Stimulating effect of phosphate ions on the dissolution kinetics of iron oxides in an acidic medium

The dissolution kinetics of iron oxides FeO, Fe2O3, and Fe3O4 in orthophosphoric acid is studied. The dependence of the rate of Fe2O3 (iron(III) oxide) dissolution on the nature of inorganic acids is examined. The values of the stationary potential in a magnetite electrode-orthophosphoric acid solution system are determined. It is established from the experimental results that the stimulating effect of phosphate ions is related to their influence on the potential at the oxide/solution interface.