Coal is usually ranked according to the Carbon content of the coal.
Anthracite is 86-97% carbon, Bituminous is 45-86%,
Subbituminous is 35-35%, Lignite is 25-35%.
Coal is usually ranked according to the Carbon content of the coal. Anthracite is 86-97% carbon, Bituminous is 45-86%, Subbituminous is 35-35%, Lignite is 25-35%.