Table 2.

Classification of coal rank by ASTM D388 [2].

Class	Group	Fixed carbon limits* [%]	Volatile matter limits* [%]	Gross calorific value limits**		Agglomerating character
				[Btu/lb]	[MJ/kg]
Anthracite	Meta-anthracite	≥98	≤2	–	–	Non-agglomerating
	Anthracite	92–98	2–8	–	–
	Semi-anthracite	86–92	8–14	–	–
Bituminous	Low volatile bituminous coal	78–86	14–22	–	–	Commonly agglomerating
	Medium volatile bituminous coal	69–78	22–31	–	–
	High volatile A bituminous	≤69	≥31	≥14,000	≥32.6
	High volatile B bituminous coal	–	–	13,000–14,000	30.2–32.6
	High volatile C bituminous coal	–	–	11,500–13,000	26.7–30.2
Subbituminous	Subbituminous A	–	–	10,500–11,500	24.4–26.7	Non-agglomerating
	Subbituminous B	–	–	9500–10,500	22.1–24.4
	Subbituminous C	–	–	8300–9500	19.3–22.1
Lignite	Lignite A	–	–	6300–8300	14.7–19.3	Non-agglomerating
	Lignite B	–	–	≤6300	≤14.7

Note: * dry, mineral-matter-free basis.

** moist, mineral-matter-free basis.