Process for leaching metal sulfides with reagents having thiocarbonyl functional groups

Patent metadata

Field	Value
Publication number	US-10954583-B2
Application number	US-202016743635-A
Country	US
Kind code	B2
Filing date	Jan 15, 2020
Priority date	Apr 17, 2015
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

This application pertains to methods of recovering metals from metal sulfides that involve contacting the metal sulfide with an acidic sulfate solution containing ferric sulfate and a reagent that has a thiocarbonyl functional group, wherein the concentration of reagent in the acidic sulfate solution is sufficient to increase the rate of metal ion extraction relative to an acidic sulfate solution that does not contain the reagent, to produce a pregnant solution containing the metal ions.

First claim

What is claimed is:

1. A method of recovering at least one base metal from at least one base metal sulfide in a material, the method comprising:
contacting a material comprising at least one base metal sulfide with an acidic sulfate solution comprising a reagent having a thiocarbonyl functional group to produce a pregnant solution containing base metal ions; and
recovering the at least one base metal from the at least one base metal sulfide from the pregnant solution,
wherein the reagent is not thiourea (Tu), and wherein the thiocarbonyl functional group of the reagent has a sulfur that bears a partial negative charge, bears negative electrostatic potential surface, and has an empty π*-antibonding orbital as its lowest unoccupied molecular orbital.

2. The method of claim 1 , wherein the acidic solution comprises ferric sulfate.

3. The method of claim 1 , wherein the reagent is N—N′ substituted thioureas; 2,5-Dithiobimea; Dithiobiuret; Thiosemicarbazide purum; Thiosemicarbazide; Thioacetamide; 2-Methyl-3-thiosemicarbazide; 4-Methyl-3-thiosemicarbazide; Vinylene trithiocarbonate purum; Vinylene trithiocarbonate; 2-Cyanothioacetamide; Ethylene trithiocarbonate; Potassium ethyl xanthogenate; Dimethylthiocarbamoyl chloride; Dimethyldithiocarbamate; Dimethyl trithiocarbonate; N,N-Dimethylthioformamide; 4,4-Dimethyl-3-thiosemicarbazide; 4-Ethyl-3-thiosemicarbazide; O-Isopropylxanthic acid; Ethyl thiooxamate; Ethyl dithioacetate; Diethylthiocarbamoyl chloride; Diethyldithiocarbamate; Tetramethylthiuram monosulfide; Tetramethylthiuram disulfide; O-Phenyl chlorothionoformate; Phenyl chlorodithioformate; 3,4-Difluorothiobenzamide; 2-Bromothiobenzamide; 3-Bromothiobenzamide; 4-Bromothiobenzamide; 4-Chlorothiobenzamide; 4-Fluorothiobenzamide; Thiobenzoic acid; Thiobenzamide; 4-Phenylthiosemicarbazide; O-(p-Tolyl) chlorothionoformate; 4-Bromo-2-methylthiobenzamide; 3-Methoxythiobenzamide; 4-Methoxythiobenzamide; 4-Methylbenzenethioamide; Thioacetanilide; Salicylaldehyde thiosemicarbazone; Indole-3-thiocarboxamide; S-(Thiobenzoyl)thioglycolic acid; 3-(Acetoxy)thiobenzamide; 4-(Acetoxy)thiobenzamide; 3-Ethoxythiobenzamide; 4-Ethylbenzene-1-thiocarboxamide; Diethyldithiocarbamic acid; 2-(Phenylcarbonothioylthio)propanoic acid; 2-Hydroxybenzaldehyde; N-ethylthiosemicarbazone; (1R,4R)-1,7,7-Trimethylbicyclo[2.2.1]heptane-2-thione; Tetraethylthiuram disulfide; 4′-Hydroxybiphenyl-4-thiocarboxamide; 4-Biphenylthioamide; Dithizone; 4′-Methylbiphenyl-4-thiocarboxamide; Tetraisopropylthiuram disulfide; Anthracene-9-thiocarboxamide; Phenanthrene-9-thiocarboxamide; Sodium dibenzyldithiocarbamate; 4,4′-Bis(dimethylamino)thiobenzophenone; or any combination thereof.

