INFLUENCE OF PRESSURE AND HYDROTHERMAL TREATMENT ON THE MICROTEXTURALCHARACTERISTICS OF COKE

The microtextural characteristics of coke produced from raw as well as from their beneficiated/demineralised counterparts both under normal and elevated pressures (22 mPa) at two temperature levels (500 to 1000 degrees C) were studied on two caking/coking and one non-caking coals . An account with emphasis on the development of well-ordered carbonfo rms under the influence of hydrothermal treatment as well as on post c arbonization of the treated coal has been put forward. The non-caking coal, which generally produces vesicular chars passed through a plasti c phase to give fully isotropic reacted carbonforms when the coal was subjected to both pressure pyrolysis and hydrothermal treatment. For t he other caking/coking coals used in the study the influence of hydrot hermal treatment on development of well-ordered coke microtexture was found to be more pronounced than that of the thermal effect alone unde r pressure. (C) 1997 Elsevier Science Ltd.