CA2517693C - Heap leach process using elemental sulphur to generate heat - Google Patents
Heap leach process using elemental sulphur to generate heat Download PDFInfo
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- CA2517693C CA2517693C CA2517693A CA2517693A CA2517693C CA 2517693 C CA2517693 C CA 2517693C CA 2517693 A CA2517693 A CA 2517693A CA 2517693 A CA2517693 A CA 2517693A CA 2517693 C CA2517693 C CA 2517693C
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- Prior art keywords
- elemental sulphur
- heap
- ore
- addition
- oxidation
- Prior art date
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- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 title claims abstract description 48
- 239000005864 Sulphur Substances 0.000 title claims abstract description 48
- 238000000034 method Methods 0.000 title claims abstract description 36
- 230000008569 process Effects 0.000 title claims abstract description 35
- 241000894006 Bacteria Species 0.000 claims abstract description 18
- 238000002386 leaching Methods 0.000 claims abstract description 17
- 239000010953 base metal Substances 0.000 claims abstract description 13
- 230000001580 bacterial effect Effects 0.000 claims abstract description 12
- 229910052976 metal sulfide Inorganic materials 0.000 claims abstract description 11
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 23
- 239000011707 mineral Substances 0.000 claims description 23
- 238000007254 oxidation reaction Methods 0.000 claims description 19
- 230000003647 oxidation Effects 0.000 claims description 17
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 claims description 11
- 229910052951 chalcopyrite Inorganic materials 0.000 claims description 11
- DVRDHUBQLOKMHZ-UHFFFAOYSA-N chalcopyrite Chemical compound [S-2].[S-2].[Fe+2].[Cu+2] DVRDHUBQLOKMHZ-UHFFFAOYSA-N 0.000 claims description 11
- 238000002156 mixing Methods 0.000 claims description 10
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 5
- 235000011149 sulphuric acid Nutrition 0.000 claims description 5
- 239000001117 sulphuric acid Substances 0.000 claims description 5
- 239000002253 acid Substances 0.000 description 3
- 238000011084 recovery Methods 0.000 description 3
- 238000009395 breeding Methods 0.000 description 2
- 230000001488 breeding effect Effects 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 230000020169 heat generation Effects 0.000 description 2
- 238000003973 irrigation Methods 0.000 description 2
- 230000002262 irrigation Effects 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 241000894007 species Species 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 241000605118 Thiobacillus Species 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 208000001970 congenital sucrase-isomaltase deficiency Diseases 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000007717 exclusion Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910021653 sulphate ion Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
- C22B15/0065—Leaching or slurrying
- C22B15/0067—Leaching or slurrying with acids or salts thereof
- C22B15/0071—Leaching or slurrying with acids or salts thereof containing sulfur
-
- 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
- C22B3/04—Extraction of metal compounds from ores or concentrates by wet processes by leaching
- C22B3/06—Extraction of metal compounds from ores or concentrates by wet processes by leaching in inorganic acid solutions, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions
- C22B3/08—Sulfuric acid, other sulfurated acids or salts thereof
-
- 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)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Biotechnology (AREA)
- Microbiology (AREA)
- Biochemistry (AREA)
- Inorganic Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Preparation Of Compounds By Using Micro-Organisms (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
An improved heap leach process for the bacterial heap leaching of base metal sulphide ores, the process characterised by the addition of elemental sulphur to the ore, whereby sulphur oxidising bacteria indigenous to, or added to, the ore may oxidise the elemental sulphur and generate heat within the ore heap.
Description
04!a2/2012 MON 15:27 PAX 604 681 4081 OWGM LLP 2003/003 -1=
MOM Lech Process usln 1 ental Sulphur to Generate He4t Field of the Invention The present invention relates to an improved heap leach. More particularly, the improved heap leach of the present Inventloi Is directed to the bacterial heap leaching of base metal sulphide ores.
