Carbon dioxide and oxygen consumption during the bioleachingof a copper ore in a large isothermal column

 

Show simple item record

dc.contributor.author Petersen, J
dc.contributor.author Minaar, S H
dc.contributor.author du Plessis, C A
dc.date.accessioned 2016-08-17T09:50:34Z
dc.date.available 2016-08-17T09:50:34Z
dc.date.issued 2010
dc.identifier http://dx.doi.org/10.1016/j.hydromet.2010.03.022
dc.identifier.citation Petersen, J., Minnaar, S. H., & du Plessis, C. A. (2010). Carbon dioxide and oxygen consumption during the bioleaching of a copper ore in a large isothermal column. Hydrometallurgy, 104(3), 356-362. en_ZA
dc.identifier.issn 0304-386X en_ZA
dc.identifier.uri http://hdl.handle.net/11427/21289
dc.identifier.uri http://www.sciencedirect.com/science/article/pii/S0304386X10001441
dc.description.abstract During large-scale column tests at BHP Billiton's Johannesburg Technology Centre (JTC) on a low-grade copper ore during 2005/6, the concentrations of both oxygen and CO2 were continuously monitored in feed and exit gas as well as at various intermediate positions over the height of the column. This paper describes results from a test run at 40 °C fed with an air stream enriched to between 1000 and 2000 ppm CO2. Oxygen consumption very closely tracks iron and copper leaching. CO2 is consumed rapidly from the bottom up, resulting in significant depletion midway through the column, even though an enriched feed was used. Oxidation rates decline in CO2 depleted zones, but were not observed to cease completely. This decline is postulated to be linked to a slowly decaying population unable to regenerate itself, and a relative rate of decay in the absence of oxygen has been estimated to be around 3%/day. A comparison between O2 and CO2 consumption rates shows a linear correlation beyond a minimum oxidation rate. This minimum rate corresponds to a non-growth maintenance energy requirement, and the slope of the linear correlation to the growth yield. Both are functions of available CO2 in the range 50 to 1000 ppm, with maintenance declining and yield increasing. The findings of this study imply that CO2 supplementation in bioheaps will stimulate microbial growth and CO2 consumption, but not necessarily increase the rate of oxygen uptake and hence leaching. Absence of CO2 is expected to result in gradual population decline, but a degree of oxidation continues on the basis of maintenance. In tall heaps, CO2 depletion with height is likely and may therefore result in impaired leaching in the upper zones. en_ZA
dc.language eng en_ZA
dc.publisher Elsevier en_ZA
dc.source Hydrometallurgy en_ZA
dc.source.uri http://www.sciencedirect.com/science/journal/0304386X
dc.subject.other Bioleaching
dc.subject.other Heaps
dc.subject.other Respirometry
dc.subject.other Carbon dioxide
dc.subject.other Oxygen
dc.subject.other Copper sulfides
dc.subject.other Leptospirillum ferriphilu
dc.title Carbon dioxide and oxygen consumption during the bioleachingof a copper ore in a large isothermal column en_ZA
dc.type Journal Article en_ZA
dc.date.updated 2016-08-17T09:49:22Z
uct.type.publication Research en_ZA
uct.type.resource Article en_ZA
dc.publisher.institution University of Cape Town
uct.type.filetype Text
uct.type.filetype Image
dc.identifier.apacitation Petersen, J., Minaar, S. H., & du Plessis, C. A. (2010). Carbon dioxide and oxygen consumption during the bioleachingof a copper ore in a large isothermal column. <i>Hydrometallurgy</i>, http://hdl.handle.net/11427/21289 en_ZA
dc.identifier.chicagocitation Petersen, J, S H Minaar, and C A du Plessis "Carbon dioxide and oxygen consumption during the bioleachingof a copper ore in a large isothermal column." <i>Hydrometallurgy</i> (2010) http://hdl.handle.net/11427/21289 en_ZA
dc.identifier.vancouvercitation Petersen J, Minaar SH, du Plessis CA. Carbon dioxide and oxygen consumption during the bioleachingof a copper ore in a large isothermal column. Hydrometallurgy. 2010; http://hdl.handle.net/11427/21289. en_ZA
dc.identifier.ris TY - Journal Article AU - Petersen, J AU - Minaar, S H AU - du Plessis, C A AB - During large-scale column tests at BHP Billiton's Johannesburg Technology Centre (JTC) on a low-grade copper ore during 2005/6, the concentrations of both oxygen and CO2 were continuously monitored in feed and exit gas as well as at various intermediate positions over the height of the column. This paper describes results from a test run at 40 °C fed with an air stream enriched to between 1000 and 2000 ppm CO2. Oxygen consumption very closely tracks iron and copper leaching. CO2 is consumed rapidly from the bottom up, resulting in significant depletion midway through the column, even though an enriched feed was used. Oxidation rates decline in CO2 depleted zones, but were not observed to cease completely. This decline is postulated to be linked to a slowly decaying population unable to regenerate itself, and a relative rate of decay in the absence of oxygen has been estimated to be around 3%/day. A comparison between O2 and CO2 consumption rates shows a linear correlation beyond a minimum oxidation rate. This minimum rate corresponds to a non-growth maintenance energy requirement, and the slope of the linear correlation to the growth yield. Both are functions of available CO2 in the range 50 to 1000 ppm, with maintenance declining and yield increasing. The findings of this study imply that CO2 supplementation in bioheaps will stimulate microbial growth and CO2 consumption, but not necessarily increase the rate of oxygen uptake and hence leaching. Absence of CO2 is expected to result in gradual population decline, but a degree of oxidation continues on the basis of maintenance. In tall heaps, CO2 depletion with height is likely and may therefore result in impaired leaching in the upper zones. DA - 2010 DB - OpenUCT DP - University of Cape Town J1 - Hydrometallurgy LK - https://open.uct.ac.za PB - University of Cape Town PY - 2010 SM - 0304-386X T1 - Carbon dioxide and oxygen consumption during the bioleachingof a copper ore in a large isothermal column TI - Carbon dioxide and oxygen consumption during the bioleachingof a copper ore in a large isothermal column UR - http://hdl.handle.net/11427/21289 ER - en_ZA


Files in this item

This item appears in the following Collection(s)

Show simple item record