New Approach to Coal Preparation of Different Metamorphism Stage

Abstract

The dry beneficiation of coal samples at different metamorphic stages (lignite, coal, anthracite) is compared, before and after heat treatment. By thermal modification of the coal in the absence of air, the unit ash content (the ratio of the ash content to the heat of combustion) may be reduced by a factor of 1.3–1.6. In other words, the ash and slag formation on combustion may be reduced. Intense magnetic and electrostatic separation may be used for dry beneficiation of high-ash fine-grain coal. The removal of the mineral fraction by such methods is more effective after pyrolysis of coal stocks at different metamorphic stages.