https://en.wikipedia.org/wiki/Bituminous_coal

Bituminous coal or black coal is a relatively soft coal containing a tarlike substance called bitumen or asphalt. It is of higher quality than lignite coal but of poorer ...

http://www.chemistryexplained.com/Ce-Co/Coal.html

(The composition of a bituminous coal by percentage is roughly: carbon [C], 75– 90; hydrogen [H], 4.5–5.5; nitrogen [N], 1–1.5; sulfur [S], 1–2; oxygen[O], 5–20; ...

http://www.coaleducation.org/q&a/what_are_the_chemical.htm

Coal is not a homogenous substance meaning it has no fixed chemical formula. ... Coals are classified into three main ranks, or types: lignite, bituminous coal, ...

https://www.purdue.edu/discoverypark/energy/assets/pdfs/cctr/outreach/Basics8-CoalCharacteristics-Oct08.pdf

NS for Bituminous Coal. C. 240. H. 90 ... anthracite forms from bituminous coal when great ... less than 1000 ppm [<0.1% of a rock's composition] of zinc, copper, .

https://www.britannica.com/science/bituminous-coal

Bituminous coal, also called soft coal, the most abundant form of coal, intermediate in rank between subbituminous coal and anthracite according to the coal ...

https://www.thebalance.com/bituminous-coal-characteristics-applications-1182545

The most common type of coal consumed in the U.S. is bituminous. Here's info about its unique characteristics and applications in energy production.

http://science.jrank.org/pages/1533/Coal-Composition-coal.html

Coal is classified according to its heating value and according to its relative content of elemental carbon. For example, anthracite contains the highest proportion ...

https://www.sciencedirect.com/topics/engineering/bituminous-coal

Bituminous coal was formed by added heat and pressure on lignite and is the .... The chemical composition of this fly ash or pfa is dependent upon the 'rank' of ...

https://geology.com/rocks/coal.shtml

Coal is a biological sedimentary rock that forms from plant debris. ... Based upon composition and properties, coals are assigned to a rank progression that ...

https://www.mindat.org/min-11368.html

A coal with between 75-90% carbon content dry ash free and between 14-46% volatiles. A 'soft' coal, often containing substantial admixed sulfur. It is of ...