caa a22 4500 378931652 CHVBK 20180305123631.0 cr unu---uuuuu 161128e20040101xx s 000 0 eng 10.1351/pac200476040847 doi (NATIONALLICENCE)gruyter-10.1351/pac200476040847 Rawlings D. E. Department of Microbiology, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa Microbially-assisted dissolution of minerals and its use in the mining industry [Elektronische Daten] [D. E. Rawlings] Biomining is currently used successfully for the commercial-scale recovery of metals such as copper, cobalt, and gold from their ores. The mechanism of metal extraction is mainly chemistry-driven and is due to the action of a combination of ferric and hydrogen ions, depending on the type of mineral. These ions are produced by the activity of chemolithotrophic microorganisms that use either iron or sulfur as their energy source and grow in highly acidic conditions. Therefore, metal extraction is a combination of chemistry and microbiology. The mixture of organisms present may vary between processes and is highly dependent on the temperature at which mineral oxidation takes place. In general, relatively low-efficiency dump and heap irrigation processes are used for base metal recovery, while the biooxidation of difficult-to-treat gold-bearing arsenopyrite concentrates is carried out in highly aerated stirred-tank reactors. Bioleaching reactions, the debate as to whether the reactions are direct or indirect, the role of microorganisms, and the types of processes by which metals are extracted from their ores are described. In addition, some new processes under development and the challenges that they present are discussed. © 2013 Walter de Gruyter GmbH, Berlin/Boston Pure and Applied Chemistry De Gruyter 76/4(2004-01-01), 847-859 0033-4545 76:4<847 2004 76 pac https://doi.org/10.1351/pac200476040847 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1351/pac200476040847 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Rawlings D. E. Department of Microbiology, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa NATIONALLICENCE 773 0- Pure and Applied Chemistry De Gruyter 76/4(2004-01-01), 847-859 0033-4545 76:4<847 2004 76 pac CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter