Leaching Copper-Containing Ores

Patent metadata

Field	Value
Publication number	US-2019345581-A1
Application number	US-201916364453-A
Country	US
Kind code	A1
Filing date	Mar 26, 2019
Priority date	May 9, 2018
Publication date	Nov 14, 2019
Grant date	—

Abstract

A method of leaching copper-containing ores includes leaching copper-containing ores or concentrates or tailings of the ores or concentrates with a leach liquor in the presence of an additive that enhances the dissolution of copper from copper minerals in the ores and concentrates by forming a complex between (a) sulfur, that has originated from copper minerals in the ores, and (b) the additive. A method of leaching copper-containing ores includes leaching copper-containing ores or concentrates or tailings of the ores or concentrates with a leach liquor includes leaching copper-containing ores or concentrates or tailings of the ores or concentrates with a leach liquor in the presence of a nitrogen-containing organic complexing additive that forms a complex between sulfur, that has originated from copper minerals in the ores, and the additive.

First claim

1 . A method of leaching copper-containing ores containing chalcopyrite and/or enargite, concentrates of the ores, or tailings of the ores or the concentrates, comprising leaching the copper-containing ores containing chalcopyrite and/or enargite, the concentrates of the ores, or the tailings of the ores or the concentrates with a leach liquor in the presence of an additive that enhances dissolution of copper from copper minerals in the ores and the concentrates by forming a complex between (a) sulfur, that has originated from copper minerals in the ores, and (b) the additive, wherein the concentration of the additive is up to 10 g/L in the leach liquor, and wherein leaching includes controlling the pH of the leach liquor to be less than 2.5.

2 . The method according to claim 1 , wherein the complex comprises sulfur from the copper minerals and the additive, with the additive breaking down a passivating layer or reducing a formation of a passivating layer and therefore increasing access for leaching copper from copper minerals during the method.

3 . The method according to claim 1 , wherein the additive comprises a nitrogen-containing complexing agent that includes at least two nitrogen atoms spaced by two carbon atoms to permit the additive to form complexes between sulfur, that has originated from copper minerals in the ores, and the additive.

4 . The method according to claim 1 , wherein the additive is a compound that contains molecular scaffold (I) or a polymer that contains molecular scaffold (I) repeated through the polymer:

wherein, the two nitrogen atoms are each independently substituted or unsubstituted, each nitrogen atom is selected from the group consisting of a primary amine group, a secondary amine group, and a tertiary amino group;
the two carbon atoms may each be substituted or unsubstituted;
the bonds between the nitrogen atoms and carbon atoms in the scaffold may be single bonds or multiple bonds; and
the bonds between the two carbon atoms in the scaffold may be single bonds or multiple bonds.

5 . The method according to claim 1 , wherein the additive is a compound of formula (II) or a polymer formed from two of more monomers of formula (III):

wherein, in formula (II) and (III),
R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are each independently selected from a lone pair electron, H, alkyl groups, alkenyl groups, alkynyl groups, or alkylamino groups, or the substituents on each of the two nitrogens together form an alkyl or alkynyl group that connect the two nitrogens to form a ring;
R 7 , R 8 , R 9 and R 10 are each independently selected from H, alkyl, alkenyl, alkynyl, OH, alkyloxy groups, alkenyloxy groups, alkynyloxy groups, C(═O)R where R is alkyl, alkenyl or alkynyl, C(O)OH, C(O)OR where R is alkyl, alkenyl or alkynyl, OC(═O)R where R is alkyl, alkenyl or alkynyl, amino, alkylamino, alkenylamino, alkynylamino, C(O)NH 2 , C(O)NHR where R is alkyl, alkenyl or alkynyl, C(O)NR 2 where R is alkyl, alkenyl or alkynyl, or R 7 and R 8 together and/or R 9 and R 10 together may be selected from ═O, ═NH, or ═NH where R is alkyl, alkenyl or alkynyl; and in formula (III),
R 1 or R 2 are each independently selected from the groups defined for R 1 and R 2 above or are connected to another monomer of formula (III).

