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Date submitted2019-05-07
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Date accepted2019-07-25
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Date published2019-10-23
Intensification of Bacterial-Chemical Leaching of Nickel, Copper and Cobalt from Sulfide Ores Using Microwave Radiation
- Authors:
- A. V. Kioresku
Currently, Russia and other countries display a steady tendency to decrease the amount of high grade and free- milling ore reserves. In this regard, the attention is being paid to the technology of bacterial-chemical leaching (BCL), which, unlike traditional pyrometallurgical enrichment methods, is well applicable for processing low-grade mineral raw materials. However, this technology has a significant drawback, which is the inability of microorganisms to create sufficiently aggressive conditions for the effective destruction of mineral complexes, which negatively affects the duration of the processes. The article presents the results of an experiment, the purpose of which was to study the multiple short-term effects of microwave radiation on the efficiency of extraction of nickel, copper, and cobalt in the process of bacterial-chemical leaching of sulfide ore. A microwave oven with a power of 900 W and a radiation frequency of 2.45 GHz was used as a source of microwave radiation. Irradiation was carried out every day throughout the experiment. The exposure time was 5 and 10 s; the flux density was 0.7 W/cm 2 . It was found that for all the studied microwave irradiation modes, a significant increase in the efficiency of biomass accumulation and the oxidizing ability of the medium was observed in comparison with the control that was not exposed to microwave radiation. Irradiation for 5 s twice a day increased the reduction of nickel by 16 %, cobalt by 15 % and copper by 6 %. The results of the study allow us to assess the prospects for the application of new biotechnology methods in the industrial practice of ore processing with an improvement in qualityindicators.
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Date submitted2018-09-02
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Date accepted2018-10-28
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Date published2019-02-22
Factors affecting bacterial and chemical processes of sulphide ores processing
- Authors:
- T. S. Khainasova
Extraction of valuable components from sulphide ores using microorganisms is a recognized biotechnological method, combining several advantages over traditional methods of mineral processing. This paper presents the main factors affecting the bacterial-chemical leaching and methods of leaching with the participation of microorganisms. Some physical-chemical (temperature, pH, oxygen, carbon dioxide, nutrients, metals and other chemical elements) and microbial (cell count and microflora activity) properties are given, either directly or indirectly (suppressing or contributing to the growth and oxidative capacity of microorganisms) affecting the kinetics of the process. The paper discusses the characteristics of the mineral substrate, including galvanic interaction of sulfide minerals and the formation of passivating layers on the surface of the ore during oxidation, emphasizing the importance of the electrochemical interaction of the components of the leaching system. Bioleaching is a complex process, which is a combination of mainly chemical reactions mediated by the microbial component, therefore, to improve the kinetics, it is necessary to consider, monitor and regulate the listed range of factors.
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Date submitted2015-07-20
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Date accepted2015-09-26
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Date published2016-02-24
Prospects of biotechnologies application in metallurgy and enrichment
- Authors:
- N. M. Telyakov
- A. A. Darin
- V. A. Luganov
In recent years, application of biotechnologies in enrichment processes and processing of metal-containing ores has gained broad development, considering essential advantages of these technologies from the point of view of economic efficiency and ecological safety. Processes with the application the hemolitotrofnykh of acidophile microorganisms of Acidithiobacillus ferrooxidans, At. thiooxidans, Leptospirillum ferrooxidans and others, are of great interest. This article is devoted to the problem of biocultures application for efficiency improvement of the ore pretreatment technology and extraction of valuable components from metal-containing crude ore. The analysis of the biotechnologies and microorganisms applied at domestic and foreign enterprises is given, alongside with the theoretical bases of ore bioprocessing, research results of oxide and sulphidic metal-containing ores processing technology development, with the application of microorganisms and research results of the mechanism of destructive impact of a certain type bacteria on siliceous ores.