Importance

Loading Importance Indicators...

Abstract

A method of improving the calorific value and preventing autogenous heating of low-rank coals is disclosed which comprises crushing the coal into a particle size range from 0.1 cm to 3 cm, immersing the particles in a distillation residuum of petroleum crude oil at a temperature between 240.degree. C. and decomposition temperature of the coal, and draining excess residuum from the particles to give a product preferably containing 2% to 15% by weight of the residuum. Some suitable residua are the vacuum residuum of a hydrogen donor-refined Athabasca bitumen and low-penetration asphalt. The residuum coating material must have a softening point of at least 80.degree. C. The decomposition temperature is defined as the temperature for a particular coal at which its rate of weight loss upon heating first reaches a maximum value, and is in the range of 340.degree. C. to 350.degree. C. for most low-rank coals.

Loading the Abstract Image...

First Claim