Systems and methods for improved metal recovery using ammonia leaching

1. A method comprising:

leaching a slurry comprising a metal bearing material comprising one of copper and cobalt and copper and cobalt compounds, and a leach medium comprising ammonia and ammonium carbonate;

adding copper powder to the slurry;

separating the slurry into a pregnant leach solution and solids, the pregnant leach solution comprising copper and cobalt; and

performing a solvent extraction on the pregnant leach solution to produce a copper bearing loaded aqueous stream and a cobalt bearing raffinate.

2. The method of claim 1 , further comprising:

producing a cobalt precipitate from the raffinate; and

subjecting the cobalt precipitate to a metal recovery process.

3. The method of claim 1 , wherein the leach medium further comprises ammonium sulfate.

4. The method of claim 1 , further comprising:

producing a cobalt precipitate and a cobalt depleted liquid phase from the raffinate; and

adding a portion of the cobalt depleted liquid phase to the slurry during leaching.

5. The method of claim 1 , wherein the solvent extraction comprises at least one of an extraction phase, a scrub stage, a wash stage, and a solvent stripping phase.

6. The method of claim 5 , wherein the extraction phase yields a cobalt-bearing raffinate.

7. The method of claim 6 , further comprising precipitating cobalt from the cobalt-bearing raffinate.

8. The method of claim 7 , wherein the precipitating yields cobalt sulfide in a solid phase.

9. The method of claim 8 , wherein the cobalt sulfide is subjected to leaching.

10. The method of claim 5 , further comprising subjecting the loaded aqueous stream to electrowinning.