Background Art The extraction of metals from sulphide ores by use of bacterially assisted heap leaching has been demonstrated previously. * The majority of the prior art prodesses involve the use of mesophilic bacteria, Incillding Thiobacillus and Leptosplrllllum species. Such bacterial species generally operate In it temperature range of 20 C to 45 C (Peterson and Dickson, Thermophillic Heap Leaching of a Chalcopyrite Concentrate, Minerals Engineering, 15 (20'02), pages 777 to 785). However, the use of bacterially assisted heap leaching In the extraction of copper from chalcopyrite ores Is an exception. in sudi circumstances higher temperatures are required In order to achieve commercially acceptable leach kinetics. In eithbr case, the success of the heap leaching operation Is largely dependent upon the oxidation of sulphide minerals to elevate the temperature within the heap above ambient levels and to keep the.
temperature at those levels.
If the sulphide mineralisation of an ore is below a particular level, the amount of heat generated will be relatively small. Consequently, only a small elevation of the internal heap temperature would be achIevod during leaching of that are, this elevation possibly not being sufficient to result in an economically acceptable leach rate: One apparent remedy for any such short fall in heat generation is to supply heat to the heap from an external source. Such an. external source might .
be the leach liquor that is conventionally applied to ft top of the heap, or the air supply, which In some operations is blown Into the base of the heap in order to promote the oxidation of sulphide minerals. Further, International Patent , PAGE 3131 RCVD AT 41212012 6:26:18 PM [Eastern Daylight Timel"SVR:F0000315"DNIS:3905 * CSID:604 6814081 "DURATION (mm.ss):00.35 Application PCT/ZA/00154 (WO 02/029124) discloses a means for supplying heat to a heap leach, the heat being generated externally of the heap in a bio-reactor.
It should be apparent that if an ore contains a sulphide mineral that requires a temperature in excess of 45 C before it will begin to leach, such as chalcopyrite, then the above circumstance is exacerbated. Irrespective of the quantity of chalcopyrite present, if there is no other sulphide mineral present that will begin to oxidise at lower temperatures, the heap cannot autogenously be brought up to the required operating temperature. As a result, the heap will remain at ambient temperature without the addition of a significant quantity of heat to start the chalcopyrite oxidation reaction. After the injection of the necessary additional heat, if there is sufficient sulphide mineral present the reaction may become self-sustaining. In International Patent Application PCT/US99/28962 (WO 00/36168) there is disclosed a heap leach process in which the process liquor may be added to the top of the heap, requiring an external source of heat. Also, the heap is described as being heated by way of the pumping of steam or hot air through supply lines into the heap, again requiring an external source of heat.
Still further, a complicated method for stacking heaps on top of an existing heat generating heap is also described, a process that may extend over several generations of heap.
It is one object of the present invention to overcome the abovementioned problems associated with the prior art, or to at least provide a useful alternative thereto.
The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge in Australia or any country, region or territory as at the priority date of the application.
Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood Received 24 August 2004 to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
Disclosure of the Invention In accordance with the present invention there is provided an improved heap leach process for the bacterial heap leaching of base metal sulphide ores containing a mineral or an assemblage of minerals that require temperatures higher than ambient for efficient oxidation of at least one of the minerals present, the process characterised . by. the addition of elemental sulphur to the ore, whereby the elemental sulphur is oxidised by mesophilic bacteria present in the ore heap, this oxidation of elemental sulphur generating heat and raising the internal temperature of the heap upwardly such that thermophilic bacteria can operate.
Preferably, chalcopyrite comprises the predominant sulphide mineral in the ore.
Still preferably, the blending or addition of elemental sulphur to the ore provides between about 2 to 20% elemental sulphur to ore (w/w).
Still further preferably, the addition of elemental sulphur to a process for the bacterial heap leaching of base metal sulphide ores generates sulphuric acid through the oxidation of elemental sulphur, in addition to the generation of heat.
