What is coal describe its typ …

Coal is a hard, black, combustible mineral that consists mainly of carbon. It is found in deep coal mines under the surface of the earth.

The following types of coal have been identified according to their physical properties:

(i) Peat Coal:
This is the first stage in the change of wood to coal. It is light brown and friable. Producer gas is manufactured from peat. It is also known as brown coal.

(ii) Lignite Coal:
Lignite burns with much smoke and flame. The first product is lignite coal which ranges in colour from yellow to dark brown, and is still rich in volatile constituents. About half of the world’s lignite is mined in Germany.(iii) Bituminous Coal:
Bituminous coals are subdivided into coking and non-coking coals and each one of them in turn is divided into gas coal and steam coal. Coking coal is used for coke-making domestic fuel, the soft coke.

It contains a higher percentage of carbon (70-75%) and less water and oxygen than lignite.

(iv) Anthracite Coal:
Anthracite coal is the last stage in coal formation. It is extremely hard, and has a brilliant black lustre. It has the highest carbon content (80-90%) and produces practically no smoke or flame. Among the nations of the world, only China and the United States have appreciable deposits of anthracite.