Mechanism of bioleaching chalcopyrite by Acidithiobacillus ferrooxidans in agar-simulated extracellular polymeric substances media

来源期刊：中南大学学报(英文版)2010年第1期

论文作者：余润兰 谭建锡 顾帼华 胡岳华 邱冠周

文章页码：56 - 61

Key words：Acidithiobacillus ferrooxidans; chalcopyrite; agar-simulated EPS media; bioleaching; mechanism

Abstract: The mechanism of leaching chalcopyrite by Acidithiobacillus ferrooxidans (A. ferrooxidans) in agar-simulated extracellular polymeric substances (EPS) media was investigated. The results indicate that bacterial EPS can release H⁺ and concentrate Fe³⁺; Fe²⁺ is movable between agar-simulated EPS phase and bulk solution phase, but it is difficult for Fe³⁺ to move due to its hydroxylation and EPS complex action; A. ferrooxidans first prefer Fe²⁺ as energy to metabolize compared with chalcopyrite, and a suitable simulated EPS environment for bacterial living is at about pH 1.8; the iron precipitates and jarosites formed by a lot of biologically oxidized Fe³⁺ cover the simulated EPS easily and form an impermeable deposit acting as a limited barrier of ion transport that attenuates the aggressiveness of the bioleaching attack. The EPS layer blocked by iron precipitates or jarosites is responsible for the chalcopyrite passivation.

基金信息：the National Basic Research Program of China
the National Nature Science Foundation of China