Why mine coal

The alternative name was 'pitcoal', because it came from mines. As steam engines took over from water wheels during the Industrial Revolution large-scale mining and use of coal grew. In , five-sixths of the world's coal was mined in Britain. In Australia, black coal was first discovered in Newcastle in and coal mining and exports commenced in These early coal mining activities made a significant contribution to the progress of European settlement in Australia.

The spread of settlers to other locations in Australia lead to further discoveries. Knowledge of the existence of brown coal in Victoria dates back to and the Yallourn North open-cut began production in In , Taronga Zoo was to be the site of an underground coal mine until the mining company was stopped by Parliament.

Instead, coal was mined in Balmain until Coal is formed in sedimentary basins. Sedimentary basins are regions where the Earth has subsided or sunk down. Water and sediments then flow into the basin and they fill with layers of sediments. Australia's black coal resources range from Permian to Jurassic in age to million years old , although most are Permian in age.

During this time, the climate was warm in Australia, and Eastern Australia, including the Sydney Basin was covered by large, meandering rivers, marshes, bogs and swamps. The sediments deposited in these environments eventually formed rocks such as shale, sandstone and coal.

Brown coal in Australia formed more recently than the black coals. These are mostly of Paleogene age 66 to 23 million years old. Coal is a sedimentary rock formed when abundant plant material is covered by sediments and the material accumulates faster than it can decay. The weight of the overlying sediments compacts the organic layers, increasing the temperature and pressure, which leads to physical and chemical changes to the plant material.

Water, carbon dioxide and methane are produced and escape, so the material becomes progressively enriched in carbon. With increasing time, and higher heat and pressure, the plant material first forms into peat, then is converted into brown coal, then sub-bituminous coal, bituminous coal, and lastly anthracite.

Australia has the fourth-largest share of coal reserves in the world. Since the late s about million tonnes of black coal and about million tonnes of brown coal have been mined in Australia and the industry still provides significant employment, capital investment and domestic and export income to the national economy.

These two states are also the largest coal producers. Locally important black coal mining operations also include Collie in Western Australia, and Fingal and Kimbolton in Tasmania. The Gippsland Basin in Victoria contains a substantial world-class deposit where seams can be up to m thick.

Minor resources occur in Tasmania's Longford Basin. Currently, brown coal is only mined in Victoria where the open-cut mines at Loy Yang and Yallourn supply coal to nearby power stations. Brown coal is also mined at Maddingley to produce soil conditioners and fertilisers. Other products from Victorian brown coal are briquettes for industrial and domestic use and low-ash and low-sulphide char products.

This destroys aquatic ecosystems and water supplies that communities depend on for drinking and agriculture. During mining operations, enormous amounts of groundwater are drained from aquifers so mining companies can access coal seams — up to 10, litres per tonne of coal. This extraction will drastically lower the water table, rendering local wells unusable and impacting nearby rivers.

Open cut mines also result in massive erosion and sedimentation of streams, wetlands and rivers. Today communities around the world — in countries as diverse as China, India, the United States, Indonesia, Australia, Colombia and South Africa — are rising up to oppose new coal mines and demand reparations and restoration for the impacts to their livelihoods and the natural environment.

This report provides estimates of the health impacts and associated economic costs of current emissions of air pollutants from coal fired power stations in South Africa. Toggle navigation. Coal Mining Hunter Valley, Australia. Coking coal is used in large-scale industrial processes. The coal is coke d, a process of heating the rock in the absense of oxygen.

This reduces the moisture content and makes it a more stable product. The steel industry relies on coking coal. Bituminous coal accounts for almost half of all the coal that is used for energy in the United States. It is mainly mined in Kentucky, Pennsylvania, and West Virginia. Anthracite Anthracite is the highest rank of coal.

It is harder, more dense, and more lustrous than other types of coal. Almost all the water and carbon dioxide have been expelled, and it does not contain the soft or fibrous sections found in bituminous coal or lignite.

Because anthracite is a high-quality coal, it burns cleanly, with very little soot. It is more expensive than other coals, and is rarely used in power plants. Instead, anthracite is mainly used in stoves and furnaces. Anthracite is also used in water- filtration systems. It has tinier pores than sand, so more harmful particles are trapped.

This makes water safer for drinking, sanitation , and industry. Anthracite can typically be found in geographical areas that have undergone particularly stressful geologic activity.