In accordance with the present invention there is further provided an improved heap leach process for the bacterial heap leaching of base metal sulphide ores containing a mineral or an assemblage of minerals that require temperatures of greater than 45 C for efficient oxidation of the or each mineral, the process characterised by the addition of elemental sulphur to the ore, whereby the elemental sulphur is oxidised at temperatures lower than about 45 C by mesophilic bacteria present in the ore heap, this oxidation of elemental sulphur generating heat and raising the internal temperature of the heap upwardly such that thermophilic bacteria can operate.
In one form of the present invention chalcopyrite comprises the predominant sulphide mineral in the ore.
;40ENDED SHEET
MOM Lech Process usln 1 ental Sulphur to Generate He4t Field of the Invention The present invention relates to an improved heap leach. More particularly, the improved heap leach of the present Inventloi Is directed to the bacterial heap leaching of base metal sulphide ores.
Background Art The extraction of metals from sulphide ores by use of bacterially assisted heap leaching has been demonstrated previously. * The majority of the prior art prodesses involve the use of mesophilic bacteria, Incillding Thiobacillus and Leptosplrllllum species. Such bacterial species generally operate In it temperature range of 20 C to 45 C (Peterson and Dickson, Thermophillic Heap Leaching of a Chalcopyrite Concentrate, Minerals Engineering, 15 (20'02), pages 777 to 785). However, the use of bacterially assisted heap leaching In the extraction of copper from chalcopyrite ores Is an exception. in sudi circumstances higher temperatures are required In order to achieve commercially acceptable leach kinetics. In eithbr case, the success of the heap leaching operation Is largely dependent upon the oxidation of sulphide minerals to elevate the temperature within the heap above ambient levels and to keep the.
temperature at those levels.
If the sulphide mineralisation of an ore is below a particular level, the amount of heat generated will be relatively small. Consequently, only a small elevation of the internal heap temperature would be achIevod during leaching of that are, this elevation possibly not being sufficient to result in an economically acceptable leach rate: One apparent remedy for any such short fall in heat generation is to supply heat to the heap from an external source. Such an. external source might .
be the leach liquor that is conventionally applied to ft top of the heap, or the air supply, which In some operations is blown Into the base of the heap in order to promote the oxidation of sulphide minerals. Further, International Patent , PAGE 3131 RCVD AT 41212012 6:26:18 PM [Eastern Daylight Timel"SVR:F0000315"DNIS:3905 * CSID:604 6814081 "DURATION (mm.ss):00.35 Application PCT/ZA/00154 (WO 02/029124) discloses a means for supplying heat to a heap leach, the heat being generated externally of the heap in a bio-reactor.
It should be apparent that if an ore contains a sulphide mineral that requires a temperature in excess of 45 C before it will begin to leach, such as chalcopyrite, then the above circumstance is exacerbated. Irrespective of the quantity of chalcopyrite present, if there is no other sulphide mineral present that will begin to oxidise at lower temperatures, the heap cannot autogenously be brought up to the required operating temperature. As a result, the heap will remain at ambient temperature without the addition of a significant quantity of heat to start the chalcopyrite oxidation reaction. After the injection of the necessary additional heat, if there is sufficient sulphide mineral present the reaction may become self-sustaining. In International Patent Application PCT/US99/28962 (WO 00/36168) there is disclosed a heap leach process in which the process liquor may be added to the top of the heap, requiring an external source of heat. Also, the heap is described as being heated by way of the pumping of steam or hot air through supply lines into the heap, again requiring an external source of heat.
Still further, a complicated method for stacking heaps on top of an existing heat generating heap is also described, a process that may extend over several generations of heap.
It is one object of the present invention to overcome the abovementioned problems associated with the prior art, or to at least provide a useful alternative thereto.
The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge in Australia or any country, region or territory as at the priority date of the application.
Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood Received 24 August 2004 to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
Disclosure of the Invention In accordance with the present invention there is provided an improved heap leach process for the bacterial heap leaching of base metal sulphide ores containing a mineral or an assemblage of minerals that require temperatures higher than ambient for efficient oxidation of at least one of the minerals present, the process characterised . by. the addition of elemental sulphur to the ore, whereby the elemental sulphur is oxidised by mesophilic bacteria present in the ore heap, this oxidation of elemental sulphur generating heat and raising the internal temperature of the heap upwardly such that thermophilic bacteria can operate.
Preferably, chalcopyrite comprises the predominant sulphide mineral in the ore.
Still preferably, the blending or addition of elemental sulphur to the ore provides between about 2 to 20% elemental sulphur to ore (w/w).
Still further preferably, the addition of elemental sulphur to a process for the bacterial heap leaching of base metal sulphide ores generates sulphuric acid through the oxidation of elemental sulphur, in addition to the generation of heat.
In accordance with the present invention there is further provided an improved heap leach process for the bacterial heap leaching of base metal sulphide ores containing a mineral or an assemblage of minerals that require temperatures of greater than 45 C for efficient oxidation of the or each mineral, the process characterised by the addition of elemental sulphur to the ore, whereby the elemental sulphur is oxidised at temperatures lower than about 45 C by mesophilic bacteria present in the ore heap, this oxidation of elemental sulphur generating heat and raising the internal temperature of the heap upwardly such that thermophilic bacteria can operate.
In one form of the present invention chalcopyrite comprises the predominant sulphide mineral in the ore.
;40ENDED SHEET
Preferably, the blending or addition of elemental sulphur to the ore provides between about 2 to 20% elemental sulphur to ore (w/w).
Still preferably, the addition of elemental sulphur to a process for the bacterial heap leaching of base metal sulphide ores generates sulphuric acid through the oxidation of elemental sulphur, in addition to the generation of heat.
Brief Description of the Drawings The improved heap leach process of the present invention will now be described, by way of example only, with reference to one embodiment thereof and the accompanying drawing, in which:-Figure 1 is a schematic representation of a process for the bacterial heap leaching of base metal sulphide ores in accordance with the present invention.
Best Mode(s) for Carrying Out the Invention In Figure 1 there is shown an improved heap leach process for the bacterial heap leaching of base metal sulphide ores in accordance with the present invention.
A
blending facility 10 is provided for the blending of a base metal sulphide ore containing chalcopyrite as the predominant sulphide mineral and an elemental sulphur. The amount of elemental sulphur to be added to the blend is calculated prior to blending so as to be sufficient to satisfy at least part of the heap requirement and/or the acid demand of the ore. Such decisions are typically made by those responsible for management of the heap leaching process.
It is to be understood that water, acid, bacteria, raffinate and other liquor streams associated with the metal recovery portion of an operating hydrometallurgical base metals recovery plant may also be utilised in the process of the present invention, as may additional reagents or chemicals.
Still preferably, the addition of elemental sulphur to a process for the bacterial heap leaching of base metal sulphide ores generates sulphuric acid through the oxidation of elemental sulphur, in addition to the generation of heat.
Brief Description of the Drawings The improved heap leach process of the present invention will now be described, by way of example only, with reference to one embodiment thereof and the accompanying drawing, in which:-Figure 1 is a schematic representation of a process for the bacterial heap leaching of base metal sulphide ores in accordance with the present invention.
Best Mode(s) for Carrying Out the Invention In Figure 1 there is shown an improved heap leach process for the bacterial heap leaching of base metal sulphide ores in accordance with the present invention.
A
blending facility 10 is provided for the blending of a base metal sulphide ore containing chalcopyrite as the predominant sulphide mineral and an elemental sulphur. The amount of elemental sulphur to be added to the blend is calculated prior to blending so as to be sufficient to satisfy at least part of the heap requirement and/or the acid demand of the ore. Such decisions are typically made by those responsible for management of the heap leaching process.
It is to be understood that water, acid, bacteria, raffinate and other liquor streams associated with the metal recovery portion of an operating hydrometallurgical base metals recovery plant may also be utilised in the process of the present invention, as may additional reagents or chemicals.
