Mechanism of solvent extraction from coal and its chars with chloroform

Chloroform extraction for Yūbari coal both raw and preheated at 300, 350 and 400 °C was carried out at various temperatures. The following results were obtained 1. (1) 50 cm³ of chloroform per 1 g of sample is sufficient to extract almost completely, whatever the extraction temperature, the chloroform-soluble material of each sample; 2. (2) with the preheated coals, the amount of chloroform extractable material increases with increase of preheating temperature but with little apparent variation of the type of extract; 3. (3) the evidence does not indicate whether the extract has a limited solubility.