Watling H.R., Perrot F.A., Shiers D.W., Grosheva A., Richards T.N.
Parker Centre for Integrated Hydrometallurgy Solutions, CSIRO Minerals, PO Box 7229, Karawara, WA 6152, Australia; Laboratory of Chemical Thermodynamics, Department of Chemistry, M.V. Lomonossov State University, Leninskie Gory 1-3, Moscow, 119992, Russian Federation; Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch 7701 Cape Town, South Africa
Watling, H.R., Parker Centre for Integrated Hydrometallurgy Solutions, CSIRO Minerals, PO Box 7229, Karawara, WA 6152, Australia; Perrot, F.A., Parker Centre for Integrated Hydrometallurgy Solutions, CSIRO Minerals, PO Box 7229, Karawara, WA 6152, Australia; Shiers, D.W., Parker Centre for Integrated Hydrometallurgy Solutions, CSIRO Minerals, PO Box 7229, Karawara, WA 6152, Australia; Grosheva, A., Laboratory of Chemical Thermodynamics, Department of Chemistry, M.V. Lomonossov State University, Leninskie Gory 1-3, Moscow, 119992, Russian Federation; Richards, T.N., Department of Chemical Engineering, University of Cape Town, Private Bag X3, Rondebosch 7701 Cape Town, South Africa
The effects of the copper extractant LIX 984N 20% v/v in Shellsol 2046 on the abilities of Acidithiobacillus ferrooxidans and Sulfobacillus thermosulfidooxidans to catalyse copper extraction from a chalcopyrite concentrate and to oxidise ferrous ion to ferric ion were compared and the possible role of Acidiphilium cryptum in ameliorating the effects of the SX reagent was examined. The SX reagent up to 250 mg/L was found to have little impact on the extraction of copper from a chalcopyrite concentrate using At. ferrooxidans. In contrast, with S. thermosulfidooxidans, copper extraction was reduced to about one third in the presence of 50 mg/L SX reagent and at 250 mg/L SX reagent, was barely more than for an abiotic test. The SX reagent strongly inhibited ferrous ion biooxidation by several bacterial species in contrast to At. ferrooxidans. The presence of 50 mg/L SX reagent caused oxidation rates to drop to between 0 and 12% of those in controls in approximately 40-hour tests. The most toxic component of the SX reagent was found to be 4-nonylphenol. A. cryptum tolerated 250 mg/L SX reagent but did not utilise it as an energy source. Bioleaching of chalcopyrite concentrate was not enhanced significantly when A. cryptum was added to test inocula. It is proposed that A. cryptum utilises fungal biomass as an energy source in managed heaps with solution recycle via solvent extraction plants. While it shares the environment with iron- and sulfur-oxidising acidophiles, it does not contribute directly to copper extraction from sulfide minerals. Crown Copyright © 2008.
Bioleaching; Biomass; Chemical oxygen demand; Copper; Copper compounds; Extraction; Ions; Iron; Oxidation; Phenols; Renewable energy resources; Solvent extraction; Solvents; Sulfide minerals; Sulfur; Acidiphilium; Acidithiobacillus; Ferrous ion oxidation; Organic reagents; Sulfobacillus; Rate constants