The potential sweep method, adsorption kinetics and isotherm studies, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) after adsorption tests of copper(I) and gold(I) ions using magnetite were performed to investigate the mechanism of selective copper(I) adsorption over gold(I) ion from chloride solution with small amount of cyanide. The electrochemical analysis reveals that the reduction potential is −0.81 V for Au and + 0.38 V for copper (vs. Ag/AgCl) which lead to selective adsorption of Cu over Au from chloride solution with cyanide because the adsorption could be achieved when the reduction potential of the metal ion is higher that of Fe₂O₃/Fe₃O₄ pair in the magnetite. By the kinetics and isotherm studies, the chemisorption was found to be well fitted to the pseudo-second-order model and monolayer adsorption of Cu ions on the surface of magnetite. The XPS and TEM results indicates that the ratio of Fe(II) in the iron of the magnetite decreased from 74% to 43% due to the oxidation. Consequently, the mechanism of adsorption using magnetite was depends on the reduction potential of metal ions to selectively receive electrons generated during the oxidation of magnetite in the chloride solution with cyanide.

在利用磁铁矿对铜（I）和金（I）离子进行吸附测试之后，进行了电势扫描方法，吸附动力学和等温线研究，X射线光电子能谱（XPS）和透射电子显微镜（TEM），以研究选择性机理。铜（I）从氯化物溶液中以少量氰化物吸附在金（I）离子上。电化学分析表明，Au的还原电位为-0.81 V，铜的还原电位为+ 0.38 V（vs。Ag / AgCl），这导致氰化物从氯化物溶液中选择性地吸附了Au上的Cu选择性吸附Cu，因为还原时可以实现吸附金属离子的电势比Fe ₂ O ₃ / Fe ₃ O _4的电势高对磁铁矿。通过动力学和等温线研究，发现化学吸附与拟二阶模型和铜离子在磁铁矿表面的单层吸附非常吻合。XPS和TEM结果表明，由于氧化作用，磁铁矿中铁中Fe（II）的比例从74％降低到43％。因此，使用磁铁矿的吸附机理取决于金属离子的还原电势，以选择性地接收氯化物溶液中氰化物与氰化物氧化过程中产生的电子。