knowledge

COAL

Coal, a commonly used fuel, is obtained from the coal mines. These mines are many miles wide and the coal is found in thick, flat layers. The thickness of these layers varies from a few centimeters to a few meters. Thousands of  laborers and engineers equipped with machines work in these mines round the clock.  Do you know how the coal was formed?

Coal information first began some 250 years ago in an age called ‘carboniferous period’. During that period our earth had many swamps. Fast growing plants and giant tree ferns grew in them. In time they died and fell in to the quiet swamp water. They did not completely rot away because enough air was not available there. Bacteria changed the tree parts into a slimy material called peat. Over the centuries, this peat was compressed by mud and sand. The peat-beds were first turned into lignite by heat and pressure of the earth layers and finally into the hard coal. In this way coal was formed in many layers inside the earth. Today we have to dig to great depths to obtain it.

         

          This theory about the coal-information is based on the fact that fern’s impressions are found within the coal. Sometimes patterns of bark are also seen on it, which again proves that it is formed from the remains of trees, plants and shrubs millions of years ago.

Coal mining is a very difficult job. First of all, the dirt above the coal deposit is removed. When the coal is exposed, explosives are used to break it into smaller pieces. Practically all of it has to be mined through machines and explosives are used to break it into smaller pieces. Practically all of it has to be mined through machines and explosives. The coal thus removed is loaded into a wagon and lifted to the surface. The miners enter and leave the mine by an elevator through a vertical space called shaft. Coal mines catch fire easily. When a mine catches fire it is very difficult to extinguish it. Hence that portion of the mine is isolated from the rest to prevent the fire from spreading.

In India coal mines exist in Andhra Pradesh, Bihar, West Bengal, Rajasthan, Maharashtra, Orissa, Assam, Jammu Kashmir, Madhya Pradesh etc. About 3 billion tons of coal is mined every year in the whole world. In India only about 100 million tones of coal is mined every year.