Anodic Behaviour of Lead Sulphide in Hydrochloric Acid

The anodic dissolution of lead sulphide is studied at various chloride concentrations and at different pH values. At 25° C it is found that in hydrochloric acid the dissolution rate reaches a maximum around 3.0 mol dm−3. It has also been observed that at concentrations between 0.7 and 1.2 mol dm−3, a crystalline sulphur deposit formed during the dissolution process leads to an independent peak on theI-E curve whereas at higher concentrations it merges with the PbCl2 peak formation. pH has no significant effect on the dissolution rate. The results of a systematic study on the kinetics of the dissolution process as a function of concentration, temperature and pH are discussed.