subbituminous
/ˌsʌbˈbɪtʃʊmɪnəs/
adjective
- Describing a type of coal that is between lignite and bituminous coal in rank, with a lower carbon content and heating value than bituminous coal.
- The mine produces mostly subbituminous coal from the Powder River Basin.
- Subbituminous coal has a higher moisture content than bituminous coal.
- Subbituminous coal is often used in power plants because it burns cleaner than other types.