Chemical composition of the coal is defined in terms of its proximate and ultimate (elemental) analyses. The parameters of proximate analysis are
moisture,
volatile matter, ash, and fixed carbon. Elemental or ultimate analysis encompasses the quantitative determination of
carbon,
hydrogen,
nitrogen,
sulfur and
oxygen within the coal. Additionally, specific physical and mechanical properties of coal and particular
carbonization properties 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.
Q can be determined
experimentally using calorimeters.
Dulong suggests the following approximate formula for
Q when the oxygen content is less than 10%: :
Q = 337
C + 1442(
H -
O/8) + 93
S, where
C is the mass percent of carbon,
H is the mass percent of hydrogen,
O is the mass percent of oxygen, and
S is the mass percent of sulfur in the coal. With these constants,
Q is given in kilojoules per kilogram. ==See also==