4. The method of claim 1 , wherein the concentration of the reagent in the acidic solution is in the range of about 0.2 mM to about 30 mM.

5. The method of claim 1 , wherein the concentration of the reagent in the acidic solution is in the range of about 0.2 mM to about 20 mM.

6. The method of claim 1 , wherein the concentration of the reagent in the acidic solution is in the range of about 0.2 mM to about 10 mM.

7. The method of claim 1 , wherein the concentration of the reagent in the acidic solution is in the range of about 0.2 mM to about 5 mM.

8. The method of claim 1 , wherein the concentration of the reagent in the acidic solution is in the range of about 0.2 mM to about 4 mM.

9. The method of claim 1 , wherein the concentration of the reagent in the acidic solution is in the range of about 0.2 mM to about 3 mM.

10. The method of claim 1 , wherein the concentration of the reagent in the acidic solution is in the range of about 0.2 mM to about 2 mM.

11. The method of claim 1 , wherein the concentration of the reagent in the acidic solution is in the range of about 0.2 mM to about 1.5 mM.

12. The method of claim 1 , wherein the concentration of the reagent in the acidic solution is in the range of about 0.2 mM to about 1.0 mM.

13. The method of claim 1 , wherein the concentration of the reagent in the acidic solution is in the range of about 0.2 mM to about 0.5 mM.

14. The method of claim 1 , wherein the at least one base metal sulfide includes at least one copper sulfide.

15. The method of claim 14 , wherein the at least one copper sulfide includes chalcopyrite.

16. The method of claim 14 , wherein the at least one copper sulfide includes covellite.

17. The method of claim 14 , wherein the at least one copper sulfide includes bornite.

18. The method of claim 14 , wherein the at least one copper sulfide includes enargite.

19. The method of claim 14 , wherein the at least one copper sulfide includes a copper sulfide of the formula Cu x S y wherein the x:y ratio is between 1 and 2.

20. The method of claim 14 , wherein the at least one copper sulfide includes chalcocite.

21. The method of claim 14 , wherein the at least one copper sulfide includes djurleite.

22. The method of claim 14 , wherein the at least one copper sulfide includes digenite.

23. The method of claim 1 , wherein the at least one base metal sulfide includes a cadmium sulfide.

24. The method of claim 23 , wherein the cadmium sulfide is greenockite.

25. The method of claim 1 , wherein the at least one base metal sulfide includes at least one nickel sulfide.

26. The method of claim 25 , wherein the at least one nickel sulfide includes pentlandite.

27. The method of claim 25 , wherein the at least one nickel sulfide includes violarite.

28. The method of claim 1 , wherein the material is an ore.

29. The method of claim 1 , wherein the material is a concentrate of the at least one base metal sulfide.

30. The method of claim 1 , wherein the material comprises agglomerated particles.

31. The method of claim 1 , wherein the acidic solution comprises ferric ions, wherein the ferric ions in the acidic solution are used to oxidize the metal sulfide.

32. The method of claim 31 , wherein the ferric ions are generated at least in part by bacteria.

33. The method of claim 1 , wherein the method is a percolation leach.

34. The method of claim 33 , wherein the percolation leach is a heap leach.

35. The method of claim 1 , wherein the leach is a vat leach.

36. The method of claim 1 , wherein the method is a tank leach.

37. The method of claim 1 , wherein the method is a column leach.

38. The method of claim 1 , wherein recovering the at least one base metal from the pregnant solution comprises solvent extraction and electrowinning.

39. The method of claim 1 , further comprising maintaining the operating potential of the acidic solution above 500 mV vs Ag/AgCl.

40. The method of claim 1 , wherein the acidic solution comprises a least one oxidizing agent.

Assignees

• Univ British Columbia

Inventors

• Dixon David
• Asselin Edouard
• Ghahreman Ahmad
• Ren Zihe

Classifications

• C25C1/08

  of nickel or cobalt · CPC title

• C25C1/16

  of zinc, cadmium or mercury · CPC title

• C22B23/0461

  by chemical methods · CPC title

• C22B15/0089

  by chemical methods · CPC title

• C22B3/18

  with the aid of microorganisms or enzymes, e.g. bacteria or algae · CPC title