Au-Cl^--SO_3^(2-)-H_2O系的电化学行为研究

Electrochemical Behaviors of Au-Cl^--SO_3^(2-)-H_2O System

根据Au-Cl--SO2-3-H2O系中可能存在的电化学反应及各组分的热力学数据,通过计算,得出Au-H2O系、Au-Cl--H2O系和H2SO3-H2O系的电化学反应和ε-pH表达式,绘制出相应的电位-pH图及H2SO3-H2O系与Au-Cl--H2O系的重叠图,确定了不同pH和电位条件下各种物质的热力学稳定区域和发生反应的可能性。结果表明:通过氯化处理,金的电位明显降低;H2SO3系总体电位明显低于Au-Cl--H2O系的电位,采用H2SO3还原金,控制pH=1.75效果最佳。

The Electrochemical reactions andε-pH formulas of Au-H2 O system,Au-Cl--H2 O system and H2SO3-H2 O system were determined based on the possible electrochemical reactions and components thermo-dynamic data in Au-Cl--SO2-3-H2 O system.Theε-pH diagrams of these systems and overlapedε-pH diagram of Au-Cl--H2 O system and H2SO3-H2 O system were charted based on thermo-dynamic data at 298 K.The thermo-dynamic stability regions of some substances and the possibility of chemical reactions under the conditions of different pH and potential were determined.The results show that by dealing with chloride,the potential of gold can be decreased obviously,and the potential of H2SO3 system is significantly lower than the that of Au-Cl--H2 O system.And H2SO3 can be using for reducing gold in liquid at the pH of 1.75.