镍硫化物阳极溶解的电化学研究

研究了合成镍硫化物的阳极过程。Ni_3S_2,Ni_7S_6和NiS的活性溶解伴随着生成表面产物层,其反应机理与电极电位有关。根据三种不同类型产物层生成规律的电化学研究,Ni溶出表观电子数的测定,以及产物层相组成分析和相的元素分析,认为存在三组平行反应:直接生成HSO_4~-或SO_(4-)~2的反应,生成中间硫化物的反应及生成元素硫的反应,每组反应具有不同的优势发展电位区。NiS_2阳极溶解时,基本上为生成HSO_(4-)或SO_(4-)~2的反应。

ELECTROCHEMICAL STUDIES ON ANODIC DISSOLUTION OF SYNTHETIC NICKEL SULPHIDES

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.