Mössbauer spectroscopic studies of the mineralogical changes in coal as a function of cleaning, pyrolysis, combustion and coalconversion processes

• Published in: Fuel (Guildford) 1980, Vol.59 (8), p.567-574
• Main Authors: Saporoschenko, Mykola, Hinckley, Conrad C., Smith, Gerard V., Twardowska, Helena, Shiley, Richard H., Griffin, Robert A., Russell, S.J.
• Format: Article
• Language: English
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/0016-2361(80)90234-3

The mineralogical changes in a Perry County, Illinois coal from the Herrin (No. 6) Member due to cleaning, pyrolysis, combustion, and coal-conversion processes were studied. Mössbauer spectroscopy was used in tandem with X-ray diffraction to follow the changes in the forms of iron originally present in the coal resulting from processing. The chemistry of the pyrite conversion is less complex than expected. Iron does not become uniformly distributed in all possible minerals but tends to form simple products. Pyrrhotites along with spinel and hydrated ferrous sulphates are the primary mineral products found in coat liquefaction and pyrolysis process residues; while mullite, ferrous silicates and the iron oxides (hematite, geothite and magnetite) are the most abundant mineral products found in Lurgi gasification and power plant fly ashes. The detailed distribution of iron, however, is dependent upon conditions in the particular process equipment in which the coal is used and the conversion process in which it is used.