工程科学学报，第40卷，第12期：1495-1501,2018年12月 Chinese Journal of Engineering,Vol.40,No.12:1495-1501,December 2018 DOI:10.13374/j.issn2095-9389.2018.12.007;http://journals.ustb.edu.cn 有菌和无菌体系下辉铜矿氧化电化学 廖勃，温建康⑧，武彪，尚鹤，陈勃伟 北京有色金属研究总院生物治金国家工程实验室，北京100088 ☒通信作者，E-mail:kang3412@126.com 摘要运用循环伏安曲线、稳态极化曲线和Tfl曲线等电化学手段以及X射线光电能谱(XPS)法研究了辉铜矿在有菌和 无菌体系下氧化过程的电化学行为.研究结果验证了辉铜矿在有菌体系和无菌体系下的两步氧化溶解机理，第一步氧化反应 为辉铜矿不断氧化生成缺铜的中间产物Cu,S(1≤x<2),直至生成CS,在较低电位下即可进行：第二步反应为中间产物CS 的氧化，需要在较高电位下才可进行，反应速率较慢，是整个氧化反应的限制性步骤.循环伏安实验显示有菌体系电流密度明 显大于无菌体系，表明细菌加快了辉铜矿的氧化速率.稳态极化实验显示辉铜矿点蚀电位较低，无菌体系第一段反应活化区 电位范围小于有菌体系，表明辉铜矿氧化过程生成的中间产物硫膜具有钝化效应，细菌可以通过自身氧化作用破坏硫膜，诚 弱辉铜矿表面的钝化效果，加快辉铜矿的氧化溶解速率.X射线光电子能谱分析显示电极表面钝化层物质组成复杂，包含了 CS、多硫化物(S~)、(S)和含(S0~)的氧化中间产物等多种物质，其中主要的饨化物为CS,表明辉铜矿的氧化遵循多硫化 物途径 关键词辉铜矿；电化学；生物浸出；钝化；多硫代物 分类号TF803.21 Electrochemistry of oxidation of chalcocite in the presence and absence of microorganisms LIAO Bo,WEN Jian-kang,WU Biao,SHANG He,CHEN Bo-wei National Engineering Laboratory of Biohydrometallurgy,General Research Institute for Nonferrous Metals,Beijing 100088,China Corresponding author,E-mail:kang3412@126.com ABSTRACT The electrochemical behavior of the chalcocite oxidation process in the presence and absence of microorganisms was in- vestigated using electrochemical techniques,including cyclic voltammetry,anodic polarization curves,Tafel curves,and X-ray photoe- lectron spectroscopy (XPS)analysis.The research results prove the stepwise dissolution mechanism of chalcocite in the presence and absence of microorganisms.The initial stage of oxidation is initiated at low redox potentials.During the initial stage,the intermediate products of Cu,S(1x<2)are successively oxidized until Cus is formed.The later stage is the oxidation of the intermediate product CuS and this period requires initiation at high redox potentials owing to the formation of a passivation layer on the electrode surface,and the reaction rate of the later stage is extremely slow;in this case,it is the rate-limiting step of the whole reaction.The cyclic voltammo- grams show that the electric current density in the presence of microorganisms is higher than that in the absence of microorganisms,in- dicating that the microorganisms accelerates the dissolution rate of chalcocite.The anodic polarization curves show that the pitting po- tential of chalcocite is low;the potential range of the first active corrosion zone in the presence of microorganisms is much wider than that in the absence of microorganisms,indicating that the intermediate products of the sulfur film are passivating,and their effects could be reduced by the oxidation of microorganisms;in this manner,the dissolution rate of chalcocite is promoted.To identify the components of the passivation layer during the process of chalcocite dissolution in the presence and absence of microorganisms,the electrodes were detected via XPS.The XPS analysis results show that the components of the passivation layer on the electrode surface 收稿日期：2017-12-27 基金项目：国家自然科学基金资助项目(51574036)工程科学学报,第 40 卷,第 12 期:1495鄄鄄1501,2018 年 12 月 Chinese Journal of Engineering, Vol. 40, No. 12: 1495鄄鄄1501, December 2018 DOI: 10. 