AU2004239345B2 - Treatment of base metal concentrate by a two-step bioleaching process - Google Patents
Treatment of base metal concentrate by a two-step bioleaching process Download PDFInfo
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- AU2004239345B2 AU2004239345B2 AU2004239345A AU2004239345A AU2004239345B2 AU 2004239345 B2 AU2004239345 B2 AU 2004239345B2 AU 2004239345 A AU2004239345 A AU 2004239345A AU 2004239345 A AU2004239345 A AU 2004239345A AU 2004239345 B2 AU2004239345 B2 AU 2004239345B2
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- primary
- bioleaching
- concentrate
- base metal
- solution
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- 238000000034 method Methods 0.000 title claims description 75
- 239000010953 base metal Substances 0.000 title claims description 29
- 239000012141 concentrate Substances 0.000 title claims description 27
- 229910052785 arsenic Inorganic materials 0.000 claims description 23
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 claims description 23
- 239000002184 metal Substances 0.000 claims description 18
- 229910052751 metal Inorganic materials 0.000 claims description 18
- 238000011084 recovery Methods 0.000 claims description 18
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 16
- 239000005864 Sulphur Substances 0.000 claims description 16
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 10
- 229910052802 copper Inorganic materials 0.000 claims description 10
- 239000010949 copper Substances 0.000 claims description 10
- 238000002386 leaching Methods 0.000 claims description 10
- 244000005700 microbiome Species 0.000 claims description 10
- 238000010979 pH adjustment Methods 0.000 claims description 10
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 8
- 229910052760 oxygen Inorganic materials 0.000 claims description 8
- 239000001301 oxygen Substances 0.000 claims description 8
- 238000000638 solvent extraction Methods 0.000 claims description 7
- 150000003568 thioethers Chemical class 0.000 claims description 7
- 239000012633 leachable Substances 0.000 claims description 6
- 229910052709 silver Inorganic materials 0.000 claims description 5
- 239000004332 silver Substances 0.000 claims description 5
- 231100000331 toxic Toxicity 0.000 claims description 5
- 230000002588 toxic effect Effects 0.000 claims description 5
- 239000001569 carbon dioxide Substances 0.000 claims description 4
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 4
- 238000005363 electrowinning Methods 0.000 claims description 3
- DJHGAFSJWGLOIV-UHFFFAOYSA-K Arsenate3- Chemical compound [O-][As]([O-])([O-])=O DJHGAFSJWGLOIV-UHFFFAOYSA-K 0.000 claims 1
- 241000237519 Bivalvia Species 0.000 claims 1
- 241000428792 Caldimicrobium Species 0.000 claims 1
- 241001527806 Iti Species 0.000 claims 1
- 229940000489 arsenate Drugs 0.000 claims 1
- 235000020639 clam Nutrition 0.000 claims 1
- 239000000243 solution Substances 0.000 description 31
- 235000019738 Limestone Nutrition 0.000 description 6
- 239000006028 limestone Substances 0.000 description 6
- 230000003647 oxidation Effects 0.000 description 6
- 238000007254 oxidation reaction Methods 0.000 description 6
- 238000001556 precipitation Methods 0.000 description 6
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 5
- 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
- 229910052500 inorganic mineral Inorganic materials 0.000 description 5
- BMWMWYBEJWFCJI-UHFFFAOYSA-K iron(3+);trioxido(oxo)-$l^{5}-arsane Chemical compound [Fe+3].[O-][As]([O-])([O-])=O BMWMWYBEJWFCJI-UHFFFAOYSA-K 0.000 description 5
- 239000011707 mineral Substances 0.000 description 5
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000012267 brine Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000007800 oxidant agent Substances 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 2
- 230000008719 thickening Effects 0.000 description 2
- 239000002562 thickening agent Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- WURBVZBTWMNKQT-UHFFFAOYSA-N 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1,2,4-triazol-1-yl)butan-2-one Chemical compound C1=NC=NN1C(C(=O)C(C)(C)C)OC1=CC=C(Cl)C=C1 WURBVZBTWMNKQT-UHFFFAOYSA-N 0.000 description 1
- 241001464929 Acidithiobacillus caldus Species 0.000 description 1
- 241000894006 Bacteria Species 0.000 description 1
- 241000589921 Leptospirillum ferrooxidans Species 0.000 description 1
- 230000001580 bacterial effect Effects 0.000 description 1
- UBAZGMLMVVQSCD-UHFFFAOYSA-N carbon dioxide;molecular oxygen Chemical compound O=O.O=C=O UBAZGMLMVVQSCD-UHFFFAOYSA-N 0.000 description 1
