Recovery of nickel
(19) AUSTRALIAN PATENT OFFICE (54) Title Recovery of nickel (51 )G International Patent Classification(s) C22B 3/06 (2006.01) 6BMEP C22B C22B 23/00 (2006.01)23/00 C22B 3/06 20060101ALI2006050 20060101AFI2006050 6BMEP PCT/AU2005/000724 (21) Application No: (22) A (87) WIPONo: WO05/113845 (30) Priority Data (31) Number 2004902740 (32) Date 2004.05.21 (33) Country AU (43) Publication Date : 2005.12.01 (71) Applicant(s) WMC Resources Ltd (72) Inventor(s) Furfaro, Domenic; Streltsova, Natalia (74) Agent/Attorney (21) Application No: (22) A (87) WIPONo: WO05/113845 (30) Priority Data (31) Number 2004902740 (32) Date 2004.05.21 (33) Country AU (43) Publication Date : 2005.12.01 (71) Applicant(s) WMC Resources Ltd (72) Inventor(s) Furfaro, Domenic; Streltsova, Natalia (74) Agent/Attorney 2005.05.20 Griffith Hack, 509 St Kilda Road, Melbourne, VIC, 3004 A process for recovering nickel from a solid feed material containing nickel in the form of millerite is disclosed. The process includes treating a slurry of the solid feed material and a process solution so that all or at least part of the nickel in the millerite forms an acid leachable solid form. The process also includes pressure acid leaching the treated slurry and leaching nickel in solids in the slurry into solution. Finally, the process includes recovering nickel from solution.
1 A process for recovering nickel from a solid feed
material containing nickel in the form of millerite which
5 includes the steps of:
(a) treating a slurry.of the solid feed material
and a process solution so that all or at least
part of the nickel in the millerite forms an
acid leachable solid form;
(b) pressure acid leaching the treated slurry from
step (a) and leaching nickel in solids in the
slurry into solution; and
(c) recovering nickel from solution.
2 The process defined in claim 1 wherein the process
solution contains at least 5g/l chlorides.
3 The process defined in claim 1 wherein the process
solution contains at least 20g/l chlorides.
4 The process defined in any one of the preceding claims
wherein step (a) includes treating the slurry of the feed
material and the process solution under non-acidic conditions.
5 The process defined in any one of the preceding claims
wherein step (a) includes treating the slurry of the feed
material and the process solution at a pH in the range of 5.5
7.
6 The process defined in claim 5 wherein step (a) includes
adjusting the pH of the slurry to be within the range of 5.5 -
7 and maintaining the pH within the range during step (a) by
the presence of acid soluble alkaline gangue minerals in the
feed material or by adding an alkaline agent to the slurry.
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7 The process defined in any one of the preceding claims
wherein step (a) includes treating the slurry of the feed
material and the process solution at an elevated temperature.
8 The process defined in claim 7 wherein the elevated
temperature is in a range of 80-160'C.
9 The process defined in claim 7 or claim 8 wherein the
elevated temperature is at least 1100C.
10 The process defined in any one of claims 7 to 9 wherein
the elevated temperature is no more than 1550C.
11 The process defined in any one of claims 7 to 9 wherein
the elevated temperature is no more than 1500C.
12 The process defined in any one of the preceding claims
wherein step (a) includes treating the slurry of the feed
material and the process solution under oxidation conditions.
13 The process defined in any one of the preceding claims
wherein step (a) includes treating the slurry of the feed
material and the process solution under pressure oxidation
conditions.
14 The process defined in any one of the preceding claims
wherein step (a) includes treating the slurry of the feed
material and the process solution under pressure oxidation
conditions with an 02 partial pressure that is suff icient to
oxidise at least substantially all of the sulphide in the
millerite to sulphate.
15 The process defined in claim 14 wherein step (a) also
includes treating the slurry of the feed material and the
process solution under pressure oxidation conditions with an 02
partial pressure that is sufficient to oxidise other sulphide
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minerals in the feed material that can be oxidised without
causing undesirable acid generation.
16 The process defined in any one of the preceding claims
wherein step (a) includes treating the slurry of the feed
material and the process solution under pressure oxidation
conditions with an 02 partial pressure in a range of 250-1000
kPa(g).
17 The process defined in claim 16 wherein the 02 partial
pressure is in a range of 500-1000 kPa(g) in step (a).
18 The process defined in any one of the preceding claims
wherein the duration of step (a) is in a range of 15-90
minutes.
19 The process defined in any one of the preceding claims
wherein step (b) includes acid leaching the treated slurry
from step (a) at a pH of 3 or less.
20 The process defined in any one of the preceding claims
wherein step (b) includes pressure acid leaching the treated
slurry from step (a) at a pH of 2 or less.
21 The process defined in any one of the preceding claims
wherein step (b) includes pressure acid leaching the treated
slurry from step (a) in sulphuric acid.
22 The process defined in any one of the preceding claims
wherein step (b) includes pressure acid leaching the treated
slurry from step (a) under oxidation conditions.
23 The process defined in any one of the preceding claims
wherein step (b) includes pressure acid leaching the treated
slurry from step (a) under pressure oxidation conditions with
an 02 partial pressure in a range of
800-1200 kPa(g).
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24 The process defined in any one of the preceding claims
wherein step (b) includes pressure acid leaching the treated
slurry from step (a) at an elevated temperature.
25 The process defined in claim 24 wherein the elevated
temperature is in a range of 100-160'C.
26 The process defined in claim 24 or claim 25 wherein the
elevated temperature is at least 130'C.
27 The process defined in any one of claims 24 to 26 wherein
the elevated temperature is no more than 1550C.
28 The process defined in any one of claims 24 to 26 wherein
the elevated temperature is no more than 1500C.
29 The process defined in any one of the preceding claims
wherein the duration of step (b) is in a range of 30-120
minutes.
30 The process defined in any one of the preceding claims
includes adding a separate slurry of a solid feed material and
a process solution to the treated slurry from step (a) prior
to or as part of step (b)