Method of ore processing

Patent metadata

Field	Value
Publication number	US-2016355906-A1
Application number	US-201615241200-A
Country	US
Kind code	A1
Filing date	Aug 19, 2016
Priority date	Jan 25, 2011
Publication date	Dec 8, 2016
Grant date	—

Abstract

A method of selectively leaching a metal such as nickel from an ore or ore processing intermediate comprising the metal and cobalt. The ore or ore processing intermediate is contacted with an acidic leach solution comprising an amount of an oxidising agent sufficient to oxidise a major portion of the cobalt to thereby cause it to be stabilised in the solid phase while a major portion of the metal is dissolved for subsequent recovery.

First claim

1 . A method of selectively leaching a metal selected from the group consisting of nickel, copper and zinc from a solid ore or solid ore processing intermediate comprising the metal and cobalt, the method including:
a) providing a mixture comprising an acidic leach solution and an oxidising agent; and b) mixing the mixture with the solid ore or solid ore processing intermediate,
wherein there is sufficient oxidising agent to stabilize greater than 95% by mass of the cobalt to cause it to be stabilised in a solid phase while greater than 50% by mass of the metal is selectively dissolved.

2 . The method of claim 1 , wherein greater than 70% by mass of the metal is selectively dissolved.

3 . The method of claim 1 , wherein greater than 90% by mass of the metal is selectively dissolved.

4 . The method of claim 1 wherein the metal is nickel.

5 . The method of claim 1 wherein the solid ore or solid ore processing intermediate is a mixed nickel-cobalt hydroxide precipitate.

6 . The method of claim 1 wherein the oxidising agent has sufficient oxidising potential to oxidise cobalt(II) to cobalt(III).

7 . The method of claim 6 wherein the oxidising agent has an oxidative potential of greater than about 0.5 V (SHE).

8 . The method of claim 6 wherein the oxidising agent has an oxidative potential of greater than 0.5 V to 3.0 V (SHE).

9 . The method of claim 1 wherein the acidic leach solution has a pH from about 1 to about 6.

10 . The method of claim 9 wherein the acidic leach solution has a pH from about 2 to about 5.

11 . The method of claim 8 wherein the oxidising agent has an oxidative potential of about 0.5 V to about 3.0 V (SHE) at a pH from 0 to 6.

12 . The method of claim 11 wherein the oxidising agent has an oxidative potential of about 0.5 V to about 1.0 V (SHE) at a pH from 4 to 6.

13 . The method of claim 11 wherein the oxidising agent has an oxidative potential of about 1.0 V to about 2.0 V (SHE) at a pH from 1 to 4.

14 . The method of claim 1 wherein the oxidising agent is selected from the group consisting of persulphates, peroxides, permanganates, perchlorates, ozone, oxides and chlorine.

15 . The method of claim 1 further including a step of controlling addition of the oxidising agent.

16 . The method of claim 1 further including a step of heating the acidic leach solution to greater than 50° C.

17 . The method of claim 1 wherein a majority of the metal has been leached into the acidic leach solution from the solid ore or solid ore processing intermediate after 1 to 5 hours.

18 . The method of claim 1 wherein the oxidising agent is present in the acidic leach solution in 80% to 200% stoichiometric equivalents to combined cobalt and manganese in the solid ore or solid ore processing intermediate.

19 . The method of claim 1 wherein the solid ore or solid ore processing intermediate further comprises manganese and treatment with the amount of oxidising agent causes a major portion of the manganese to be stabilised in a solid phase while a major portion of the metal is dissolved.

20 . The method of claim 1 wherein, after leaching is complete, extracted metal can be recovered directly from the acidic leach solution by electrowinning or hydrogen reduction.

21 . A method of recovering nickel and cobalt from a mixed nickel-cobalt hydroxide precipitate including the steps of:
(a) providing a mixture comprising an acidic leach solution and an oxidising agent, wherein there is sufficient oxidising agent to stabilise greater than 95% by mass of the cobalt to cause it to be stabilized in the solid phase while greater than 50% by mass of the nickel is selectively dissolved; (b) mixing the mixture with the mixed nickel-cobalt hydroxide precipitate, (c) separating the cobalt in the solid phase from the acidic leach solution containing dissolved nickel to recover the cobalt in the solid phase; and (d) recovering the nickel from the acidic leach solution.

22 . The method of claim 21 wherein the mixed nickel-cobalt hydroxide precipitate further comprises manganese and addition of an amount of oxidising agent also causes a major portion of the manganese to be stabilised in a solid phase.

Assignees

• Univ Queensland

Inventors

• Vaughan James
• Hawker William

Classifications

• C22B19/22

  with leaching with acids · CPC title

• C22B23/0476 Primary

  Separation of nickel from cobalt · CPC title

• C22B23/0461

  by chemical methods · CPC title

• C22B23/043

  Sulfurated acids or salts thereof · CPC title

• C25C1/08

  of nickel or cobalt · CPC title