- 230000010261 cell growth Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000011143 downstream manufacturing Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007717 exclusion Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B15/00—Obtaining copper
- C22B15/0063—Hydrometallurgy
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B11/00—Obtaining noble metals
- C22B11/04—Obtaining noble metals by wet processes
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B15/00—Obtaining copper
- C22B15/0063—Hydrometallurgy
- C22B15/0084—Treating solutions
- C22B15/0089—Treating solutions by chemical methods
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
- C22B3/18—Extraction of metal compounds from ores or concentrates by wet processes with the aid of microorganisms or enzymes, e.g. bacteria or algae
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Organic Chemistry (AREA)
- Metallurgy (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Microbiology (AREA)
- Geology (AREA)
- Geochemistry & Mineralogy (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Biotechnology (AREA)
- Biochemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Preparation Of Compounds By Using Micro-Organisms (AREA)
- Processing Of Solid Wastes (AREA)
- Extraction Or Liquid Replacement (AREA)
Description
WO 2004/101834 PCT/ZA2004/000052 TREATMENT OF BASE METAL CONCENTRATE BACKGROUND OF THE INVENTION [0001] This invention relates to the treatment of a base metal containing concentrate.
[0002] The recovery of a base metal such as copper from a concentrate, which contains arsenic, using a bioleaching process, can be problematic for it is necessary to avoid producing a bioleach residue which is contaminated with arsenic.
[0003] US patent No. 6,461,577 addresses the problem of arsenic toxicity of extremely thermophilic bacterial cultures by means of a two-stage leaching process.
In a first mesophilic stage a major part of the arsenic contained in the material being treated is leached from the material and then oxidised from As(lll) to As(V). The remaining leachable metal content of the material being treated is leached out in a second thermophilic stage. The concentration of pentavalent arsenic falls quickly and the toxic effect thereof on the thermophilic bacteria thus falls at the same rate.
[0004] It is desirable though to remove the soluble arsenic as ferric arsenate which passes EPA limits and is safe for land disposal and which, to the extent possible, is not in a bioleach residue.
SUMMARY OF INVENTION [0005] The invention provides a method of treating a concentrate containing at least one base metal which includes the steps of subjecting the concentrate to a primary WO 2004/101834 PCT/ZA2004/000052 mesophilic and moderate thermophilic bioleaching process to leach sulphides in the concentrate, processing a residue of the primary bioleach process to recover at least one metal from the primary bioleach residue, subjecting a residue from the metal recovery process to a thermophilic secondary bioleaching process to release the at least one base metal from the metal recovery residue into solution, and recovering the at least one base metal at least from the solution produced by the thermophilic secondary bioleaching process.
[0006] The primary bioleaching process may be carried out at a temperature of from 0 C to 50 0
C.
[0007] Preferably the at least one base metal is also recovered from a solution produced by the primary bioleach bioleaching process.
[0008] The method preferably includes the step of preleaching the concentrate, before the primary bioleach bioleaching process, using leach solution from at least one of the bioleaching processes. Preferably the leach solution is derived from the primary bioleaching process and the thermophilic secondary bioleaching process.
[0009] The preleaching step is used to remove easily leachable base metal from the concentrate before the primary bioleaching process. Elemental sulphur which may accumulate during the preleach step due to rapid leaching of easily leachable sulphides, may be removed during the bioleaching stages, especially during the thermophilic secondary bioleaching process at elevated temperatures.
[0010] The primary bioleaching process may be carried out in a series of continuously stirred tank reactors which are operated at a temperature of from WO 2004/101834 PCT/ZA2004/000052 to 50°C in the presence of an active mixed culture of mesophilic and moderate thermophilic microorganisms.
