Bioleaching of a cobaltcontaining pyrite in stirred reactors. The variations of ferrous content, total iron, ph and redox potential in. Through using bioleaching, the cost of the project is greater but the returns are greater as well. In order to improve the bioleaching efficiency of arsenicrich gold concentrates. Bioleaching has been proven to be very efficient in the destruction of pathogenic microorganisms 98.
Apr 30, 2015 microbial leaching of refractory process metal ores to enhance gold and silver recovery is one of the promising applications gold is obtained through bioleaching of arsenopyritepyrite silver is also obtained by bioleaching of arsenopyrite but it is more readily solubilized than gold during microbial leaching of iron sulphide. However a study by mujeeburrehman shows that 75 percent of the copper in the ore studied was leached in 144 hours. Certain bacteria such as thiobacillus ferrooxidans oxidize ferrous ions to ferric ions and in this process it transfers the electrons form iron to oxygen. Bioleaching of arsenicrich gold concentrates by bacterial flora. Bioleaching and bioprecipitation of nickel and iron from. During bioleaching, metals such as copper, nickel or zinc are oxidized through microbial action from the waterinsoluble sulfide to the soluble sulfate forms. Extraction of iron in a blast furnace iron is also below carbon in the reactivity series, so therefore carbon can be used to reduce it note. Biological methods of metal extraction higher material.
Bioleaching definition of bioleaching by medical dictionary. The technology has its origins in chile, where acidsoluble copper oxide heap leach operations were adapted to treat secondary copper sulfide ores. Simpleheaderfooter allows text based headers to be added, with the option to merge in dynamic data. Sulfidic iron ores can be added to speed up the process and provide a source of iron. Important leaching bacteria are aerobic, acidophilic iron ii andor sulfur compoundoxidizing species such as for example acidithiobacillus ferrooxidans formerly thiobacillus ferrooxidans. Ppt biomining and bioleaching powerpoint presentation. Bioleaching of realgar by acidithiobacillus ferrooxidans using ferrous iron and elemental sulfur as the sole and mixed energy sources. Similar results were also observed in the iron based bioleaching process 95.
Some question the use of bioleaching by claiming that it is a time consuming process. Bioleaching of nonsulfidic ores such as pitchblende also uses ferric iron as an oxidant e. Copperii sulfide gives copper and sulfur dioxide during thermal decomposition. A well known example of an indirect bioleaching process is the extraction of uranium from ores, when insoluble tetravalent uranium is oxidized to the. Bio leaching group members mehwish nazeer, kanza saleem, nazish mehmood m. Bioleaching is one of latest technologiesthe used to recover many important metals like copper. Bioleaching and phytomining are increasingly used to extract copper from low grade ores see below. Alternatively, the copper compounds can be dissolved and the solution. Improve isolates by conventional mutation and selection or by genetic engineering. However, to date the molecular mechanisms involved in the regulation of biofilm formation by bioleaching microorganisms are still unknown. The future of bioleaching isolate new bacterial strains from extreme environments, such as minedrainage sites, hot springs, and waste sites, and use these to seed bioleaching processes. Some of the types of bacteria used in this process include leptospirillum ferrooxidans, thiobacillus ferrooxidans, and some species of sulfolobus, acidianus, and sulfobacillus. Pdf files, and powerpoint files could be flashconverted for smaller file size and for an add.
Pdf bioleaching and biomining for the industrial recovery of metals. Apr 17, 2004 bioleaching definition is the extraction of valuable metals such as copper and gold from ores through the action of microorganisms such as bacteria. Pdf bioleaching and bioprecipitation of nickel and iron. Natural bioleaching has been taking place for almost as long as the history of the world, but it is only in the last few decades that we have realized that bioleaching is responsible for acid production in some mining wastes, and that this bacterial activity can be used to liberate some metals. This paper presents a mathematical kinetic model based on the shrinking core concept for bioleaching of lowgrade ores to extract iron by mesophilic and thermophilic bacteria in a 4meter column reactor. The leaching experiment showed that the copper extraction rate of the. By the acid leaching, a less quantity of fe is leached in the produced pregnant. Bioleaching of chalcopyrite university of birmingham. Bioleaching bioleaching is the extraction of metals from their.
