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 Bihar ,
West Bengal , Rajasthan, Maharashtra , Orissa ,
Assam India
