Bioleaching can be applied to various ore types through microbial generation of leach agents. Bacterial extraction of gold from sulfide bearing ores has been studied by many investigators. The latest versions of adobe reader do not support viewing pdf files within firefox on mac os and if. In an effort to develop alternate techniques to recover metals from waste electrical and electronic equipment weee, this research evaluated the bioleaching efficiency of gold au, copper cu and nickel ni by two strains of aspergillus niger in the presence of gold plated finger integrated circuits found in computer motherboards gficms and cellular phone printed circuit boards pcbs. Bacteria can mine for bioleacihng, clean oil spills, purify gold, and use radioactive elements for energy. The gold is recovered from this solution by electrowinning, zinc precipitation or refining technology such as the mintek minataur process. Bioleaching of metal sulfides is caused by diverse groups of bacteria. It may have been the first metal used by humans and wa. Bioleaching of gold, copper and nickel from waste cellular phone. It was induced by uv ultraviolet, ultrasonic, and microwave, and their. The decomposition of the mineral sulfide matrix is required after bioleaching, more than 95% of the gold is extracted future aspects. Pdf bioleaching of gold, copper and nickel from waste. Introduction gold has been known and highly valued since prehistoric times.
The dissolution biochemistry signifies two types of. Bioleaching is one of several applications within biohydrometatallargy and several methods are used to recover copper, zinc, lead, gold and nickel. It finds application in the extraction of metals from their ores. Bioleaching of gold, copper and nickel from waste cellular phone pcbs and.
Bioleaching where microorganisms are used to facilitate the mining of metals. Usually, bioleaching is referring to the conversion of solid metal values into their water soluble forms using microorgan isms. Bioleaching of nonsulfidic ores by layering of waste sulfides and elemental sulfur, colonized by acidithiobacillus spp. Potential of biotechnology for metals extraction in zimbabwe saimm. By 1990 mass field pilots had begun on sulfur containing ore, investigating the effectiveness, as well as the economics involved in bioleaching of gold ore. Sustainability free fulltext a brief note on the heap. The understanding and funding of bench, pilot, and fullscale programs is steadily increasing. Bioleaching is the extraction of metals from their ores through the use of buomining organisms.
Universal reserves of highgrade ores are diminishing at an alarming rate due to the rapid increase in the demand for metals. Gold ore is also preatreated by bioleaching in heaps by newmont mining in the carlin trend region, nevada. Bioleaching has enabled the transformation of uneconomic resources to reserves, and thus helped to alleviate the challenges related to continually declining ore grades. Bioleaching of gold pyrite tailings with adapted bacteria. Heap or dump bioleaching, tank bioleaching, in situ or in place bioleaching. This is much cleaner than the traditional leaching processes like heap leaching using cyanide or other chemicals. Jul 01, 2015 in contrast, knowledge of metal bioleaching from weee by filamentous fungi is still scarce. For biomining specialized microorganisms are used in order to recover valuable metals from ores via bioleaching. Bioleaching of gold can be performed using a number of different techniques and various microbes depending on the factors of the operation in question.
Leaching process was first observed in pumps and pipelines installed in mine pits containing acid water. Because the price of gold has risen many mineral companies now take 6. The encapsulation of precious metal particles gives rise to the refractory nature of such ores to current extraction methods. History of biohydrometallurgy in china 1999, ecological and genomic research of bioleaching microorganisms were to carry out by central south university cooperated with oak ridge national laboratory in usa. However, within a biooxidation heap, oxygen mass transfer limitations can limit the applicability of this technology, due to the large amount of oxygen. The understanding and funding of bench, pilot, and fullscale programs. And today, over 115 years later, most of the worlds gold is recovered with cyanide playing a large part in the beneficiation of the yellow precious metal.
Optimization of parameters affecting recovery of copper from sarcheshmeh lowgrade sulfide ore using bioleaching m. This process was later on employed for recovering metals from ores containing low quantity of the metal. The refractory gold ores contain finely disseminated gold particles associated with sulfide minerals including arsenopyrite and pyrite. Incidentally, 14k gold is commonly used in jewelry manufacture. In the case of gold mining, brazil, chile, ghana, indonesia. In the industrial microbial leaching process popularly known as bioleachinglow grade ore is dumped in a large pile the leach dump and a dilute sulfuric acid solution ph 2 is percolated down through the pile. Gold and silver leaching todays microbial leaching of refractory precious metal ores to enhancegold and silver recovery is one of the most promising applications. Studies on the bioleaching of refractory concentrates. Auriferous sulfide ores often contain very finely disseminated gold and other precious metal particles inside the sulfide crystals. However, within a biooxidation heap, oxygen mass transfer limitations can limit the applicability of this technology, due to the large amount of oxygen required to biooxidize the sulfides. The bacterial strain that was used in the leaching experiments was isolated from the jaduguda mine water sample. Bioleaching is one of latest technologiesthe used to recover many important metals like copper.
