User:Milton Beychok/Sandbox

Classification of Coals by Rank ^(a)

Class or Rank	Group	Fixed Carbon (b) (wt % dry mmf)		Volatile Matter (b) (wt % dry mmf)		Gross Heating Value (c) (Btu/lb moist mmf)
		Equal or greater than	Less than	Greater than	Equal or less than	Equal or greater than	Less than
Anthracitic	Metaanthracite (d) Anthracite (d) Semianthracite (d)	98 92 86	98 92	2 8	2 8 14
Bituminous	Low-volatile bituminous (d) Medium-volatile bituminous (d) High-volatile A bituminous High-volatile B bituminous High-volatile C bituminous High-volatile C bituminous	78 69	86 78 69	14 22 31	22 31	14,000 13,000 11,500 10,500	14,000 13,000 11,500
Subbituminous	Subbituminous A Subbituminous B Subbituminous C					10,500 9,500 8,300	11,500 10,500 9,500
Lignite	Lignite A Lignite B					6,300	8,300 6,300
(a) This classification does not inclued a few coals (referred to as unbanded coals) having unusual physical and chemical properties falling within the fixed carbon and heating value ranges of the high-volatile bituminous and subbituminous ranks. (b) Percentage by weight on a dry and mineral matter free basis (mmf). (c) Gross Heating Value on a moist and mineral matter free basis. Moist refers to the natural inherent water contained in a coal but does not include visible water (if any) on the surface of the coal. Multiply Btu/lb by 0.002326 to convert to MJ/kg. (d) Coals containing 69 wt % or more fixed carbon on a dry mmf basis are ranked according to their fixed carbon content regardless of their Gross Heating Value.