Anodic dissolution of gold in cyanide solutions: Effect of temperature

It is shown that a temperature increase has a complex effect on the anodic dissolution of gold. At negative potentials (in the standard hydrogen scale), in the absence of heavy metals, the effective activation energy for the dissolution is close to 48 kJ/mol and weakly depends on the polarization. At more positive potentials, the temperature dependence of the gold dissolution rate reflects the temperature effect on competitive adsorption of cyanide and hydroxide ions, the surface development during electrolysis, and the accumulation of the cyanide ion decomposition products and their passivating action. Near 0.6 V, the temperature affects transport processes.