The kinetics of anodic dissolution of gold in cyanide electrolytes and the interface layer composition

Current-potential curves for anodic dissolution of gold that are undistorted by the influence of impurities and effects of the surface development are obtained at electrodes renewed by cutting. The effective values of the reaction order by cyanide and the transfer coefficient in the region of negative potentials are found to be equal to 0.17 and 0.10, respectively. It is established that these data can be conciliated with the results of studying thermodynamics inherent in adsorption of the cyanide ions, assuming that the adsorption process is accompanied by a considerable charge transfer and adopting the stage of the surface complex activation, which allows the second cyanide ion to be rapidly attached, as the limiting stage of the gold dissolution process.