13374 / j. issn2095鄄鄄9389. 2018. 12. 007; http: / / journals. ustb. edu. cn 有菌和无菌体系下辉铜矿氧化电化学 廖 勃, 温建康苣 , 武 彪, 尚 鹤, 陈勃伟 北京有色金属研究总院生物冶金国家工程实验室, 北京 100088 苣通信作者, E鄄mail: kang3412@ 126. com 摘 要 运用循环伏安曲线、稳态极化曲线和 Tafel 曲线等电化学手段以及 X 射线光电能谱(XPS)法研究了辉铜矿在有菌和 无菌体系下氧化过程的电化学行为. 研究结果验证了辉铜矿在有菌体系和无菌体系下的两步氧化溶解机理,第一步氧化反应 为辉铜矿不断氧化生成缺铜的中间产物 CuxS(1臆x < 2),直至生成 CuS,在较低电位下即可进行;第二步反应为中间产物 CuS 的氧化,需要在较高电位下才可进行,反应速率较慢,是整个氧化反应的限制性步骤. 循环伏安实验显示有菌体系电流密度明 显大于无菌体系,表明细菌加快了辉铜矿的氧化速率. 稳态极化实验显示辉铜矿点蚀电位较低,无菌体系第一段反应活化区 电位范围小于有菌体系,表明辉铜矿氧化过程生成的中间产物硫膜具有钝化效应,细菌可以通过自身氧化作用破坏硫膜,减 弱辉铜矿表面的钝化效果,加快辉铜矿的氧化溶解速率. X 射线光电子能谱分析显示电极表面钝化层物质组成复杂,包含了 CuS、多硫化物(S 2 - n )、(S 0 )和含(SO 2 - 4 )的氧化中间产物等多种物质,其中主要的钝化物为 CuS,表明辉铜矿的氧化遵循多硫化 物途径. 关键词 辉铜矿; 电化学; 生物浸出; 钝化; 多硫代物 分类号 TF803郾 21 收稿日期: 2017鄄鄄12鄄鄄27 基金项目: 国家自然科学基金资助项目(51574036) Electrochemistry of oxidation of chalcocite in the presence and absence of microorganisms LIAO Bo, WEN Jian鄄kang 苣 , WU Biao, SHANG He, CHEN Bo鄄wei National Engineering Laboratory of Biohydrometallurgy, General Research Institute for Nonferrous Metals, Beijing 100088, China 苣Corresponding author, E鄄mail: kang3412@ 126. com ABSTRACT The electrochemical behavior of the chalcocite oxidation process in the presence and absence of microorganisms was in鄄 vestigated using electrochemical techniques, including cyclic voltammetry, anodic polarization curves, Tafel curves, and X鄄ray photoe鄄 lectron spectroscopy (XPS) analysis. The research results prove the stepwise dissolution mechanism of chalcocite in the presence and absence of microorganisms. The initial stage of oxidation is initiated at low redox potentials. During the initial stage, the intermediate products of CuxS (1臆x < 2) are successively oxidized until CuS is formed. The later stage is the oxidation of the intermediate product CuS and this period requires initiation at high redox potentials owing to the formation of a passivation layer on the electrode surface, and the reaction rate of the later stage is extremely slow; in this case, it is the rate鄄limiting step of the whole reaction. The cyclic voltammo鄄 grams show that the electric current density in the presence of microorganisms is higher than that in the absence of microorganisms, in鄄 dicating that the microorganisms accelerates the dissolution rate of chalcocite. The anodic polarization curves show that the pitting po鄄 tential of chalcocite is low; the potential range of the first active corrosion zone in the presence of microorganisms is much wider than that in the absence of microorganisms, indicating that the intermediate products of the sulfur film are passivating, and their effects could be reduced by the oxidation of microorganisms; in this manner, the dissolution rate of chalcocite is promoted. To identify the components of the passivation layer during the process of chalcocite dissolution in the presence and absence of microorganisms, the electrodes were detected via XPS. The XPS analysis results show that the components of the passivation layer on the electrode surface