How Is Coal Formed? The Complete Guide To Coal Formation
Bituminous coal is dense and mediumgrade coal that has a higher heating value than lignite and subbituminous coal. Bituminous coal contains 4586% carbon and is between 100300 million years old. Anthracite is hard, shiny, and nonporous coal that burns slowly with a blue flame and little smoke. It is the hardest and densest form of coal ...