ELECTROCHEMICAL STUDIES ON ANODIC DISSOLUTION OF SYNTHETIC NICKEL SULFIDES

The anodic behavior of synthetic nickel sulfides in sulfuric acid solutions was studied.Whenthe anodes of NiS,NiSand NiS are actively dissolved respectively,a solid layer forms onthe electrode surface with its nature and composition depending on the potentials applied.Based on the electrochemical phenomena,phase and elemental compositions of the solid layerformed on the electrode surface were determined.The apparent number of electrons transfer-red during dissolution of Niwas also measured.It can be considered that there are threeparallel reactions ocurred on the electrode:the reaction with formation of HSO~- or SO,the reaction with formation of sulfides as intermediates and the reaction of Jorming elementalsulfur.With NiSas an anode,formation of SOor HSO~- can be considered as the only re-action occurred on the electrode.