For example, the coal reserves on the Allegheny Plateau in Kentucky and West Virginia stretch to the base of the Appalachian Mountains. Here, the process of orogeny , or mountain formation, contributed to temperatures and pressures high enough to create anthracite.

China dominates the mining of anthracite, accounting for almost three-quarters of anthracite coal production. Graphite Graphite is an allotrope of carbon, meaning it is a substance made up only of carbon atoms.

Diamond is another allotrope of carbon. Graphite is the final stage of the carbonization process. Graphite conducts electricity well, and is commonly used in lithium ion batteries. It can be used in products such as fire-resistant doors, and missile parts such as nose cones. Coal Mining Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly for heating and industrial processes or to fuel power plants for electricity.

Surface Mining If coal is less than 61 meters feet underground, it can be extracted through surface mining. In surface mining, workers simply remove any overlying sediment, vegetation, and rock, called overburden.

Economically, surface mining is a cheaper option for extracting coal than underground mining. About two and a half times as much coal can be extracted per worker, per hour, than is possible with underground mining. The environmental impacts of surface mining are dramatic. The landscape is literally torn apart, destroying habitats and entire ecosystem s.

Surface mining can also cause landslide s and subsidence when the ground begins to sink or cave in. Toxic substances leach ing into the air, aquifer s, and water table s may endanger the health of local residents. In the United States, the Surface Mining Control and Reclamation Act of regulates the process of coal mining, and is an effort to limit the harmful effects on the environment.

The act provides funds to help fix these problems and clean up abandoned mining sites. The three main types of surface coal mining are strip mining, open-pit mining, and mountaintop removal MTR mining. Surface Mining: Strip Mining Strip mining is used where coal seams are located very near the surface and can be removed in massive layers, or strips.

Overburden is usually removed with explosives and towed away with some of the largest vehicles ever made. Dump trucks used at strip mines often weigh more than tons and have more than 3, horsepower. Strip mining can be used in both flat and hilly landscapes. Strip mining in a mountainous area is called contour mining.

Contour mining follows the ridges, or contours, around a hill. A pit, sometimes called a borrow, is dug in an area. This pit becomes the open-pit mine , sometimes called a quarry. Open-pit mines can expand to huge dimensions, until the coal deposit has been mined or the cost of transporting the overburden is greater than the investment in the mine.

Open-pit mining is usually restricted to flat landscapes. After the mine has been exhausted, the pit is sometimes converted into a landfill. After the summit is cleared of vegetation, explosives are used to expose the coal seam. After the coal is extracted, the summit is sculpted with overburden from the next mountaintop to be mined. By law, valuable topsoil is supposed to be saved and replaced after mining is done. Barren land can be replanted with trees and other vegetation.

Mountaintop removal began in the s as a cheap alternative to underground mining. It is now used for extracting coal mainly in the Appalachian Mountains of the U.

MTR is probaby the most controversial coal mining technique. The environmental consequences are radical and severe. Waterways are cut off or contaminated by valley fill. Habitats are destroyed. Toxic byproduct s of the mining and explosive processes can drain into local waterways and pollute the air.

Miners travel by elevator down a mine shaft to reach the depths of the mine, and operate heavy machinery that extracts the coal and moves it above ground. The immediate environmental impact of underground mining appears less dramatic than surface mining.

There is little overburden, but underground mining operations leave significant tailings. Tailings are the often-toxic residue left over from the process of separating coal from gangue , or economically unimportant minerals. Toxic coal tailings can pollute local water supplies. To miners, the dangers of underground mining are serious. Underground explosions, suffocation from lack of oxygen, or exposure to toxic gases are very real threats.

To prevent the buildup of gases, methane must be constantly ventilated out of underground mines to keep miners safe. There are three major types of underground coal mining: longwall mining, room-and-pillar mining, and retreat mining. Underground Mining: Longwall Mining During longwall mining , miners slice off enormous panels of coal that are about 1 meter 3 feet thick, kilometers The panels are moved by conveyor belt back to the surface.

The roof of the mine is maintained by hydraulic supports known as chock s. As the mine advances, the chocks also advance. The area behind the chocks collapses. Longwall mining is one of the oldest methods of mining coal. Before the widespread use of conveyor belts, ponies would descend to the deep, narrow channels and haul the coal back to the surface. Today, almost a third of American coal mines use longwall mining.

Columns pillars of coal support the ceiling and overburden. Transporting coal can be more expensive than the cost of mining coal. Some coal consumers, such as coal-fired electric power plants, are near coal mines to lower transportation costs. Coal explained Mining and transportation of coal.

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