AU4719000A - Process for dissolving precious metals - Google Patents
Process for dissolving precious metals Download PDFInfo
- Publication number
- AU4719000A AU4719000A AU47190/00A AU4719000A AU4719000A AU 4719000 A AU4719000 A AU 4719000A AU 47190/00 A AU47190/00 A AU 47190/00A AU 4719000 A AU4719000 A AU 4719000A AU 4719000 A AU4719000 A AU 4719000A
- Authority
- AU
- Australia
- Prior art keywords
- slurry
- precious metal
- bearing material
- metal bearing
- ore
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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- 239000010970 precious metal Substances 0.000 title claims description 36
- 238000000034 method Methods 0.000 title claims description 28
- 230000008569 process Effects 0.000 title description 10
- 239000002002 slurry Substances 0.000 claims description 29
- 238000004090 dissolution Methods 0.000 claims description 17
- AMWRITDGCCNYAT-UHFFFAOYSA-L manganese oxide Inorganic materials [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 claims description 16
- 229910052736 halogen Inorganic materials 0.000 claims description 15
- 150000002367 halogens Chemical class 0.000 claims description 15
- 239000007800 oxidant agent Substances 0.000 claims description 14
- 239000011504 laterite Substances 0.000 claims description 12
- 229910001710 laterite Inorganic materials 0.000 claims description 12
- 239000000243 solution Substances 0.000 claims description 12
- 239000012141 concentrate Substances 0.000 claims description 11
- 239000000203 mixture Substances 0.000 claims description 10
- 239000007787 solid Substances 0.000 claims description 10
- 239000008139 complexing agent Substances 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 9
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 6
- 235000011149 sulphuric acid Nutrition 0.000 claims description 6
- 239000001117 sulphuric acid Substances 0.000 claims description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical group [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 5
- 150000007522 mineralic acids Chemical class 0.000 claims description 5
- 239000001301 oxygen Substances 0.000 claims description 5
- 229910052760 oxygen Inorganic materials 0.000 claims description 5
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 4
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 4
- PPNAOCWZXJOHFK-UHFFFAOYSA-N manganese(2+);oxygen(2-) Chemical class [O-2].[Mn+2] PPNAOCWZXJOHFK-UHFFFAOYSA-N 0.000 claims description 4
- 229910017604 nitric acid Inorganic materials 0.000 claims description 4
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 claims description 3
- 239000003929 acidic solution Substances 0.000 claims description 3
- -1 halide ion Chemical class 0.000 claims description 3
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 claims description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 claims description 2
- XTEGARKTQYYJKE-UHFFFAOYSA-N chloric acid Chemical class OCl(=O)=O XTEGARKTQYYJKE-UHFFFAOYSA-N 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 claims description 2
- 239000012433 hydrogen halide Substances 0.000 claims description 2
- 229910000039 hydrogen halide Inorganic materials 0.000 claims description 2
- XMBWDFGMSWQBCA-UHFFFAOYSA-N hydrogen iodide Chemical compound I XMBWDFGMSWQBCA-UHFFFAOYSA-N 0.000 claims description 2
- 150000003839 salts Chemical class 0.000 claims description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 32
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 18
- 229910052759 nickel Inorganic materials 0.000 description 16
- 229910017052 cobalt Inorganic materials 0.000 description 15
- 239000010941 cobalt Substances 0.000 description 15
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 15
- 229910052500 inorganic mineral Inorganic materials 0.000 description 14
- 239000011707 mineral Substances 0.000 description 14
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 10
- 229910052751 metal Inorganic materials 0.000 description 10
- 239000002184 metal Substances 0.000 description 10
- 230000003647 oxidation Effects 0.000 description 9
- 238000007254 oxidation reaction Methods 0.000 description 9
- 229910052697 platinum Inorganic materials 0.000 description 9
- 238000004458 analytical method Methods 0.000 description 8
- 239000010953 base metal Substances 0.000 description 8
- 238000002386 leaching Methods 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 7
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 6
- 150000002739 metals Chemical class 0.000 description 6
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 5
- 229910052737 gold Inorganic materials 0.000 description 5
- 239000010931 gold Substances 0.000 description 5
- 239000011159 matrix material Substances 0.000 description 5
- 229910052763 palladium Inorganic materials 0.000 description 5
- 238000011084 recovery Methods 0.000 description 5
- 239000003795 chemical substances by application Substances 0.000 description 4
- 239000000706 filtrate Substances 0.000 description 4
- 150000004706 metal oxides Chemical group 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 239000006228 supernatant Substances 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- 229910021607 Silver chloride Inorganic materials 0.000 description 3
- 229910044991 metal oxide Inorganic materials 0.000 description 3
- 229910052976 metal sulfide Inorganic materials 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical group O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 229910001882 dioxygen Inorganic materials 0.000 description 2
- 238000009854 hydrometallurgy Methods 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- QZPSXPBJTPJTSZ-UHFFFAOYSA-N aqua regia Chemical compound Cl.O[N+]([O-])=O QZPSXPBJTPJTSZ-UHFFFAOYSA-N 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000005381 potential energy Methods 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 239000011343 solid material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 150000004763 sulfides Chemical group 0.000 description 1
- 229910021653 sulphate ion Inorganic materials 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 238000004148 unit process Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Landscapes
- Manufacture And Refinement Of Metals (AREA)
Description
AUSTRALIA
PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT (Original) APPLICATION NO:
LODGED:
COMPLETE SPECIFICATION LODGED:
ACCEPTED:
PUBLISHED:
RELATED ART: NAME OF APPLICANT: ACTUAL INVENTOR(S): JAMES HAMILTON KYLE JAMES HAMILTON KYLE oooeoo ADDRESS FOR SERVICE: LORD COMPANY Patent Trade Mark Attorneys 4 Douro Place West Perth, Western Australia, 6005
AUSTRALIA.