Bioleaching osprey aviation elite units pdf technology in minerals processing. Because of this flexibility, biooxidation can be effectively integrated into gold processing. If gold occurs finely disseminated within the sulfide ore matrix such as in pyrite, arsenopyrite and pyrrhotite, the leachant can not penetrate into the inside of solid ore in order to leach the enclosed submicron size gold particles. Therefore, for the case of pyrite bioleaching the primary role of the bacteria is the oxidation of the ferrousiron to the ferric form, thereby maintaining a high redox potential within the system and. Therefore, this study evaluated the tolerance to gold of four strains of aspergillus and the bioleaching efficiency of gold, copper and nickel from pcbs and gficms by aspergillusstrains with higher tolerance to gold. Bioleaching of lowgrade uranium ore using acidithiobacillus. Bioleaching technology for the extraction of base metals from sulfide ores and. Bioleaching of gold via heap biooxidation is proving to be an. Comparison of gold extraction yields by cyanide treatment vs. Metal recovery from sulfide minerals is based on the activity of chemolithotrophic bacteria, mainly thiobacillus ferrooxidans and t. Studies on the bioleaching of refractory gold concentrates substrate, and that the bioleaching of pyrite occurs via a multiple subprocess mechanism. Microbial oxidation of gold ores and gold bioleaching. Gold leaching using alternative reagents to cyanide. Using add reply allows you to attach images or pdf files and provide a more.
Biomining is done in two steps often called bioleaching and biooxidation. Bioleaching of gold, copper and nickel from waste cellular phone pcbs and computer goldfinger motherboards by two aspergillus nigerstrains. Bioleaching of arsenicrich gold concentrates by bacterial flora. Mar 09, 2010 bioleaching of uranium was carried out with turamdih ore sample procured from uranium corporation of india limited, jaduguda. The bioleaching and processing of refractory gold ore. Heap leaching provides mining operators with a benign. During the bioleaching process, lasting 40 days, over 80 % of pb and zn, 67 % of cu, 50 % of ni, 44 % of as, 31 % of ba, 26 % of cr and about 11 % of fe and. Microbial oxidation of gold ores and gold bioleaching olson.
Biomining is the extraction of specific metals from their ores through biological means, usually microorganism. Bioleaching of gold by metabolic products of microorganisms has received less attention, but also offers opportunities for industrial application, especially if future regulations restrict the use of cyanide. Pdf present and future of bioleaching in developing countries. To achieve a satisfactory extraction of gold grain, an oxidative treatment is required to break down the blockade of sulfide minerals before cyanide. It is cheaper currently to use traditional smelting to extract copper from its ore, so bioleaching is not used in this case, but it is used more and more in gold extraction, since much of the ore has very little gold in it, so bioleaching is a cost effective option here bioleaching is also used for refractory gold ore, that is, ore in which. Bioleaching can be applied to various ore types through microbial generation of.
Bioleaching of uranium pdf furthermore, control tests were performed to demonstrate the effect of a. This work presents the application of bioleaching technology in. Pdf bioleaching is a biochemical mining technique in which specific biological organism is used for the removal of a specific metal from. Bioleaching has also some potential for metal recovery and detoxification of industrial waste products, sewage sludge and soil contaminated with heavy metals. The bioleaching and processing of refractory gold ore springerlink. Nov 02, 2009 major advances in bioleaching of gold ore were made when newmont mining corporation began laboratory investigations of biooxidation in the late 1980s. In an effort to develop alternate techniques to recover metals from waste electrical and electronic equipment weee, this research evaluated the bioleaching efficiency of gold au, copper cu and nickel ni by two strains of aspergillus niger in the presence of gold plated finger integrated circuits found in computer motherboards gficms and cellular phone printed. Optimization of parameters affecting recovery of copper from. Bio leaching group members mehwish nazeer, kanza saleem, nazish mehmood m. It may have been the first metal used by humans and was valued for ornamentation and rituals. 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. Microbial leaching is the process by which metals are dissolved from ore bearing rocks using microorganisms.
In contrast, the bioleaching of cu by aspergillus niger mxpe6 was 24 and 5%. Thus, 14karat 14k gold indicates a composition of 14 parts of gold and 10 parts of other metals. Gold cyanide solution leaching gold with cyanide since the 1890s, cyanide has been used to recover gold from gold bearing ores. The liberation of the metal by use of bacteria involves a complex chemistry. April learn how and when to remove this template message. Bioreactor for metal bioleaching in the geomicrobiology laboratory of bgr source. For their liberation, the sulfide bearing ore is subjected to. Therefore, a method for leaching or dissolving gold from ores or precious. Maximizing economic performance in the mining industry by. Biotechnology economic geology metallurgical processes applied microbiology. Microbial oxidation of gold ores and gold bioleaching fems. Commercial biomining applications have mainly targeted copper, gold. In the case of copper, copper sulfide is microbially oxidized to copper sulfate and metal values are present in.
