Surface oxidation of synthetic pyrrhotite during wetting-drying treatment

The surface changes of synthetic hexagonal pyrrhotite Fe10S11 during labora tory wetting-drying treatment at 45 degreesC were investigated using FTIR ( DRIFT) spectroscopy, FTIR Raman microscopy, and scanning electron microscop y. alpha -FeO(OH) (goethite) and elemental sulphur were the main products o f the surface pyrrhotite oxidation. The formation of goethite and elemental sulphur was studied on the basis of the corrosion theory and using a poten tial-pH (Pourbaix) diagram. The appearance of oxidation products on the sur face of pyrrhotite grains was detected between 10 and 20 h of treatment. Th e obtained results can be used for comparison of oxidation processes of syn thetic pyrrhotite with that of natural sulphide minerals in dumps.