[0011] A mixed culture of mesophile (20°C to 40 0 C) and moderate thermophile to 55°C) microorganisms is preferably used to maximise sulphide bioleaching and sulphur biooxidation during the treatment process. The mixed culture may contain microorganisms like Leptospirillum ferrooxidans and Acidithiobacillus caldus, a good iron oxidiser and a good sulphur oxidiser respectively.
[0012] The primary bioleach process may also contain thermophilic microorganisms, which are not effectively active at the temperature range of 35°C to 50*C. Such microorganisms will, however, still be living but will be dormant or slowly metabolising. When the temperature increases during the thermophilic secondary bioleaching process these microorganisms will reactivate their activity. This may be very useful for base metal concentrates, as the thermophilic secondary bioleaching stage would be continuously re-inoculated.
[0013] The pH of the concentrate or pulp in reactors in which the primary bioleaching is carried out may be controlled at a value of from 1,2 to 1,7. This may be achieved by the addition of limestone or raffinate produced in the base metal recovery step, to the reactors.
[0014] Oxygen may be supplied to the concentrate in the reactors in the form of enriched air which may contain from 95% to 98% oxygen, during at least part of the bioleaching processes.
WO 2004/101834 PCT/ZA2004/000052 [0015] An objective of operating the primary bioleaching process under the aforementioned conditions is to maximise the leaching of the sulphides in the concentrate and to maximise mass loss, and to minimise the precipitation in pentavalent form of arsenic which may be present in solution. The product from the primary bioleach residue may contain high concentrations of elemental sulphur due to the maximised bioleaching conditions.
[0016] In the metal recovery process toxic silver may be removed from the primary bioleaching residue. The silver may be removed using a brine leaching process.
[0017] The thermophilic secondary bioleaching process may be carried out in a series of continuously stirred tank reactors at a temperature of from 650C to 80°C in the presence of active quantities of extreme thermophilic microorganisms.
[0018] The method may include, the step of controlling the pH of the pulp in the thermophilic reactors at a value of from 1,,0 to 1,7. This may be achieved by the addition of limestone or raffinate produced in the metal recovery step. Oxygen carbon dioxide may be supplied to the reactors in the form of enriched gas containing from 95% to 98% oxygen and 1% to 5% carbon dioxide.
[0019] An objective of operating the thermophilic secondary bioleaching process under the aforementioned parameters is to maximise the oxidation of sulphides minerals and mass loss, and to minimise the precipitation in pentavalent form of arsenic which may be present in solution.
[0020] Furthermore sulphur oxidation at thermophilic temperature conditions is maximised and thus any elemental sulphur produced during the proceeding pre- WO 2004/101834 PCT/ZA2004/000052 leach and primary bioleach may be fully oxidised. This is very important if further treatment of the thermophilic secondary bioleach residue is required for precious group metals (PGM's) recovery like gold. Elemental sulphur increases cyanide consumption during cyanidation to recover gold and thus contributes significantly to the increase in cyanidation costs. Additionally, elemental sulphur not oxidised decreases the acid produced in the bioleach solution and thus may decrease the effectiveness of any preleach step using recycled bioleach solution.
[0021] As indicated the at least one base metal is recovered from the leach solutions produced by the bioleaching processes. Preferably the pH of the solution produced in the preleaching step is adjusted to maximise recovery of the at least one base metal using solvent extraction techniques.
[0022] Arsenic present in the solution may be caused to precipitate as ferric arsenate by increasing the pH of the solution to at least 2.
[0023] The pH of the solution may be increased by the addition of limestone slurry to the solution.
[0024] The pH adjustment may be carried out in a series of continuously stirred tank reactors which are operated at a temperature of from 600C to 80 0
C.
[0025] The at least one base metal, eg. copper, may be recovered by concentrating the copper and stripping, followed by cathode production by electrowinning.
WO 2004/101834 PCT/ZA2004/000052 BRIEF DESCRIPTION OF THE DRAWING [0026] The invention is further described by way of example with reference to the accompanying drawing which is a flow sheet illustrating various steps in a method of treating a concentrate obtaining at least one base metal in accordance with the principles of the invention.