INVENTION TITLE: "PROCESS
METALS"
FOR DISSOLVING PRECIOUS The following Statement is a full description of this invention including the best method of performing it known to me/us:
TITLE
"PROCESS FOR DISSOLVING PRECIOUS METALS" FIELD OF THE INVENTION The present invention relates to a process for dissolving precious metals, particularly precious metals present in trace amounts, from mineral ores and concentrates. The term precious metals in this application should be understood to include also minerals formed from such metals.
BACKGROUND OF THE INVENTION It is well established in hydrometallurgical mineral processing that a range of leaching agents are available to facilitate dissolution of first row transition metals such as cobalt, nickel, or copper, from mineral ores and concentrates. The efficacy of oooeo most leaching agents relies on the oxidation and/or selective complexation of metal cations in solution, sometimes coupled with an ability of the leaching agent to lower the oxidation potential of the metal such that potential energy savings in the hydrometallurgical process is possible compared with more traditional •pyrometallurgical processing.
The precious metals are considered to be "noble" metals, and include gold, platinum, o palladium, rhodium, ruthenium, osmium and iridium. They normally remain inert to oxidation and dissolution under ambient or high temperature and pressure conditions within acidic and/or oxidising leaching solutions. Furthermore, trace amounts of precious metals may occur with, or be occluded by base metal ores in the mineral matrix, thereby preventing physical contact between the leaching agent and the precious metals, and inhibiting the reaction therebetween. Thus, under the conditions of known hydrometallurgical processes, trace amounts of precious metals commonly reside in the leach residues and a separate leaching process is generally required in order for the precious metals to be recovered.
It is known to provide methods for the dissolution of precious metals from materials containing said metals. Hydrometallurgical recovery of precious metals has traditionally been achieved by extraction with cyanides, aqua regia, and more recently by oxidative treatment with elemental halogens. Such materials are not only expensive but because of their toxicity, particularly in the case of cyanide, expensive transportation, storage and environmental protection facilities are required for their use in a processing installation.
Furthermore, it is common practice for some precious metal containing ores particularly sulphidic ores to be subjected to high temperature roasting of the ore prior to hydrometallurgical leaching, to liberate precious metals occluded by the mineral matrix.
The present invention seeks to overcome at least some of the aforementioned **.disadvantages.
:eooto SUMMARY OF THE INVENTION In accordance with one aspect of the present invention there is provided a method for the dissolution of a precious metal, including heating a Slurry to a temperature of at least 150'C in the presence of a complexing agent and a non-halogen oxidising agent, the complexing agent being selected to form soluble complexes of the precious metals leached into solution during dissolution, wherein the slurry comprises a precious metal bearing material and an aqueous acidic solution, and the slurry is maintained at a pH of less than 4 during dissolution.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The process of the present invention is suitable for the dissolution of precious metals present in trace amounts in solid materials, such as mineral ores and concentrates, wherein the precious metal is in an elemental form, a metal oxide form, a metal sulphide form, or other form. It will be understood that the mineral ore or concentrate may also contain one or more base metals, for example copper, cobalt, nickel, or zinc.
It will also be understood that the mineral ore or concentrate may include metal sulphides, metal oxides or other minerals formed by the precious metals.
