On the action of pyridine as a swelling agent of low-rank coals

The swelling by pyridine/benzene mixtures of low-rank coal briquette fragments is investigated, and the results are very close to those previously reported for pyridine/benzene mixtures acting on a run-of-mine coal from the same source. This is in spite of major differences in porosity between the two coals. The conclusion is that pore entry by the solvent plays no part in the swelling process.