WO2017216610A1 - A bacterial strain isolated from the species leptospirillum sp., likallfu; a microbial inoculum comprising same; and a method for bioleaching minerals in which said microbial inoculum is inoculated. - Google Patents
A bacterial strain isolated from the species leptospirillum sp., likallfu; a microbial inoculum comprising same; and a method for bioleaching minerals in which said microbial inoculum is inoculated. Download PDFInfo
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- WO2017216610A1 WO2017216610A1 PCT/IB2016/053536 IB2016053536W WO2017216610A1 WO 2017216610 A1 WO2017216610 A1 WO 2017216610A1 IB 2016053536 W IB2016053536 W IB 2016053536W WO 2017216610 A1 WO2017216610 A1 WO 2017216610A1
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- Prior art keywords
- mineral
- leptospirillum
- alicyclobacillus
- spp
- strain
- Prior art date
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- 229910052500 inorganic mineral Inorganic materials 0.000 title claims abstract description 50
- 239000011707 mineral Substances 0.000 title claims abstract description 50
- 238000000034 method Methods 0.000 title claims abstract description 47
- 241000589920 Leptospirillum sp. Species 0.000 title claims abstract description 20
- 239000002068 microbial inoculum Substances 0.000 title claims abstract description 11
- 230000001580 bacterial effect Effects 0.000 title claims abstract description 7
- 230000008569 process Effects 0.000 claims abstract description 43
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims abstract description 40
- 238000002386 leaching Methods 0.000 claims abstract description 22
- 229910052751 metal Inorganic materials 0.000 claims abstract description 20
- 239000002184 metal Substances 0.000 claims abstract description 20
- 239000012141 concentrate Substances 0.000 claims abstract description 11
- 238000005065 mining Methods 0.000 claims abstract description 7
- 244000005700 microbiome Species 0.000 claims description 28
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 claims description 14
- 230000000813 microbial effect Effects 0.000 claims description 11
- 230000002401 inhibitory effect Effects 0.000 claims description 9
- 241000266272 Acidithiobacillus Species 0.000 claims description 6
- 241000605272 Acidithiobacillus thiooxidans Species 0.000 claims description 6
- 241001147780 Alicyclobacillus Species 0.000 claims description 6
- 241000775208 Leptospirillum ferriphilum Species 0.000 claims description 6
- BWFPGXWASODCHM-UHFFFAOYSA-N copper monosulfide Chemical class [Cu]=S BWFPGXWASODCHM-UHFFFAOYSA-N 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 6
- 241000589925 Leptospirillum Species 0.000 claims description 5
- 230000002068 genetic effect Effects 0.000 claims description 5
- 239000002054 inoculum Substances 0.000 claims description 5
- 241000521593 Acidimicrobium Species 0.000 claims description 4
- 238000011065 in-situ storage Methods 0.000 claims description 4
- 241000605222 Acidithiobacillus ferrooxidans Species 0.000 claims description 3
- 241000589921 Leptospirillum ferrooxidans Species 0.000 claims description 3
- 241001502776 Acidicaldus Species 0.000 claims description 2
- 241001261672 Acidicaldus organivorans Species 0.000 claims description 2
- 241001254560 Acidiplasma cupricumulans Species 0.000 claims description 2
- 241000266271 Acidithiobacillus albertensis Species 0.000 claims description 2
- 241001464929 Acidithiobacillus caldus Species 0.000 claims description 2
- 241000501828 Acidocella Species 0.000 claims description 2
- 241001502216 Acidocella aluminiidurans Species 0.000 claims description 2
- 241001468099 Acidocella aminolytica Species 0.000 claims description 2
- 241000588844 Acidocella facilis Species 0.000 claims description 2
- 241001063273 Alicyclobacillus acidiphilus Species 0.000 claims description 2
- 241000640374 Alicyclobacillus acidocaldarius Species 0.000 claims description 2
- 241000193412 Alicyclobacillus acidoterrestris Species 0.000 claims description 2
- 241000147324 Alicyclobacillus aeris Species 0.000 claims description 2
- 241000193415 Alicyclobacillus cycloheptanicus Species 0.000 claims description 2
- 241000147225 Alicyclobacillus disulfidooxidans Species 0.000 claims description 2
- 241000850378 Alicyclobacillus fastidiosus Species 0.000 claims description 2
- 241001484817 Alicyclobacillus ferripilum Species 0.000 claims description 2
- 241000518477 Ferrimicrobium Species 0.000 claims description 2
- 241000518479 Ferrimicrobium acidiphilum Species 0.000 claims description 2
- 241001501215 Ferrithrix Species 0.000 claims description 2
- 241001261719 Ferrithrix thermotolerans Species 0.000 claims description 2
- 241001280345 Ferroplasma Species 0.000 claims description 2
- 241000393058 Ferroplasma acidarmanus Species 0.000 claims description 2
- 241001280344 Ferroplasma acidiphilum Species 0.000 claims description 2
- 241001352153 Ferroplasma thermophilum Species 0.000 claims description 2
- 241001018496 Ferrovum Species 0.000 claims description 2
- 241000976122 Leptospirillum ferrodiazotrophum Species 0.000 claims description 2
- 241001049330 Leptospirillum rubarum Species 0.000 claims description 2
- 241001134777 Sulfobacillus Species 0.000 claims description 2
- 241000521591 Sulfobacillus acidophilus Species 0.000 claims description 2
- 241000784241 Sulfobacillus benefaciens Species 0.000 claims description 2
- 241001129207 Sulfobacillus sibiricus Species 0.000 claims description 2
- 238000004064 recycling Methods 0.000 claims description 2
- 241000521595 Acidimicrobium ferrooxidans Species 0.000 claims 1
- 241000850382 Alicyclobacillus contaminans Species 0.000 claims 1
- 241001484819 Alicyclobacillus ferrooxydans Species 0.000 claims 1
- 231100000701 toxic element Toxicity 0.000 abstract description 5
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 abstract description 4
- 239000011593 sulfur Substances 0.000 abstract description 3
- 229910052717 sulfur Inorganic materials 0.000 abstract description 3
- 241001465227 Chilena Species 0.000 abstract 1
- 230000001747 exhibiting effect Effects 0.000 abstract 1
- 239000010949 copper Substances 0.000 description 31
- 229910052802 copper Inorganic materials 0.000 description 30
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 26
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 13
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 11
- 230000000694 effects Effects 0.000 description 9
- 241000894007 species Species 0.000 description 9
- 239000002253 acid Substances 0.000 description 8
- 238000011084 recovery Methods 0.000 description 8
- 238000011081 inoculation Methods 0.000 description 7
- 238000009854 hydrometallurgy Methods 0.000 description 6
- 150000002500 ions Chemical class 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- 239000011780 sodium chloride Substances 0.000 description 5
- DVRDHUBQLOKMHZ-UHFFFAOYSA-N chalcopyrite Chemical compound [S-2].[S-2].[Fe+2].[Cu+2] DVRDHUBQLOKMHZ-UHFFFAOYSA-N 0.000 description 4
- 229910052951 chalcopyrite Inorganic materials 0.000 description 4
- 238000011161 development Methods 0.000 description 4
- 238000011534 incubation Methods 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 230000001590 oxidative effect Effects 0.000 description 4
- 150000004763 sulfides Chemical class 0.000 description 4
- 241000894006 Bacteria Species 0.000 description 3
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 3
- 229910052948 bornite Inorganic materials 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- NIFIFKQPDTWWGU-UHFFFAOYSA-N pyrite Chemical compound [Fe+2].[S-][S-] NIFIFKQPDTWWGU-UHFFFAOYSA-N 0.000 description 3
- 229910052683 pyrite Inorganic materials 0.000 description 3
- 239000011028 pyrite Substances 0.000 description 3
- 238000007670 refining Methods 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- 241000205101 Sulfolobus Species 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 238000003556 assay Methods 0.000 description 2
- 238000003501 co-culture Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000001963 growth medium Substances 0.000 description 2
- 229940113601 irrigation solution Drugs 0.000 description 2
- 238000009629 microbiological culture Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 230000002459 sustained effect Effects 0.000 description 2
- UDPGUMQDCGORJQ-UHFFFAOYSA-N (2-chloroethyl)phosphonic acid Chemical compound OP(O)(=O)CCCl UDPGUMQDCGORJQ-UHFFFAOYSA-N 0.000 description 1
- 241000726121 Acidianus Species 0.000 description 1
- 241000321173 Acidihalobacter prosperus Species 0.000 description 1
- 241000588853 Acidiphilium Species 0.000 description 1
- 241001448474 Acidithiobacillus cuprithermicus Species 0.000 description 1
- 241000532138 Alicyclobacillus herbarius Species 0.000 description 1
- 241000032588 Alicyclobacillus hesperidum Species 0.000 description 1
- 241000850379 Alicyclobacillus kakegawensis Species 0.000 description 1
- 241000850381 Alicyclobacillus macrosporangiidus Species 0.000 description 1
- 241000298912 Alicyclobacillus mali Species 0.000 description 1
- 241001185617 Alicyclobacillus pomorum Species 0.000 description 1
- 241000850377 Alicyclobacillus sacchari Species 0.000 description 1
- 241001442202 Alicyclobacillus sendaiensis Species 0.000 description 1
- 241000850380 Alicyclobacillus shizuokensis Species 0.000 description 1
- 241001502326 Alicyclobacillus tengchongensis Species 0.000 description 1
- 241001347567 Alicyclobacillus vulcanalis Species 0.000 description 1
- 241000203069 Archaea Species 0.000 description 1
- 241000616920 Effusibacillus pohliae Species 0.000 description 1
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 1
- 239000007836 KH2PO4 Substances 0.000 description 1
- 241001074129 Macromonas Species 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 241000134732 Metallosphaera Species 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- 241001134779 Sulfobacillus thermosulfidooxidans Species 0.000 description 1
- 241000216226 Sulfolobus metallicus Species 0.000 description 1
- 241000204667 Thermoplasma Species 0.000 description 1
- 241000605234 Thiovulum sp. Species 0.000 description 1
- DGEZNRSVGBDHLK-UHFFFAOYSA-N [1,10]phenanthroline Chemical compound C1=CN=C2C3=NC=CC=C3C=CC2=C1 DGEZNRSVGBDHLK-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical class [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 1
- AQLMHYSWFMLWBS-UHFFFAOYSA-N arsenite(1-) Chemical compound O[As](O)[O-] AQLMHYSWFMLWBS-UHFFFAOYSA-N 0.000 description 1
- 238000001479 atomic absorption spectroscopy Methods 0.000 description 1
- 230000001651 autotrophic effect Effects 0.000 description 1
- 239000012620 biological material Substances 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004737 colorimetric analysis Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000002860 competitive effect Effects 0.000 description 1
- 230000001143 conditioned effect Effects 0.000 description 1
- 238000004690 coupled electron pair approximation Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000010429 evolutionary process Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 229910001447 ferric ion Inorganic materials 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 238000001033 granulometry Methods 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- -1 ion chloride chloride Chemical class 0.000 description 1
- 231100001231 less toxic Toxicity 0.000 description 1
- 239000010808 liquid waste Substances 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000002609 medium Substances 0.000 description 1
- 230000002503 metabolic effect Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 229910000402 monopotassium phosphate Inorganic materials 0.000 description 1
- 235000019796 monopotassium phosphate Nutrition 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 235000015097 nutrients Nutrition 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000003204 osmotic effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- GNSKLFRGEWLPPA-UHFFFAOYSA-M potassium dihydrogen phosphate Chemical compound [K+].OP(O)([O-])=O GNSKLFRGEWLPPA-UHFFFAOYSA-M 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000009853 pyrometallurgy Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052569 sulfide mineral Inorganic materials 0.000 description 1
- 125000000101 thioether group Chemical group 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 230000003442 weekly effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N1/00—Microorganisms, e.g. protozoa; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
- C12N1/20—Bacteria; Culture media therefor
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
- C12N1/00—Microorganisms, e.g. protozoa; Compositions thereof; Processes of propagating, maintaining or preserving microorganisms or compositions thereof; Processes of preparing or isolating a composition containing a microorganism; Culture media therefor
- C12N1/20—Bacteria; Culture media therefor
- C12N1/205—Bacterial isolates
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12R—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES C12C - C12Q, RELATING TO MICROORGANISMS
- C12R2001/00—Microorganisms ; Processes using microorganisms
- C12R2001/01—Bacteria or Actinomycetales ; using bacteria or Actinomycetales
Definitions
- the present invention relates to extractive mining by hydrometallurgical processes in a temperature range of 10 to 45 ° C.
