Coal
Coal is a generally known as a fossil fuel formed as a result of the thriving ecosystem over the years where plant remains were hoarded by water and mud from the process of oxidation of the material and constant biodegradation. Coal is a willingly Combustible fuel source. The emission in the likes of coal is slightly higher than petroleum. The fossil fuels are extracted by means of mining. The hauling of the fuel is essentially carried out in terms of deep pit mines. Usage of coal as a fuel is almost obsolete over the years apart from the very few industries that still continue to use it for their highly price advantageous sense.
How Is Coal Mined ?
There are two basic ways to mine coal:
Surface mining : is used when coal is found close to the surface or on hillsides. It involves removing the topsoil and subsoil and setting them aside. Machines such as draglines, wheel excavators, and large shovels remove the earth and rock and uncover the coal. This removed material is called overburden. After the coal is removed and loaded into trucks, the area is refilled with the overburden, covered with the soils that were removed, and reseeded. To the extent possible, the area is restored to its original condition or improved.
Underground mining : is used to extract coal that is deep beneath the surface or in seams exposed on hillsides. It involves drilling two openings called shafts into the coal bed—one to transport miners and equipment, and the other to bring coal to the surface. Next, the coal is broken into manageable sizes and mined by Conventional mining, or using explosives to break up a coal seam; Continuous mining, or using machines with large, rotating cutters that break into the coal and with arms that scoop the coal onto a built-in conveyor; or Long wall mining, or using cutting machines that work along walls of coal up to 1,000 feet long to cut coal and drop it onto a conveyor belt.
Lignite (soft): This type of coal contains a lot of moisture and ash and breaks apart easily. Of the four types, lignite has the lowest carbon content and heating value. Also called brown coal, lignite is used mainly at electricity-generating plants.
Sub bituminous (medium-soft): This dull black coal has less moisture than lignite. Sub bituminous is generally used to produce steam for electricity generation. Reserves of sub bituminous coal are found mostly in western states and Alaska.
Bituminous (medium-hard): This type of coal, which contains very little moisture, has high heat value. It is used to generate electricity and to produce coke, a coal residue used in the steel industry. Bituminous coal is the most plentiful type in the United States.
Anthracite (hard): This type of coal has the highest carbon content and the lowest moisture and ash content. Anthracite burns slowly and makes a good heating fuel for homes. The United States has about 7.3 billion tons of anthracite, most of which can be found in Pennsylvania.