MOSSBAUER-SPECTROSCOPY OF IRON IN COAL AND COAL HYDROGENATION PRODUCTS

The chemical states of iron in a Kentucky coal and in the products of its hydrogenation were determined by Mössbauer spectroscopy. The iron in the coal was present chiefly as pyrite, FeS2. There was, however, evidence for some non-pyritic iron, most likely present as szomolnokite (FeSO4·H2O). The products from hydrogenation of this coal by the SYNTHOIL process at 723° K and 28 MPa contained all the iron as FeSx where x = 1.0 to 1.14. There was no evidence for unreduced FeS2 or FeSO4. There was also no evidence for elemental iron. At the experimental conditions for hydrogenation of coal in this work, the reactor gas contained 0.32% H2S. Evidently, FeSx is not reduced to elemental iron in the presence of this concentration of H2S in the reducing gas. © 1978.