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The kilogram per cubic metre (symbol: kg·m −3, or kg/m 3) is the unit of density in the International System of Units (SI). It is defined by dividing the SI unit of mass, the kilogram, by the SI unit of volume, the cubic metre. [1]
Its bank density (the density of a coal seam prior to breaking up during mining) is about 1346 kg/m 3 (84 lb/ft 3) while the bulk density of extracted coal is up to 833 kg/m 3 (52 lb/ft 3). [12] Bituminous coal characteristically burns with a smoky flame and softens and swells during combustion. [13]
Density system unit unit-code symbol or abbrev. notes sample default conversion combination output units Metric: kilogram per cubic metre: kg/m3 kg/m 3: 1.0 kg/m 3 (1.7 lb/cu yd)
The energy density of coal is roughly 24 megajoules per kilogram [80] (approximately 6.7 kilowatt-hours per kg). For a coal power plant with a 40% efficiency, it takes an estimated 325 kg (717 lb) of coal to power a 100 W lightbulb for one year.
Relative density or specific gravity of the coal depends on the rank of the coal and degree of mineral impurity. Knowledge of the density of each coal play is necessary to determine the properties of composites and blends. The density of the coal seam is necessary for conversion of resources into reserves.
The calorific value Q of coal [kJ/kg] is the heat liberated by its complete combustion with oxygen. Q is a complex function of the elemental composition of the coal [citation needed]. Q can be determined experimentally using calorimeters. Dulong suggests the following approximate formula for Q when the oxygen content is less than 10%:
Anthracite, also known as hard coal and black coal, is a hard, compact variety of coal that has a submetallic lustre.It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the highest ranking of coals.
Densities using the following metric units all have exactly the same numerical value, one thousandth of the value in (kg/m 3). Liquid water has a density of about 1 kg/dm 3, making any of these SI units numerically convenient to use as most solids and liquids have densities between 0.1 and 20 kg/dm 3. kilogram per cubic decimetre (kg/dm 3)