BENEFICIATION OF LOW-RANK COALS BY IMMERSION IN RESIDUUM

摘要

ABSTRACTBENEFICIATION OF LOW-RANK COALS BY IMMERSION IN RESIDUUMA method of improving the calorific value andpreventing autogenous heating of low-rank coals is disclosedwhich comprises crushing the coal into a particle size range from0.1 cm to 3 cm, immersing the particles in a distillationresiduum of petroleum crude oil at a temperature between240°C and the decomposition temperature of the coal, anddraining excess residuum from the particles to give a productpreferably containing 2% to 15% by weight of the residuum.Some suitable residuum are the vacuum residuum of a hydrogendonor-refined Athabasca bitumen and low-penetration asphalt.The residuum coating material must have a softening point of atleast 80°C. The decomposition temperature is defined as thetemperature for a particular coal at which its rate of weight lossupon heating first reaches a maximum value, and is in the rangeof 340°C to 350°C for most low-rank coals.