Influence of ferric and ferrous iron on chemical and. Thiobacillus ferroxidans n11 isolated from hyper saline soils of kolhapur district of maharashtra, india on 9 k medium. Direct detection of feii in extracellular polymeric substances eps. Finally, this work attempted to extract copper from a lowgrade ore using bioleaching techniques. The decomposition of the mineral sulfide matrix is required after bioleaching, more than 95% of the gold is extracted future aspects. Heap bioleaching of ores a rapidly developing technology undoubtedly, heap bioleaching has had a considerably bigger impact on the base metal industry than tank bioleaching. Feasibility step i bioleaching pilot testwork in brgm process hall 100l str, 5 kgd residence time, solid load, mass transfer pulp homogeneity, gas dispersion, energy. The bioleaching process that takes place in such systems is employed in biomining biotechnology 2. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Presently certain metals from sulfide ores and other ores are. Introduction, methods, application, copper, microorganisms, and processes. Pdf bioleaching of metal sulfides is caused by astonishingly diverse groups of bacteria.
Biomining and bioleaching a free powerpoint ppt presentation displayed as a flash slide show on id. One key factor that influences soil ph, and consequently iron levels is the process of leaching. Several studies reveal that bioleaching efficiency is improved by biofilm formation on minerals 3,4. Bioleaching of gold, copper and nickel from waste cellular phone pcbs and computer goldfinger motherboards by two aspergillus niger strains jorge enrique madrigalarias1, rosalba argumedodelira2, alejandro alarcon4.
I direct bioleaching in direct bioleaching minerals which are susceptible to oxidation undergoes direct enzymatic attack by the microorganisms. Bioleaching is performed mostly by iron and sulfide oxidizing bacteria, or acid producing fungus. The dissolution biochemistry signifies two types of. Bioleaching study was carried out in both shake flask as well as bioreactor. These include surface science, biochemistry of iron and sulfur. Pdf the microbial solubilization of metals in acid environments is productively used in. Bioleaching definition of bioleaching by merriamwebster. As soil ph increases the ferrous iron becomes ferric iron. Bioleaching of copper from low grade ore bornite using. Bioleaching of gold, copper and nickel from waste cellular. Mesophiles moderately thermophilic bacteria extremophiles. Recent development has shown commercial application of the process and, concurrently, details pertaining to the key microorganisms involved in these processes have been described. Gcse chemistry extraction of copper thermal decomposition. The mesophilic chemolithotrophic iron and or sulphur oxidizing.
Bioleaching of metal sulfides is caused by diverse groups of bacteria. The process of leaching metals from ore by using bacteria or fungi to convert the metals into a soluble form. Mineralogical characterization of chalcopyrite bioleaching. When the interests of gencor and gold fields of south africa were merged. This is much cleaner than the traditional leaching processes like heap leaching using cyanide or other chemicals. Introduction bioleaching is the simple and effective technology for metal extraction from low grade ores and mineral concentrate by the use of micro organisms. It was identified using bergeys manual of systematic bacteriology. Thermal decomposition means that the compound breaks down into other substances when it is heated. Bioleaching technology in minerals processing john neale mintek, biotechnology division private bag x3015, randburg, 2125, south africa bioleaching is a process that employs microorganisms to dissolve leach sulphide minerals. Biomining is the use of microorganisms in the recovery of metals from ores. Chalcopyrite bioleaching of an in situ leaching system by.
Ask a question convert html to pdf to create pdfs in. Bioleaching is a simple and effective technology for metal extraction from lowgrade ores. A probable explanation for the feii in detected eps is the leaching of feii. This process was later on employed for recovering metals from ores containing low quantity of the metal. It finds application in the extraction of metals from their ores. Biomining is a technique of extracting metals from ores and other solid materials typically using prokaryotes or fungi. Leaching process was first observed in pumps and pipelines installed in mine pits containing acid water. These organisms secrete different organic compounds that chelate metals from the environment and bring it back to the cell where they are typically used to coordinate electrons.
Htmlheaderfooter allows the developer to render html headers and footers to pdf files. Bioleaching application of biotechnology in mining industry. Bioleaching involves the use of microorganisms to catalyze the oxidation of iron sulfides to create ferric sulfate and sulfuric acid. Bioleaching circuits can be made more flexible and simpler to merge with. Apr 01, 2010 read bioleaching of iron from kaolin using feiiireducing bacteria with various carbon nitrogen sources, applied clay science on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. The traditional method of extraction is to heat the copper sulfide. Extraction of iron in a blast furnace reduction haematite o. 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. Since iron is cheaper than copper, the use of scrap iron is a costeffective way to produce copper from the leachate. Bioleaching of chalcopyrite ores and concentrates using mesophilic microorganisms does not yield acceptable copper extraction, mainly due to problems associated with mineral surface passivation by elemental sulfur, iron hydroxide precipitates jarosites, and intermediate polysulfides at the temperatures and redox potentials encountered under. For biomining specialized microorganisms are used in order to recover valuable metals from ores via bioleaching. Bioinformatic prediction of gene functions regulated by. Simplified model showing iron and sulfur oxidation reactions in. Furthermore, by combining the c and fe nexafs results, we.