- the present invention relates to mesophilic acidophilic microorganisms (optimal growth up to 45 ° C) and their use in processes of obtaining metals from low grade sulfide ores and / or copper sulphide concentrates through of biohydrometallurgical processes in agitated tanks or reactors, trays, batteries, dumps, in situ and / or in place.
- the present invention relates to an isolated bacterial strain of the species Leptospirillum sp., Deposited in the CChRGM (Chilean Collection of Microbial Genetic Resources, Chillán, Chile) under the name RGM 2261 on October 17, 2015 and designated by the Applicants such as Likallfu strain; This strain is useful in bioleaching processes in mining, since it has a high resistance to the toxic element chloride ion.
- the invention also contemplates a microbial inoculum for use in the leaching of sulphided metal ores or metal concentrates, comprising the strain Leptospirillum sp., Likallfu, RGM 2261; and a mineral bioleaching process where a mineral is provided, chosen from a sulphided metal ore or metal concentrates where said mineral is inoculated with the microbial inoculum of the invention, and is maintained at a pH in the range of 1 to 4, and at a temperature in the range of 10 to 45 ° C.
- Halotolerant microorganisms are characterized by tolerating salt concentrations above 0.2 M. These microorganisms that include bacteria and archaea are not common among acidophilic microorganisms, so there is a lack of bioleaching processes in the presence of solutions with high ionic charge. .
- Chloride is an abundant element in mining processes, and particularly in those with water scarcity, where it is associated with the recirculation of solutions in the presence of oxidized copper species such as atacamite.
- oxidized copper species such as atacamite.
- the present invention allows solving the problem of low recovery of copper content in low grade primary sulphide ores since it increases by 57% the recovery of copper in processes with high concentration of chloride ion, solving the problem of the incompatibility of bioleaching with refining solutions of hydrometallurgical processes with significant concentrations of chloride ion, as well as the use of seawater, given that the latter currently requires pre-treatment for its use.
- the advantage of the invention is that the inoculation of the acidophilic strain Leptospirillum sp. Likallfu strain increases by at least 55% the recovery of copper from low grade primary sulphide minerals in the presence of high concentrations of chloride ion.
- the present invention relates to the acidophilic bacterium Leptospirillum sp. Likallfu strain, and its use in processes of obtaining metals from low grade sulfide minerals through biohydrometallurgical processes, particularly in batteries and dumps, in order to increase the recovery of copper from primary sulphides, the above in conjunction with its greater resistance to the toxic elements corresponding to chloride ions, with respect to a reference strain.
- Patent application WO / 2012/001501 A Chloride Method for Bioleaching describes a method for recovering copper from sulphurated minerals, mainly secondary and sulphide mixtures, which includes a first stage of chemical leaching with chloride ion between 7 and 80 g / L, and a second bioleaching stage with a chloride ion concentration below 6 g / L, without mentioning microorganisms of any kind, and less to species or strains of the genus Leptospirillum with halophilic or halotolerant properties.
- Patent application WO / 2010/012030 “Process for Controlled Homogeneous Acid Leaching” describes a leaching solution for leaching target metals.
- the solution is determined empirically, in view of the characteristics of the minerals to be leached.
- the solution contains, among others, Thiobacillus thiooxidans, T.ferrooxidans, Leptospinllum sp., Sulfobacillus thermosulfidooxidans, Sulfolobus br ⁇ erleyi, S.acidocaldar ⁇ us, Sulfolobus BC, S.solfatar ⁇ cus, S.metallicus, Thiomicrosatraium, Thiomicrosatium, Thiomicrosatium, Thiomicrosatium, Thiomicrosatium spiomic sp., Macromonas sp., Thiobacter ⁇ um sp., Thiospora sp., Thiovulum sp., Acidithiobacillus, Acidimicrobium, Ferr ⁇ microbium acidiphilum, Alicyclobacillus, Acidianus, Metallosphaera, Thermoplasma
- halotolerant microorganism which is Thiobacillus prosperus sp. nov., but does not refer to this characteristic with respect to species or strains of the genus Leptospinllum.
- use of microorganisms in this case is not critical, as it is proposed as a preferred but not exclusive alternative.
- FIG. 1 Growth kinetics and ferrooxidant activity of Leptospirillum sp.
- RGM 2261 Likallfu strain in KMD culture medium (990 mg / L (NH 4 ) 2 S0 4 , 145 mg / L NaH 2 P0 4 - H 2 0.52 mg / L KH2PO4, 100 mg / L MgS0 4 -7H 2 0, and 21 mg / L CaCI 2 ) supplemented with 9 g / L Fe (ll), 5 g / L chloride ion and incubation with stirring (150 rpm) and constant temperature at 30 ° C and initial pH 1, 6 .
- the invention discloses an autotrophic bacterial strain capable of oxidizing Fe (ll) ion in aerobic conditions with optimal growth at 37 ° C and pH 1.0-2.0 and which also has a minimum inhibitory concentration of chloride ion of 7 g / L, which implies a resistance 3.5 times higher with respect to the collection strain Leptospir ⁇ llum ferrooxidans ATCC 29047.
- the invention also contemplates the microbial inoculum comprising the strain described above and the bioleaching process of sulphured copper ores in the presence of chloride ion concentrations greater than 2 g / L, which uses the bacterial strain isolated from the species Leptospir ⁇ llum sp., Likallfu, deposited in the CChRGM (Chilean Collection of Microbial Genetic Resources, Chillán, Chile) under the name RGM 2261 on October 17, 2015.
- the invention discloses a mineral bioleaching process where a mineral is provided, chosen from a sulphide metal ore or metallic concentrate.
- Bioleaching of minerals in dumps The minerals that are placed under the law of cut, which are extracted from a farm to "open pit” are collected "run of mine” or with a primary crushing, in streams that have appropriate characteristics for control the infiltration of solutions or surfaces where a waterproof folder has been previously installed and the leaching solution is irrigated on the surface, in the presence of acidophilic microorganisms, extracting copper dissolved in an acid solution by the base.
- Bio-leaching of minerals "in situ” or “n place” Deposits of mineral in its natural state or that have been fractured, due to previous mining operations, are leached directly in place by irrigating the leaching solution on the surface, in the presence of acidophilic microorganisms, extracting copper dissolved in an acid solution by the base
- Inoculum pure or mixed microbial culture that will act as an active biological material during the bioleaching process
- CChRGM Chilean Collection of Microbial Genetic Resources
- Low grade sulphide minerals minerals whose metal content of interest does not allow its economic exploitation through conventional technologies.
- the present invention considers a particular strain of Leptospirillum sp. denominated Likallfu deposited in the CChRGM (Chilean Collection of Microbial Genetic Resources, Chillán, Chile) under the denomination RGM 2261 on October 17, 2015.
- This strain has been identified as an iron oxidizing, Gram-negative, acidophilic and mesophilic bacteria .
- This strain has a resistance to the toxic element chloride ion between 2 and 8 times greater than the nearest collection strains.
- the strain described in the present invention was identified as a species of Leptospirillum sp.
- a microbial inoculum is considered, for use in the leaching of sulphided metal ores, which comprises the strain Leptospinllum sp. Likallfu RGM 2261.
- the microbial inoculum comprises the strain Leptospirillum sp. Likallfu RGM 2261 in pure culture or in combination with biomineros microorganisms selected from Acidithiobacillus spp., Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Acidithiobacillus caldus, Acidithiobacillus ferr ⁇ vorans, Acidithiobacillus albertensis, Acidithiobacillus cuprithermicus, Leptospirillum spp., Leptospirillum ferrooxidans, Leptospirillum ferriphilum, Leptospirillum ferrodiazotrophum, Leptospirillum rubarum, Ferroplasma spp., Ferroplasma acidarmanus, Ferroplasma acidiphilum, Ferroplasma cupricumulans, Ferroplasma thermophilum, Sulfobacillus s
- a mineral leaching process is considered, where i) a mineral is provided, chosen from a sulphided metal ore or metal concentrates, ii) subsequently said mineral is inoculated with an inoculum of the present invention, and iii) is maintained at a pH in the range of 1 to 4, and at a temperature in the range of 10 to 45 ° C.
- the leaching process considers a preferred pH range of 1, 4 and 3.5, and a preferred temperature range between 20 to 40 ° C.
- the ore to be leached in the leaching process is a sulphided metal ore.
- the metal concentrate contains primary copper sulphides.
- the mineral leaching process can be performed according to leaching in situ, in place, in trays, tanks, reactors, batteries or dumps.
- the mineral leaching process considers a watering of the minerals with recycle solutions containing chloride ion concentrations above 2 g / L.
- the mineral in the leaching process contains chloride ion concentrations above 0.01% w / w (0.1 g / L).
