LLB, Chief Operations Officer
It is derived from plants that once formed lush vegetation in swamps or lagoons. The plants, when they died, were partially decomposed by microorganisms and buried by other sediment that protected them from total destruction. At the volatile components were released, the carbon became concentrated and the plant accumulations successively passed through the stages of tuba, lignite (hard coal) and eventually, graphite if geological conditions favored their metamorphism.
Lignite or brown coal
Composition of coal
The main components of coal are macerals and ashes. The are macerated but still recognizable plant remains, which make up the organic part of the charcoal.
Three types are distinguished:
Huminite, is the main group in most coals and comes from the woody tissues of plants.
Liptinite, appears in smaller proportion than the previous group and comes from resinous and waxy parts of plants.
Inertinite is the scarcest component in coals and is practically inert throughout the carbonization process.
A typical bituminous coal may have an ultimate analysis on a dry, ash-free basis of 84.4% carbon, 5.4% hydrogen, 6.7% oxygen, 1.7% nitrogen, and 1.8% sulfur, on a weight basis.
Ash Composition, Weight percent
Na2O & K2O