Abstract
The digestion process of bituminous coal in pitch oil and coal tar pitch of medium softening point (80-85°C R & B) at 270-280°C under at mospheric pressure was traced by means of measuring viscosity of the coal-pitch-pitch oil system with a penetrometer, and the mechanism of the process was discussed rheologically.
The test results suggested that the digestion process comprises, for the most part, simple swelling of coal particles.
Through solvent extraction of coal digestion pitch and redigestion of the extraction residue, the authors have not only recognized that the micelles of coal particles were not destructed to colloidal state, but also noted that the extraction residue was increased by swelling of coal particles during digestion process.