- RGM 2261 strain Likallfu was grown in KMD medium (990 mg / L (NH 4 ) 2 S0 4 , 145 mg / L NaH 2 P0 4 -H 2 0, 52 mg / L KH 2 P0 4 , 100 mg / L MgS0 4 -7H 2 0, and 21 mg / L CaCI 2 ) supplemented with 9 g / L Fe (ll), 5 g / L chloride ion and incubation with stirring (150 rpm) and constant temperature at 30 ° C and initial pH 1, 6.
- Figure 1 shows the increase in cell concentration and oxide-reduction potential (ORP) resulting from the ferrooxidant activity of Leptospirillum sp.
- EXAMPLE 2 Minimum Inhibitory Concentration Assays
- the minimum inhibitory concentration (MIC) assays were performed in 6-well plates with 5 mL of KMD culture medium inoculated with 1 x 10 7 cells / mL and incubated with shaking at 150 rpm, 30 ° C and initial pH 1, 6. Concentrations of 0, 2, 4, 5, 7 and 10 g / L chloride ion (added as NaCI), were tested and evaluated for growth by monitoring by optical count and ferrooxidant activity by measuring the oxide-reduction potential. The concentration for which no growth and / or oxidizing activity was observed corresponds to the Minimum Inhibitory Concentration (MIC). From these MIC tests, the highest resistance of Leptospirillum sp.
- MIC Minimum Inhibitory Concentration
- RGM 2261 Likallfu strain to chloride ions (such as sodium chloride) at 30 ° C compared to the collection strain Leptospirillum ferriphilum ATCC 29047. As shown in Table 1, it is possible to conclude that the Likallfu strain has a resistance 3.5 times higher with respect to the collection strain Leptospir ⁇ llum ferr ⁇ philum ATCC 29047, which is very relevant for the use of this microorganism in bioleaching processes.
- chloride ions such as sodium chloride
- Table 1 Minimum Inhibitory Concentration (MIC) at 30 ° C for the Toxic Element ion Chloride (sodium) for Likallfu strain and strain collection.
- MIC Minimum Inhibitory Concentration
- EXAMPLE 3 Bioleaching test with the addition of Leptospir ⁇ llum sp. RGM 2261 Likallfu strain in the presence of chloride ion.
- RGM 2261 Likallfu strain separately.
- the inoculation was performed at a dose of 1 x 10 7 cells / g of ore.
- the columns were incubated at 30 ° C. 5 g / L chloride ion added in the recirculation irrigation solution such as NaCl was added. No basal nutrients or iron were added in the irrigation solution.
- Weekly cell count, total Fe and Cu (ll) determinations were made by atomic absorption spectrometry (Aanalyst 400, Perkin Elmer). The determination of Fe (ll) was performed using the o-phenanthroline colorimetric method.
- the present invention can be used in bioleaching processes in the presence of industrial refining solutions with chloride ion concentrations greater than 2 g / L, considered inhibitory for microorganisms known in the state of the art.
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Abstract
The present invention relates to a bacterial strain isolated from the species Leptospirillum sp., Likallfu, deposited in the CChRGM (Colección Chilena de Recursos Genéticos Microbianos, Chillán, Chile) on 17 October 2015 with reference RGM 2261; said strain being useful in bioleaching processes in the mining industry by exhibiting a high resistance to the toxic element chloride ion. The invention also relates to a microbial inoculum for use in the leaching of sulfur-containing metal ores or metal concentrates, said incoculum comprising the strain Leptospirillum sp., Likallfu, RGM 2261; and a process for bioleaching minerals in which a mineral selected from amongst a sulfur-containing metal ore or metal concentrate is supplied. Said mineral is subsequently inoculated with the microbial inoculum of the invention and maintained at a pH in the range 1 to 4 and at a temperature in the range 10 to 45 °C.
Description
CEPA BACTERIANA AISLADA DE LA ESPECIE LEPTOSPIRILLUM SP., LIKALLFU; INOCULO MICROBIANO QUE LA COMPRENDE; Y PROCESO DE BIOLIXIVIACIÓN DE MINERALES DONDE ES INOCULADO DICHO INOCULO MICROBIANO. BACTERIAL CEPA ISOLATED FROM THE LEPTOSPIRILLUM SP., LIKALLFU; MICROBIAL INOCULUS THAT UNDERSTANDS IT; AND MINERAL BIOLIXIVIATION PROCESS WHERE IT IS INOCULATED SUCH MICROBIAL INOCULATE.
DESCRIPCIÓN La presente invención se relaciona a la minería extractiva mediante procesos hidrometalúrgicos en un rango de temperatura de 10 a 45 °C. En particular, la presente invención se refiere a microorganismos acidófilos mesófilos (crecimiento óptimo hasta 45 °C) y el uso de los mismos en procesos de obtención de metales desde minerales del tipo sulfuros de baja ley y/o concentrados de sulfuros de cobre a través de procesos biohidrometalúrgicos en tanques o reactores agitados, bateas, pilas, botaderos, in situ y/o in place. Más específicamente la presente invención se refiere a una cepa bacteriana aislada de la especie Leptospirillum sp., depositada en la CChRGM (Colección Chilena de Recursos Genéticos Microbianos, Chillán, Chile) bajo la denominación RGM 2261 el 17 de octubre de 2015 y denominada por los solicitantes como cepa Likallfu; esta cepa es útil en procesos de biolixiviación en minería, ya que presenta una alta resistencia al elemento tóxico ion cloruro. La invención también contempla un inoculo microbiano para ser usado en la lixiviación de menas metálicas sulfuradas o concentrados metálicos, que comprende la cepa Leptospirillum sp., Likallfu, RGM 2261 ; y un proceso de biolixiviación de minerales donde se provee un mineral, escogido entre una mena metálica sulfurada o concentrados metálicos en donde dicho mineral es inoculado con el inoculo microbiano de la invención, y se mantiene a un pH en el rango de 1 a 4, y a una temperatura en el rango de 10 a 45 °C. DESCRIPTION The present invention relates to extractive mining by hydrometallurgical processes in a temperature range of 10 to 45 ° C. In particular, the present invention relates to mesophilic acidophilic microorganisms (optimal growth up to 45 ° C) and their use in processes of obtaining metals from low grade sulfide ores and / or copper sulphide concentrates through of biohydrometallurgical processes in agitated tanks or reactors, trays, batteries, dumps, in situ and / or in place. More specifically, the present invention relates to an isolated bacterial strain of the species Leptospirillum sp., Deposited in the CChRGM (Chilean Collection of Microbial Genetic Resources, Chillán, Chile) under the name RGM 2261 on October 17, 2015 and designated by the Applicants such as Likallfu strain; This strain is useful in bioleaching processes in mining, since it has a high resistance to the toxic element chloride ion. The invention also contemplates a microbial inoculum for use in the leaching of sulphided metal ores or metal concentrates, comprising the strain Leptospirillum sp., Likallfu, RGM 2261; and a mineral bioleaching process where a mineral is provided, chosen from a sulphided metal ore or metal concentrates where said mineral is inoculated with the microbial inoculum of the invention, and is maintained at a pH in the range of 1 to 4, and at a temperature in the range of 10 to 45 ° C.
ANTECEDENTES BACKGROUND
En el año 2015 se produjeron 18,7 millones de toneladas de cobre en el mundo, de las cuales alrededor de un 80% proviene de procesos pirometalúrgicos de molienda-flotación- fundición, con altos consumos de agua y energía. Sin embargo, debido a la baja sostenida de las leyes de cobre que han experimentado los yacimientos, la aplicación de las tecnologías pirometalúrgicas en muchos casos no es económicamente viable. Por su parte, debido a sus menores costos de inversión y operación, el uso de la hidrometalurgia y en particular de la biohidrometalurgía o biolixiviación permite extraer cobre desde recursos que no son explotables a través del proceso pirometalúrgico. Si bien las tecnologías hidrometalúrgicas convencionales son muy eficientes en la recuperación de cobre desde óxidos, la biolixiviación permite alcanzar eficiencias no siempre rentables desde sulfuros de cobre. Al respecto y dado que más de un 90% de los recursos y reservas de cobre del i
mundo se encuentran en forma de sulfuros primarios, se hace imperativo el desarrollo y posicionamiento de tecnologías de biolixiviación competitivas para la recuperación de cobre desde sulfuros primarios presentes en minerales de baja ley. Al respecto, las tecnologías actuales de biolixiviación, se basan en la recirculación de soluciones de refino industrial a través de pilas o botaderos de mineral, de forma de reducir tanto el consumo de agua como la generación de residuos líquidos, promoviendo el desarrollo de microorganismos nativos capaces de generar y/o reciclar agentes lixiviantes como el ácido sulfúrico y el ion férrico (Fe(lll)) (Johnson DB; Biomining— biotechnologies for extracting and recoveríng metáis from ores and waste materials; Current Opinión in Biotechnology, Vol.30, p24-31 , 2014). Sin embargo, en la mayoría de los procesos de biolixiviación actualmente en operación se observa por una parte que el desarrollo de la flora microbiana nativa es lento (Olga V. Tupikina OV, Minnaar SH, Rautenbach GF, Dew DW, Harrison STL; Effect of inoculum size on the rates of whole ore colonisation of mesophilic, modérate thermophilic and thermophilic acidophiles; Hydrometallurgy, Vol. 149, p244-251 , 2014), y por otra que las soluciones en recirculación alcanzan una alta carga iónica que inhibe dicha actividad microbiana (C.S. Davis-Belmar CS, Cautivo D, Demergasso C, Rautenbach G; Bioleaching of copper secondary sulfide ore in the presence of chloride by means of inocularon with chloride- tolerant microbial culture; Hydrometallurgy Vol. 150, p308-312, 2015), fenómenos que reducen significativamente la cinética de recuperación de cobre y en muchos casos limitan la extracción final, lo que se traduce en procesos que no son rentables económicamente. In 2015, 18.7 million tons of copper were produced in the world, of which around 80% comes from pyrometallurgical milling-flotation-smelting processes, with high water and energy consumption. However, due to the sustained decline in copper laws experienced by the deposits, the application of pyrometallurgical technologies in many cases is not economically viable. For its part, due to its lower investment and operating costs, the use of hydrometallurgy and in particular biohydrometallurgical or bioleaching allows to extract copper from resources that are not exploitable through the pyrometallurgical process. Although conventional hydrometallurgical technologies are very efficient in recovering copper from oxides, bioleaching allows efficiencies not always profitable from copper sulphides. In this regard and given that more than 90% of the copper resources and reserves of the i The world is in the form of primary sulphides, the development and positioning of competitive bioleaching technologies for the recovery of copper from primary sulphides present in low grade minerals becomes imperative. In this regard, current bioleaching technologies are based on the recirculation of industrial refining solutions through mineral piles or dumps, in order to reduce both water consumption and the generation of liquid waste, promoting the development of native microorganisms capable of generating and / or recycling leaching agents such as sulfuric acid and ferric ion (Fe (lll)) (Johnson DB; Biomining— biotechnologies for extracting and recovering metais from ores and waste materials; Current Opinion in Biotechnology, Vol.30, p24-31, 2014). However, in most of the bioleaching processes currently in operation it is observed on the one hand that the development of native microbial flora is slow (Olga V. Tupikina OV, Minnaar SH, Rautenbach GF, Dew DW, Harrison STL; Effect of inoculum size on the rates of whole ore colonization of mesophilic, modify thermophilic and thermophilic acidophiles; Hydrometallurgy, Vol. 149, p244-251, 2014), and on the other that recirculation solutions reach a high ionic charge that inhibits such microbial activity ( CS Davis-Belmar CS, Captive D, Demergasso C, Rautenbach G; Bioleaching of copper secondary sulfide ore in the presence of chloride by means of inoculated with chloride- tolerant microbial culture; Hydrometallurgy Vol. 150, p308-312, 2015), phenomena which significantly reduce the recovery kinetics of copper and in many cases limit the final extraction, which translates into processes that are not economically profitable.
