Coal the heat and pressure of deep burial causes the loss of water, methane and carbon dioxide and an increase in the proportion of carbon. Thus first lignite (also called "brown coal"), then sub-bituminous coal, bituminous coal, and lastly anthracite (also called "hard coal" or "black coal") may be formed. The wide, shallow seas of the Carboniferous Period provided ideal conditions for coal formation, although coal is known from most geological periods. The exception is the coal gap in the Permian–Triassic extinction event, where coal is rare. Coal is known from Precambrian strata, which predate land plants—this coal is presumed to
Coal burner coal burners have a wide range of uses in industrial production and daily life, such as providing heat for boilers, hot mix asphalt plant, cement kiln, metal furnace, annealing, quenching furnace, precision casting shell burning furnace, melting furnace, forging furnace and other heating furnace or kiln. "Note: These indexes are the lowest requirements for the coal, the better coal will be better at practice." Coal burner A coal burner (or pulverized coal burner) is a mechanical device that burns pulverized coal (also known as powdered coal or coal dust since it is as fine as face powder in cosmetic makeup)