Bacterial leaching kinetics for copper dissolution from a lowgrade Indian chalcopyrite ore
Open Access
- 1 June 2013
- journal article
- Published by FapUNIFESP (SciELO) in Rem: Revista Escola de Minas
- Vol. 66 (2) , 245-250
Abstract
Bio-leaching of copper (0.3%) from a low grade Indian chalcopyrite ore of Malanjkhand copper mines, using a native mesophilic isolate predominantly Acidithiobacillus ferrooxidans (A.ferrooxidans), is reported. A bio-recovery of 72% Cu was recorded in the presence of this culture (not adapted), which increased to 75% with an ore adapted culture after 35 days at 35ºC and pH 2.0 with <50fim particles. The kinetic data showed best fit for the diffusion-controlled shrinking core model, exhibiting linear plots for [1- 2/3X-(1-X)2/3] vs time (X-fraction leached). Apparently, the role of the bacteria is to convert the ferrous ion to the ferric state, which oxidizes the chalcopyrite in order to dissolve copper, while maintaining a high redox potential. The activation energy value (E) was calculated to be 96 and 108 kJ/mol for the un-adapted culture and the ore adapted culture respectively in the temperature range 25-35ºC. This leaching mechanism was corroborated by XRD phase identification and SEM studies of the leach residue.Keywords
This publication has 14 references indexed in Scilit:
- Bioleaching of a low grade nickel–copper–cobalt sulfide oreHydrometallurgy, 2011
- Bioleaching of copper via iron oxidation from chalcopyrite at elevated temperaturesFood and Bioproducts Processing, 2010
- Bioleaching of chalcopyrite by pure and mixed cultures of Acidithiobacillus spp. and Leptospirillum ferriphilumInternational Biodeterioration & Biodegradation, 2008
- Copper leaching from primary sulfides: Options for biological and chemical extraction of copperHydrometallurgy, 2006
- A comparison of bioleaching of chalcopyrite using pure culture or a mixed cultureMinerals Engineering, 2005
- Critical evaluation of coupling particle size distribution with the shrinking core modelChemical Engineering Science, 2004
- New information on the chalcopyrite bioleaching mechanism at low and high temperatureHydrometallurgy, 2003
- Oxidation of chalcopyrite by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in shake flasksProcess Biochemistry, 2002
- Control of the redox potential by oxygen limitation improves bacterial leaching of chalcopyriteBiotechnology and Bioengineering, 2002
- The role of iron-hydroxy precipitates in the passivation of chalcopyrite during bioleachingMinerals Engineering, 2000