Por otra parte, el desarrollo de vida en ambientes de alta carga iónica se ha originado a través de diversos procesos evolutivos. Los microorganismos halotolerantes se caracterizan por tolerar concentraciones de sales por sobre 0,2 M. Estos microorganismos que incluyen bacterias y arqueas no son comunes entre los microorganismos acidófilos, por lo que existe una carencia de procesos de biolixiviación en presencia de soluciones con alta carga iónica. On the other hand, the development of life in high ionic load environments has originated through various evolutionary processes. Halotolerant microorganisms are characterized by tolerating salt concentrations above 0.2 M. These microorganisms that include bacteria and archaea are not common among acidophilic microorganisms, so there is a lack of bioleaching processes in the presence of solutions with high ionic charge. .
Un elemento importante que interfiere en el funcionamiento de microorganismos acidófilos en general es el aumento en la concentración de ion cloruro en los procesos de biolixiviación. El cloruro es un elemento abundante en procesos mineros, y en particular en aquellos con escases de agua, donde se asocia a la recirculación de soluciones en presencia de especies oxidadas de cobre como la atacamita. Hasta la fecha si bien se han encontrado algunos microorganismos acidófilos halotolerantes, estos no presentan cinéticas rápidas de oxidación de hierro (II), de forma que presentan una utilidad muy acotada para procesos biomineros. Al respecto, se ha reportado que la presencia específica de ion cloruro inhibe la oxidación de hierro (II) por parte de microorganismos biomineros (Gahan CS,
Sundkvist JE, Dopson M, Sandstróm A; Effect of chloride on ferrous ¡ron oxidation by a Leptospirillum ferriphilum-dominated chemostat culture; Biotechnology & Bioengineering Vol.106, No. 3, p.422-431 , 2010) y que la adaptación de este tipo de cultivos a concentraciones mayores de ion cloruro está altamente restringida (Shiers DW, Blight KR, Ralph DE; Sodium sulphate and sodium chloride effects on batch culture of iron oxidising bacteria; Hydrometallurgy Vol.80, Nos. 1 -2, p.75-82, 2005). An important element that interferes with the functioning of acidophilic microorganisms in general is the increase in the concentration of chloride ion in bioleaching processes. Chloride is an abundant element in mining processes, and particularly in those with water scarcity, where it is associated with the recirculation of solutions in the presence of oxidized copper species such as atacamite. To date, although some halotolerant acidophilic microorganisms have been found, they do not have rapid iron (II) oxidation kinetics, so that they have a very limited utility for biomining processes. In this regard, it has been reported that the specific presence of chloride ion inhibits the oxidation of iron (II) by biomining microorganisms (Gahan CS, Sundkvist JE, Dopson M, Sandstróm A; Effect of chloride on ferrous ron oxidation by a Leptospirillum ferriphilum-dominated chemostat culture; Biotechnology & Bioengineering Vol. 106, No. 3, p.422-431, 2010) and that the adaptation of such crops to higher concentrations of chloride ion is highly restricted (Shiers DW, Blight KR, Ralph DE; Sodium sulphate and sodium chloride effects on batch culture of iron oxidising bacteria; Hydrometallurgy Vol. 80, Nos. 1 -2, p.75-82, 2005).
Más allá de la presencia de sales en las faenas mineras, la presente invención permite solucionar el problema de la baja recuperación del cobre contenido en minerales sulfurados primarios de baja ley ya que aumenta en un 57% la recuperación de cobre en procesos con alta concentración de ion cloruro, solucionando el problema de la incompatibilidad de la biolixiviación con soluciones de refino de procesos hidrometalúrgicos con concentraciones significativas de ion cloruro, así como del uso de agua de mar, dado que actualmente esta última requiere de pre-tratamiento para su uso. Beyond the presence of salts in mining operations, the present invention allows solving the problem of low recovery of copper content in low grade primary sulphide ores since it increases by 57% the recovery of copper in processes with high concentration of chloride ion, solving the problem of the incompatibility of bioleaching with refining solutions of hydrometallurgical processes with significant concentrations of chloride ion, as well as the use of seawater, given that the latter currently requires pre-treatment for its use.
Más particularmente, la ventaja de la invención radica en que la inoculación de la cepa acidófila Leptospirillum sp. cepa Likallfu aumenta en al menos un 55% la recuperación de cobre desde minerales sulfurados primarios de baja ley en presencia de altas concentraciones de ion cloruro. More particularly, the advantage of the invention is that the inoculation of the acidophilic strain Leptospirillum sp. Likallfu strain increases by at least 55% the recovery of copper from low grade primary sulphide minerals in the presence of high concentrations of chloride ion.
ARTE PREVIO PRIOR ART
La presente invención se refiere a la bacteria acidófila Leptospirillum sp. cepa Likallfu, y su uso en procesos de obtención de metales desde minerales del tipo sulfuros de baja ley a través de procesos biohidrometalúrgicos, particularmente en pilas y botaderos, de forma de aumentar la recuperación de cobre desde sulfuros primarios, lo anterior en conjunto a su mayor resistencia a los elementos tóxicos correspondientes a iones cloruro, con respecto a una cepa de referencia. A continuación se resumen algunos documentos relacionados con la presente invención. The present invention relates to the acidophilic bacterium Leptospirillum sp. Likallfu strain, and its use in processes of obtaining metals from low grade sulfide minerals through biohydrometallurgical processes, particularly in batteries and dumps, in order to increase the recovery of copper from primary sulphides, the above in conjunction with its greater resistance to the toxic elements corresponding to chloride ions, with respect to a reference strain. Some documents related to the present invention are summarized below.
La solicitud de patente WO/2012/001501 "A Chloride Method for Bioleaching" , describe un método para recuperar cobre desde minerales sulfurados, principalmente secundarios y mezclas de sulfuros, que incluye una primera etapa de lixiviación química con ion cloruro entre 7 y 80 g/L, y una segunda etapa de biolixiviación con una concentración de ion cloruro bajo 6 g/L, sin hacer mención de microorganismos de ningún tipo, y menos a especies o cepas del género Leptospirillum con propiedades halófilas ni halotolerantes.
La solicitud de patente WO/2010/012030 "Process for Controlled Homogeneous Acid Leaching", describe una solución de lixiviación para lixiviar metales objetivo. Se indica que la solución se determina empíricamente, en vista de las características de los minerales a lixiviar. En particular, se menciona que la solución contiene, entre otros, Thiobacillus thiooxidans, T.ferrooxidans, Leptospinllum sp., Sulfobacillus thermosulfidooxidans, Sulfolobus bríerleyi, S.acidocaldaríus, Sulfolobus BC, S.solfatarícus, S.metallicus, Thiomicrospora sp., Achromatium sp., Macromonas sp., Thiobacteríum sp., Thiospora sp., Thiovulum sp., Acidithiobacillus, Acidimicrobium, Ferrímicrobium acidiphilum, Alicyclobacillus, Acidianus, Metallosphaera, Thermoplasma y mezclas de ellos. Este documento menciona un microorganismo halotolerante, que es Thiobacillus prosperus sp. nov., pero no hace referencia a dicha característica con respecto a especies o cepas del género Leptospinllum. Además el uso de microorganismos en este caso no es crítico, ya que se propone como una alternativa preferente pero no exclusiva. Patent application WO / 2012/001501 "A Chloride Method for Bioleaching" describes a method for recovering copper from sulphurated minerals, mainly secondary and sulphide mixtures, which includes a first stage of chemical leaching with chloride ion between 7 and 80 g / L, and a second bioleaching stage with a chloride ion concentration below 6 g / L, without mentioning microorganisms of any kind, and less to species or strains of the genus Leptospirillum with halophilic or halotolerant properties. Patent application WO / 2010/012030 "Process for Controlled Homogeneous Acid Leaching" describes a leaching solution for leaching target metals. It is indicated that the solution is determined empirically, in view of the characteristics of the minerals to be leached. In particular, it is mentioned that the solution contains, among others, Thiobacillus thiooxidans, T.ferrooxidans, Leptospinllum sp., Sulfobacillus thermosulfidooxidans, Sulfolobus bríerleyi, S.acidocaldaríus, Sulfolobus BC, S.solfatarícus, S.metallicus, Thiomicrosatraium, Thiomicrosatium, Thiomicrosatium, Thiomicrosatium, Thiomicrosatium spiomic sp., Macromonas sp., Thiobacteríum sp., Thiospora sp., Thiovulum sp., Acidithiobacillus, Acidimicrobium, Ferrímicrobium acidiphilum, Alicyclobacillus, Acidianus, Metallosphaera, Thermoplasma and mixtures thereof. This document mentions a halotolerant microorganism, which is Thiobacillus prosperus sp. nov., but does not refer to this characteristic with respect to species or strains of the genus Leptospinllum. In addition, the use of microorganisms in this case is not critical, as it is proposed as a preferred but not exclusive alternative.
