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Topic: Bioleaching


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In the News (Fri 31 Oct 14)

  
  Bioleaching - Wikipedia, the free encyclopedia
Bioleaching is the extraction of specific metals from their ores through the use of bacteria.
Bioleaching is a technique used by the mining industry to extract minerals such as gold and copper from their ores.
economical: bioleaching is generally simpler and therefore cheaper to operate and maintain than traditional processes, since fewer specialists are needed to operate complex chemical plants.
en.wikipedia.org /wiki/Bioleaching   (954 words)

  
 Present and future of bioleaching in developing countries
In the period of 1950 to 1980, bioleaching was thought mostly as an appropriate technology for the recovery of copper and other metals from damps and low-grade ores.
Bioleaching is also successfully applied in gold mining, when the metal is covered with a film of insoluble metal sulphides that difficult the extraction of gold with cyanide solutions.
Another ongoing project is a heap bioleaching plant to treat zinc sulphide concentrates that is being developed in the Kumba's Rosh Pinah mine in Namibia (Anonymous, 2001b).
www.ejbiotechnology.info /content/vol5/issue2/issues/01/index.html   (1464 words)

  
 Innovations in Copper: Mining & Extraction: Producing copper nature's way: Bioleaching
Bioleaching is the extraction of a metal from sulfide ores or concentrates using materials found native to the environment; namely, water, air and microorganisms.
Bioleaching is used today in commercial operations to process ores of copper, nickel, cobalt, zinc and uranium, whereas, biooxidation is used in gold processing and coal desulfurization.
Bioleaching does not recover the precious metals in the ore. The precious metals are often an important component in the profitability of the operation.
www.copper.org /innovations/2004/05/producing_copper_natures_way_bioleaching.html   (4373 words)

  
 Talvivaara Mining Company - Bioleaching   (Site not responding. Last check: 2007-10-20)
Bioleaching is a process, whereby metals are leached from ore as a result of bacterial action.
In nature, bioleaching is triggered spontaneously by micro-organisms in the presence of air and water.
Commercially applied bioleaching technologies utilize the same phenomenon, but accelerate the process significantly by increasing the amount of bacteria and by improving their living conditions through added air, water and nutrients.
www.talvivaara.com /processes_2.html   (328 words)

  
 BacTech Mining Corporation - Technical Details - Overview - Wed Jan 3, 2007   (Site not responding. Last check: 2007-10-20)
Bioleaching is an environmental alternative technique to roasting that does not create gaseous emissions, and is often a cheaper alternative to both roasting and other methods (such as pressure leaching) that might also be considered.
Bioleaching can be used to oxidize metal-containing sulphides into soluble sulphate forms, and metals such as copper, nickel, cobalt and zinc can be extracted and purified into a saleable form directly at the minesite.
Bioleaching is a natural process that has a remarkable ability to adapt to treating a variety of sulphide minerals from a single deposit.
www.bactech.com /s/TechDetails.asp?ReportID=84471&_Title=Overview   (2002 words)

  
 Research Group -- Chemical Engineering   (Site not responding. Last check: 2007-10-20)
Research in minerals bioprocessing is focused on two main areas, viz., the bioleaching of sulphide minerals and bioprocesses for the treatment of sulphate containing wastewaters from acid mine drainage and other minerals processing operations.
Bioleaching is gaining increasing importance and application for the treatment of refractory gold ores and for the leaching of copper, nickel, cobalt and zinc with several large plants in operation and more under construction throughout the world.
In bioleaching the research focuses on the development of kinetic models for the three main processes involved which are; the bacterial oxidation of ferrous iron, the chemical ferric leaching of the sulphide mineral and the bacterial oxidation of the sulphur moiety formed.
www.chemeng.uct.ac.za /groups/biomin   (464 words)

  
 bioleaching
Bioleaching involves the use of micro-organisms to extract metals from low grade ores and has been performed successfully on Earth to obtain gold, copper and uranium[2].
Bioleaching of nickel, zinc and cobalt can be done with thermophyllic bacteria but has not proven economical; however, on the Moon where resources are sparse and imports comparatively expensive, this may be worthwhile.
If bioleaching becomes a major industrial activity on the Moon we will be pressed to conserve our vital water and hydrogen resources for this instead of wasting them in the form of rocket fuel.
www.moonminer.com /bioleaching.html   (496 words)

