Bacterial leaching kinetics for copper dissolution from a lowgrade Indian chalcopyrite ore

Rem: Revista Escola de Minas

Rib-type="author"> Abhilash [1] ,CSIR National Metallurgical Laboratory Jamshedpur,INDIA

关键词: Chalcopyrite;    bioleaching;    A.ferrooxidans;    adaptation;    diffusion controlled kinetics;    Calcopirita;    biolixiviação;    A.ferrooxidans;    adaptação;    difusão;    controle cinético;   

DOI  :  10.1590/S0370-44672013000200017

来源: SciELO

【 摘 要 】

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.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License