DESCRIPTION OF PREFERRED EMBODIMENT [0027] In the method of the invention a concentrate 10 which contains a base metal such as copper and which may have a high arsenic content is subjected to a preleaching step 12. In this step the fresh concentrate is contacted with bioleach overflow solutions 14 and 16 respectively produced in subsequent primary and thermophilic secondary bioleaching stages 18 and [0028] The solutions 14 and 16 are rich in ferric and remove easily leachable copper from the feed 10. This ensures a lower residual copper tenor in the bioleaching tanks in the stages 18 and [0029] The product 22 of the preleaching stage is subjected to solid/liquid separation 24. An overflow solution 26 from the separation step 24 is directed to a pH adjustment stage 28 while the underflow 30, diluted with water 32 and raffinate 34 from a solvent extraction section 36, is fed to the primary bioleaching stage 18.
[0030] The purpose of the primary bioleaching stage 18 is to oxidise sulphide minerals in the feed and release base metals of interest into solution. The bioleaching is carried out in a series of continuously stirred tank reactors which are WO 2004/101834 PCT/ZA2004/000052 operated at a temperature of 35°C to 50°C in the presence of active quantities of mesophilic and moderate thermophilic microorganisms.
[0031] The pH of the pulp of the reactors in the primary bioleaching stage is controlled at a value of from 1,2 to 1,7 by the addition of limestone 40 or raffinate 34.
Oxygen 42, required for the oxidative reaction, is supplied in the form of enriched air with an oxygen content of from 95% to 98%.
[0032] By operating the primary bioleaching stage 18 under the aforementioned conditions the oxidation of the sulphide minerals and the mass loss are maximised while, if arsenic is present in the feed, the precipitation thereof in pentavalent form is minimised.
[0033] The product 44 of the primary bioleaching section 18 reports to bioleach thickening and washing 46. As has been indicated the overflow solution 14 is fed to the preleaching step 12 while the underflow 48 is the feed to a metal recovery section [0034] The purpose of the step 46 is to separate the liquids and the solids so that the base metals of interest and arsenic, if present, report to the pH adjustment section 28 via the preleaching step 12. In the metal recovery step 50 toxic silver 52 is removed from the primary bioleaching residue 48 using a brine leaching or other suitable method.
[0035] The residue 54 from the metal recovery step is repulped with water 56 and raffinate 34 and the resulting slurry is fed to the thermophilic secondary bioleaching stage WO 2004/101834 PCT/ZA2004/000052 [0036]The purpose of the stage 20 is to oxidise, to the extent possible, the sulphide minerals and the elemental sulphur which were not leached in the primary bioleaching stage 18. The base metals of interest are thereby released into solution.
The thermophilic secondary bioleaching process is carried out in a series of continuously stirred tank reactors which are operated at a temperature of from 650C to 80 0 C in the presence of active quantities of extreme thermophilic microorganisms.
[0037] The pH of the pulp in the thermophilic reactors is controlled at a value of from to 1,7 by the addition of limestone 40 or raffinate 34. Oxygen 42 required for the oxidative reactions is supplied in the form of enriched gas with an oxygen content of from 95% to 98%. Carbon dioxide 57 may be required for improved thermophilic cell growth is supplied in the form of enriched gas with a carbon dioxide content of 1% to by volume. By operating the thermophilic secondary bioleaching sections under these conditions the oxidation of the sulphide minerals and the mass loss are maximised while the precipitation of arsenic which may be present in the slurry 54, in the form of pentavalent arsenic, is minimised.
[0038] The product 60 of the thermophilic bioleaching section 20 reports to a bioleach thickening and washing step 62. The overflow solution 16 is fed to the preleaching section 12 while the underflow 64 is directed to a tailings pond 66 for disposal. If the underflow 64 contains PGM's then the underflow is directed to a metal recovery step 67 where the metal is removed from the underflow using cyanide as a leaching process for gold or other suitable method.
