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.]] Coal mining is the extraction or removing of Coal from the Earth for use as Fuel . A coal mine and its accompanying structures are collectively known as a '''colliery'''. For the world history see History Of Coal Mining . See also World Coal Reserves and Major Coal Exporters . METHODS OF EXTRACTION The most economical method of coal extraction from coal seams depends on the depth and quality of the seams, and also the geology and environmental factors of the area being mined. Coal mining processes are generally differentiated by whether they operate on the surface or underground. Many coals extracted from both surface and underground mines require washing in a Coal Preparation Plant . Surface and mountaintop mining coal mine.]] If the coal seams are near the surface, the coal is extracted by Strip Mining . Strip mining exposes the coal by the advancement of an open pit or strip. As the coal is exposed and extracted, the Overburden from the still-covered coal fills the former pit, and the strip progresses. Most open cast mines in the United States extract Bituminous Coal . In South Wales open casting for Steam Coal and Anthracite is practiced. Mountaintop Removal is a form of surface mining that takes place at the topmost portion of a mountain, and is a technique that is commonly applied in Appalachia . Utilized for the past 30 years, mountaintop mining involves removing the highest part of the mountain for the maximum recovery of coal. The process is highly controversial for the drastic changes in topography, the practice of ''hollow fills'', or filling in valleys with mining debris, and for covering streams and disrupting ecosystems. Mountaintop mining Underground mining Most coal seams are too deep underground for open cast mining and thus this type of mining is called underground mining. In deep mining, the Room And Pillar or Board And Pillar method progresses along the seam, while pillars and timber are left standing to support the coal mine roof. A very dangerous method of operation in deep mining is known as ''robbing the pillars'' or Retreat Mining . This is when miners attempt to remove and/or retreat between the timbers in order to get coal out of the main coal seam, allowing the roof to cave in. There are four major underground mining methods:
HISTORY See Also: History of coal mining The oldest continuously worked deep-mine in the UK and possibly the world is Tower Colliery at the northern end of the South Wales Valleys . This colliery was started in 1805 and at the end of the 20th century it was bought out by its miners rather than being allowed to be closed. The World Championships in coal-carrying take place every Easter Monday, at Ossett in West Yorkshire , UK The race starts from the site of the old Savile & Shaw Cross colliery. The first commercial coal mines in the United States were started in 1748 in Midlothian, Virginia , near Richmond, Virginia . Historical Overview Of The Midlothian Coal Mining Company Tract, Chesterfield County, Virginia , Martha W. McCartney, December, 1989 In the 1880s, Coal-cutting machines became available (prior to that, coal was mined underground by hand.) By 1912, Surface Mining was underway with steam shovels specifically designed for coal mining. MODERN MINING IN AMERICA Technological advancements have made Coal mining today more productive than it has ever been. To keep up with technology and to extract coal as efficiently as possible modern mining personnel must be highly skilled and well trained in the use of complex, State-of-the-art instruments and equipment. Future coal miners have to be highly educated and many jobs require four-year college degrees. Computer knowledge has also become greatly valued within the industry as most of the machines and safety monitors are computerized. The increase in technology has significantly decreased the mining workforce from 335,000 coal miners working at 7,200 mines fifty years ago to 104,824 miners working in fewer than 2,000 mines today. As some might see this as a sign that coal is a declining industry its advances has reported an 83% increase of production from 1970 to 2004. These statistics are provided by the National Mining Association . DANGERS TO MINERS Historically, coal mining has been a very dangerous activity. Open cut hazards are principally slope failure, underground mining roof collapse and gas explosions. Most of these risks can be greatly reduced in modern mines, and multiple fatality incidents are now rare in some parts of the developed world. Respiratory Protection in Coal Mines However, in lesser developed countries and some developed countries, many miners continue to die annually, either through direct accidents in coal mines or through adverse health consequences from working under poor conditions. reported 28 deaths in the same yearhttp://www.msha.gov/stats/charts/coalbystate.asp. Coal production in China is twice that of the United Stateshttp://www.worldcoal.org/pages/content/index.asp?PageID=104, while the number of coal miners is around 50 times that of the USA, making deaths in coal mines in