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EP-4214343-B1 - EXTRACTING BASE METALS USING A WETTING AGENT AND A THIOCARBONYL FUNCTIONAL GROUP REAGENT

EP4214343B1EP 4214343 B1EP4214343 B1EP 4214343B1EP-4214343-B1

Inventors

  • REN, Zihe
  • MORA HUERTAS, Nelson
  • DIXON, DAVID
  • ASSELIN, Edouard

Dates

Publication Date
20260506
Application Date
20210910

Claims (17)

  1. A method for extracting a base metal from a base metal sulfide in a material, the method comprising contacting the material with an aqueous acidic mixture comprising a wetting agent, an oxidizing agent, and a reagent, wherein the reagent comprises: a reagent comprising a thiocarbonyl functional group or formamidine disulfide (FDS).
  2. The method of claim 1, wherein the material is contacted with the wetting agent and the reagent comprising the thiocarbonyl functional group by a method comprising agglomerating the material with the wetting agent prior to contact with the acidic mixture.
  3. The method of any one of claims 1 and 2, wherein the oxidizing agent comprises ferric ions.
  4. The method of any one of claims 1 to 3, wherein the base metal sulfide comprises a copper sulfide.
  5. The method of claim 4, wherein the copper sulfide ore comprises chalcopyrite, bornite, enargite, covellite, chalcocite, a copper sulfide of the formula Cu x S y wherein the x:y ratio is between 1 and 2 or combinations thereof.
  6. The method of any one of claims 1 to 5, wherein the reagent comprising the thiocarbonyl functional group comprises thiourea, ethylene thiourea, thioacetamide, sodium dimethyldithiocarbamate, trithiocarbonate, thiosemicarbazide or combinations thereof.
  7. The method of any one of claims 1 to 6, wherein the wetting agent is a non-ionic wetting agent.
  8. The method of claim 7, wherein the non-ionic wetting agent is a non-ionic ethoxylate surfactant, a polyethylene glycol or combinations thereof.
  9. The method of claim 8, wherein the non-ionic ethoxylate surfactant is selected from a polysorbate, a polyethylene glycol, an alkylphenyl ether of polyethylene glycol or a reduced form thereof, an alkylether of polyethylene glycol, and combinations thereof.
  10. The method of claim 9, wherein the polysorbate is one or more compounds of formula (I): wherein R 1 is C 4-30 alkyl, C 4-30 alkenyl or C 4-30 alkynyl; and j + k + l + m = 20.
  11. The method of claim 9 or 10, wherein the polysorbate is polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 80 or combinations thereof.
  12. The method of any one of claims 9 to 11, wherein the polysorbate is one or more compounds of formula (1): wherein R 1 is C10-20alkyl, C10-20alkenyl.
  13. The method of claim 9, wherein the alkylphenyl ether of polyethylene glycol is one or more compounds of the Formula (II): wherein x is 5-20.
  14. The method of claim 13, wherein the alkylphenyl ether of polyethylene glycol is one or more compounds of the Formula (II): , wherein x is 9-10.
  15. The method of claim 9, wherein the non-ionic wetting agent is a polyethylene glycol.
  16. The method of claim 9 or 15, wherein the polyethylene glycol has a number average molecular weight of from 100 g/mol to 300 g/mol.
  17. The method of claim 9 or 15, wherein the polyethylene glycol is polyethylene glycol 200.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present disclosure claims the benefit of priority from U.S. provisional application no. 63/080,578 filed on September 18, 2020 and U.S. provisional application no. 63/212, 518 filed on June 18, 2021. FIELD The present disclosure relates to the use of a wetting agent such as a non-ionic wetting agent and a reagent comprising a thiocarbonyl functional group, for example, in a process/method for extracting a base metal such as copper from a material comprising the base metal. BACKGROUND Chalcopyrite, a copper iron sulfide having the chemical formula CuFeS2 accounts for approximately 70% of known copper reserves. Hydrometallurgical processing accounts for approximately 20% of copper produced worldwide but it is not currently used for chalcopyrite ores. Rather, pyrometallurgical methods are used for concentrates of these ores. Aqueous processing of minerals may present several advantages over pyrometallurgical approaches, particularly when dealing with complex and/or low-grade ores. The main disadvantage of known hydrometallurgical processes/methods, when applied to chalcopyrite and some other sulfide ores, is the low extraction rates. Certain surfactants such as Tween™ 20, Tween™ 40, Tween™ 60, Tween™ 80 and Triton™ X-100 have been used as a leaching aid for the extraction of copper from its ores such as chalcopyrite. Similar to Triton X-100 and the Tween series surfactants containing a repeating ethoxylate (EO) functional group, polyethylene glycol (PEG) has also been reported to have a catalytic effect in the bioleaching of chalcopyrite. It has also been shown that a thiocarbonyl compound can increase the extraction of metal sulfides in an acidic ferric environment. However, it remains desirable to develop new methods where high copper extractions are achieved in shorter timescales that are of industrial interest. US2018135148A1 prior art discloses a method for extracting a base metal (copper) from a base metal sulfide with an aqueous acidic mixture, containing thiourea, an oxidizing agent (ferric sulfate). US10344353B2 prior art discloses a method for extracting a base metal (copper) from a base metal containing material with an aqueous reductive mixture, containing a wetting agent. J. A. Whitehead et al. discloses in 'Application of 1-alkyl-3-methyl-imidazolium ionic liquids in the oxidative leaching of sulphidic copper, gold and silver ores' the application of an ionic liquid wetting agent for extracting base metals from base metal sulfides. SUMMARY The invention is defined in the appended claims. A hydrometallurgical process/method for extracting base metals such as copper from materials such as copper sulfide ores using a reagent having/comprising a thiocarbonyl functional group and wetting agents as enhancers for the process/method is described herein. In the examples described in greater detail below, the use of the reagent having/comprising a thiocarbonyl functional group with the wetting agents creates a synergistic effect which enhanced extraction in comparison to use of either reagent alone. Accordingly, the present disclosure includes a method for extracting a base metal from a material comprising the base metal, the method comprising contacting the material under acidic conditions with a wetting agent and a reagent comprising a thiocarbonyl functional group. In an embodiment, the material is contacted with the reagent comprising a thiocarbonyl functional group by a method comprising: contacting the material with an acidic mixture comprising the reagent comprising a thiocarbonyl functional group. In another embodiment, the acidic mixture further comprises the wetting agent and the material is contacted with the wetting agent and the reagent comprising a thiocarbonyl functional group by a method comprising: contacting the material with the acidic mixture comprising the wetting agent and the reagent comprising a thiocarbonyl functional group. Alternatively described, the present disclosure includes a method of recovering at least one base metal ion from a material comprising at least one base metal, the method comprising: contacting the material under acidic conditions with a reagent comprising a thiocarbonyl functional group and a wetting agent to produce a pregnant solution comprising the at least one base metal ion; and recovering the at least one base metal ion from the pregnant solution. In embodiments where the reagent comprising a thiocarbonyl functional group is provided in the form of the corresponding dimer, i.e. FDS, the method comprises: contacting the material under acidic conditions with FDS and a wetting agent to produce a pregnant solution comprising the at least one base metal ion; and recovering the at least one base metal ion from the pregnant solution. In an embodiment, contacting the material to produce the pregnant solution comprises extracting the at least one base metal ion from the material. In an embodiment, the material is agglom