caking coal

Caking coal is a type of bituminous coal that softens, swells, and forms a plastic mass when heated. This plastic mass then resolidifies into a porous solid. Coals that exhibit strong caking properties and produce a solid product suitable for use in blast furnaces are known as coking coals.1

When heated to high temperatures out of contact with air, caking coals undergo carbonization, a process that drives off volatile constituents and leaves behind a solid residue primarily composed of carbon. This residue is called coke. The thermoplastic properties of caking coal are influenced by its petrographic composition, with different components like liptinite and vitrinite exhibiting varying degrees of fluidity. While these properties are beneficial for coke making and liquefaction, they can be problematic during combustion and gasification, potentially causing blockages.21