Process for multiple stage direct electrowinning of copper
View Patent ↗A system and process for recovering copper from a copper-containing ore, concentrate, or other copper-bearing material to produce high quality cathode copper from a leach solution without the use of copper solvent/solution extraction techniques or apparatus. A process for recovering copper from a copper-containing ore generally includes the steps of providing a feed stream containing comminuted copper-containing ore, concentrate, or other copper-bearing material, leaching the feed stream to yield a copper-containing solution, conditioning the copper-containing solution through one or more physical or chemical conditioning steps, and electrowinning copper directly from the copper-containing solution in multiple electrowinning stages, without subjecting the copper-containing solution to solvent/solution extraction prior to electrowinning.
1. A method of recovering copper from a copper-bearing material, comprising the steps of:
subjecting a feed stream comprising a copper-containing material and an acid to pressure leaching at a temperature of from about 100° C. about 250° C. to yield a product slurry comprising a copper-bearing solution and a residue;
electrowinning copper from at least a portion of said copper-bearing solution in a first electrowinning stage to produce copper cathode and a first stage lean electrolyte stream;
electrowinning copper from at least a portion of said first stage lean electrolyte stream in a second electrowinning stage to produce copper cathode and a second stage lean electrolyte stream; and
recycling at least a portion of said first stage lean electrolyte stream to said pressure leaching step.
2. The method of claim 1 , wherein said feed stream in said step of subjecting comprises at least one of a copper-bearing sulfide ore, a concentrate, and a precipitate.
3. The method of claim 1 , wherein said feed stream in said step of subjecting comprises at least one of chalcopyrite, chalcocite, bornite, covellite, digenite, enargite, or mixtures or combinations thereof.
4. The method of claim 1 , further comprising the step of separating at least a portion of said copper-containing material from said acid in said feed stream to yield a copper-containing feed stream comprising a copper-bearing material.
5. The method of claim 4 , wherein said separating step comprises reacting at least a portion of the copper in a copper-containing electrolyte stream to precipitate at least a portion of said copper in said copper-containing electrolyte stream as copper sulfide in said feed stream.
6. The method of claim 4 , wherein said separating step comprises reacting at least a portion of the copper in a copper-containing electrolyte stream in the presence of sulfur dioxide, whereby at least a portion of said copper in said copper-containing electrolyte stream precipitates as copper sulfide in said feed stream.
7. The method of claim 1 , wherein said pressure leaching of said subjecting step comprises pressure leaching said feed stream in the presence of a surfactant selected from the group consisting of lignin derivatives, orthophenylene diamine, alkyl sulfonates, and mixtures thereof.
8. The method of claim 1 , wherein said pressure leaching of said subjecting step comprises pressure leaching said feed stream in the presence of a surfactant in an amount of from about 2 to about 20 kilograms per tonne of concentrate in the copper-containing feed stream.
9. The method of claim 1 , wherein said step of electrowinning copper from at least a portion of said first stage lean electrolyte stream in a second electrowinning stage comprises electrowinning copper from at least a portion of said first stage lean electrolyte stream without subjecting said first stage lean electrolyte stream to solvent/solution extraction.
10. The method of claim 4 , wherein said step of electrowinning copper from at least a portion of said first stage lean electrolyte stream in a second electrowinning stage comprises electrowinning copper from at least a portion of said first stage lean electrolyte stream without subjecting said first stage lean electrolyte stream to solvent/solution extraction.
11. The method of claim 1 , further comprising the step of using a portion of said second stage lean electrolyte stream in a leaching operation.
12. The method of claim 4 , further comprising the step of recycling a portion of said second stage lean electrolyte stream to said separating step.