The blended ore and elemental sulphur are then stacked to form a heap 20. The heap 20 is fitted with pipes to supply air and/or other gasses to the heap 20.
Further, an irrigation system (not shown) is provided in or on the heap to allow liquor from a liquor pond 30 to be circulated therebetween.
A bacteria breeding facility 40, separate to the ore heap 20, is provided such that bacteria can be added to the ore. It is envisaged that the bacteria may be added to the ore prior to, during, or after blending with the elemental sulphur.
Alternately, the bacteria may be added to the heap 20, before or after irrigation of the heap 20 has commenced.
During the process of the present invention mesophilic bacteria ("mesophiles") indigenous to the ore heap 20, or added to the ore heap 20 from the bacteria breeding facility 40, will begin the oxidation of elemental sulphur at temperatures of about 20 C, and possibly as low as 10 C. The oxidation reaction of elemental sulphur to form sulphate is exothermic, thereby releasing heat into the ore heap 20 and raising the temperature thereof. The increased temperature within the heap 20 resulting from the action of the mesophiles on the elemental sulphur increases the temperature within the heap 20 such that thermophilic bacteria begin to operate efficiently and oxidise the chalcopyrite within the ore heap 20.
This provides a more efficient bacterial heap leach process with greater recoveries of base metal than might otherwise have been achieved without the addition of elemental sulphur to the ore heap 20.
Savings compared to processes of the prior art are also achieved with the process of the present invention with respect to the generation of sulphuric acid through the oxidation of elemental sulphur. This is particularly the case if the ore to be leached is an overall consumer of acid during the leaching process.
It is envisaged that blending of the elemental sulphur with the ore may be adequately achieved during agglomeration of the ore or might be added to the ore at another point prior to, or during stacking of the ore heap 20. In addition, the elemental sulphur might also be added directly to the top of the ore heap subsequent to stacking, whereby the leach liquor would be heated as it passes downwardly thorough the layer of the heap containing the elemental sulphur undergoing oxidation.
It is envisaged that the blending or addition of elemental sulphur to ore provides between about 2 to 20% elemental sulphur to ore (w/w).
The improved process of the present invention can be seen from the above description to embody several advantages when compared with prior art processes requiring heat generation externally of the ore heap, after which the heat is required to be passed to the heap, or the heating of the ore prior to stacking.
Modifications and variations such as would be apparent to the skilled addressee are considered to fall within the scope of the present invention.
Further, an irrigation system (not shown) is provided in or on the heap to allow liquor from a liquor pond 30 to be circulated therebetween.
A bacteria breeding facility 40, separate to the ore heap 20, is provided such that bacteria can be added to the ore. It is envisaged that the bacteria may be added to the ore prior to, during, or after blending with the elemental sulphur.
Alternately, the bacteria may be added to the heap 20, before or after irrigation of the heap 20 has commenced.
During the process of the present invention mesophilic bacteria ("mesophiles") indigenous to the ore heap 20, or added to the ore heap 20 from the bacteria breeding facility 40, will begin the oxidation of elemental sulphur at temperatures of about 20 C, and possibly as low as 10 C. The oxidation reaction of elemental sulphur to form sulphate is exothermic, thereby releasing heat into the ore heap 20 and raising the temperature thereof. The increased temperature within the heap 20 resulting from the action of the mesophiles on the elemental sulphur increases the temperature within the heap 20 such that thermophilic bacteria begin to operate efficiently and oxidise the chalcopyrite within the ore heap 20.
This provides a more efficient bacterial heap leach process with greater recoveries of base metal than might otherwise have been achieved without the addition of elemental sulphur to the ore heap 20.
Savings compared to processes of the prior art are also achieved with the process of the present invention with respect to the generation of sulphuric acid through the oxidation of elemental sulphur. This is particularly the case if the ore to be leached is an overall consumer of acid during the leaching process.
