SWELLING OF A GERMAN BROWN-COAL IN ACETONE-WATER AND METHANOL-WATER MIXTURES

Samples of a German brown coal were treated with acetone-water and met hanol-water mixtures of different compositions and the consequent coal swelling was measured. Owing to the very high solubility parameter of pure water, these mixtures have higher solubility parameters than bin ary organic solvent mixtures commonly used in such experiments. The re sults are interpreted on the basis that matching of coal and solvent s olubility parameters maximizes swelling, although note is also taken o f supplementary effects including those accompanying entry of solvent into the coal pores. (C) 1997 Elsevier Science Ltd.