  
 Directory of open access journals
Bioleaching is a process that has been used in the past in mineral pretreatment of refractory sulfides, mainly in the gold, copper and uranium benefit.
Bioleaching kinetic data of arsenic solubilization were used to estimate the dilution rate for a continuous culture.
The process of bioleaching is expected to be influenced by mechanisms that still need to be established due to the diversity of the minerals involved and by the presence of traces of metals in the concentrate.
www.doaj.org /abstract?id=102886&toc=y   (504 words)

  
 BioMetMine - What is Bioleaching?
Bioleaching refers to the use of bacteria, principally Thiobacillus ferrooxidans, Leptospirillum ferrooxidans and thermophilic species of Sulfobacillus, Acidianus and Sulfolobus, to leach a metal of value such as copper, zinc, uranium, nickel and cobalt from a sulphide mineral.
Bioleaching places the metal values of interest in the solution phase during oxidation.
Mineral biooxidation refers to a pretreatment process that uses the same bacteria as bioleaching to catalyze the degradation of mineral sulphides, usually pyrite or arsenopyrite, which host or occlude gold, silver or both.
technology.infomine.com /biometmine/biopapers/biomet_bioleaching.asp   (151 words)

  
 BioPortal | Biomining
Bioleaching is the use of microorganisms to extract metals from an ore. Leaching is the process of removing a
Bioleaching is used commercially in the extraction of copper.
Bioleaching of copper, and biooxidation of refractory gold ores are the only well-established large scale processes that are commercially carried out today.
www.biobasics.gc.ca /english/view.asp?x=797   (798 words)

  
 Mining & Minerals: Factsheets   (Site not responding. Last check: 2007-10-20)
Bioleaching of sulfide minerals is now an established industrial technology for the recovery of gold from refractory arsenical pyrite ores and for the bioleaching of copper.
There are some problems associated with bioleaching; such as it is slower than conventional techniques which may increase the cost; not all ore types can be bioleached, either – just the ores containing sulphur, and in some cases scientists don't know how to make the bacteria stop extracting the minerals once they've started.
Bioleaching is not yet developed to a level where it is profitable to apply it to the recovery of zinc, nickel, cobalt, and other metals.
www.nrcan-rncan.gc.ca /biotechnology/english/m_bioleach.html   (539 words)

  
 BioMetMine - Types of Bioleaching Technologies Available
In situ bioleaching — in-situ treatment refers to the process where ore is treated without mining to remove the rock to a treatment process on the surface.
Stirred tank bioleaching — bacterial oxidation of ground mineral slurry can be carried out in aerated agitated vessels, when the value of the metal is sufficient to justify the cost of installing and operating the equipment.
The reaction vessel can be either a mechanically stirred tank with a means of introducing oxygen into the slurry or an air agitated pachuca reactor where the introduction of the air provides not only the oxygen but the agitation of the slurry.
technology.infomine.com /biometmine/biopapers/biomet_types.asp   (915 words)

  
 www.mineweb.net | co_releases BacTech Mining   (Site not responding. Last check: 2007-10-20)
BacTech has successfully demonstrated their proprietary bioleaching technology on chalcopyrite in 1998 at Mount Lyell copper mine in Australia and more recently, in 2001, at a demonstration pilot plant in Monterrey, Mexico, as part of a program in partnership with Industrias Peï¿1/2oles and Mintek of South Africa.
Bioleaching technology is also an environmentally friendly technology in comparison to smelting, producing benign solid by-products as opposed to harmful gases.
The use of bioleaching in complex ores to extract gold is well understood and accepted by the industry.
www.mineweb.net /co_releases/303438.htm   (818 words)

  
 Bioleaching - Biologische Reinigung schwermetallbelasteter Sedimente   (Site not responding. Last check: 2007-10-20)
During the washing step, the solubilised heavy metals are washed from the solid material, precipitated from the solution and concentrated in a heavy-metal gypsum sludge with a mass of just 5-7% of the original sediment.
The bioleaching technique is being optimised together with commercial partners experienced in the area of remediation and soil treatment.
In the BIOLEA pilot plant the bioleaching technique is being advanced to commercial application.
www.bauerumweltgruppe.com /en/gruppe/forschung/bioleaching.htm   (515 words)

  
 Creamer Media's Mining Weekly Online, South African Mining News :: News Today
Bioleaching, the process that uses bacteria to help extract metal from ore, and which was perfected in South Africa, now seems set to be taken into the twenty-first century through the exploitation of the dramatic advances in genetics, but in Chile, not South Africa.
Bioleaching was originally perfected in South Africa by the old Gencor for use in gold extraction, the technology being known as Biox, and later developed for base metals as well, leading to the BioCOP technology for copper.
Bioleaching is very much a ‘horses for courses’ concept – different systems fit different ores, so the choice of a system is very much site-specific.
www.miningweekly.co.za /min/news/today/?show=30487   (627 words)

