Maria Coal Pyrolysis Studied by Fourier Transform Infrared and Mossbauer Spectroscopy

Maria coal sample from Teruel, Spain, and its derivatives, the carbonized material of Maria at 600 degrees C in an argon atmosphere, and the Maria coal ash produced at 850 degrees C in air, have been mainly characterized by Fourier transform infrared and Mossbauer spectroscopy. The ultimate chemical and sulfur analysis, as well as the calorific values, are given. From the analysis of both chemical and Fourier transform infrared, the coal sample was identified as sub-bituminous coal with a high content of mineral matter, mainly kaolinite, which is altered during pyrolysis due to the loss of hydroxyl groups. On the other hand, the room temperature Mossbauer spectrum of the starting coal sample showed the presence of Fe(2+) in pyrite and Fe(3+) in jarosite. Further, the Mossbauer spectra of Maria samples (char and ash) showed, respectively, the presence of pyrrhotite (Fe(0.881)S) and hematite (Fe(2)O(3)). However, the chemical changes in jarosite after pyrolysis was not relevant. The structure of pyrrhotite as obtained from its average magnetic field is discussed.