Properties and structure of hard coals from a borehole Niedobczyce IG-1 in the Rybnik Coal district, Upper Silesian Coal Basin, their petrographic and group constituents .3. Changes in the chemical structure of primary tars with increase in coalification degree of the parent coals

The primary tars obtained by the Fischer-Schraeder method fr om coals described in earlier papers [1] were studied using infrared (i.r.) and H-1 nuclear magnetic resonance (nmr) spectroscopy methods. With the object of achieving a broader evaluation of the properties and structure of these primary tars with increase in coalification of the parent coals-from 78 to 86% C-daf, in the range from gasflame (according to Polish classification) 611-VII (according to international classification and statistical groups) to orthocoking 435-VB coals-they were distilled to the temperature of 543 K under normal pressure. Products obtained were also analysed by the i.r. and H-1 nmr spectroscopy methods, while the distillates/fraction boiling up to 543 K/were additionally analysed by the pas chromatography-mass spectrometry (g.c.-m.s.) and C-13 nmr methods. A comparative X-ray analysis of the coals and the semi-cokes obtained from them was also conducted. (C) 1997 Elsevier Science B.V.