Gold from refractory gold concentrates by stirred tank leaching as a pretreatment step. In the first step, chemolithotrophic acidophilic acidithiobacillus ferrivorans and acidithiobacillus thiooxidans were used. Biomining biotechnological systems bioleaching and. Biomining is the process of using microorganisms microbes to extract metals of economic interest from rock ores or mine waste. Major advances in bioleaching of gold ore were made when newmont mining corporation began laboratory investigations of biooxidation in the late 1980s. Presently certain metals from sulfide ores and other ores are. Bioleaching bioleaching is the extraction of metals from their. Bioleaching is a simple and effective technology for metal extraction from lowgrade ores and mineral concentrates. The process design of gold leaching and carboninpulp circuits. Copper from lowgrade secondary copper sulfide ores by heap bioleaching. Introduction bioleaching is the simple and effective technology for metal extraction from low grade ores and mineral concentrate by the use of micro organisms. Leaching of gold, silver and accompanying metals from circuit boards pcbs waste jana ficeriova1, peter balaz1 and eberhard gock2 auag noble metal wastes represent a wide range of waste types and forms, with various accompanying metallic elements. Today, biooxidation technology is successful in a range of conditions, from ideal to the most severe climates in the world. The original mixed bacterial flora had been enrichedin acid mine drainage of dexing copper mine, jiangxi province, china.
However, during the bioleaching of gold, no toxic chemical compound is used and can therefore b e seen as an ecofriendly, sustainable and low cost alternative than cyanidation techniques. Silver is more readily solubilized than gold during microbial leaching of iron sulfide. Mesophiles moderately thermophilic bacteria extremophiles. The dissolved gold in solution is adsorbed onto activated carbon. Bioleaching is one of latest technologiesthe used to recover many important metals like copper, zinc, lead, uranium, arsenic, antimony, nickel, molybdenum, gold, silver and cobalt. Several species of fungi and bacteria are used for bioleaching. This work has been done worldwide and has resulted in several pilot plant and commercial scale operations for gold ore biooxidation. In order to improve the bioleaching efficiency of arsenicrich gold concentrates, a mixed bacterial flora had been developed, and the mutation breeding method was adopted to conduct the research. Bioleaching of uranium pdf united pdf comunication.
Bioleaching of uranium was carried out with turamdih ore sample procured from uranium corporation of india limited, jaduguda. These bacteria need to be cultivated and adapted to achieve maximal results. Introduction, methods, application, copper, microorganisms, and processes. Gold and copper are the dominating valuable metals that are commercially extracted. Bioleaching of gold via heap biooxidation is proving to be an inexpensive method to oxidize sulfidic ores, including those that are low grade, difficult to concentrate or slow to biooxidize. Gold ores need to be pretreated by roasting or by pressure oxidation to free the gold prior to cyanide leaching. An effective strategy for environmentally sound biological recovery of copper and gold from discarded printed circuit boards pcb in a twostep bioleaching process was experimented. Phytomining and bioleaching 9 pdf files past papers. The biooxidation residue is further treated by cyanide leaching to recover gold. Department of mining, shahrood branch, islamic azad university, shahrood, iran 2. Bioleaching bioleaching is the extraction of specific metals from their ores through the use of living organisms. Biomining biotechnological systems bioleaching and biosorption for the extraction and recovery of metals from secondary sources.
Gold bearing gravels are shoveled into the upper end of the sluiceway. 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. In microbial leaching or bioleaching metals can be extracted from large quantities of low grade ores this process has been used for centuries to recover copper form the drainage water of mines the role of microbes in the bioleaching came into notice some 40 years ago. Gold is obtained through bioleaching of arsenopyritepyrite ore and its cyanidation process. Bioleaching of gold by metabolic products of microorganisms has received less. Table 2 lists the existing commercial stirredtank bioleach.
When the carbon is loaded with enough gold it is removed from the circuit and sent to elution where the adsorption process is reversed and the gold is stripped off the carbon back into solution, electrowon and smelted into bars. A method for leaching or dissolving gold from ores or. When the carbon is loaded with enough gold it is removed from the circuit and sent to elution where the adsorption process is reversed and the gold is stripped off the carbon back. Heap leaching is a lowcost technology used in industrial mining to recover precious metals such as gold and uranium, along with several other highly sought after metals like copper, from their primary resources ores and minerals. School of mining engineering, college of engineering, university of tehran, tehran. Twostep bioleaching of copper and gold from discarded. Consideration of influential factors on bioleaching of gold ore. Bioleaching of gold, copper and nickel from waste cellular. Oct 24, 2014 curtin university scientists have developed a gold and copper extraction process using an amino acidhydrogen peroxide system, which could provide an environmentally friendly and cheaper. Pdf nowadays bioleaching occupies an increasingly important place among the available. Willner et al biohydrometallurgical methods for metals recovery from waste materials metals from red mud was conducted by using a. Leaching of gold, silver and accompanying metals from circuit.
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