biomining presentation

8/15/2019 Biomining Presentation

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Bioleaching/BiocorrosionBioleaching/Biocorrosion

Metals/BiominingMetals/Biomining

Lisa Smith

Marian Cummins

Deborah Mc Auliffe


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• Metal Contamination of soil environments

and the assessment of its potential risk to

terrestrial environments and human health

is one of the most challenging tasksconfronting scientists today.


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• Challenge for mining companies – Serviceno long term impact on environment

• !ncreasing interest in microbial approachesfor recovery of base and precious metals


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"iomining"iomining

• #se of microorganisms

– $res of high %uality rapidly being depleted

– &nvironmentally friendly alternative


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"iomining"iomining

• 'aturally e(isting microorganisms leach

and o(idate

). "ioleaching

*. "ioo(idation


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• "ioleaching

– &(traction of metals +ith the use of

microorganisms

• "ioo(idation

– Microorganisms make metal ready for

e(traction


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,eneral -roperties,eneral -roperties

• Chemolithotrophic rock eating/

• Autotrophic

• Acidophilic 0 acid loving1

• #se o(ygen as the preferred electron acceptor


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Specific MicroorganismsSpecific Microorganisms

Most common2

• Thiobacillus ferrooxidans

• Thiobacillus thiooxidans


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Thiobacillus ferrooxidansThiobacillus ferrooxidans

• 3od shaped

• 3elatively %uick gro+ing

• ,ram negative

• Strictly aerobic• Aerobic conditions uses 4e*5 or reduced S 0S*1 as

electron acceptor

• Ano(ic conditions use 4e65 as electron acceptor

• Mod. 7hermophilic8 temperatures of *96: degree C andp; of *.9


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Thiobacillus thioxidansThiobacillus thioxidans

•


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7he -rocess7he -rocess

• * Methods Direct and indirect

• Direct en>ymatic attack and occurs at the

cell membrane

• !ndirect bacteria produce 4e65 0 ferric iron1

by o(idi>ing 4e*5 0ferrous iron1

• 4e65

is a po+erful o(idi>ing agent thatreacts +ith the metals and so produces

4e*5 in a continuous cycle.


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Copper -rocessCopper -rocess

• *:? Copper production is recovered by

biomining

• MS 5 *$* MS$@

• Metal sulphide is insoluble and metal sulphate is

usually +ater soluble

• Cu ore contains CuS and Cu4eS*

• T. ferrooxidans brings about both direct andindirect o(idation of CuS via the generation of

04e651 ferric iron from 04e*51 ferrous sulphate


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• Cu is recovered by solvent e(traction or by

using scrap iron +here the iron replaces

the Cu

• CuS$@

5 4e Cu 5 4eS$@


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$ther Application of "iomining$ther Application of "iomining

• ,old

• Due to depletions by the )B9=s

• Dependent on lo+er grade ore

• ,old is encased in the sulphide minerals• T. ferrooxidans

• 4airvie+ mine in S. Africa

• 3ecovery rate of 9? to :?


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Cont=dCont=d

• -hosphates industry

• *nd largest agriculture chemical

• :.: million tons year in the #S

• 7raditional method +as burning at high temperatures0solid phosphorus1 or +ith ;* S$@0phosphoric acid and

gypsum1

• Pseudomonas cepacia E37 and Erwinia herbicola

• ,lucose gluconic and * ketogluconic acid• &nvironmentally friendly as no ;s S$@ re%uired and it

occurs at room temperature.


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Case Studies

5

&conomics of "iomining


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Microbes E7$ 7ACFL& M!'&Microbes E7$ 7ACFL& M!'&

GAS7&=GAS7&=

• Scientists are using microbes to clean up theproblem of corrosive acid pollution left over asmining +aste

• Some of the microbes being used +ere found in America8 Gales and the Caribbean island

• "y discovering microbes +hich can survive inthis environment8 +ill help address seriousenvironmental ha>ards at abandoned mines andsoil heaps


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!ndustrial "iotechnology "iomining!ndustrial "iotechnology "iomining

• Commercial Capabilities

• #nderpinning &(isting Capabilities

• &merging Capabilities

• !nstitutional Capabilities

• Fno+ledge Skills


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Chile "iomining -rogramChile "iomining -rogram

• Gorlds first biggest producer of Copper

• !n )) copper mines +ere nationali>ed

• "ut in )9 Chile returned to democracy

• Started in )9 +ith target H*.:m tons for theyear *999

• 7his 4igure +as superseded in ): andproduction e(ceeded :m tons late )9=s


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&conomic Study of the Canadian&conomic Study of the Canadian

"iotechnology"iotechnology

• Canadian environmental I industrial

biotechnology firms

• Microorganisms in applications such as

bioremediation leaching8 energy production

• Canadian Stakeholders +ithJ #.S8

&uropean8 Kapanese environmental

regulators


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"iomining"iomining7here=s ,$LD in them thar= -lants/7here=s ,$LD in them thar= -lants/

• ,old rush miners might have been better

off using plants to find gold rather than

panning streams for precious metal

• &arly prospectors in &urope used certain

+eeds as indicator plants that signaled the

presence of metal ore


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3emediation3emediation

• 3esponse to human health effects

• 3esponse to environmental effects

• 3edevelopment


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"ioremediation"ioremediation

• Destroys or renders harmless various

contaminants using microbial activity

• "ioremediation of metalcontaminated soil

– Soil 4lushing

– Soil Gashing

– -hytostabili>ation

– -hytoremediation


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-hytostabili>ation-hytostabili>ation

• !mmobili>ation of a contaminant in soilthrough – Absorption I Accumulation

– Adsorption – -recipitation

• Also use of plant I plant root to prevent

contaminant migration• Soil is then farmed to improve gro+th and

reduce mobility and to(icity of contaminant


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-hytoremediation-hytoremediation

• #se of plants to remove contaminants

from soil

• Certain plant speciesmetal

hyperaccumulators

– e(tract metals8 concentrate them in their

leaves

• -revent recontaminationplants harvested


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• Leaves accumulate

metals and are

harvested

• 3oots take up metals

from contaminated

soil and transport to

the stem8 leaves


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"iomining"iomining5Carried out insitu

5Less energy input

5'o to(icno(ious gases produced

5'o noise or dust problems

5-rocess is self generating

5Large or small scale operations

5Gide variety of metals 0Cu8 Ag8 -b8 Au8 n1

5Gork on lo+ grade ores

Slo+ process


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Traditional extraction causes

environmental problems and

degradation, biomining offers an

environmentally friendly alternative!!!!!!

biomining presentation

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