Hydropyrolysis of a high-sulphur,high-calcite Italian Sulcis coal: 3. Pyrite behaviour

The chars obtained from hydtopytolysis of Sulcis coal were examined by scanning electron microscopy coupled with an energy dispersion analyser. Under 3 MPa of He at 540 °C, pyrite is transformed into FeS_1.5. Under H₂ pressure, pyrite reduction depends on the temperature. At 780 °C, pyrite is completely reduced to iron. The complete reduction is made possible because the H₂S formed reacts with the caleite of this coal and thus does not limit the reducing reaction.