酸性氯化物水溶液电积铜的反应机理研究

THE REACTION MECHANISM OF COPPER ELECTROWINNING FROM AN AQUEOUS CHLORIDE SOLUTION

采用多种电化学研究方法探讨了酸性氯化物水溶液中Cu(Ⅰ)和Cu(Ⅱ)离子在铜电极上阴极还原的电极反应机理和电极过程动力学规律。研究表明,酸性氯化物水溶液中Cu(Ⅰ)和Cu(Ⅱ)离子在铜电极上阴极还原的电极过程都表现为扩散传质步骤控制的可逆电极过程动力学规律。Cu(Ⅰ)离子主要以CuCl_2^(2-)络离子形式存在时的电极反应机理为: CuCl_3^(2-)CuCl_2^-+Cl^- CuCl_2^-+e—→Cu+2Cl^- Cu(Ⅱ)离子主要以CuCl_4^(2-)络离子形式存在时的电极反应机理为: CuCl_4^(2-)+Cu+2Cl^-2CuCl_3^(2-) 2CuCl_3^(2-)2CuCl_2^-+2Cl^- 2CuCl_2^-+2e—→2Cu+4Cl^-

The kinetics and reaction mechanisms of copper electrowinning from an aqueous chloride solution have been studied by four electrochemical methods. It was found experimently that the cathodic reductions of copper (Ⅰ)ion and copper (Ⅱ)ion on the copper electrode in an aqueous chloride solution are reversible electrode processes and the diffusion is a rate-determining step. The mechanism of cathodic reaction of copper (Ⅰ)ion may be expressed as follows: CuCl_3^(2-)(?)CuCl_2^-+Cl^- CuCl_2-+e→Cu+2Cl^- The mechanism of cathodic reaction of copper (Ⅱ)ion may be expressed as follows: CuCl_4^(2-)+Cu+2Cl^-(?)2CuCl_3^(2-) 2CuCl_2^(2-)(?)2CuCl_2^-+2Cl^- 2CuCl_2^-+2e→2Cu+4Cl^-