Anodic dissolution of gold in cyanide solutions containing ions of thallium(I)

The potential dependence of the gold dissolution rate in alkali-cyanide sol utions with and without 1.5 x 10(-5) M TlNO3 is studied using the technique of the electrode surface renewal prior to taking measurements. The thalliu m ions accelerate the gold dissolution at potentials below 0.2 V and inhibi t it at more positive potentials. The effect depends on the time the electr ode is in contact with solution before the measurements, the potential scan rate, and concentrations of KCN and KOH. Possible approaches to interpreti ng the discovered phenomena are suggested.