WO 2004/101834 PCT/ZA2004/000052 [0039] The purpose of the step 62 is to separate liquid and solids so that base metals of interest and arsenic, if present, are reported in solution to the pH adjustment section 28 via the preleaching stage 12.
[0040] The pH adjustment section 28 includes a series of continuously stirred tank reactors which are operated at a temperature of from 60°C to 80°C. The pH of the solution 26 is increased to a required level using limestone 40 or any other suitable neutralising agent. The product 70 of the pH adjustment section is then thickened in a step 72. The thickener underflow 74, which contains precipitated ferric arsenate, is directed to a tailings pond 76 for disposal. The overflow from the thickener step reports as pregnant leach solution (PLS) 80 to the solvent extraction section 36.
[0041] The purpose of the pH adjustment section 28 is to increase the pH of the pregnant leach solution, which is fed to the solvent extraction section 36, to above so that the solvent extraction efficiency is maximised. Arsenic which-is present in' the solution 26 is caused, by the increase in the pH, to precipitate primarily as ferric arsenate which is not readily dissolved. The ferric arsenate passes EPA limits and is safe for land disposal.
[0042] In the solvent extraction section 36 dissolved copper is recovered from the pregnant leached solution. The copper is stripped followed by cathode production (84) by electrowinning.
[0043] In the process of the invention the base metal containing concentrate is subjected to primary mesophilic and or moderate thermophilic leaching, metal recovery and thermophilic secondary leaching in combination so that secondary sulphides are successfully and economically leached in the primary section, toxic WO 2004/101834 PCT/ZA2004/000052 silver is removed in the metal recovery section, and a residue containing unleached primary sulphides and elemental sulphur is leached to completion successfully and economically in the thermophile secondary section. If arsenic is present in the concentrate the primary and thermophilic secondary sections are operated so that the redox potential of the solutions produced result in the natural oxidation of As(lll) to As(V). Arsenic precipitation in the bioleaching sections is intentionally minimised so that the arsenic is precipitated externally in the pH adjustment section 28. This avoids the production of a bioleach residue contaminated with arsenic.
[0044] It is cost effective to reduce the arsenic reporting to the thermophilic stage by causing the arsenic to precipitate in a separate dedicated process step ie. the pH adjustment section 28. By minimising precipitation in the mesophilic stage 18 the mass loss throughout the process is maximised. This reduces the capital and operating cost of the downstream processes including the thermophilic section [0046] Furthermore sulphur oxidation at thermophilic temperature conditions is maximised and thus any elemental sulphur produced during the proceeding preleach and primary bioleach may be fully oxidised. This is important if further treatment of the thermophilic secondary bioleach residue is required for precious group metals (PGM's) recovery like gold. Elemental sulphur increases cyanide consumption during cyanidation to recover gold and thus contributes significantly to the increase in cyanidation costs. Additionally, elemental sulphur not oxidised decreases the acid produced in the bioleach solution and thus may decrease the effectiveness of any preleach step using recycled bioleach solution.
00 [0046] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising",. will be understood to imply the inclusion of a stated D) element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
[0047] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of Cc providing a context for the present invention. It is not to be taken as an admission that Cc any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority :1 date of each claim of this application.
Claims (14)
1.A Me3thod of treating a concentrate containing at least one base metal which Incrludes the steps of subjecting the concentrate to a primary mesophifie and moderate thermophilic bloleaching grocess to leach sulphides In the concentrate, 6 processing a residue of the primary bloleach process to recover at least one metal from the primary bloleach residue, subjecino a residue fom the metal recovery process to a themophilic secondary bioleaching process to release the at least one base metal firom the metal recovery residue Into solution, and recoverfng thc at least one base metal at least from the solution produced by the thermophilic secondary 0 bloleaching process, and which. Is characterized In that It Includes the step of preleaching the concentrate, be foro the primary bloleachIng process, using leach solution from at least one of the bloleachIng processes which Increases ferric In the preleaching step thereby to Increase the leaching of easily leachable base metal before the primary bioleaching process.
2. A method according to claim I wherein the primary bloleaching process is carried out at a temperature of from 350'C to 50 0 C.
