Effect of carbon dioxide concentration on the bioleaching of a pyrite–arsenopyrite ore concentrate

Nagpal, Soumitro; Dahlstrom, D.A.; Oolman, T.

doi:10.1002/bit.260410409

Cited by 47 publications

(23 citation statements)

References 7 publications

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“…Also gaseous compounds can show inhibitory effects on metal leaching: Aqueous-phase carbon dioxide at concentration > 10 mg L-' was inhibiting growth of 7: ferrooxidans on pyrite-arsenopyrite-pyrrothite ore (NAGPAL et al, 1993). Optimal concentrations of carbon dioxide were found to be in the range of 3 to 7 mg L-'.There are reports on the stimulation of bacterial leaching and the increase of leaching rates by supplementing leaching fluids with carbon dioxide (ACEVEDO et al, 1998;BRIER-LEY, 1978;TORMA et al, 1972).…”

Section: Tab 1 Factors and Parameters Influencing Bacterial Mineralmentioning

confidence: 94%

Microbial Leaching of Metals

Brandl¹

2001

Biotechnology Set

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Section: Tab 1 Factors and Parameters Influencing Bacterial Mineralmentioning

confidence: 94%

Microbial Leaching of Metals

Brandl¹

2001

Biotechnology Set

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“…Because bioleaching bacteria rely on carbon dioxide as their sole carbon source, biosynthetic activity was measured in terms of carbon dioxide consumption. Nagpal et al (1993) found protein synthesis in Thiobacillus ferrooxidans to be directly related to carbon dioxide ®xation, validating the use of carbon dioxide consumption as an accurate measure of biomass generation.…”

Section: Introductionmentioning

confidence: 94%

“…At 30°C, sulfur oxidation, according to reaction, 6 yielded a free energy change of )415 kJ/mol whereas ferrous oxidation, according to reaction 5, gave only )30.6 kJ/mol, a dierence of over 10 times, as calculated from Chase et al (1986). Carbon dioxide ®xation by way of the enzyme ribulose 1,5-bisphosphate carboxylase is the only option available for chemolithotrophic bacteria to generate biomass (Nagpal, et al, 1993). Substantial metabolic energy and reducing power are required for carbon dioxide assimilation, hence the higher yield of carbon dioxide uptake obtained with growth on sulfur rather than iron.…”

Section: Growth On Ferrous Ion and Elemental Sulfurmentioning

confidence: 99%

Comparison of biooxidation with carbon dioxide assimilation during bacterial growth on ferrous ion or elemental sulfur

Lizama

Zieliński²,

Kerby³

et al. 2001

Biotech & Bioengineering

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Biomass and oxygen uptake activity profiles of a mixed bioleaching culture were studied and compared at various temperatures. Bacteria were grown on ferrous ion or elemental sulfur in a Micro-Oxymax respirometer apparatus that allowed measurement of both oxygen consumption and carbon dioxide assimilation. Balanced growth was observed between 10 degrees C and 35 degrees C, with an optimum at 30 degrees C, on both energy sources. No significant growth was observed at the lowest temperature used, 5 degrees C, or at the highest temperature used, 40 degrees C. The oxygen to carbon dioxide molar yield was 50:1 when growing on ferrous ion but only 17:1 when growing on elemental sulfur. Upon transfer from a sulfide ore to a new energy source, greater numbers in the inoculum reduced the duration of the lag phase. Lag phase duration was also reduced by proximity to the optimum growth temperature. A longer lag phase decreased the achievable growth rate of the cells exponentially, significantly affecting biooxidation activity.

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“…The magnitude of the transfer potential, C*-C L , is severely limited, leading to CO 2 limited growth, as air flow rate is commonly determined based in the oxygen demand. Carbon dioxide limitation has been demonstrated by several authors (Torma et al 1972;Norris, 1989;Boogard et al 1990;Haddadin et al 1993;Nagpal et al 1993;Jensen and Webb, 1995;Jaworska and Urbanek, 1997;Acevedo et al 1998;Boon and Heijen, 1998), but more work is required on this topic.…”

Section: Gas Mass Transfermentioning

confidence: 99%

“…The CO 2 transfer coefficient can be experimentally determined by a dynamic method on the exit gas (André et al 1981) or estimated from de oxygen transfer coefficient (Liu et al 1983;Nagpal et al 1993…”

Section: Gas Mass Transfermentioning

confidence: 99%

The use of reactors in biomining processes

2002

Fuel and Energy Abstracts

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Microbial processes applied to mining operations are gaining increasing interest in the last years. Potential and current applications include the mining of gold, copper and other heavy metals, desulfurization of coal and oil, tertiary recovery of oil and biosorption of metal ions. Currently, bacterial leaching of copper and biooxidation of refractory gold concentrates are wellestablished large-scale processes that are carried on using heaps and tank reactors. Heap operation is simple and adequate to handle large volumes of minerals, but their productivity and yields are limited because of the severe difficulties in exerting an adequate process control. On the other hand, reactors can economically handle moderate volumes of material, but they allow for a close control of the variables involved, rendering significantly better performances. This paper reviews the basis of reactor selection and design for bioleaching processes. Special attention is given to the influence of oxygen and carbon dioxide mass transfer, process stoichiometry, solids suspension and slurry homogeneity, and the use of bioreactors in gold mining. It is concluded that the future of reactors in biomining is promising and that new applications, such as the bioleaching of copper concentrates, will soon be a reality.Microbial processes are gaining increasing interest in the mining industry. Bioleaching of heavy metals, biooxidation of gold ores, desulfurization of coal and oil, tertiary recovery of oil and biosorption of metal ions are examples of the wide variety of potential and actual applications of microorganisms in mining and related fields (Karavaiko, 1985;Kelley and Tuovinen, 1988;Lawrence and Poulin, 1995;Rawlings, 1997;Brierley and Brierley, 1999). Currently, bacterial leaching and biooxidation are largescale processes that are being successfully used in copper and gold processing (Acevedo et al. 1993;Brierley, 1997).The term biomining have been coined to refer to the use of microorganisms in mining processes. Biomining encompasses two related microbial processes that are useful in the extractive metallurgy of heavy metals: bacterial leaching, also known as bioleaching, and biooxidation. Leaching is the solubilization of one or more components of a complex solid by contact with a liquid phase. In bacterial leaching, the solubilization is mediated by bacteria. So bacterial leaching is a process by which the metal of interest is extracted from the ore by bacterial action, as in the case of bacterial leaching of copper. On the other hand, biooxidation implies the bacterial oxidation of reduced sulfur species accompanying the metal of interest, as in the biooxidation of refractory gold minerals.For many years bioleaching was thought as a technology for the recovery of metals from low-grade ores, flotation tailings or waste material (Torma, 1977;Gentina and Acevedo, 1985). Today bioleaching is being applied as the main process in large-scale operations in copper mining and as an important pretreatment stage in the processing of refractory go...

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Effect of carbon dioxide concentration on the bioleaching of a pyrite–arsenopyrite ore concentrate

Cited by 47 publications

References 7 publications

Microbial Leaching of Metals

Microbial Leaching of Metals

Comparison of biooxidation with carbon dioxide assimilation during bacterial growth on ferrous ion or elemental sulfur

The use of reactors in biomining processes

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