Heap leaching

Patent metadata

Field	Value
Publication number	US-10526685-B2
Application number	US-201816154276-A
Country	US
Kind code	B2
Filing date	Oct 8, 2018
Priority date	Oct 30, 2015
Publication date	Jan 7, 2020
Grant date	Jan 7, 2020

Abstract

A method of leaching chalcopyrite ores includes the steps of forming agglomerates of fragments of chalcopyrite ores and silver and leaching the agglomerates with suitable leach liquor.

First claim

The invention claimed is:

1. A method of leaching chalcopyrite ores includes the steps of:
(a) forming agglomerates of fragments of chalcopyrite ores and silver, defined herein as “added silver”, the agglomeration step including adding silver in a solution as a spray or a mist or in a solid form as an aerosol to the chalcopyrite ore fragments while the fragments are being mixed together; and
(b) leaching the agglomerates with suitable leach liquor.

2. The method defined in claim 1 wherein the agglomerates formed in the agglomeration step (a) have a low added silver concentration of less than 2 g silver per kg copper in the ore in the agglomerates.

3. The method defined in claim 1 wherein the agglomeration step (a) includes adding silver to the chalcopyrite ore fragments in the aerosol.

4. The method defined in claim 1 wherein the agglomeration step (a) includes adding silver in the mist or the spray.

5. The method defined in claim 1 wherein the agglomeration step (a) includes forming agglomerates by also mixing together an acid with the chalcopyrite ore fragments and the added silver.

6. The method defined in claim 5 wherein the acid is sulfuric acid.

7. The method defined in claim 1 wherein the agglomeration step (a) includes forming agglomerates by also mixing microorganisms that can assist leaching of copper with the chalcopyrite ore fragments and added silver.

8. The method defined in claim 1 wherein the agglomeration step (a) includes simultaneously mixing and agglomerating fragments and the added silver.

9. The method defined in claim 1 wherein the leaching step (b) is a heap leaching step.

10. The method defined in claim 9 wherein the heap leaching step (b) includes controlling the heap temperature to be less than 75° C.

11. The method defined in claim 10 wherein the heap leaching step (b) includes controlling the heap temperature to be less than 65° C.

12. The method defined in claim 10 wherein the heap leaching step (b) includes controlling the heap temperature to be less than 60° C.

13. The method defined in claim 9 includes controlling the oxidation potential of the leach liquor during an active leaching phase of the step to be less than 700 mV versus the standard hydrogen electrode in the heap leaching step (b).

14. The method defined in claim 1 wherein the agglomerates formed in the agglomeration step (a) have an added silver concentration of less than 1 g silver per kg copper in the ore in the agglomerates.

15. A method of leaching chalcopyrite ores includes the steps of:
(a) forming agglomerates of fragments of chalcopyrite ores and silver, defined herein as “added silver”, wherein the agglomerates formed in the agglomeration step (a) have a low added silver concentration of less than 1 g silver per kg copper in the ore in the agglomerates; and
(b) heap leaching the agglomerates with suitable leach liquor, wherein the heap leaching step (b) includes controlling the heap temperature to be less than 75° C.

16. The method defined in claim 15 wherein the added silver concentration in the agglomerates is less than 0.5 g silver per kg copper in the ore in the agglomerates.

17. The method defined in claim 16 wherein the added silver concentration in the agglomerates is less than 0.25 g silver per kg copper in the ore in the agglomerates.

18. The method defined in claim 16 wherein the added silver concentration in the agglomerates is less than 0.125 g silver per kg copper in the ore in the agglomerates.

19. The method defined in claim 16 wherein the added silver concentration in the agglomerates is less than 0.075 g silver per kg copper in the ore in the agglomerates.

20. The method defined in claim 15 wherein the heap leaching step (b) includes controlling the heap temperature to be less than 65° C.

21. The method defined in claim 15 includes controlling the oxidation potential of the leach liquor during an active leaching phase of the step to be less than 700 mV versus the standard hydrogen electrode in the heap leaching step (b).

22. The method defined in claim 15 wherein the heap leaching step (b) includes controlling the heap temperature to be less than 60° C.

23. The method defined in claim 15 wherein the heap leaching step (b) includes controlling the heap temperature to be less than 55° C.

Assignees

• Tech Resources Pty Ltd

Inventors

• Brown Paul Leslie
• Hackl Ralph Peter
• Grocott Stephen Charles

Classifications

• C22B3/06

  in inorganic acid solutions {, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions} · CPC title

• C22B15/0067

  with acids or salts thereof · CPC title

• C22B15/0071 Primary

  containing sulfur · CPC title

• C22B1/14

  Agglomerating; Briquetting; Binding; Granulating · CPC title

• C22B15/0065

  Leaching or slurrying (with organic compounds C22B3/16) · CPC title