Electrochemical and XPS analysis of chalcopyrite (CuFeS2) dissolution in sulfuric acid solution
Electrochemical and XPS analysis of chalcopyrite (CuFeS2) dissolution in sulfuric acid solution
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DOI：
10.1016/j.electacta.2012.07.119
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发表时间：
2013-01-01
影响因子：
6.6
通讯作者：
Asselin, E.
中科院分区：
文献类型：
--
作者：
Ghahremaninezhad, A.;Dixon, D. G.;Asselin, E.
在25℃的0.5 M硫酸溶液中，采用循环伏安法、计时安法、恒电位法和动电位极化法研究了电位对黄铜矿电溶过程中物质形态和表面膜形成的影响。采用x射线衍射（XRD）和x射线光电子能谱（XPS）对电溶前后表面的矿物和产物层进行了分析。黄铜矿电极对高达0.90 V-SHE的电位是无源的。超过这个电位，就发生透溶。XPS研究结果表明，由硫化亚铜（Cu-S）和硫化铁（Fe-S）键组成的缺金属硫化物膜（Cu1-xFe1-yS2-z）是最可能钝化黄铜矿表面的含铜和含铁硫化物相。结果表明，黄铜矿的透溶与硫的氧化密切相关（从被动膜中的硫化物到单质硫，可能还有更高氧化态的硫种，如硫代硫酸盐）。当电位低于0.90 V-SHE时，表面未检测到单质硫或多硫化物。(C) 2012 Elsevier Ltd.版权所有。
The influence of potential on the species and surface films formed during electrodissolution of chalcopyrite were investigated in 0.5 M sulfuric acid solution at 25 degrees C. Cyclic voltammetry, chronoamperometry, potentiostatic and potentiodynamic polarization methods were applied. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to analyze the minerals and product layers on the surface before and after electrodissolution. The chalcopyrite electrode was shown to be passive for potentials up to 0.90 V-SHE. Above this potential, transpassive dissolution occurs. Results of XPS studies have suggested that a metal-deficient sulfide film (Cu1-xFe1-yS2-z) consisting of cuprous sulfide (Cu-S) and iron sulfide (Fe-S) bonds, is the most plausible copper and iron containing sulfide phase which passivates the surface of chalcopyrite. It is demonstrated that the transpassive dissolution of chalcopyrite is significantly linked to oxidation of sulfur (from sulfide in the passive film to elemental sulfur and maybe sulfur species with higher oxidation states, e.g. thiosulfate). No elemental sulfur or polysulfide species were detected on the surface for potentials below 0.90 V-SHE. (C) 2012 Elsevier Ltd. All rights reserved.