Systems and methods for metal recovery
View Patent ↗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, leaching the roasted metal hearing material in a basic medium to yield a pregnant leach solution, conditioning the pregnant leach solution to thrill a preprocessed metal bearing material; and leaching the preprocessed metal bearing material in acid medium.
1. A process comprising:
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;
leaching the roasted metal bearing material in a basic medium to yield a pregnant leach solution;
conditioning the pregnant leach solution to form a preprocessed metal bearing material; and
leaching the preprocessed metal bearing material in acid medium.
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 2 , wherein the acid medium comprises sulfuric acid.
4. The process of claim 2 , wherein the conditioning comprises crystallizing the pregnant leach solution to form the preprocessed metal bearing material and a vapor.
5. The process of claim 1 , wherein the oxidizing conditions comprise an oxygen gas containing atmosphere.
6. The process of claim 1 , wherein the reducing conditions comprise at least one of a carbon monoxide gas containing atmosphere and a hydrogen gas containing atmosphere.
7. The process of claim 4 , further comprising condensing the vapor into a condensate and recycling the condensate into the basic medium.
8. The process of claim 4 , further comprising washing the preprocessed metal bearing material with water.
9. The process of claim 4 , further comprising adding seed crystals to the pregnant leach solution.
10. The process of claim 5 , wherein the oxidizing conditions further comprise a temperature of from about 550° C. to about 700° C.
11. The process of claim 6 , wherein the reducing conditions further comprise a temperature of from about 475° C. to about 575° C.
12. The process of claim 1 , further comprising grinding a metal bearing ore to yield the metal bearing material.
13. The process of claim 1 , wherein the leaching the preprocessed metal bearing material in acid medium yields an acidic pregnant leach solution and further comprising recovering a metal value from the acidic pregnant leach solution.
14. A process comprising:
oxidizing sulfides of copper by roasting under oxygen gas to produce an oxidized copper bearing material;
reducing copper by roasting the oxidized copper bearing material under at least one of hydrogen and carbon monoxide to produce a roasted copper bearing material;
leaching the roasted copper bearing material with ammonia to yield a pregnant leach solution;
precipitating copper containing compounds from the pregnant leach solution; and
leaching the copper containing compounds in acid medium.
15. The process of claim 14 , further comprising precipitating cobalt containing compounds from the pregnant leach solution.
16. The process of claim 14 , wherein the precipitating comprises adding copper containing seed crystals to the pregnant leach solution.
17. The process of claim 14 , wherein the acid medium comprises sulfuric acid.
18. The process of claim 14 , further comprising washing the copper containing compounds with water.
19. The process of claim 14 , wherein the oxidizing occurs at a temperature of from about 550° C. to about 700° C.
20. The process of claim 14 , wherein the reducing occurs at a temperature of from about 475° C. to about 575° C.