Process for Leaching Metal Sulfides with Reagents Having Thiocarbonyl Functional Groups

Patent metadata

Field	Value
Publication number	US-2020181736-A1
Application number	US-202016748553-A
Country	US
Kind code	A1
Filing date	Jan 21, 2020
Priority date	Apr 17, 2015
Publication date	Jun 11, 2020
Grant date	—

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

1 .- 59 . (canceled)

60 . A method of recovering at least one metal from an ore containing at least one metal sulfide, the method comprising:
contacting the ore with an acidic sulfate solution containing ferric sulfate and a reagent having a thiocarbonyl functional group to extract metal ions from the at least one metal sulfide, wherein the concentration of the reagent in the acidic sulfate solution is sufficient to increase the rate of the metal ion extraction relative to an acidic sulfate solution that does not contain the reagent, to produce a pregnant solution containing the metal ions; and recovering the at least one metal from the pregnant solution, wherein the at least one metal includes: copper, wherein the at least one metal sulfide includes chalcopyrite, covellite, bornite, enargite, a copper sulfide of the formula CuxSy wherein the x:y ratio is between 1 and 2, or a combination thereof; cadmium, wherein the at least one metal sulfide is greenockite; nickel, wherein the at least one metal sulfide is pentlandite, violarite, or a combination thereof; or a combination thereof.

61 . The method of claim 60 , wherein the concentration of the reagent in the acidic sulfate solution is in the range of about 0.2 mM to about 30 mM.

62 . The method of claim 60 , wherein the concentration of the reagent in the acidic sulfate solution is in the range of about 0.2 mM to about 20 mM.

63 . The method of claim 60 , wherein the concentration of the reagent in the acidic sulfate solution is in the range of about 0.2 mM to about 10 mM.

64 . The method of claim 60 , wherein the concentration of the reagent in the acidic sulfate solution is in the range of about 0.2 mM to about 5 mM.

65 . The method of claim 60 , wherein the concentration of the reagent in the acidic sulfate solution is in the range of about 0.2 mM to about 4 mM.

66 . The method of claim 60 , wherein the concentration of the reagent in the acidic sulfate solution is in the range of about 0.2 mM to about 3 mM.

67 . The method of claim 60 , wherein the concentration of the reagent in the acidic sulfate solution is in the range of about 0.2 mM to about 2 mM.

68 . The method of claim 60 , wherein the concentration of the reagent in the acidic sulfate solution is in the range of about 0.2 mM to about 1.5 mM.

69 . The method of claim 60 , wherein the concentration of the reagent in the acidic sulfate solution is in the range of about 0.2 mM to about 1.0 mM.

70 . The method of claim 60 , wherein the concentration of the reagent in the acidic sulfate solution is in the range of about 0.2 mM to about 0.5 mM.

71 . The method of claim 60 , wherein the at least one metal includes copper and the at least one metal sulfide includes chalcopyrite.

72 . The method of claim 60 , wherein the at least one metal includes copper and the at least one metal sulfide includes covellite.

73 . The method of claim 60 , wherein the at least one metal includes copper and the at least one metal sulfide includes a copper sulfide of the formula CuxSy wherein the x:y ratio is between 1 and 2.

74 . The method of claim 73 , wherein the copper sulfide includes chalcocite.

75 . The method of claim 73 , wherein the copper sulfide includes djurleite.

76 . The method of claim 73 , wherein the copper sulfide includes digenite.

77 . The method of claim 60 , wherein the at least one metal includes copper and the at least one metal sulfide includes bornite.

78 . The method of claim 60 , wherein the at least one metal includes copper and the at least one metal sulfide includes enargite.

79 . The method of claim 60 , wherein the at least one metal includes cadmium and the at least one metal sulfide includes greenockite.

80 . The method of claim 60 , wherein the at least one metal includes nickel and the at least one metal sulfide includes pentlandite.

81 . The method of claim 60 , wherein the at least one metal includes nickel and the at least one metal sulfide includes violarite.

82 . The method of claim 60 , wherein the reagent is thiourea (Tu).

83 . The method of claim 60 , wherein the reagent is thioacetamide (TA).

84 . The method of claim 60 , wherein the reagent is sodium dimethyldithiocarbamate (SDDC).

85 . The method of claim 60 , wherein the reagent is ethylene trithiocarbonate (ETC).

86 . The method of claim 60 , wherein the reagent is thiosemicarbazide (TSCA).

87 . The method of claim 60 , wherein the ore is provided as coarse particles.

88 . The method of claim 87 , wherein the coarse particles are agglomerated particles.

89 . The method of claim 60 , wherein ferric ions are used to oxidize the at least one metal sulfide.

90 . The method of claim 89 , wherein the ferric ions are generated at least in part by bacteria.

91 . The method of claim 60 , wherein the method is a percolation leach.

92 . The method of claim 91 , wherein the percolation leach is a heap leach.

93 . The method of claim 91 , wherein the leach is a vat leach.

94 . The method of claim 60 , wherein the leach is a tank leach.

95 . The method of claim 60 , wherein recovering the at least one metal from the pregnant solution comprises solvent extraction and electrowinning.

Assignees

• Univ British Columbia

Inventors

• Dixon David
• Olvera Olmedo Oscar
• 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