En la solicitud de patente WO/2010/009481 "A Method of Treating a Sulphide Mineral', se describe un procedimiento que comprende la biolixiviación de sulfuros de cobre con contenido de calcopirita con una solución de ion cloruro entre 5 y 30 g/L, y un cultivo acidofílico mixto compuesto por Leptospríllium ferríphilum y un microorganismo oxidante de azufre halofílico o halotolerante, que si bien hace referencia a especies o cepas del género Leptospinllum con característica de halofílica o halotolerante, lo hace en mezcla con al menos un microorganismo sulfooxidante halofílico o halotolerante, a diferencia de la presente invención que no requiere de la presencia de un microorganismo sulfooxidante, sea o no halofílico o halotolerante. Por otra parte, las concentraciones de ion cloruro indicadas en la solicitud WO/2010/009481 corresponden a una mezcla de sales de ion cloruro, incluyendo sales de magnesio y aluminio, que de acuerdo al estado del arte son menos tóxicas que la adición exclusiva de ion cloruro como cloruro de sodio (Suzuki I, Lee D, Mackay B, Harahuc L, Oh JK; Effect of varíous ions, pH, and osmotic pressure on oxidation of elemental sulfur by Thiobacillus thiooxidans. Applied and Environmental Microbiology Vol.65, p.5163-5168, 1999), y que se describe como crítica para el cultivo de dicha solicitud, a diferencia de la presente invención en que se utiliza cloruro de sodio como única fuente de ion cloruro. In the patent application WO / 2010/009481 "A Method of Treating a Sulphide Mineral ', a process is described comprising the bioleaching of copper sulfides containing chalcopyrite with a chloride ion solution between 5 and 30 g / L, and a mixed acidophilic culture composed of Leptosprillium ferríphilum and a halophilic or halotolerant sulfur oxidizing microorganism, which while referring to species or strains of the genus Leptospinllum with a halophilic or halotolerant characteristic, does so in admixture with at least one halophilic sulfooxidant microorganism or Halotolerant, unlike the present invention which does not require the presence of a sulfooxidant microorganism, whether or not halophilic or halotolerant.On the other hand, the chloride ion concentrations indicated in the application WO / 2010/009481 correspond to a mixture of salts of chloride ion, including magnesium and aluminum salts, which according to the state of the art are less toxic than the adi exclusive ion chloride chloride as sodium chloride (Suzuki I, Lee D, Mackay B, Harahuc L, Oh JK; Effect of various ions, pH, and osmotic pressure on oxidation of elemental sulfur by Thiobacillus thiooxidans. Applied and Environmental Microbiology Vol.65, p.5163-5168, 1999), and which is described as critical for the cultivation of said application, unlike the present invention in that sodium chloride is used as the sole source of chloride ion.
Tal como se describió previamente, en el estado del arte se pueden apreciar varios documentos que describen el uso conjunto de microorganismos en procesos de biolixiviación. Para el caso de especies o cepas del género Leptospinllum con característica de halofílica o halotolerante, solo se hace mención en un documento, en particular en
mezcla con al menos un microorganismo sulfooxidante halofílico o halotolerante, lo que es la principal diferencia con la presente invención, ya que esta invención no requiere de la presencia de un microorganismo sulfooxidante. En base a lo anterior, ningún documento hace mención al uso exclusivo de especies o cepas del género Leptospirillum con característica de halofílica o halotolerante para su uso en la biolixiviación de minerales sulfurados de cobre. Junto a lo anterior, es sabido que las mezclas de microorganismos así como los consorcios microbianos presentan resistencia a mayores concentraciones de compuestos inhibitorios con respecto a cultivos puros (Jiang H, Liang Y, Yin H, Xiao Y, Guo X, Xu Y, Hu Q, Liu H, Liu X; Effects of Arsenite Resistance on the Growth and Functional Gene Expression of Leptospirillum ferriphilum and Acidithiobacillus thiooxidans in Pure Culture and Coculture; BioMed Research International, Vol.2015, p.1 -13, 2015; Xu Y, Yin H, Jiang H, Liang H, Guo X, Ma L, Xiao Y,Liu X; Comparative study of nickel resistance o f pure culture and co- culture of Acidithiobacillus thiooxidans and Leptospirillum ferriphilum; Archives of Microbiology, Vol. 195, p.637-646, 2013), característica que es otorgada por la relación metabólica entre distintas especies, lo que permite aumentar la tolerancia a compuestos tóxicos e inhibitorios. En base a lo anterior, es bastante probable que en el cultivo señalado en la solicitud de patente internacional WO/2010/009481 , la tolerancia del indicado Leptospirillum ferriphilum a ion cloruro se sustente en su co-cultivo con otro microorganismo y no en sí misma, lo que claramente diferencia dicha solicitud de la presente invención. As previously described, several documents describing the joint use of microorganisms in bioleaching processes can be seen in the state of the art. In the case of species or strains of the genus Leptospinllum with a halophilic or halotolerant characteristic, mention is only made in one document, in particular in mixing with at least one halophilic or halotolerant sulfooxidant microorganism, which is the main difference with the present invention, since this invention does not require the presence of a sulfooxidant microorganism. Based on the above, no document mentions the exclusive use of species or strains of the genus Leptospirillum with a halophilic or halotolerant characteristic for use in the bioleaching of copper sulphide minerals. Along with the above, it is known that mixtures of microorganisms as well as microbial consortia have resistance to higher concentrations of inhibitory compounds with respect to pure cultures (Jiang H, Liang Y, Yin H, Xiao Y, Guo X, Xu Y, Hu Q, Liu H, Liu X; Effects of Arsenite Resistance on the Growth and Functional Gene Expression of Leptospirillum ferriphilum and Acidithiobacillus thiooxidans in Pure Culture and Coculture; BioMed Research International, Vol. 2015, p. 1-13, 2015; Xu Y, Yin H, Jiang H, Liang H, Guo X, Ma L, Xiao Y, Liu X; Comparative study of nickel resistance of pure culture and co-culture of Acidithiobacillus thiooxidans and Leptospirillum ferriphilum; Archives of Microbiology, Vol. 195, p. 637-646, 2013), characteristic that is granted by the metabolic relationship between different species, which allows to increase the tolerance to toxic and inhibitory compounds. Based on the above, it is quite probable that in the culture indicated in the international patent application WO / 2010/009481, the tolerance of the indicated Leptospirillum ferriphilum to chloride ion is sustained in its co-culture with another microorganism and not in itself , which clearly differentiates said application from the present invention.
DESCRIPCIÓN DE LAS FIGURAS DESCRIPTION OF THE FIGURES
Figura 1 . Cinética de crecimiento y actividad ferrooxidante de Leptospirillum sp. RGM 2261 cepa Likallfu en medio de cultivo KMD (990 mg/L (NH4)2S04, 145 mg/L NaH2P04- H20, 52 mg/L KH2PO4, 100 mg/L MgS04-7H20, and 21 mg/L CaCI2) suplementado con 9 g/L de Fe(ll), 5 g/L de ion cloruro e incubación con agitación (150 rpm) y temperatura constante a 30 °C y pH inicial 1 ,6. Concentración celular (■); ORP(Ag/AgCI) (♦). Figure 1 . Growth kinetics and ferrooxidant activity of Leptospirillum sp. RGM 2261 Likallfu strain in KMD culture medium (990 mg / L (NH 4 ) 2 S0 4 , 145 mg / L NaH 2 P0 4 - H 2 0.52 mg / L KH2PO4, 100 mg / L MgS0 4 -7H 2 0, and 21 mg / L CaCI 2 ) supplemented with 9 g / L Fe (ll), 5 g / L chloride ion and incubation with stirring (150 rpm) and constant temperature at 30 ° C and initial pH 1, 6 . Cellular concentration (■); ORP (Ag / AgCI) (♦).
Figura 2. Recuperación de Cu (II) en ensayos de biolixiviación en columnas de mineral sulfurado primario (43% calcopirita, 24% Bornita, 18% Pirita, 12% Calcosina, 1 % Covelina y 1 % Tenantita) de baja ley de cobre (0,35% Cu) con 5 g ion cloruro/L, incubación a 30 °C y adición de Leptospirillum sp. RGM 2261 cepa Likallfu (■); Leptospirillum ferrooxidans ATCC 29047 ( A ) ; Control sin inoculación (♦). Figure 2. Recovery of Cu (II) in bioleaching tests on columns of primary sulphide ore (43% chalcopyrite, 24% Bornite, 18% Pyrite, 12% Calcosine, 1% Covelin and 1% Tenantite) of low copper grade ( 0.35% Cu) with 5 g chloride / L ion, incubation at 30 ° C and addition of Leptospirillum sp. RGM 2261 strain Likallfu (■); Leptospirillum ferrooxidans ATCC 29047 (A); Control without inoculation (♦).
Figura 3. Cinética de actividad ferrooxidante en términos de la evolución del ORP(Ag/AgCI) en el tiempo en ensayos de biolixiviación en columnas de mineral sulfurado primario (43%
calcopirita, 24% Bornita, 18% Pirita, 12% Calcosina, 1 % Covelina y 1 % Tenantita) de baja ley de cobre (0,35% Cu) con 5 g ion cloruro/L, incubación a 30 °C y adición de Leptospiríllum sp. RGM 2261 cepa Likallfu (■); Leptospiríllum ferrooxidans ATCC 29047 (A ); Control sin inoculación (♦). BREVE DESCRIPCIÓN DE LA INVENCIÓN Figure 3. Kinetics of ferrooxidant activity in terms of the evolution of the ORP (Ag / AgCI) over time in bioleaching tests on columns of primary sulphide ore (43% chalcopyrite, 24% Bornite, 18% Pyrite, 12% Calcosine, 1% Covelin and 1% Tenantite) of low copper grade (0.35% Cu) with 5 g chloride / L ion, incubation at 30 ° C and adding Leptospiríllum sp. RGM 2261 strain Likallfu (■); Leptospiríllum ferrooxidans ATCC 29047 (A); Control without inoculation (♦). BRIEF DESCRIPTION OF THE INVENTION
La invención divulga una cepa bacteriana autótrofa capaz de oxidar ion Fe(ll) en condiciones aeróbicas con un crecimiento óptimo a 37 °C y pH 1 ,0-2,0 y que además presenta una concentración mínima inhibitoria a ion cloruro de 7 g/L, lo que implica una resistencia 3,5 veces superior con respecto a la cepa de colección Leptospiríllum ferrooxidans ATCC 29047. The invention discloses an autotrophic bacterial strain capable of oxidizing Fe (ll) ion in aerobic conditions with optimal growth at 37 ° C and pH 1.0-2.0 and which also has a minimum inhibitory concentration of chloride ion of 7 g / L, which implies a resistance 3.5 times higher with respect to the collection strain Leptospiríllum ferrooxidans ATCC 29047.
