聚乙二醇对氧化亚铁硫杆菌浸出黄铜矿的影响

摘要

为提高黄铜矿生物浸出率，研究聚乙二醇(PEG)对Acidithiobacillus ferrooxidans strain XZ11 Fe2+氧化活性和黄铜矿生物浸出过程的影响，并采用SEM和EDS对浸出后矿物表面形貌和相组成进行表征。结果表明：相对分子质量大于200的PEG对Acidithiobacillus ferrooxidans Fe2+氧化活性具有一定的促进作用，添加30 mg/L PEG 2000时，浸出20 d后，铜浸出量高达451.70 mg/L，较不添加FEG时提高了1.11倍；添加PEG时，黄铜矿表面的侵蚀面呈沟壑状，出现溶蚀坑，并生成Fe3+的羟基化多聚物Fe(Ⅲ)—O—OH。PEG的添加提高了浸出体系中细菌浓度和Fe3+浓度，加速了黄铜矿的溶解。%Polyethylene glycol (PEG) was used to improve the bioleaching rate of chalcopyrite byAcidithiobacillus ferrooxidans (At.f) strain XZ11. The effect of PEG on the Fe2+ oxidizing activities ofAcidithiobacillus ferrooxidan and bioleaching of chalcopyrite were investigated. The surface morphologies and phase composition of chalcopyrite after bioleaching were characterized by SEM and EDS. The results show that PEG with relative molecular mass greater than 200 can promote the Fe2+ oxidizing activities ofAcidithiobacillus ferrooxidan After bioleaching for 20 d, the copper extraction yield of chalcopyrite with 30 mg/L PEG 2000 is 451.70 mg/L, which increases by about 1.11 times compared with the bioleaching without PEG. Native-like structure, holes and Fe(III)—O—OH form on the erosion surface of chalcopyrite. PEG can increase the cell density ofAcidithiobacillus ferrooxidan and Fe3+ concentration in the leaching solution, consequently, accelerates the chalcopyrite oxidation dissolution.