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…
Sub-bituminous C
Sub-bituminous C is a specific rank of coal that plays a quiet but important role in global energy systems. Positioned between lignite and higher-rank bituminous coals, sub-bituminous C combines relatively…
Sub-bituminous B
Sub-bituminous B coal is a low- to medium-rank thermal coal that plays an important role in contemporary energy systems, particularly for power generation. It sits between lignite and bituminous coal…