La invención también contempla el inoculo microbiano que comprende la cepa antes descrita y el proceso de biolixiviacion de minerales sulfurados de cobre en presencia de concentraciones de ion cloruro mayores a 2 g/L, que utiliza la cepa bacteriana aislada de la especie Leptospiríllum sp., Likallfu, depositada en la CChRGM (Colección Chilena de Recursos Genéticos Microbianos, Chillán, Chile) bajo la denominación RGM 2261 el 17 de octubre de 2015. The invention also contemplates the microbial inoculum comprising the strain described above and the bioleaching process of sulphured copper ores in the presence of chloride ion concentrations greater than 2 g / L, which uses the bacterial strain isolated from the species Leptospiríllum sp., Likallfu, deposited in the CChRGM (Chilean Collection of Microbial Genetic Resources, Chillán, Chile) under the name RGM 2261 on October 17, 2015.
Además la invención divulga un proceso de biolixiviacion de minerales donde se provee un mineral, escogido entre una mena metálica sulfurada o concentrado metálico. Furthermore, the invention discloses a mineral bioleaching process where a mineral is provided, chosen from a sulphide metal ore or metallic concentrate.
DESCRIPCIÓN DETALLADA DE LA INVENCIÓN Para mayor comprensión de los procesos entiéndanse como: a) Biolixiviacion de minerales en bateas: proceso que se realiza en un estanque con fondo falso donde se carga el mineral inundándolo con la solución lixiviante la cual se hace circular a través de las partículas de mineral, en presencia de microorganismos acidófilos, extrayendo el cobre disuelto en una solución ácida. b) Biolixiviacion de minerales en tanques o reactores agitados: el proceso de biolixiviacion se realiza en un estanque agitado donde se mezcla el mineral finamente dividido con la solución lixiviante, formando una pulpa con un contenido de sólidos de hasta 20%, con presencia de microorganismos acidófilos, extrayendo el cobre disuelto en una solución ácida.
c) Biolixiviación de minerales en pilas: En este proceso el mineral chancado a una granulometría definida se acopia sobre una superficie impermeable, de baja pendiente y la solución lixiviante se irriga sobre la superficie, en presencia de microorganismos acidófilos, extrayendo por la base el cobre disuelto en una solución ácida. d) Biolixiviación de minerales en botaderos: Los minerales que se sitúan bajo la ley de corte, que se extraen desde una explotación a "rajo abierto" son acopiados "run of mine" o con un chancado primario, en quebradas que tengan características apropiadas para controlar la infiltración de soluciones o superficies donde se haya instalado con anterioridad una carpeta impermeable y la solución lixiviante se irriga sobre la superficie, en presencia de microorganismos acidófilos, extrayendo por la base el cobre disuelto en una solución ácida. e) Biolixiviación de minerales " in sitü' o "¡n place": Depósitos de mineral en estado natural o que se hayan fracturados, debido a anteriores operaciones mineras, son lixiviados directamente en su lugar irrigando la solución lixiviante sobre la superficie, en presencia de microorganismos acidófilos, extrayendo por la base el cobre disuelto en una solución ácida. f) Inoculo: cultivo microbiano puro o mixto que actuará como material biológico activo durante el proceso de biolixiviación. g) CChRGM: Colección Chilena de Recursos Genéticos Microbianos. h) Minerales sulfurados de baja ley: minerales cuyo contenido del metal de interés no permite su explotación económica a través de tecnologías convencionales. DETAILED DESCRIPTION OF THE INVENTION For a better understanding of the processes, it is understood as: a) Mineral bioleaching in trays: a process that is carried out in a pond with a false bottom where the mineral is loaded by flooding it with the leaching solution which is circulated through the mineral particles, in the presence of acidophilic microorganisms, extracting the copper dissolved in an acid solution. b) Bioleaching of minerals in tanks or stirred reactors: the bioleaching process is carried out in a stirred tank where the finely divided mineral is mixed with the leaching solution, forming a pulp with a solids content of up to 20%, with the presence of microorganisms acidophilus, extracting the copper dissolved in an acid solution. c) Bioleaching of minerals in piles: In this process the ore crushed at a defined granulometry is collected on an impermeable surface, with a low slope and the leaching solution is irrigated on the surface, in the presence of acidophilic microorganisms, extracting copper from the base dissolved in an acid solution. d) Bioleaching of minerals in dumps: The minerals that are placed under the law of cut, which are extracted from a farm to "open pit" are collected "run of mine" or with a primary crushing, in streams that have appropriate characteristics for control the infiltration of solutions or surfaces where a waterproof folder has been previously installed and the leaching solution is irrigated on the surface, in the presence of acidophilic microorganisms, extracting copper dissolved in an acid solution by the base. e) Bio-leaching of minerals "in situ" or "n place": Deposits of mineral in its natural state or that have been fractured, due to previous mining operations, are leached directly in place by irrigating the leaching solution on the surface, in the presence of acidophilic microorganisms, extracting copper dissolved in an acid solution by the base f) Inoculum: pure or mixed microbial culture that will act as an active biological material during the bioleaching process g) CChRGM: Chilean Collection of Microbial Genetic Resources h) Low grade sulphide minerals: minerals whose metal content of interest does not allow its economic exploitation through conventional technologies.
La presente invención considera una cepa particular de Leptospirillum sp. denominada Likallfu depositada en la CChRGM (Colección Chilena de Recursos Genéticos Microbianos, Chillán, Chile) bajo la denominación RGM 2261 el 17 de octubre de 2015. Dicha cepa ha sido identificada como una bacteria oxidante de hierro, Gram-negativa, acidófila, y mesófila. Microbiológicamente caracterizada con una temperatura de crecimiento óptima de 37 °C y un rango de pH óptimo de 1 ,0 a 2,0, cuando se crece en presencia de Fe2+. Esta cepa presenta una resistencia al elemento tóxico ion cloruro entre 2 y 8 veces mayor que las cepas de colección más cercanas. En base a análisis filogenéticos, la cepa descrita en la presente invención se identificó como una especie de Leptospirillum sp.
En una realización particular de la invención, se considera un inoculo microbiano, para ser usado en la lixiviación de menas metálicas sulfuradas, que comprende la cepa Leptospinllum sp. Likallfu RGM 2261 . The present invention considers a particular strain of Leptospirillum sp. denominated Likallfu deposited in the CChRGM (Chilean Collection of Microbial Genetic Resources, Chillán, Chile) under the denomination RGM 2261 on October 17, 2015. This strain has been identified as an iron oxidizing, Gram-negative, acidophilic and mesophilic bacteria . Microbiologically characterized with an optimum growth temperature of 37 ° C and an optimum pH range of 1.0 to 2.0, when grown in the presence of Fe 2+ . This strain has a resistance to the toxic element chloride ion between 2 and 8 times greater than the nearest collection strains. Based on phylogenetic analyzes, the strain described in the present invention was identified as a species of Leptospirillum sp. In a particular embodiment of the invention, a microbial inoculum is considered, for use in the leaching of sulphided metal ores, which comprises the strain Leptospinllum sp. Likallfu RGM 2261.
En otra realización de la invención, el inoculo microbiano comprende la cepa Leptospirillum sp. Likallfu RGM 2261 en cultivo puro o en combinación con microorganismos biomineros escogidos entre Acidithiobacillus spp., Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Acidithiobacillus caldus, Acidithiobacillus ferrívorans, Acidithiobacillus albertensis, Acidithiobacillus cuprithermicus, Leptospirillum spp., Leptospirillum ferrooxidans, Leptospirillum ferriphilum, Leptospirillum ferrodiazotrophum, Leptospirillum rubarum, Ferroplasma spp., Ferroplasma acidarmanus, Ferroplasma acidiphilum, Ferroplasma cupricumulans, Ferroplasma thermophilum, Sulfobacillus spp. Sulfobacillus acidophilus, Sulfobacillus benefaciens, Sulfobacillus sibiricus, Acidimicrobium spp., Acidimicrobium ferrooxidans, Alicyclobacillus spp., Alicyclobacillus acidiphilus, Alicyclobacillus acidocaldarius, Alicyclobacillus acidoterrestris, Alicyclobacillus aeris, Alicyclobacillus contaminans, Alicyclobacillus cycloheptanicus, Alicyclobacillus disulfidooxidans, Alicyclobacillus fastidiosus, Alicyclobacillus ferripilum, Alicyclobacillus ferrooxydans, Alicyclobacillus herbarius, Alicyclobacillus hesperidum, Alicyclobacillus kakegawensis, Alicyclobacillus macrosporangiidus, Alicyclobacillus mali, Alicyclobacillus pohliae, Alicyclobacillus pomorum, Alicyclobacillus sacchari, Alicyclobacillus sendaiensis, Alicyclobacillus shizuokensis, Alicyclobacillus tengchongensis, Alicyclobacillus tolerans, Alicyclobacillus vulcanalis, Acidicaldus spp., Acidicaldus organivorans, Acidocella spp., Acidocella aluminiidurans, Acidocella aminolytica, Acidocella facilis, Ferrimicrobium spp., Ferrimicrobium acidiphilum, Ferrithrix spp., Ferrithrix thermotolerans Ferrovum spp. y mezclas de los mismos. En una realización más específica de la invención se considera un proceso de lixiviación de minerales, donde i) se provee un mineral, escogido entre una mena metálica sulfurada o concentrados metálicos, ii) posteriormente dicho mineral es inoculado con un inoculo de la presente invención, y iii) se mantiene a un pH en el rango de 1 a 4, y a una temperatura en el rango de 10 a 45 °C. En otra realización de la invención, el proceso de lixiviación considera un rango preferente de pH de 1 ,4 y 3,5, y un rango de temperatura preferente entre 20 a 40°C. In another embodiment of the invention, the microbial inoculum comprises the strain Leptospirillum sp. Likallfu RGM 2261 in pure culture or in combination with biomineros microorganisms selected from Acidithiobacillus spp., Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Acidithiobacillus caldus, Acidithiobacillus ferrívorans, Acidithiobacillus albertensis, Acidithiobacillus cuprithermicus, Leptospirillum spp., Leptospirillum ferrooxidans, Leptospirillum ferriphilum, Leptospirillum ferrodiazotrophum, Leptospirillum rubarum, Ferroplasma spp., Ferroplasma acidarmanus, Ferroplasma acidiphilum, Ferroplasma cupricumulans, Ferroplasma thermophilum, Sulfobacillus spp. Sulfobacillus acidophilus, Sulfobacillus benefaciens, Sulfobacillus sibiricus, Acidimicrobium spp., Ferrooxidans Acidimicrobium, Alicyclobacillus spp., Alicyclobacillus acidiphilus, Alicyclobacillus acidocaldarius, Alicyclobacillus acidoterrestris, Alicyclobacillus Aeris contaminans Alicyclobacillus, Alicyclobacillus cycloheptanicus, Alicyclobacillus disulfidooxidans, Alicyclobacillus fastidiosus, Alicyclobacillus ferripilum, ferrooxydans Alicyclobacillus, Alicyclobacillus herbarius, Alicyclobacillus hesperidum, Alicyclobacillus kakegawensis, Alicyclobacillus macrosporangiidus, Alicyclobacillus mali, Alicyclobacillus pohliae, Alicyclobacillus pomorum, Alicyclobacillus sacchari, Alicyclobacillus sendaiensis, Alicyclobacillus shizuokensis, Alicyclobacillus tengchongensis, tolerans Alicyclobacillus, Alicyclobacillus vulcanalis, Acidicaldus spp., Acidicaldus organivorans, Acidocella spp., Acidocella aluminiidurans, Acidocella aminolytica, Acidocella facilis, Ferrimicrobium spp., Ferrimicr obium acidiphilum, Ferrithrix spp., Ferrithrix thermotolerans Ferrovum spp. and mixtures thereof. In a more specific embodiment of the invention, a mineral leaching process is considered, where i) a mineral is provided, chosen from a sulphided metal ore or metal concentrates, ii) subsequently said mineral is inoculated with an inoculum of the present invention, and iii) is maintained at a pH in the range of 1 to 4, and at a temperature in the range of 10 to 45 ° C. In another embodiment of the invention, the leaching process considers a preferred pH range of 1, 4 and 3.5, and a preferred temperature range between 20 to 40 ° C.