6 . (canceled)

7 . The method according to claim 1 , wherein leaching includes controlling the temperature to be less than 100° C.

8 . The method according to claim 1 , wherein leaching includes controlling the temperature to be at least 5° C.

9 . The method according to claim 1 , wherein leaching includes controlling the oxidation potential of the leach liquor during an active leaching phase to be less than 900 mV, wherein the oxidation potential is determined with respect to a standard hydrogen electrode.

10 . (canceled)

11 . The method according to claim 1 , wherein leaching includes controlling the pH of the leach liquor to be greater than 0.5.

12 . The method according to claim 1 , wherein leaching includes bioleaching with microorganisms to assist leaching of copper.

13 . The method according to claim 1 , wherein leaching includes adding chemical oxidants to the leach liquor.

14 . The method according to claim 1 , includes recovering copper from the leach liquor in downstream copper recovery steps.

15 . The method according to claim 1 , includes adding the additive to the leach liquor continuously or periodically during the method to maintain a required concentration during the method.

16 . The method according to claim 1 , includes adding the additive to ore fragments prior to the leaching.

17 . The method according to claim 16 , includes forming agglomerates of ore fragments and adding the additive to agglomerates prior to the leaching.

18 . The method according to claim 16 , includes forming agglomerates of ore fragments and adding the additive while forming agglomerates.

19 . The method according to claim 16 , includes forming agglomerates of ore fragments, wherein the additive is polyethylenimine (PEI), and the forming agglomerates includes:
(a) forming a PEI solution having a pH greater than pH 4.5; (b) optionally heating the solution to at least 50° C. to speed up dissolution/dilution of the PEI; and (c) adding the PEI solution to ore fragments at the start of the forming agglomerates.

20 . The method according to claim 1 , includes regenerating the leach liquor and recycling the regenerated leach liquor to heap.

21 . The method according to claim 20 , includes adjusting the concentration of the additive in the regenerated leach liquor to maintain a concentration of up to 10 g/L in the leach liquor.

22 . The method according to claim 20 , includes adding or removing the additive to the regenerated leach liquor to maintain a concentration of up to 10 g/L in the leach liquor.

23 . A method of leaching copper-containing ores, concentrates of the ores, or tailings of the ores or concentrates, that includes leaching the copper-containing ores, the concentrates or the tailings of the ores or the concentrates with a leach liquor in the presence of a nitrogen-containing organic complexing additive that forms a complex between sulfur, that has originated from copper minerals in the ores, and the additive wherein the additive is a degradation product that forms under conditions of the leach.

24 . The method defined in claim 23 , wherein the complex comprises sulfur in a passivating layer on copper minerals and the additive, with the complex breaking down the passivating layer or reducing formation of the layer and therefore allowing greater access for leaching copper from copper minerals during the method.

25 . (canceled)

26 . The method defined in claim 23 , wherein the degradation product is a degradation product of another additive.

27 . The method defined in claim 23 , wherein the nitrogen-containing organic complexing additive includes at least two nitrogen atoms.

28 . The method defined in claim 27 wherein each of the at least two nitrogen atoms in the additive is present as a primary amine group, a secondary amine gro

Assignees

• Tech Resources Pty Ltd

Inventors

• Kittelty Daniel Arthur
• Brown Paul Leslie
• Hackl Ralph Peter
• Najjar Pauline Maree
• Zonneveld Anna
• Young Jason Maurice

Classifications

• C22B3/1666

  Leaching with heterocyclic compounds · CPC title

• C22B15/0067 Primary

  with acids or salts thereof · CPC title

• C22B3/1625

  with amines (amino acids C22B3/165) · CPC title

• C22B15/0073

  containing nitrogen · CPC title

• C22B3/08

  Sulfuric acid {, other sulfurated acids or salts thereof} · CPC title