X-RAY-ANALYSIS OF LIQUID-TREATED COALS - 1 - EFFECTS OF PYRIDINE ON THE SHORT-RANGE STRUCTURING IN BEULAH-ZAP LIGNITE

The X-ray scattering curves are statistically indistinguishable, excep t for a small difference at very low angle, for a sample of ''as recei ved'' Beulah Zap lignite and for the Beulah Zap which has been dried a t 107 degrees C in a convection oven. The addition of pyridine to Beul ah Zap causes a significant change in the X-ray scattering curves obta ined in the 1.0-2.5 Angstrom(-1) region of reciprocal space, and this difference is also found in the resulting structure curves which have been calculated in molecular (real) space. A model that suggests pyrid ine is hydrogen bonded to the oxygens contained in attachments which a re covalently bonded to the ''planar'' C-9 units of Beulah Zap has bee n suggested, and both the specific and the average atom-pair distances calculated from this model are consistent with the structure function calculated from the X-ray scattering curve of the BZ-PYR sample.