It is envisaged that blending of the elemental sulphur with the ore may be adequately achieved during agglomeration of the ore or might be added to the ore at another point prior to, or during stacking of the ore heap 20. In addition, the elemental sulphur might also be added directly to the top of the ore heap subsequent to stacking, whereby the leach liquor would be heated as it passes downwardly thorough the layer of the heap containing the elemental sulphur undergoing oxidation.
It is envisaged that the blending or addition of elemental sulphur to ore provides between about 2 to 20% elemental sulphur to ore (w/w).
The improved process of the present invention can be seen from the above description to embody several advantages when compared with prior art processes requiring heat generation externally of the ore heap, after which the heat is required to be passed to the heap, or the heating of the ore prior to stacking.
Modifications and variations such as would be apparent to the skilled addressee are considered to fall within the scope of the present invention.
Claims (8)
1. An improved heap leach process for the bacterial heap leaching of base metal sulphide ores containing a mineral or an assemblage of minerals that require temperatures higher than ambient for efficient oxidation of at least one of the minerals present, the process characterised by the addition of elemental sulphur to the ore, whereby the elemental sulphur is oxidised by mesophilic bacteria present in the ore heap, this oxidation of elemental sulphur generating heat and raising the internal temperature of the heap upwardly such that thermophilic bacteria operate.
2. A process according to claim 1, wherein chalcopyrite comprises the predominant sulphur mineral in the ore.
3. A process according to claim 1 or 2, wherein the blending or addition of elemental sulphur to ore provides between about 2 to 20% elemental sulphur to ore (w/w).
4. A process according to any one of claims 1 to 3, wherein the addition of elemental sulphur generates sulphuric acid through the oxidation of elemental sulphur, in addition to the generation of heat.
5. An improved heap leach process for the bacterial heap leaching of base metal sulphide ores containing a mineral or an assemblage of minerals that require temperatures of greater than 45°C for efficient oxidation of the or each mineral, the process characterised by the addition of elemental sulphur to the ore, whereby the elemental sulphur is oxidised at temperatures lower than about 45°C by mesophilic bacteria present in the ore heap, this oxidation of elemental sulphur generating heat and raising the internal temperature of the heap upwardly such that thermophilic bacteria operate.
6. A process according to claim 5, wherein chalcopyrite comprises the predominant sulphide mineral in the ore.
7. A process according to claim 5 or 6, wherein the blending or addition of elemental sulphur to ore provides between about 2 to 20% elemental sulphur to ore (w/w).
8. A process according to any one of claims 5 to 7, wherein the addition of elemental sulphur generates sulphuric acid through the oxidation of elemental sulphur, in addition to the generation of heat.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU2003901105A AU2003901105A0 (en) | 2003-03-12 | 2003-03-12 | Improved heap leach |
| AU2003901105 | 2003-03-12 | ||
| PCT/AU2004/000236 WO2004081241A1 (en) | 2003-03-12 | 2004-02-24 | Improved heap leach |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2517693A1 CA2517693A1 (en) | 2004-09-23 |
| CA2517693C true CA2517693C (en) | 2012-08-14 |
Family
ID=31500149
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2517693A Expired - Lifetime CA2517693C (en) | 2003-03-12 | 2004-02-24 | Heap leach process using elemental sulphur to generate heat |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US20060248983A1 (en) |
