Lignite
This article explores lignite — the lowest-rank form of coal often called “brown coal” — examining its geological origins, physical and chemical properties, where it occurs and is mined, its…
Low-volatile bituminous coal
Low-volatile bituminous coal is a high-rank coal grade prized for its elevated carbon content, strong coking properties and relatively low volatile matter. This article examines its geological characteristics, global distribution,…
High-volatile bituminous coal
High-volatile bituminous coal occupies an important place among the ranks of coal used around the world. This article summarizes its geological characteristics, where it occurs and is mined, economic and…
Bituminous coal
Bituminous coal is one of the most important and widely used ranks of coal worldwide. It occupies an intermediate position in the coalification scale between sub-bituminous coal and anthracite, combining…





