不同成因类型黄铜矿细菌浸出钝化

Passivation of different genetic types of chalcopyrite bioleaching

利用嗜酸氧化亚铁硫杆菌为浸矿菌种,采用SEM,XRD和XPS等手段研究2种不同成因类型黄铜矿(黄铁矿型和斑岩型)表面钝化机理。研究结果表明:2种类型黄铜矿表面形成的钝化层性质不同。黄铁矿型黄铜矿浸渣中产生S8和硫砷铜矿,其表面结构疏松;而斑岩型黄铜矿浸渣中出现Cu18.32Fe15.9S32和Cu2S,表面结构致密。黄铁矿型黄铜矿浸渣表面阻碍层为硫及其多聚物,斑岩型黄铜矿浸渣表面为富铜贫铁层。它们阻碍黄铜矿的继续浸出,且富铜贫铁层对黄铜矿的钝化能力强于硫层对黄铜矿的钝化能力。

The passivation of chalcopyrite of two different genetic types（the pyritic and the porphyry） in the presence of Acidithiobacillus ferrooxidans was investigated by scanning electron microscopy（SEM）,X-ray diffraction（XRD）,and X-ray photoelectron spectroscopy（XPS）.The results show that the passivation layers on the surface of two types of chacolpyrite have distinct nature.From the XRD spectra and SEM micrograph,the layer with loose structure can be observed on the outer surface of the pyritic chalcopyrite residues,which contains S8 and enargite.In the porphyry chalcopyrite residues,talnakhite（Cu18.32Fe15.9S32） and chalcocite（Cu2S） are detected,and the surface has a compact structure.The XPS evidences a copper-rich iron-deficient surface layer on the surface of the porphyry chalcopyrite slag,and a sulphur layer on the surface of the pyritic chalcopyrite residues,both finally cause the passivation of chalcopyrite,and the copper-rich iron-deficient surface layer has more powerful restrain ability than the sulphur layer has.