ELECTROCHEMICAL STUDIES ON ANODIC DISSOLUTION OF SYNTHETIC NICKEL SULPHIDES
镍硫化物阳极溶解的电化学研究

The anodic behaviours of synthetic nickel sulphides in H_2SO_4 solution were studied. When the anodes of Ni_3S_2, Ni_7S_6 and NiS are actively dissolved respec- tively, a solid layer is formed on the electrode surface with its nature and com- position depend on the applied potential. Based on the electrochemical Phenomena, phase and elemental compositions of the solid layer formed on the electrode surface were determined. The apparent number of electrons transfered during dissolution of one Ni~(2+) was also measured. It can be considered that there are three parallel reac- tions occurred on the electrode: the reaction with formation of HSO_4~- or SO_4~(2-), the reaction with formation of sulphides as intermediates and the reaction of forming elemental S. With NiS_2, as an anode, formation of SO_4~(2-). or HSO_4~- can be consider- ed as the only reaction ocurred on the electrode.