Preferably, the mineral ore or concentrate may be first ground to form a fine particulate solid of approximately 200 micron or less. In this way, the surface area of •go.
each particulate is greatly increased to allow optimum exposure to the leaching chemicals. Preferably, the fine particulate solid is slurried in aqueous solution during comminution or alternatively mixed with an aqueous solution after comminution to form a slurry which may contain from 5 to 50 weight percent solids in water.
A complexing agent is introduced or mixed with the slurry. Preferably, the complexing agent is a halide ion, such as chloride, bromide, iodide, fluoride or a S mixture thereof Typically, at least a sufficient amount of the complexing agent is added to the slurry to form soluble complexes of the precious metals leached into 20 solution during the dissolution process.
The slurry may then be transferred to a pressure vessel or autoclave.
The slurry in the pressure vessel or autoclave may then be heated to a temperature of at least 150'C, preferably between 200'C to 250'C. Preferably, the acid is then added to the slurry. Preferably, the acid is a strong inorganic acid, such as sulphuric acid, nitric acid, an aqueous hydrogen halide or a mixture thereof.
The slurry is treated under the above mentioned conditions with a non-halogen oxidising agent. Preferably, the non-halogen oxidising agent is oxygen gas, which may be supplied to the pressure vessel or autoclave at an overpressure from about kPa to 500 kPa. Alternatively, the non-halogen oxidising agent may be hydrogen peroxide, nitric acid, peroxymonosulphate salts, manganese oxides, chlorate salts, or a mixture thereof It will be appreciated that non-gaseous non-halogen oxidising agents are typically mixed into the slurry, or in the case of a gas, either dispersed into the slurry and/or applied to the atmosphere above the slurry, after the slurry is transferred to the pressure vessel or autoclave.
Preferably, the dissolution process may be conducted over a period from about minutes to 2 hours. Preferably, the final pH of the slurry is less than Under the reaction conditions described above, both base metals and precious metals are dissolved into solution. The precious metals can be separated from the base metals and removed from the solution via conventional techniques.
For lateritic ores or concentrates, the primary role of the inorganic acid is to dissolve the base metal oxides into solution to facilitate contact between the precious metals, which are occluded by the base metal oxides in the mineral matrix, and the non- :°o.o halogen oxidising agent. The inorganic acid also provides a lower pH medium in which the dissolved metal ions and metal ion complexes are more likely to be soluble.
:i 20 In sulphide ores or concentrates, the precious metals may occur with, or are occluded by base metal sulphides in the mineral matrix. The non-halogen oxidising agent oxidises insoluble sulphide species to soluble higher oxidation state sulphur species, such as sulphate. The non-halogen oxidising agent also oxidises the precious metals to a higher oxidation state ionic species which are conducive to forming soluble precious metal complexes with the complexing agent.
6 The advantage of the present invention is that the precious metals as well as the other base metals present in the mineral matrix are dissolved into solution in the same unit process. The various metals can then be separated and recovered from solution by well established processes.
The following example illustrates the invention: Example 1 A laterite ore, containing nickel, cobalt and platinum, was screened at 212 micron, and the oversize crushed to less than 212 micron.
An ore slurry formed from the crushed laterite ore (600g) and a saline solution (1800g) of 2.5 M NaCI and 0.4 M MgSO 4 was placed in an autoclave vessel. The autoclave vessel was sealed and heated to 250 0 C. At this temperature, the steam •*og pressure was 4,800 kPa. An oxygen gas overpressure of 400 kPa was supplied to the sealed autoclave vessel and maintained throughout the dissolution reaction.
Concentrated sulphuric acid (300g) was then added to the sealed autoclave vessel through an inlet valve and the reaction was allowed to proceed for 2 hours. The resultant slurry was then cooled to below 100C, and a representative sample was taken for analysis. The supernatant was filtered from the solid.
Analytical test results were as follows. The final pH of the solution was 0.6. The oxidation/reduction potential of the filtrate was 800 mV (vs Ag/AgCl). The final 20 concentration of H 2 S0 4 was 35 g/L. The recovery values of nickel, cobalt and platinum after dissolution under the conditions specified above were 95%, 97% and respectively.
Example 2 A laterite ore, containing nickel, cobalt, gold, platinum and palladium together with high concentrations of manganese oxides, was screened at 212 micron, and the 7 oversize was ground to less than 212 micron. The concentrations of nickel, cobalt and manganese in the ore were 0.11%, and respectively.
An ore slurry formed from the crushed laterite ore (600g) and a saline solution (1800g) of 1.0 M NaCl was placed in an autoclave vessel. The autoclave vessel was sealed and heated to 250 0 C. At this temperature, the steam pressure was 4,800 kPa.
In contrast to Example 1, an overpressure of oxygen was not supplied to the vessel.