En una realización específica de la presente invención, el mineral a ser lixiviado en el proceso de lixiviación es una mena metálica sulfurada.
En otra realización específica de la invención, el concentrado metálico contiene sulfuros primarios de cobre. In a specific embodiment of the present invention, the ore to be leached in the leaching process is a sulphided metal ore. In another specific embodiment of the invention, the metal concentrate contains primary copper sulphides.
En una realización aún más específica de la presente invención, el proceso de lixiviación de minerales se puede realizar de acuerdo a una lixiviación in situ, in place, en bateas, tanques, reactores, pilas o botaderos. In an even more specific embodiment of the present invention, the mineral leaching process can be performed according to leaching in situ, in place, in trays, tanks, reactors, batteries or dumps.
En otra realización el proceso de lixiviación de minerales considera un regado de los minerales con soluciones de reciclo que contienen concentraciones de ion cloruro por sobre 2 g/L. In another embodiment the mineral leaching process considers a watering of the minerals with recycle solutions containing chloride ion concentrations above 2 g / L.
En otra realización de la invención, en el proceso de lixiviación el mineral contiene concentraciones de ion cloruro por sobre 0,01 % p/p (0,1 g/L). In another embodiment of the invention, in the leaching process the mineral contains chloride ion concentrations above 0.01% w / w (0.1 g / L).
EJEMPLOS EXAMPLES
EJEMPLO 1 : Condiciones de Cultivo EXAMPLE 1: Growing Conditions
Leptospirillum sp. RGM 2261 cepa Likallfu fue cultivada en medio KMD (990 mg/L (NH4)2S04, 145 mg/L NaH2P04-H20, 52 mg/L KH2P04, 100 mg/L MgS04-7H20, and 21 mg/L CaCI2) suplementado con 9 g/L de Fe(ll), 5 g/L de ion cloruro e incubación con agitación (150 rpm) y temperatura constante a 30 °C y pH inicial 1 ,6. En la Figura 1 se observa el aumento de la concentración celular y del potencial de óxido-reducción (ORP) producto de la actividad ferrooxidante de Leptospirillum sp. RGM 2261 cepa Likallfu en presencia de ion cloruro. EJEMPLO 2: Ensayos de Concentración Mínima Inhibitoria Leptospirillum sp. RGM 2261 strain Likallfu was grown in KMD medium (990 mg / L (NH 4 ) 2 S0 4 , 145 mg / L NaH 2 P0 4 -H 2 0, 52 mg / L KH 2 P0 4 , 100 mg / L MgS0 4 -7H 2 0, and 21 mg / L CaCI 2 ) supplemented with 9 g / L Fe (ll), 5 g / L chloride ion and incubation with stirring (150 rpm) and constant temperature at 30 ° C and initial pH 1, 6. Figure 1 shows the increase in cell concentration and oxide-reduction potential (ORP) resulting from the ferrooxidant activity of Leptospirillum sp. RGM 2261 Likallfu strain in the presence of chloride ion. EXAMPLE 2: Minimum Inhibitory Concentration Assays
Los ensayos de concentración mínima inhibitoria (CMI) se realizaron en placas de 6 pocilios con 5 mL de medio de cultivo KMD inoculados con 1 x107 cel/mL e incubados con agitación a 150 rpm, 30 °C y pH inicial 1 ,6. Concentraciones de 0, 2, 4, 5, 7 y 10 g/L de ion cloruro (agregado como NaCI), fueron ensayadas y evaluadas por crecimiento mediante monitoreo por recuento óptico y actividad ferrooxidante mediante medición del potencial de óxido- reducción. La concentración para la que no se observó crecimiento y/o actividad oxidante corresponde a la Concentración Mínima Inhibitoria (CMI). A partir de estos ensayos de CMI se confirma la mayor resistencia de Leptospirillum sp. RGM 2261 cepa Likallfu a iones cloruro (como cloruro de sodio) a 30°C en comparación con la cepa de colección Leptospirillum ferriphilum ATCC 29047. Como se muestra en la Tabla 1 , es posible concluir
que la cepa Likallfu tiene una resistencia 3,5 veces superior con respecto a la cepa de colección Leptospiríllum ferríphilum ATCC 29047, lo que es muy relevante para el uso de este microorganismo en procesos de biolixiviación. The minimum inhibitory concentration (MIC) assays were performed in 6-well plates with 5 mL of KMD culture medium inoculated with 1 x 10 7 cells / mL and incubated with shaking at 150 rpm, 30 ° C and initial pH 1, 6. Concentrations of 0, 2, 4, 5, 7 and 10 g / L chloride ion (added as NaCI), were tested and evaluated for growth by monitoring by optical count and ferrooxidant activity by measuring the oxide-reduction potential. The concentration for which no growth and / or oxidizing activity was observed corresponds to the Minimum Inhibitory Concentration (MIC). From these MIC tests, the highest resistance of Leptospirillum sp. RGM 2261 Likallfu strain to chloride ions (such as sodium chloride) at 30 ° C compared to the collection strain Leptospirillum ferriphilum ATCC 29047. As shown in Table 1, it is possible to conclude that the Likallfu strain has a resistance 3.5 times higher with respect to the collection strain Leptospiríllum ferríphilum ATCC 29047, which is very relevant for the use of this microorganism in bioleaching processes.
Tabla 1 . Concentración Mínima Inhibitoria (CMI) a 30 °C para el Elemento Tóxico ion Cloruro (de sodio) para cepa Likallfu y cepa de colección. Table 1 . Minimum Inhibitory Concentration (MIC) at 30 ° C for the Toxic Element ion Chloride (sodium) for Likallfu strain and strain collection.
EJEMPLO 3: Ensayo de biolixiviación con adición de Leptospiríllum sp. RGM 2261 cepa Likallfu en presencia de ion cloruro. EXAMPLE 3: Bioleaching test with the addition of Leptospiríllum sp. RGM 2261 Likallfu strain in the presence of chloride ion.
Los ensayos de biolixiviación bajo condiciones mesófilas se llevaron a cabo en duplicado en columnas. Cada columna de acrílico de 6 cm de diámetro conteniendo 500 g de mineral sulfurado primario (43% calcopirita, 24% Bornita, 18% Pirita, 12% Calcosina, 1 % Covelina y 1 % Tenantita ) de baja ley de cobre (0,35% Cu), el que fue acondicionado con solución ácida diluida con pH 0,8 por 24 h y pH 1 ,4 por 24 h adicionales en circuito abierto para remover todo el cobre soluble, para luego regar en circuito cerrado con solución ácida pH 1 ,4, sin inoculación en el caso del control, inoculando con la cepa de colección Leptospiríllum ferrooxidans ATCC 29047, o con Leptospiríllum sp. RGM 2261 cepa Likallfu por separado. La inoculación se realizó a una dosis de 1 x107 cel/g de mineral. Las columnas fueron incubadas a 30 °C. Se adicionaron 5 g/L de ion cloruro agregados en la solución de riego en recirculación como NaCI. No se adicionaron nutrientes básales ni hierro en la solución de riego. Se realizaron determinaciones semanales de recuento celular, Fe total y Cu(ll) por espectrometría de absorción atómica (Aanalyst 400, Perkin Elmer). La determinación de Fe(ll) se realizó usando el método colorimétrico de la o-fenantrolina. Bioleaching tests under mesophilic conditions were carried out in duplicate in columns. Each 6 cm diameter acrylic column containing 500 g of primary sulphide ore (43% chalcopyrite, 24% Bornite, 18% Pyrite, 12% Calcosine, 1% Covelin and 1% Tenantite) of low copper grade (0.35 % Cu), which was conditioned with dilute acid solution with pH 0.8 for 24 h and pH 1, 4 for an additional 24 h in open circuit to remove all soluble copper, then watering in closed circuit with acid solution pH 1, 4, without inoculation in the case of the control, inoculating with the collection strain Leptospiríllum ferrooxidans ATCC 29047, or with Leptospiríllum sp. RGM 2261 Likallfu strain separately. The inoculation was performed at a dose of 1 x 10 7 cells / g of ore. The columns were incubated at 30 ° C. 5 g / L chloride ion added in the recirculation irrigation solution such as NaCl was added. No basal nutrients or iron were added in the irrigation solution. Weekly cell count, total Fe and Cu (ll) determinations were made by atomic absorption spectrometry (Aanalyst 400, Perkin Elmer). The determination of Fe (ll) was performed using the o-phenanthroline colorimetric method.
En estos ensayos se observa que la adición de la cepa Likallfu incrementó la recuperación de cobre en un 57 % con respecto a los controles sin inoculación e inoculado con Leptospiríllum ferrooxidans ATCC 29047 (ver Figura 2). Estos resultados evidencian las
ventajas de la adición de la cepa Likallfu en presencia de ion cloruro, (5 g ion cloruro/L) respecto de la adición de la cepa control, así como de la condición sin inoculación. Para el caso con adición de Leptospirillum sp. RGM 2261 cepa Likallfu se observa un rápido aumento de la actividad microbiana ferrooxidante (Figura 3) así como una cinética acelerada de biolixiviacion de un mineral de baja ley de cobre y con un alto contenido de sulfuros primarios (Figura 2). In these tests it is observed that the addition of the Likallfu strain increased the recovery of copper by 57% with respect to controls without inoculation and inoculated with Leptospiríllum ferrooxidans ATCC 29047 (see Figure 2). These results show the advantages of the addition of the Likallfu strain in the presence of chloride ion, (5 g chloride / L ion) over the addition of the control strain, as well as the condition without inoculation. In the case with the addition of Leptospirillum sp. RGM 2261 strain Likallfu shows a rapid increase in ferrooxidant microbial activity (Figure 3) as well as an accelerated bioleaching kinetics of a low grade copper ore with a high content of primary sulphides (Figure 2).
