INTERACTIONS BETWEEN ORGANIC-MATTER AND MINERALS IN 2 BITUMINOUS COALS OF DIFFERENT RANK

The association between specific mineral and organic constituents in t wo Asturian bituminous coals of different rank was studied. For this, raw coals were fractionated by density and the variation of a number o f parameters was followed in parallel. Results of coal chemical analys es, including analyses for 22 elements, were used to establish the ele mental association with coal organic matter. Petrographic analyses det ermined the distribution of macerals among densimetric fractions, vitr inite reflectance being at a minimum in the intermediate density fract ions. Mineral species were identified by X-ray diffraction, FT-IR spec troscopy and Mossbauer spectroscopy. Comparison of trends for differen t parameters determined using this set of techniques allowed classific ation of the various minerals according to their association with orga nic matter. Carbonates seem to be specifically associated with the org anic matter of the low-volatile bituminous coal whereas sulfides conce ntrate in the organic matter of the high-volatile bituminous coal. Vit rinite is the maceral exhibiting the most probable association with in organic matter. The possibility of a merely physical association of fi ne-grained detrital minerals with organic matter cannot be excluded; n evertheless, one must bear in mind that even this type of interaction is important due to its effect on various coal preparation and utiliza tion processes.