Sufficient manganese oxide was present in the laterite ore to act as the non-halogen oxidising agent.
Concentrated sulphuric acid (220g) was then added to the sealed autoclave vessel through an inlet valve and the reaction was allowed to proceed for 2 hours. The resultant slurry was then cooled to below 100'C, and a representative sample was *ooo o taken for analysis. The supernatant was filtered from the solid.
Analytical test results were as follows. The oxidation/reduction potential of the filtrate was 810 mV (vs Ag/AgCl). The final concentration of H 2 S0 4 was 40 g/L.
15 The recovery values of nickel, cobalt, gold, platinum and palladium after dissolution •go* se. under the conditions specified above were 96%, 97%, 80%, 85%, and respectively.
Example 3 A nickel refinery waste product, containing significant metal values of nickel, cobalt 0:00 20 and platinum group metals, was mixed with a nickel/cobalt laterite ore containing high concentrations of manganese oxides. The mass ratio of the waste product to the laterite ore was 2:1.
The concentrations of nickel, cobalt and manganese in the ore were 0.52%, and respectively. The refinery waste contained 3.0% nickel, 0.3% cobalt, 4 ppm gold, 200 ppm platinum, and 150 ppm palladium.
8 The mixture of waste product and laterite ore was screened at 212 micron, and the oversize was crushed to less than 212 micron.
An ore slurry formed from the crushed mixture (600g) and a saline solution (1800g) of 0.5 M NaCI was placed in an autoclave vessel. The autoclave vessel was sealed and heated to 250'C. At this temperature, the steam pressure was 4,800 kPa.
In contrast to Example 1, an overpressure of oxygen was not supplied to the vessel..
Sufficient manganese oxide is present in the mixture to act as the non-halogen oxidising agent.
Concentrated sulphuric acid (250g) was then added to the sealed autoclave vessel through an inlet valve and the reaction was allowed to proceed for 2 hours. The resultant slurry was then cooled to below 100C, and a representative sample was oo taken for analysis. The supernatant was filtered from the solid.
Analytical test results were as follows. The oxidation/reduction potential of the filtrate was 790 mV (vs Ag/AgCl). The final concentration of H 2 S0 4 was 50 g/L.
The recovery values of nickel, cobalt, gold, platinum, and palladium after dissolution under the conditions specified above were 97%, 97%, 85%, 90%, and respectively.
Example 4 A manganese oxide ore, containing approximately 25% manganese, was mixed with a 20 nickel/cobalt laterite in a mass ratio of three parts laterite ore to one part manganese oxide ore. The concentrations of nickel, cobalt and platinum in the ore were 1.2%, 0.12%, and 0.2 ppm respectively. The manganese oxide ore contained only minuscule quantities of these metals.
The mixed ore was screened at 212 micron, and the oversize was ground to less than 212 micron. An ore slurry formed from the crushed ore mixture (600g) and a saline 9 solution (1800g) of 0.2 M NaCI was placed in an autoclave vessel. The autoclave vessel was sealed and heated to 250'C. At this temperature the steam pressure was 4800 kPa. An overpressure of oxygen was not supplied to the vessel as sufficient manganese oxide was present in the laterite ore to act as the non-halogen oxidising agent.
Concentrated sulphuric acid (270g) was then added to the sealed autoclave vessel through an inlet valve and the reaction was allowed to proceed for 2 hours. The resultant slurry was then cooled to blow 100'C, and a representative sample was taken for analysis. The supernatant was filtered from the solid.
Analytical test results were as follows. The oxidation/reduction potential of the filtrate was 800 mV (vs Ag/AgCI). The final concentration of H 2 S0 4 was 50 g/L.
oo The recovery values of nickel, cobalt, and platinum after dissolution under the conditions specified above were 95%, 95% and 90% respectively.
While the present invention has been particularly described with reference to certain specific embodiments thereof it will be understood that various modification may be made to the process by persons skilled in the art without departing from the spirit and scope of the invention.
o*ooo*
Claims (12)
1. A method for the dissolution of a precious metal, including heating a slurry to a temperature of at least 150C in the presence of a complexing agent and a non- S halogen oxidising agent, the complexing agent being selected to form soluble complexes of the precious metals leached into solution during dissolution, wherein the slurry comprises a precious metal bearing material and an aqueous acidic solution, and the slurry is maintained at a pH of less than 4 during dissolution.
