Comparative study on the passivation layers of copper sulphide minerals during bioleaching

• Published in: International journal of minerals, metallurgy and materials metallurgy and materials, 2012-10, Vol.19 (10), p.886-892
• Main Authors: Fu, Kai-bin, Lin, Hai, Mo, Xiao-lan, Wang, Han, Wen, Hong-wei, Wen, Zi-long
• Format: Article
• Language: English
• Subjects: Bacterial leaching; Bornite; Ceramics; Chalcopyrite; Characterization and Evaluation of Materials; Chemistry and Materials Science; Comparative studies; Composites; Copper; Copper sulfides; Corrosion and Coatings; Covellite; Glass; Jarosite; Leaching; Materials Science; Metallic Materials; Minerals; Natural Materials; Passivation; Passivity; Photoelectrons; Residues; Scanning electron microscopy; Sulfides; Sulfur; Surface layers; Surfaces and Interfaces; Thin Films; Tribology; X ray photoelectron spectroscopy; X-ray diffraction; X-rays; X-射线光电子能谱; X-射线衍射; 多硫化物; 扫描电子显微镜; 氧化亚铁硫杆菌; 生物浸出; 硫化铜矿物; 钝化层
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-012-0643-x

The bioleaching of copper sulphide minerals was investigated by using A. ferrooxidans ATF6. The result shows the preferential order of the minerals bioleaching as djurleite〉bomite〉pyritic chalcopyrite〉covellite〉porphyry chalcopyfite. The residues were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. It is indicated that jarosite may not be responsible for hindered disso- lution. The elemental sulfur layer on the surface of pyritic chalcopyrite residues is cracked. The compact surface layer of porphyry chalcopy- rite may strongly hinder copper extraction. X-ray photoelectron spectroscopy （XPS） further confirms that the passivation layers of covellite, pyritic chalcopyrite, and porphyry chalcopyrite are copper-depleted sulphide Cu4S11, S8, and copper-rich iron-deficient polysulphide CtuFe2S9, resoectivelv. The ability of these oassivation layers was found as Cu4Fe2S9〉Cu4S11〉S8〉iarosite.