Method for recovery of metals from metal-containing materials using medium temperature pressure leaching
View Patent ↗The present invention relates generally to a process for recovering copper and other metal values from metal-containing materials using controlled, super-fine grinding and medium temperature pressure leaching. Processes embodying aspects of the present invention may be beneficial for recovering a variety of metals such as copper, gold, silver, nickel, cobalt, molybdenum, rhenium, zinc, uranium, and platinum group metals, from metal-bearing materials, and find particular utility in connection with the extraction of copper from copper sulfide ores and concentrates.
1. A method for recovering metal from a metal-bearing material, comprising the steps of:
(a) providing a feed stream comprising a metal-bearing material;
(b) subjecting at least a portion of said feed stream to controlled, super-fine grinding to form an inlet stream, wherein said controlled, super-fine grinding comprises reducing the particle size of said feed stream to a P98 of less than about 25 microns;
(c) leaching at least a portion of said inlet stream in the presence of oxygen at an elevated temperature and pressure to form a metal-bearing solution;
(d) recovering at least one metal value from said metal-bearing solution.
2. The method of claim 1 , wherein said step of providing a feed stream comprising a metal-bearing material comprises providing a feed stream comprising a copper sulfide ore or concentrate.
3. The method of claim 1 , wherein said step of providing a feed stream comprising a metal-bearing material comprises providing a feed stream comprising chalcopyrite.
4. The method of claim 1 , wherein said step of subjecting said feed stream to controlled, super-fine grinding comprises reducing the particle size of said feed stream to a P98 of from about 10 to about 23 microns.
5. The method of claim 1 , wherein said step of subjecting said feed stream to controlled, super-fine grinding comprises reducing the particle size of said feed stream to a P98 of from about 13 to about 15 microns.
6. The method of claim 1 , wherein said step of leaching said inlet stream comprises leaching said inlet stream at a temperature of from about 140° C. to about 180° C. and at a pressure of from about 100 psi to about 750 psi.
7. The method of claim 1 , wherein said step of leaching said inlet stream comprises leaching said inlet stream at a temperature of from about 1500° C. to about 1750° C. and at a pressure of from about 100 psi to about 750 psi.
8. The meted of claim 1 , wherein said step of leaching said inlet stream further comprises leaching said inlet stream in the presence of a surfactant.
9. The method of claim 1 , wherein said step of leaching said inlet stream further comprises leaching said inlet stream in the presence of a surfactant selected from the group consisting of lignin derivatives, orthophenylene diamine, alkyl sulfonates, and mixtures thereof.
10. The method of claim 1 , wherein said step of leaching said inlet stream further comprises leaching said inlet stream in the presence of calcium lignosulfonate.
11. The method of claim 1 , wherein said step of leaching said inlet stream further comprises leaching said inlet stream in the presence of a surfactant in an amount of from about 2 to about 20 kilograms per tonne of concentrate in the inlet stream.
12. The method of claim 1 further comprising the step of combining at least a portion of said inlet stream with a liquid prior to step (c) to form an inlet stream having a solid-liquid ratio.
13. The method of claim 12 , wherein said step of combining at least a portion of said inlet stream with a liquid comprises combining at least a portion of said inlet stream with at least one of process water, raffinate, pregnant leach solution, and lean electrolytc.
14. The method of claim 12 , wherein said step of combining at least a portion of said inlet stream with a liquid comprises combining at least a portion of said inlet stream with a liquid to form an inlet stream having a solid-liquid ratio of from about 5 percent to about 50 percent.
15. The method of claim 12 , wherein said step of combining at least a portion of said inlet stream with a liquid comprises combining at least a portion of said inlet stream with a liquid to form an inlet stream having a solid-liquid ratio of from about 10 percent to about 35 percent.