loaded organic oxime produced in step (d) with a highly concentrated ammonium carbonate salt solution to strip a portion of the nickel loaded on the organic oxime; f. stripping ammonia from the strip solution of step (e) to precipitate nickel contained in the strip solution as a basic carbonate; g. recovering nickel from the precipitated carbonate of step (f); h. recycling the nickel stripped organic oxime of step (e) to step (a), to extract copper, the recycling of the nickel stripped organic oxime to the copper extraction circuit of step (a) preventing the build-up of copper in the organic oxime used for nickel extraction; and, recycling the organic stripped of copper in step (b) to step (d) to be used in extracting nickel.

Claim 11

The process as set forth in claim 6 wherein in step (b) the copper loaded organic oxime is stripped with sulfuric acid.

Claim 12

The process as set forth in claim 6 wherein in step (e) the nickel loaded organic oxime is contacted with a solution containing approximately 150 g/l ammonia and 90 g/l CO 2 to strip a portion of the nickel loaded on the organic oxime.

Claim 13

The process as set forth in claim 6 wherein in step (g) the carbonate is calcined to form nickel oxide.

Claim 14

The process as set forth in claim 6 wherein cobalt and molybdenum remain in the copper and nickel depleted raffinate.