Question

What are the different varieties of coal.

Answer 1

• Coal is a black, hard amorphous form of carbon and the cheapest source of power fuel contributing to almost 40% of the world's electricity production.
• The formation of coal goes back to 300 million years ago when the Earth was enveloped with swampy forests.
• With the passage of time, the plants, tress, mosses, and ferns died and fell into these swamps resulting in the formation of thick layers of dead vegetation.
• After the decomposition of this organic matter under high pressure, high temperature, and absence of air the carbon-rich deposit was formed.
• Based on the carbon content present, there are different varieties of coal namely: anthracite, lignite, bituminous, sub-bituminous, and peat.
• Among these anthracite bearing the highest rank of coal contains a high concentration of carbon and is hard.
• While lignite is the softest and considered as lowest grade coal as it is having low carbon concentration.
• Bituminous and sub-bituminous have a moderate level of carbon concentration.