  
 Planet Ark - Codelco, BHP Billiton plan copper bioleach plant
"The new pilot plant for the bioleaching project is to treat the equivalent of 20,000 tonnes of copper, in the form of dirty concentrates," Juan Medel, assistant manager of strategic planning at Codelco's Chuquicamata Division, told Reuters.
Bioleaching is the extraction of copper from sulfide ore or concentrates using microorganisms found within the environment.
"Bioleaching technology is an enormous development in the treatment of concentrates and therefore with this pilot plant we will have to reevaluate how we do things in the future," Medel said.
www.planetark.com /avantgo/dailynewsstory.cfm?newsid=11642   (284 words)

  
 Microbial metal mobilization and recovery from solid metal-containing materials
The objective of the project is to apply a bacterial leaching process ("bioleaching") for the recovery of metals from solid materials such as incineration residues, galvanic sludge, or electronic scrap as well as metal-contaminated soils.
Bioleaching allows the cycling of metals by a process close to natural biogeochemical cycles reducing the demand for ressources such as ores, energy, or landfill space.
Bioleaching represents a biological technique which is not dependent on high energy inputs and is competitively in juxtaposition to thermal techniques.
www.research-projects.unizh.ch /p786.htm   (269 words)

  
 Microbial Cell Factories | Full text | Characteristics and adaptability of iron- and sulfur-oxidizing microorganisms ...
Both are oxidation processes, but where the metal to be recovered is extracted into solution the process is known as bioleaching, whereas when the metal remains in the mineral, bioleaching is an inappropriate term and the process should strictly be referred to as biooxidation.
Bioleaching processes are carried out at a range of temperatures from ambient to a demonstration plant that has been operated at 80°C [72].
Commercial bioleaching can take place using what may be considered to be a low technology process, the irrigation of waste ore dumps [13].
www.microbialcellfactories.com /content/4/1/13   (9950 words)

  
 Water Science & Technology 48:8 (2003) 151-158 - S.Y. Chen et al. - Effects of ferric ion on bioleaching of heavy ...
Bioleaching is one of the promising procedures for removal of heavy metals from contaminated sediments.
Besides, the growth of sulfur-oxidizing bacteria was not affected by addition of ferric ion in the bioleaching.
It was concluded that the kinetics of metal solubilization were enhanced by addition of ferric ion in the bioleaching process.
www.iwaponline.com /wst/04808/wst048080151.htm   (297 words)

  
 Biogeotechnology for Industry and Land Management - CSIRO Land and Water
Colonies of bioleaching microorganisms then become established, the ore is oxidised and the target metals are released into the water, which is collected as it exits the heap.
Bioleaching is currently used commercially for the recovery of base metals such as zinc, copper, nickel, and cobalt, and precious metals such as gold.
Economic modelling of the potential associated with thermophilic heap bioleaching has shown that the economic return to a single mine operation over a five year period could be as high as $AUS100 million for a 30 megatonne chalcocite/chalcopyrite mixed resource (Strategic Technology Evaluation and Management, 2002).
www.clw.csiro.au /research/urban/protection/biogeotechnology/projects.html   (1279 words)

  
 SurfWax: News, Reviews and Articles On Bioleaching
For example, a process known as bioleaching is used by mining companies to remove contaminants and pollutants associated with mining practices, and bioremediation is used to treat waste and clean up oil spills and other forms of industrial contamination.
Using biotechnology or a technique known as "bioleaching" a bacteria introduced to the ore, eats on iron sulphur and produces sulphuric acid which in turn dissolves the ore and separates the uranium...
Bioleaching is a commercially accepted and environmentally friendly alternative to conventional smelting operations and provides BacTech with a distinct market advantage in the acquisition and operation of mineral properties.
news.surfwax.com /chemistry/files/Bioleaching.html   (420 words)

  
 Biodegradation and recovery of gallium and other metals from integrated circuits - Patent 5030425
The particular culture medium containing the bacteria and crushed chips is preferably mixed during the bioleaching process.
Bioleaching of gallium and germanium is accomplished by seeding a bioreactor with 10% bacterial culture of ATCC 53921 acclimated on a 10% solids raw material input.
While the invention has been specifically described herein with reference to bioleaching of valuable metals or metal compounds such as GaAs from integrated circuits, the invention may be used to leach gallium, germanium and gallium compounds from a conglomeration of materials, especially scrap manufactured components containing such metals as metallic compounds.
www.freepatentsonline.com /5030425.html   (5377 words)

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