Controlled metal leach recovery circuit
View Patent ↗The present invention relates generally to a process for controlled leaching and sequential recovery of two or more metals from metal-bearing materials. In one exemplary embodiment, recovery of metals from a leached metal-bearing material is controlled and improved by providing a high grade pregnant leach solution (“HGPLS”) and a low grade pregnant leach solution (“LGPLS”) to a single solution extraction plant comprising at least two solution extractor units, at least two stripping units, and, optionally, at least one wash stage.
1. A method comprising:
producing a high grade pregnant leach solution and a low grade pregnant leach solution by subjecting a metal value containing product slurry to a solid-liquid separation process, wherein said low grade pregnant leach solution has a lower concentration of a metal value than said high grade pregnant leach solution;
subjecting said low grade pregnant leach solution to a solution extraction plant comprising at least two solution extractors and at least two stripping units to produce a low grade raffinate and a partially loaded organic solution; and
subjecting said high grade pregnant leach solution to said solution extraction plant to produce a high grade raffinate and a metal-loaded solution by contacting said high grade pregnant leach solution with said partially loaded organic solution.
2. The method of claim 1 , further comprising creating said product slurry using a reactive process.
3. The method of claim 1 , wherein said metal value is-stripped from said metal-loaded solution in at least one stripping unit.
4. The method of claim 3 , wherein a barren organic solution is produced by at least one stripping unit.
5. The method of claim 2 , wherein said reactive process is a leaching process.
6. The method of claim 5 , wherein said high grade raffinate is recycled to said leaching process.
7. The method of claim 1 , wherein said low grade raffinate comprises a secondary metal value.
8. The method of claim 7 , wherein said low grade raffinate is subjected to secondary metal recovery processing.
9. The method of claim 7 , wherein said secondary metal value is selected from the group consisting of gold, silver, platinum group metals, molybdenum, zinc, nickel, cobalt, uranium, rhenium, rare earth metals, and actinide metals.
10. A method comprising:
producing a low grade raffinate and a partially loaded organic solution in a first solution extractor unit by contacting a low grade pregnant leach solution with a barren organic solution;
producing a high grade raffinate and a metal-loaded organic solution in a second solution extractor unit by contacting a high grade pregnant leach solution with said partially loaded organic solution;
producing said barren organic solution by stripping a metal value from said metal-loaded organic solution in a stripping unit.
11. The method of claim 10 , wherein said high grade pregnant leach solution has a greater concentration of a metal value than said low grade pregnant leach solution.
12. The method of claim 10 , wherein said first solution extractor unit and said second solution extractor unit are in a solution extraction plant.
13. The method of claim 10 , further comprising adding a metal-specific extraction reagent to said barren organic solution prior to contacting with said low grade pregnant leach solution.
14. The method of claim 10 , wherein said high grade pregnant leach solution is generated from at least one of an atmospheric leaching process, a pressure leaching process, an agitation leaching process, a heap leaching process, a stockpile leaching process, a pad leaching process, a thin-layer leaching process, and a vat leaching process.
15. The method of claim 10 , wherein said low grade raffinate is subjected to secondary metal recovery processing.
16. The method of claim 15 , wherein the low grade raffinate comprises a secondary metal selected from the group consisting of silver, platinum group metals, molybdenum, zinc, nickel, cobalt, uranium, rhenium, rare earth metals, and actinide metals.