Electrochemical kinetics of the anodic dissolution of nickel matte and synthetic Ni_3S_2

摘要

Commercial nickel matte anode material (International Nickel Company) and synthetic Ni_3S_2 were oxidized anodically under a varety of conditions. Reaction products were identified by cyclic voltammetry, X-ray diffraction analysis, Raman spectroscopy, and X-ray photoelectron spectroscopy. Kinetics of surface film growth were measured using chronoamperometry techniques. Variables considered include maximum scan potential, time at a fixed potential, temperature, solution pH and the effect of stirring. Electrochemical reactions occurring on the nickel sulfide surface are proposed based on electrochemical measurements and identification of surface reaction products. The results obtained for nickel matte were compared with those from synthetic heazlewoodite (Ni_3S_2).