China 4 times as common per worker (50 times as common per unit output) as in the USA. When compared to industrial countries such as China, the U.S. fatality rate is low. However in 2006 fatal work injuries among U.S. miners doubled from the previous year, totaling 47. Bureau of Labor Statistics. (2006). Census of Fatal Occupational Injuries Summary, 2006. Washington D.C.: U.S. Department of Labor. Available: http://www.bls.gov/news.release/cfoi.nr0.htm These figures can in part be attributed to the Sago Mine Disaster . The recent mine accident in Utah's Crandall Canyon Mine , where nine miners were killed and six entombed, speaks to the increase in occupational risks faced by U.S. miners.Associated Press. (2007, September 4). Panel to Explore Deadly Mine Accident. New York Times: http://www.nytimes.com/aponline/us/AP-Utah-Mine-Collapse.html. Chronic lung diseases, such as Pneumoconiosis (black lung) were once common in miners, leading to reduced Life Expectancy . In some mining countries black lung is still common, with 4000 new cases of black lung every year in the USA (4% of workers annually) and 10 000 new cases every year in China (0.2% of workers). http://www.abelard.org/briefings/fossil_fuel_disasters.php Rates may be higher than reported in some regions. Build-ups of a hazardous gas are known as damps, possibly from the German word "Dampf" which means steam or vapor:
(See: Mining Accidents ) coal sludge]] SAFER TIMES IN MODERN MINING Improvements in mining methods (e.g. longwall mining), hazardous gas monitoring (such as Safety-lamp s or more modern electronic gas monitors), gas drainage, and ventilation have reduced many of the risks of rock falls, explosions, and unhealthy air quality. Statistical analyses performed by the U.S. Department of Labor’s Mine Safety And Health Administration (MSHA) show that between 1990 and 2004, the industry cut the rate of injuries by more than half and fatalities by two-thirds. However according to the Bureau Of Labor Statistics , mining remains the second most dangerous occupation in America.http://stats.bls.gov/iif/oshwc/cfoi/cfch0005.pdf ENVIRONMENTAL IMPACTS AND MITIGATION Coal mining causes adverse environmental impacts. These include: # Release of Methane , a dangerous Greenhouse Gas # Interference with Groundwater and Water Table levels # Impact of water use on flows of rivers and consequential impact on other land-uses # Dust # Subsidence above tunnels, sometimes damaging infrastructure (e.g., roads in the Lake Macquarie area in NSW, Australia). # Rendering land unfit for the common usage of the area. In addition, burning of coal, mainly for power generation, introduces a large amount of carbon dioxide into the atmosphere. Strip mining severely alters the landscape, which damages Environmental value in the surrounding land. Mountaintop Removal to remove coal is a large negative change to the environment. While there are sometimes requirements for remediation of the strip mined area, the remediation is often delayed for decades. One of the legacies of coal mining is the low coal content waste forming Boney Piles . In response to negative land effects of coal mining and the abundance of abandoned mines in the USA, the federal government enacted the Surface Mining Control And Reclamation Act Of 1977 (SMCRA), which requires Reclamation plans for future coal mining sites. Reclamation plans must be approved and permitted by federal or state authorities before mining begins. As of 2003, over 2 million acres (8000 km&2) of previously mined lands have been reclaimed in the United States . All forms of mining are likely to generate areas where coal is stacked and where the coal has significant Sulphur content, such coal heaps generate highly acidic, metal-laden drainage when exposed to rainfall. These liquors can cause severe environmental damage to receiving water-courses. Coal mining releases approximately twenty toxic release chemicals, of which 85% is said to be managed on site. In modern mining, operations must, under federal and state law, meet standards for protecting surface and ground waters from contamination, including Acid Mine Drainage (AMD). To mitigate these problems, water is continuously monitored at coal mines. The five principal technologies used to control water flow at mine sites are: diversion systems, containment ponds, groundwater pumping systems, subsurface drainage systems, and subsurface barriers. In the case of AMD, contaminated water is generally pumped to a treatment facility that neutralizes the contaminants. Still, AMD remains a large problem, emanating from coal mines abandoned in the United States prior to SMCRA. It is also thought that coal mining is harmful to the quality of air in the surrounding regions. While burning of coal in power plants is most harmful to air quality, the process of mining can release pockets of hazardous gases. These gases may pose a threat to coal miners as well as a minor source of air pollution. In recent years, there has also been concern for the safety of miners who work in subsurface coal mines. NOTES REFERENCES
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