| EP (1) | EP1620576A4 (en) |
| CN (1) | CN1320138C (en) |
| AR (1) | AR043514A1 (en) |
| AU (1) | AU2003901105A0 (en) |
| CA (1) | CA2517693C (en) |
| PE (1) | PE20050303A1 (en) |
| WO (1) | WO2004081241A1 (en) |
| ZA (1) | ZA200506897B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| PE20071046A1 (en) | 2005-03-21 | 2007-12-21 | Bioheap Ltd | LEACHING BY SULFIDE MINERALS STACKS |
| WO2008054648A2 (en) * | 2006-10-18 | 2008-05-08 | Earth Based Solutions, Llp | Method for producing sulfuric acid |
| WO2009059336A1 (en) * | 2007-10-31 | 2009-05-07 | Bhp Billiton Sa Limited | High temperature leaching process |
| CL2011001440A1 (en) * | 2010-06-15 | 2011-10-28 | Teck Resources Ltd | Process for recovering copper from heap leaching rubble, which comprises mixing said rubble with a material to form a mixture or agglomerating the rubble of the leaching into batteries, and leaching the pile of the rubble treated of the leaching into batteries with a solution of leaching. |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4497778A (en) * | 1981-04-06 | 1985-02-05 | University College Cardiff Consultants Limited | Microbial leaching of sulphide-containing ores |
| US4729788A (en) * | 1987-01-23 | 1988-03-08 | Advanced Mineral Technologies, Inc. | Thermophilic microbial treatment of precious metal ores |
| US5914441A (en) * | 1996-06-12 | 1999-06-22 | Yellowstone Environmental Science, Inc. | Biocatalyzed anaerobic oxidation of metal sulfides for recovery of metal values |
| AUPP444298A0 (en) * | 1998-07-01 | 1998-07-23 | Bactech (Australia) Pty Limited | Leaching of low sulphur ores |
| DE19835291A1 (en) * | 1998-08-05 | 2000-02-10 | Herberts Gmbh | Plastic container for storing liquid coating agents |
| US6110253A (en) * | 1998-12-14 | 2000-08-29 | Geobiotics, Inc. | High temperature heap bioleaching process |
| AU2843500A (en) * | 1998-12-15 | 2000-07-03 | Electric Fuel Limited | Structure for a prism-shaped metal-air battery cell with features to prevent electrolyte leakage and to maintain connectivity between an air cathode and a casing element |
| US6245125B1 (en) * | 1999-09-15 | 2001-06-12 | Billiton S.A. Limited | Copper, nickel and cobalt recovery |
| US6387239B1 (en) * | 1999-11-17 | 2002-05-14 | Bhp Minerals International, Inc. | Recovery of metals from ore |
| DE19960132A1 (en) * | 1999-12-14 | 2001-06-21 | Alexander Beckmann | Process for the extraction of copper and other metals |
| CN1132945C (en) * | 2000-02-22 | 2003-12-31 | 中国科学院化工冶金研究所 | Microbe leaching-out method of valuable metals from deep-sea polymetal nodule |
-
2003
- 2003-03-12 AU AU2003901105A patent/AU2003901105A0/en not_active Abandoned
-
2004
- 2004-02-24 EP EP04713821A patent/EP1620576A4/en not_active Withdrawn
- 2004-02-24 CA CA2517693A patent/CA2517693C/en not_active Expired - Lifetime
- 2004-02-24 US US10/548,470 patent/US20060248983A1/en not_active Abandoned
- 2004-02-24 CN CNB2004800065903A patent/CN1320138C/en not_active Expired - Fee Related
- 2004-02-24 WO PCT/AU2004/000236 patent/WO2004081241A1/en active Application Filing
- 2004-03-08 PE PE2004000247A patent/PE20050303A1/en not_active Application Discontinuation
- 2004-03-09 AR ARP040100744A patent/AR043514A1/en not_active Application Discontinuation
-
2005
- 2005-08-29 ZA ZA200506897A patent/ZA200506897B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU2003901105A0 (en) | 2003-03-27 |
| US20060248983A1 (en) | 2006-11-09 |
| CN1759193A (en) | 2006-04-12 |
| CA2517693A1 (en) | 2004-09-23 |
| AR043514A1 (en) | 2005-08-03 |
| PE20050303A1 (en) | 2005-07-08 |
| WO2004081241A1 (en) | 2004-09-23 |
| CN1320138C (en) | 2007-06-06 |
| EP1620576A4 (en) | 2008-05-21 |
| ZA200506897B (en) | 2007-02-28 |
| EP1620576A1 (en) | 2006-02-01 |
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