3. A method according to claim 1 or 2 wherein the at least one base metal Is also recovered from a solution produced by the primary bloleach bloleaching process.
4. A method according to claim 1, 2 or 3 wherein the leach solution Is derived from the primary bloleaching process and the thermophillc secondary bloleaching process. 00 A method Gccording to any one of ciaims I to 4 wherein base metal which Is leached during the preleaching step is removed from the concentrate before the primary 16loleachIng process.
6. A method according to any one of clams; 1 to 6 wherein elemental sulphur which accumnulates during the preleach step due to rapid leaching of easily leachable Is removed during the bioleaching wtages,
7. A method according to any one of claim.1 to 6 which Includes the step of adjusting the pH of a solution. produced In the prelsoohing step to maxlmlso recovery of the at least one base metal using solvent extraction techniques, S. A method according to *claim 7 which Includes the stop of causing arsenic In the solution to precipitate as fenic arsenate by Increasing the pH of the solution to at least 2. S. A method according to cleim 7 or 8 wherein the pH adjustment is carried out at a temperature orf from*60 0 C to 80 0 C.
10. A method according to any one of claims 1 to 9 wherein the primary bioleaching process is carried out In a series of continuously stirred tank reactors which are operated at a temperature of from 3SC to SO'C In thd presence of an active mixed culture of mesophllic arnd moderate therrnophillc micoorganisms.
11. A meithod according to any one of claims 1 to 10 wherein a mixed culture of mesophile and moderate thermophile microorganisms are used to maximise 0 uiphide bileaching and sulphur booxide~on during the priMary boleaching c-i procesg, V)12. A method according to claim 11weei h mixed culture contains. Leptospirdllum ferrOOxIdans and Addithlobacillus Caldus. c~ 5
13.A method according to claim I1I or 12 wherein the mixed culture 'of mbcroorganims also contains thermophilloc microorganims, which are not effectively active at the temperature range of 35 0 C to 14, A method according to any one of clms 1 to 13 wherein the pH of the concentrate during the primary bioleaching processes is controlled at a value of from1,2 to1,7. A method according to any one of claims 1 to 14 which includes the step of supplying air with an oxygen content of from 95% to 98% to the concentrate during at least part of the bioleaching processes.
16. A method according to any one of claims I to 15 which Includes the step of removing toxic silver from the primary bloleaching residue. 1'7. A method according to any one of claims I to 16 wherein the thermophilc secondary bioleaching process is carried out at a temperature of from G5*C to In the presence of active quant ities of extreme thermophilic microorganims, 00 O O
18. A method according to any one of claims 1 to 17 which includes the step of 0 controlling the pH of the concentrate during the secondary bioleaching process at a value of from 1,0 to 1,7. O
19. A method according to any one of claims 1 to 18 which includes the step of supplying air with a carbon dioxide content of from 1% to 5% to the concentrate during Cc at least part of the bioleaching processes.
20. A method according to any one of claims 1 to 19 wherein the at least one base metal is copper which is recovered by concentrating the copper and stripping, followed c by cathode production by electrowinning.
