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2019, Chemical Papers
This investigation compares bacterial leaching to chemical leaching to solubilize copper from a copper containing ore of the new site Northern Qarashoshaq in Zhylandy (Kazakhstan) which is currently under commercial development. From ICP-OES analysis the bulk ore sample contains 1.5% of Cu and a trace level at 0.0024 % of Ag. Phase analysis shows the main copper containing minerals are covellite, сhalcocite, malachite, chrysocolla and chalcopyrite. According to X-ray diffraction analysis silver is mainly presented as jalpaite (Ag3CuS2) minerals. Copper leaching was carried out by acidophilic bioleaching for comparison with extraction by chemical methods involving the addition of sulfuric acid and Fe3+ or only sulfuric acid in flasks, as well as column leaching tests to simulate heap leaching. Ag was extracted by cyanidation methods again in flasks as well as column leaching tests. Results showed that copper extraction is up to 95% when using bioleaching in the flask, 83% in the case of Fe3+ with sulfuric acid and 76% for sulfuric acid. Furthermore, subsequent extraction of Ag reaches 97% for bioleaching and 92% for chemical leaching. Column bioleaching tests showed an 82.3% yield of copper after 70 days of the experiment and a 70% of silver, whereas for chemical leaching the yield of copper is 66.8% and silver is 51%. In conclusion this investigation demonstrated higher extraction for both copper and silver from the primary ore in the bioleaching sample compared to the chemical leaching sample. More silver was extracted in the bioleaching case as there was less copper remaining to compete for the cyanide anions.
Emerging trends in …
Biomineral Processing for Extraction of Copper Metal from Lean Ore of Malanjkhand Copper Project2005 •
2022 •
Flotation wastes are becoming a valuable secondary raw material and source of many metals and semimetals worldwide with the possibilities of industrial recycling. The flotation tailings contain oxide and sulfide minerals that have not been sufficiently stabilized and form acidic mine waters, which in turn contaminate groundwater, rivers, and reservoi6sediments. An effective way to recycle these mine wastes is to recover the metals through leaching. While the focus is on acid bioleaching by iron- and sulfur-oxidizing bacteria, alkaline leaching, and the removal of iron-containing surface coatings on sulfide minerals contribute significantly to the overall environmental efficiency of leaching. For this study, static and percolate bioleaching of copper from flotation waste at the Bor copper mine in Serbia was investigated in alkaline and then acidic environments. The aim of the study was to verify the effect of alkaline pH and nutrient stimulation on the bioleaching process and element...
Journal of the Serbian Chemical Society
Bioleaching of copper from old flotation tailings samples (Copper Mine Bor, Serbia)2014 •
2015 •
Bioleaching of samples taken from depths of 10, 15, and 20 m from old flotation tailings of the Copper Mine Bor was conducted in shaken flasks using the extremely acidic water of Lake Robule as lixiviant. The yields of copper after five weeks of the bioleaching experiments were 68.34±1.21 % for the 15-m sample, 72.57±0.57 % for the 20-m sample and 97.78±5.50 % for the 10-m sample. The obtained results were compared to the results of acid leach- ing of the same samples and it was concluded that bioleaching was generally more efficient for the treatment of samples taken from depths of 10 and 20 m. The content of pyrite in the 20-m sample, which contained the highest amount of this mineral, was reduced after bioleaching. The benefits of this approach are recovery of substantial amounts of copper, reducing the environmental impact of flotation tailings and the application of abundant and free water from the acidic Robule Lake as lixiviant. The obtained results showed that bioleach- ing ...
MINERAL PROCESSING TECHNOLOGY(MPT)
Bioleaching: A Promising Method of Selective Leaching of Metals2017 •
Leaching is a common practice of hydro-metallurgical operations in mineral extraction. The Bioleaching also called Bio-hydroleaching, have played greater role to recover of valuable metals from various minerals of oxides and sulphide ores especially for low grade ores. An increase in research and development for laboratory scale to large-scale industrial operations of Bioleaching finds attention in now a day. Bioleaching is a simple and effective technology for metal extraction from low-grade ores and mineral concentrates. With little complexity in attaining operational conditions of Bioleaching that are distinct from the conventional practices of leaching of oxides or sulphide by either acid-base reactions or redox chemical reactions. The kinetic mechanisms and feasibility for selective digestion of metals from mineral ores can be discussed. Bacterial leaching type in an acid environment at pH values usually between 1.5 and 3 at which most metal ions remain in solution. They are much cleaner than the traditional and are used to recover metal like - copper, zinc, lead, nickel, gold, silver, cobalt, etc. Stirred tank bioleaching has been commercialized for cobalt recovery and for bio-oxidation of refractory gold ores. The microorganisms used in bioleaching type, like: Thiobacillus, Leptospirillum, Acidithiobacillus, Thermophilic bacteria, Heterotrophic bacteria, Fungi, etc. The mechanism of bioleaching is done by Direct and indirect bacterial leaching. Bioleaching has also some potential for metal recovery and detoxification of industrial waste products, sewage sludge and soil contaminated with heavy metals. In the present work, present trends in practices of Bioleaching and its advantages for recovery of metals from mineral ores, industrial and sewage wastages will be discussed. The kinetic understanding of selectivity cases with different bacterial and microorganisms will be discussed. Along with the feasibility of adoption of such practice and conversion of laboratory investigations to industrial Leaching practices.
Bioprocess and Biosystems Engineering
Process engineering aspects of the bioleaching of copper ores1989 •
The bioleaching of minerals is a complex process that is affected by a number of biological, mineralogical, electrochemical and engineering factors. This work presents and discusses the most significant process engineering aspects involved in the bacterial leaching of copper ores, i.e. bacterial population, type of mineral and particle size, nutrients and inhibitors, oxygen and carbon dioxide, temperature and pH, leaching
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