Reductive dissolution of magnetite in ethylenediaminedisuccinic acid solutions

Ethylenediaminedisuccinic acid (EDDS) was used to dissolve magnetite reductively. Fe2+ ions increased the dissolution rate, and this increase depended on the solution acidity, temperature and [EDDS]:[Fe2+] ratios. The EDDS–Fe2+ complex was able to dissolve magnetite film coated on an iron surface. Iron metal enhanced the dissolution of magnetite from its surface. However, metal exposed to the solution suffered more corrosion than iron free of magnetite.

The dissolution of magnetite in EDDS+Fe2+ solutions followed the contracting core law. The dissolution rate was found to depend on solution acidity, temperature and Fe2+:EDDS molar ratio. The dissolution of magnetite film on iron metal surface was enhanced by the metal. Galvanic coupling between magnetite and iron metal led to metal corrosion which was greater than the corrosion of metal free from magnetite film.