中等嗜热混合菌介导的不同产地斑铜矿浸出差异的比较

Comparison of leaching of bornite from different regions mediated by mixed moderately thermophilic bacteria

本文通过嗜铁钩端螺旋菌、嗜酸喜温硫杆菌以及嗜热硫氧化硫化杆菌三种中等嗜热混合菌对三种不同产地的斑铜矿进行生物浸出,结合X射线光电子能谱(XPS)、X射线衍射(XRD)和扫描电子显微镜(SEM)研究了不同产地斑铜矿浸出行为的差异性。浸出实验结果表明,与空白组相比,生物浸出组的浸出效率和氧化还原电位有显著提高。三种斑铜矿的铜浸出率在前12天一直快速增长,18天后不再增长,此时浸出率分别83.7%,96.5%,86.6%。浸出渣的XRD结果表明,三种斑铜矿在浸出后期均产生黄钾铁矾,其中大冶和云南的浸出渣中含有大量的硫元素。XPS分析和扫描电子显微镜实验结果表明,矿渣表面是黄钾铁矾,浸出渣中几乎没有铜。

Bioleaching experiments combined with X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and scanning electron microscopy(SEM)were conducted to investigate three kinds of bornites from different regions leached by moderately thermophilic mixed bacteria of Leptospirillum ferriphilum YSK,Acidithiobacillus caldus D1 and Sulfobacillus thermosulfidooxidans ST.The results of bioleaching experiments showed that the leaching efficiency and the redox potential were significantly increased.The copper extraction efficiencies of three kinds of bornite maintained rapid growth until around the 12th day and no longer increased after the 18th,reaching 83.7%,96.5%and 86.6%,respectively.The XRD results of the leaching residue indicated that three kinds of bornites all produced jarosite in the late stage of leaching,and the leaching residues from of Daye Museum and Yunnan Geological Museum contained a mass of elemental sulfur.XPS analysis and scanning electron microscopy experiments showed that the surface of mineral particles was jarosite and the copper in the leaching residue was almost dissolved.