Systems and methods for copper recovery via roasting and leaching
Various embodiments provide a process roasting a metal bearing material under oxidizing conditions to produce an oxidized metal bearing material, roasting the oxidized metal bearing material under reducing conditions to produce a roasted metal bearing material, and leaching the roasted metal bearing material in a basic medium to yield a pregnant leach solution.
1. A process comprising:
roasting a metal bearing material comprising a copper carbonate under oxidizing conditions, at a temperature between about 625° C. and about 675° C.;
roasting the metal bearing material under reducing conditions, at a temperature of about 500° C. or greater; and
leaching the metal bearing material in a basic medium to yield a pregnant leach solution.
2. The process of claim 1 , wherein the basic medium comprises at least one of ammonia, ammonium carbonate and ammonium sulfate.
3. The process of claim 1 , wherein the oxidizing conditions comprise an oxygen gas containing atmosphere.
4. The process of claim 1 , wherein the reducing conditions comprise a hydrogen gas containing atmosphere.
5. The process of claim 1 , further comprising subjecting the pregnant leach solution to a solution extraction process to yield a loaded aqueous stream.
6. The process of claim 5 , wherein an extraction stage of the solution extraction yields a cobalt-bearing raffinate.
7. The process of claim 6 , further comprising precipitating cobalt from the cobalt-bearing raffinate.
8. The process of claim 7 , wherein the precipitating yields cobalt sulfide.
9. The process of claim 8 , wherein the cobalt sulfide is subjected to leaching.
10. The process of claim 5 , subjecting the loaded aqueous stream to electrowinning.
11. The process of claim 1 , wherein the copper carbonate comprises at least one of azurite and malachite.
12. A process comprising:
oxidizing a metal bearing material comprising a copper carbonate to produce an oxidized metal bearing material at a temperature between about 625° C. and about 675° C.;
reducing the oxidized metal bearing material at a temperature of about 540° C. to produce a roasted metal bearing material; and
leaching the roasted metal bearing material in a basic medium to yield a pregnant leach solution.
13. The process of claim 12 , wherein the basic medium comprises at least one of ammonia, ammonium, ammonium carbonate and ammonium sulfate.
14. The process of claim 12 , wherein the oxidizing is performed using an oxidizing agent, and wherein the reducing is performed using a reducing agent.
15. The process of claim 12 , further comprising at least one of preparing the metal bearing material and quenching the roasted metal bearing material.
16. The process of claim 12 , further comprising subjecting the pregnant leach solution to a solution extraction process to yield at least one of a loaded aqueous stream and a cobalt-bearing raffinate.
17. The process of claim 16 , further comprising precipitating cobalt from the cobalt-bearing raffinate.
18. The process of claim 17 , wherein the precipitating yields cobalt sulfide.
19. The process of claim 18 , subjecting the loaded aqueous stream to electrowinning.