La presente invención puede ser utilizada en procesos de biolixiviacion en presencia de soluciones de refino industrial con concentraciones de ion cloruro mayor a 2 g/L, considerado inhibitorio para los microorganismos conocidos en el estado del arte.
The present invention can be used in bioleaching processes in the presence of industrial refining solutions with chloride ion concentrations greater than 2 g / L, considered inhibitory for microorganisms known in the state of the art.
Claims
1 . Cepa bacteriana aislada, CARACTERIZADA porque es de la especie Leptospiríllum sp. depositada en la CChRGM (Colección Chilena de Recursos Genéticos Microbianos, Chillán, Chile) bajo el registro RGM 2261 del 17 de octubre de 2015 denominada Likallfu; esta cepa es útil en procesos de biolixiviación en minería, ya que presenta una concentración mínima inhibitoria al ion cloruro de 7g/L. 1 . Isolated bacterial strain, CHARACTERIZED because it is from the species Leptospirillum sp. deposited in the CChRGM (Chilean Collection of Microbial Genetic Resources, Chillán, Chile) under registration RGM 2261 of October 17, 2015 called Likallfu; This strain is useful in bioleaching processes in mining, since it has a minimum inhibitory concentration to the chloride ion of 7g/L.
2. Inoculo microbiano, para ser usado en la lixiviación de menas metálicas sulfuradas, CARACTERIZADO porque comprende la cepa Leptospiríllum sp. Likallfu RGM 2261 de acuerdo a la reivindicación 1 . 2. Microbial inoculum, to be used in the leaching of sulfide metallic ores, CHARACTERIZED because it includes the strain Leptospirillum sp. Likallfu RGM 2261 according to claim 1.
3. Inoculo microbiano, de acuerdo a la reivindicación 2 CARACTERIZADO porque comprende la cepa Leptospiríllum sp. Likallfu RGM 2261 en cultivo puro o en combinación con microorganismos biomineros escogidos entre Acidithiobacillus spp., Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Acidithiobacillus caldus, Acidithiobacillus ferrívorans, Acidithiobacillus albertensis, Acidithiobacillus cupríthermicus, Leptospiríllum spp., Leptospiríllum ferrooxidans, Leptospiríllum ferriphilum, Leptospiríllum ferrodiazotrophum, Leptospiríllum rubarum, Ferroplasma spp., Ferroplasma acidarmanus, Ferroplasma acidiphilum, Ferroplasma cupricumulans, Ferroplasma thermophilum, Sulfobacillus spp. Sulfobacillus acidophilus, Sulfobacillus benefaciens, Sulfobacillus sibiricus, Acidimicrobium spp., Acidimicrobium ferrooxidans, Alicyclobacillus spp., Alicyclobacillus acidiphilus, Alicyclobacillus acidocaldarius, Alicyclobacillus acidoterrestris, Alicyclobacillus aeris, Alicyclobacillus contaminans, Alicyclobacillus cycloheptanicus, Alicyclobacillus disulfidooxidans, Alicyclobacillus fastidiosus, Alicyclobacillus ferripilum, Alicyclobacillus ferrooxydans, Alicyclobacillus herbarius, Alicyclobacillus hesperidum, Alicyclobacillus kakegawensis, Alicyclobacillus macrosporangiidus, Alicyclobacillus mali, Alicyclobacillus pohliae, Alicyclobacillus pomorum, Alicyclobacillus sacchari, Alicyclobacillus sendaiensis, Alicyclobacillus shizuokensis, Alicyclobacillus tengchongensis, Alicyclobacillus tolerans, Alicyclobacillus vulcanalis, Acidicaldus spp., Acidicaldus organivorans, Acidocella spp., Acidocella aluminiidurans, Acidocella aminolytica, Acidocella facilis, Ferrimicrobium spp., Ferrimicrobium acidiphilum, Ferrithrix spp., Ferrithrix thermotolerans, Ferrovum spp. y mezclas de los mismos. 3. Microbial inoculum, according to claim 2 CHARACTERIZED because it comprises the strain Leptospirillum sp. Likallfu RGM 2261 in pure culture or in combination with biomining microorganisms chosen from Acidithiobacillus spp., Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Acidithiobacillus caldus, Acidithiobacillus ferrívorans, Acidithiobacillus albertensis, Acidithiobacillus cupríthermicus, Leptospirillum spp. ., Leptospirillum ferrooxidans, Leptospirillum ferriphilum, Leptospirillum ferrodiazotrophum, Leptospirillum rubarum, Ferroplasma spp., Ferroplasma acidarmanus, Ferroplasma acidiphilum, Ferroplasma cupricumulans, Ferroplasma thermophilum, Sulfobacillus spp. Sulfobacillus acidophilus, Sulfobacillus benefaciens, Sulfobacillus sibiricus, Acidimicrobium spp., Acidimicrobium ferrooxidans, Alicyclobacillus spp., Alicyclobacillus acidiphilus, Alicyclobacillus acidocaldarius, Alicyclobacillus acidoterrestris, Alicyclobacillus aeris, Alicyclobacillus contaminans, Alicyclobacillus cycloheptanicus, Alicycl obacillus disulfidooxidans, Alicyclobacillus fastidiosus, Alicyclobacillus ferripilum, Alicyclobacillus ferrooxydans, Alibaba obacillus vulcanalis, Acidicaldus spp., Acidicaldus organivorans, Acidocella spp., Acidocella aluminiidurans, Acidocella aminolytica, Acidocella facilis, Ferrimicrobium spp., Ferrimicrobium acidiphilum, Ferrithrix spp., Ferrithrix thermotolerans, Ferrovum spp. and mixtures thereof.
4. Proceso de biolixiviación de minerales, CARACTERIZADO porque se provee un mineral, escogido entre una mena metálica sulfurada o concentrados metálicos,
posteriormente dicho mineral es inoculado con el inoculo de acuerdo a la reivindicación 2, y se mantiene a un pH en el rango de 1 a 4, y a una temperatura en el rango de 10 a 45 °C. 4. Mineral bioleaching process, CHARACTERIZED because a mineral is provided, chosen from a sulfide metallic ore or metallic concentrates, Subsequently, said mineral is inoculated with the inoculum according to claim 2, and is maintained at a pH in the range of 1 to 4, and a temperature in the range of 10 to 45 °C.
5. Proceso de biolixiviación de minerales, CARACTERIZADO porque se provee un mineral, escogido entre una mena metálica sulfurada o concentrados metálicos, posteriormente dicho mineral es inoculado con el inoculo de acuerdo a la reivindicación 3, y se mantiene a un pH en el rango de 1 a 4, y a una temperatura en el rango de 10 a 45 °C. 5. Mineral bioleaching process, CHARACTERIZED because a mineral is provided, chosen from a sulfide metallic ore or metallic concentrates, subsequently said mineral is inoculated with the inoculum according to claim 3, and is maintained at a pH in the range of 1 to 4, and at a temperature in the range of 10 to 45 °C.
6. Proceso de biolixiviación de minerales de acuerdo con la reivindicación 4 ó 5, CARACTERIZADO porque el pH se mantiene entre 1 ,4 y 3,5, y la temperatura se mantiene en el rango de 20 a 40 °C. 6. Mineral bioleaching process according to claim 4 or 5, CHARACTERIZED in that the pH is maintained between 1.4 and 3.5, and the temperature is maintained in the range of 20 to 40 °C.
7. Proceso de biolixiviación de minerales de acuerdo a la reivindicación 4 ó 5, CARACTERIZADO porque la mena metálica sulfurada o el concentrado metálico contiene sulfuros primarios de cobre. 7. Mineral bioleaching process according to claim 4 or 5, CHARACTERIZED because the sulfide metal ore or the metal concentrate contains primary copper sulfides.
8. Proceso de biolixiviación de minerales de acuerdo a la reivindicación 4 ó 5, CARACTERIZADO porque el mineral se lixivia in situ, in place, en bateas, tanques, reactores, pilas o botaderos. 8. Mineral bioleaching process according to claim 4 or 5, CHARACTERIZED because the mineral is leached in situ, in place, in pans, tanks, reactors, piles or dumps.
9. Proceso de biolixiviación de minerales de acuerdo a la reivindicación 4 ó 5, CARACTERIZADO porque el mineral es regado con soluciones de reciclo que contienen concentraciones de ion cloruro por sobre 2 g/L. 9. Mineral bioleaching process according to claim 4 or 5, CHARACTERIZED because the mineral is irrigated with recycling solutions that contain chloride ion concentrations above 2 g/L.
1 0. Proceso de biolixiviación de minerales de acuerdo a la reivindicación 4 ó 5, CARACTERIZADO porque el mineral contiene concentraciones de ion cloruro por sobre1 0. Mineral bioleaching process according to claim 4 or 5, CHARACTERIZED because the mineral contains concentrations of chloride ion above
0,01 % p/p.
0.01% w/w.
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| PCT/IB2016/053536 WO2017216610A1 (en) | 2016-06-15 | 2016-06-15 | A bacterial strain isolated from the species leptospirillum sp., likallfu; a microbial inoculum comprising same; and a method for bioleaching minerals in which said microbial inoculum is inoculated. |
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| WO2010009481A2 (en) * | 2008-06-29 | 2010-01-21 | Bhp Billiton Sa Limited | A method of treating a sulphide mineral |
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| WO2010009481A2 (en) * | 2008-06-29 | 2010-01-21 | Bhp Billiton Sa Limited | A method of treating a sulphide mineral |
Non-Patent Citations (2)
| Title |
|---|
| DAVIS-BELMAR,C.S ET AL.: "Bioleaching of copper secondary sulfide ore in the presence of chloride by means of inoculation with chloride-tolerant microbial culture", HYDROMETALLURGY, vol. 150, 2014, pages 308 - 312, XP055230276 * |
| GAHAN, C.S. ET AL.: "Effect of chloride on ferrous iron oxidation by a Leptospirillumferriphilum-dominated chemostat culture", BIOTECHNOL BIOENG, vol. 106, no. 3, 15 June 2010 (2010-06-15), pages 422 - 31, XP055450628 * |
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