摘要
The leaching of Cu from low-grade polymetallic complex chalcopyrite ore(LPCCO)in acidic ferric electrolyte was increased by adding tartrate.To explain the reason resulting in this phenomenon,a systematical study about the effects of tartrate on the interfaces where reactions occurred was conducted by using electrochemical methods.The Mott−Schottky experiment results showed that whether tartrate was added or not,the initial n-type LPCCO surface transformed to the surface with a p−n junction that seriously hindered charge transfer.After adding tartrate,a shorter Debye length and higher charge carrier density were obtained,which were related to the decrease in intergranular energy barrier height by tartrate’s bridging semiconductor particles.Additionally,EIS results combined with Tafel and LSV analysis revealed thin passive film and double-layer,large diffusion coefficient,and low apparent activation energy.These favorable changes in interface properties facilitated the LPCCO dissolution.
通过添加酒石酸钠,提高低品位多金属复杂黄铜矿(LPCCO)在酸性铁电解液中铜的浸出率。利用电化学方法系统研究酒石酸钠对浸出反应界面的影响。Mott−Schottky实验结果表明,无论是否添加酒石酸钠,初始的n型LPCCO表面都会转变为具有严重阻碍电荷转移的p−n结的表面。添加酒石酸钠后,因酒石酸根桥接半导体颗粒降低了晶间能垒高度,获得了更小的Debye长度和更高的电荷载流子密度;结合Tafel和LSV分析的EIS结果表明,加入酒石酸钠后反应界面转变为更薄的钝化膜和电双层,具有较大的扩散系数,从而降低了浸出反应的表观活化能,这些界面性质促进了LPCCO的溶解。
基金
supported by the National Natural Science Foundation of China(No.21978122).