2. The method according to claim 1, characterised in that the complexing agent is a halide ion selected from a halide ion group including chloride, bromide, iodide, fluoride or a mixture thereof
3. The method according to claim 1 or claim 2, characterised in that the slurry is heated to a temperature between 150C to 300 0 C. .:oo.i
4. The method according to claim 3, characterised in that the slurry is heated to a temperature between 200 C to 250 0 C. The method according to any one of claims 1 to 3, characterised in that the aqueous acidic solution is comprised of a strong inorganic acid.
6. The method according to claim 5, characterised in that the strong inorganic acid is selected from a group including sulphuric acid, nitric acid, an aqueous 20 hydrogen halide, or a mixture thereof
7. The method according to any one of claims 1 to 6, characterised in that the non-halogen oxidising agent is oxygen.
8. The method according to claim 7, characterised in that oxygen is supplied at an overpressure from about 50kPa to 500kPa. 11
9. The method according to any one of claims 1 to 6, characterised in that the non-halogen oxidising agent is selected from a group including hydrogen peroxide, nitric acid, peroxymonosulphate salts, manganese oxides, chlorate salts, or a mixture thereof.
10. The method according to any one of claims 1 to 9, characterised in that the precious metal bearing material is a fine particulate solid screened in a range of 150 to 300 micron.
11. The method according to claim 10, characterised in that the precious metal bearing material is a fine particulate solid less than about 200 micron.
12. The method according to any one of claims 1 to 11, characterised in that the slurries contains 5% to 50% w/w solids. S= 13. The method according to any one of claims 1 to 12, characterised in that the precious metal bearing material is a sulphide ore or concentrate.
14. The method according to any one of claims 1 to 12, characterised in that the precious metal bearing material is an oxide ore or concentrate. The method according to any one of claims 1 to 12, characterised in that the precious metal bearing material is a laterite ore or concentrate. DATED THIS 13TH DAY OF JULY 2000. s ee**: JAMES HAMILTON KYLE By his Patent Attorneys LORD COMPANY PERTH, WESTERN AUSTRALIA.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU47190/00A AU4719000A (en) | 1999-07-13 | 2000-07-13 | Process for dissolving precious metals |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AUPQ1591A AUPQ159199A0 (en) | 1999-07-13 | 1999-07-13 | Process for dissolving precious metals |
| AUPQ1591 | 1999-07-13 | ||
| AU47190/00A AU4719000A (en) | 1999-07-13 | 2000-07-13 | Process for dissolving precious metals |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| AU4719000A true AU4719000A (en) | 2001-01-18 |
Family
ID=25627769
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU47190/00A Abandoned AU4719000A (en) | 1999-07-13 | 2000-07-13 | Process for dissolving precious metals |
Country Status (1)
| Country | Link |
|---|---|
| AU (1) | AU4719000A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005093107A1 (en) * | 2004-03-25 | 2005-10-06 | Intec Ltd | Recovery of metals from oxidised metalliferous materials |
| WO2006119559A1 (en) | 2005-05-13 | 2006-11-16 | Bhp Billiton Ssm Technology Pty Ltd | An improved process for heap leaching of nickeliferous oxidic ores |
| CN102154561A (en) * | 2011-05-23 | 2011-08-17 | 长春黄金研究院 | Non-cyanide gold leaching method for refractory gold concentrate |
| WO2014008540A1 (en) * | 2012-07-09 | 2014-01-16 | Direct Nickel Pty Ltd | Method for the recovery of nickel from sulphide ores |
-
2000
- 2000-07-13 AU AU47190/00A patent/AU4719000A/en not_active Abandoned
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005093107A1 (en) * | 2004-03-25 | 2005-10-06 | Intec Ltd | Recovery of metals from oxidised metalliferous materials |
| EA010061B1 (en) * | 2004-03-25 | 2008-06-30 | Интэк Лтд. | Recovery of metals from oxidised metalliferous materials |
| US8323377B2 (en) | 2004-03-25 | 2012-12-04 | Intec, Ltd. | Recovery of metals from oxidised metalliferous materials |
| WO2006119559A1 (en) | 2005-05-13 | 2006-11-16 | Bhp Billiton Ssm Technology Pty Ltd | An improved process for heap leaching of nickeliferous oxidic ores |
| EP1880029A4 (en) * | 2005-05-13 | 2009-08-12 | Bhp Billiton Ssm Dev Pty Ltd | IMPROVED METHOD FOR THE HEART EXTRACTION OF NICKEL-CONTAINING OXIDIC OINTMENTS |
| CN102154561A (en) * | 2011-05-23 | 2011-08-17 | 长春黄金研究院 | Non-cyanide gold leaching method for refractory gold concentrate |
| WO2014008540A1 (en) * | 2012-07-09 | 2014-01-16 | Direct Nickel Pty Ltd | Method for the recovery of nickel from sulphide ores |
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