Galvanic interaction between galena and pyrite in an open system

Galvanic interactions between sulfide minerals have very important influences on hydrometallurgical processes, the supergene enrichment of sulfides and the formation of acid mine drainage. By changing the concentrations of Fe3+, the pH values, status of the flowing of the solution and the solution salinity (e.g. the concentrations of Na2SO4) and monitoring the galvanic currents and potentials, studies were conducted in this work on the galvanic interaction between pyrite acting as the anode and galena acting as the cathode. The results indicated that the concentrations of Fe3+, pH values and the flowing of the solution exhibit a great effect on the galvanic interaction of galena-pyrite couple, while the salinity of the solution has only a slight influence on the interaction. The experiments also revealed that in case cracks exist on the surface of pyrite electrode, the potential of pyrite will decrease so sharply as to be lower than that of galena under the same experimental condition. The experimental results were explained in terms of the Butler-Volume equation and the theory of mixed potential.