21. A method according to claim 1, substantially as hereinbefore described.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA200303621 | 2003-05-19 | ||
| ZA2003/3621 | 2003-05-19 | ||
| PCT/ZA2004/000052 WO2004101834A2 (en) | 2003-05-19 | 2004-05-15 | Treatment of base metal concentrate by a two-step bioleaching process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU2004239345A1 AU2004239345A1 (en) | 2004-11-25 |
| AU2004239345B2 true AU2004239345B2 (en) | 2008-09-25 |
Family
ID=33453094
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2004239345A Ceased AU2004239345B2 (en) | 2003-05-19 | 2004-05-15 | Treatment of base metal concentrate by a two-step bioleaching process |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US20070028721A1 (en) |
| CN (1) | CN100339493C (en) |
| AP (1) | AP1973A (en) |
| AR (1) | AR044408A1 (en) |
| AU (1) | AU2004239345B2 (en) |
| CA (1) | CA2526104A1 (en) |
| PE (1) | PE20050453A1 (en) |
| WO (1) | WO2004101834A2 (en) |
| ZA (1) | ZA200509214B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3825424A1 (en) | 2014-01-31 | 2021-05-26 | Goldcorp Inc. | Process for stabilisation of an arsenic solution comprising thiosulfates |
| CN105087900A (en) * | 2015-05-25 | 2015-11-25 | 厦门紫金矿冶技术有限公司 | Dearsenification method of gold concentrates |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000023629A1 (en) * | 1998-10-16 | 2000-04-27 | Mintek | Process for bioleaching of copper concentrates |
| EP1050593A1 (en) * | 1999-05-05 | 2000-11-08 | Boliden Mineral Ab | Two-stage bioleaching of sulphidic materials containing metal values and arsenic |
| US6383255B1 (en) * | 1999-06-22 | 2002-05-07 | Boliden Mineral Ab | Method for recovering the valuable metal content of a sulphuric acid leaching solution |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1214043A (en) * | 1983-01-26 | 1986-11-18 | Albert Bruynesteyn | Biological-acid leach process |
| CN1074465C (en) * | 1997-03-27 | 2001-11-07 | 比利顿股份有限公司 | Copper recovery |
| AUPP444298A0 (en) * | 1998-07-01 | 1998-07-23 | Bactech (Australia) Pty Limited | Leaching of low sulphur ores |
| CA2384451C (en) * | 1999-09-01 | 2008-07-15 | Billiton Sa Limited | Base metal recovery from a tailings dump by bacterial oxidation |
| US6245125B1 (en) * | 1999-09-15 | 2001-06-12 | Billiton S.A. Limited | Copper, nickel and cobalt recovery |
| US7314604B1 (en) * | 1999-09-30 | 2008-01-01 | Billiton Intellectual Property, B.V. | Stable ferric arsenate precipitation from acid copper solutions whilst minimising copper losses |
-
2004
- 2004-05-14 PE PE2004000501A patent/PE20050453A1/en not_active Application Discontinuation
- 2004-05-15 US US10/557,410 patent/US20070028721A1/en not_active Abandoned
- 2004-05-15 CN CNB2004800000311A patent/CN100339493C/en not_active Expired - Fee Related
- 2004-05-15 AP AP2005003447A patent/AP1973A/en active
- 2004-05-15 WO PCT/ZA2004/000052 patent/WO2004101834A2/en not_active Ceased
- 2004-05-15 AU AU2004239345A patent/AU2004239345B2/en not_active Ceased
- 2004-05-15 CA CA 2526104 patent/CA2526104A1/en not_active Abandoned
- 2004-05-19 AR ARP040101742 patent/AR044408A1/en active IP Right Grant
-
2005
- 2005-11-15 ZA ZA200509214A patent/ZA200509214B/en unknown
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000023629A1 (en) * | 1998-10-16 | 2000-04-27 | Mintek | Process for bioleaching of copper concentrates |
| EP1050593A1 (en) * | 1999-05-05 | 2000-11-08 | Boliden Mineral Ab | Two-stage bioleaching of sulphidic materials containing metal values and arsenic |
| US6383255B1 (en) * | 1999-06-22 | 2002-05-07 | Boliden Mineral Ab | Method for recovering the valuable metal content of a sulphuric acid leaching solution |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1697887A (en) | 2005-11-16 |
| CA2526104A1 (en) | 2004-11-25 |
| AR044408A1 (en) | 2005-09-14 |
| PE20050453A1 (en) | 2005-06-23 |
| AP2005003447A0 (en) | 2005-12-31 |
| AP1973A (en) | 2009-03-12 |
| CN100339493C (en) | 2007-09-26 |
| US20070028721A1 (en) | 2007-02-08 |
| ZA200509214B (en) | 2006-09-27 |
| WO2004101834A3 (en) | 2005-03-03 |
| WO2004101834A2 (en) | 2004-11-25 |
| AU2004239345A1 (en) | 2004-11-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FGA | Letters patent sealed or granted (standard patent) | ||
| MK14 | Patent ceased section 143(a) (annual fees not paid) or expired |