Surface mining is a type of mining in which soil and rock overlying the mineral deposit are removed. The State of Wyoming ( is a sparsely populated state in the western region of the United States. Mining is the extraction of valuable Minerals or other geological materials from the earth usually (but not always from an Ore body It is the opposite of underground mining, in which the overlying rock is left in place, and the mineral removed through shafts or tunnels.
Surface mining is used when deposits of commercially useful minerals or rock are found near the surface; that is, where the overburden (surface material covering the valuable deposit) is relatively thin or the material of interest is structurally unsuitable for tunneling (as would usually be the case for sand, cinder, and gravel). A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere Sand is a naturally occurring Granular material composed of finely divided rock and Mineral particles A cinder is a pyroclastic material Cinders are extrusive Igneous rocks Cinders are similar to Pumice, which has so many cavities and is such low-density Gravel is rock that is of a specific Particle size range In Geology, gravel is any loose rock that is larger than two millimeters (2mm Where minerals occur deep below the surface—where the overburden is thick or the mineral occurs as veins in hard rock— underground mining methods are used to extract the valued material. Surface mines are typically enlarged until either the mineral deposit is exhausted, or the cost of removing larger volumes of overburden makes further mining uneconomic.
In most forms of surface mining, heavy equipment, such as earthmovers, first remove the overburden - the soil and rock above the deposit. Engineering vehicles, known by the other terms construction Equipment, earth movers heavy equipment or just plain equipment are machines specifically designed to execute Overburden is the term used in Mining to describe material that lies above the area of economic interest e Next, huge machines, such as dragline excavators, extract the mineral. Dragline excavation systems are Heavy equipment used in Civil engineering and surface Mining.
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Types of surface mining
There are five main forms of surface mining, detailed below.
Strip mining
Strip mining is the practice of mining a seam of mineral by first removing a long strip of overlying soil and rock (the overburden). Mining is the extraction of valuable Minerals or other geological materials from the earth usually (but not always from an Ore body Overburden is the term used in Mining to describe material that lies above the area of economic interest e It is most commonly used to mine coal or tar sand. Strip mining is only practical when the ore body to be excavated is relatively near the surface. This type of mining uses some of the largest machines on earth, including bucket-wheel excavators which can move as much as 12,000 cubic meters of earth per hour. Bucket-wheel excavators are Heavy equipment used in Surface mining and Civil engineering.
There are two forms of strip mining. The more common method is area stripping, which is used on fairly flat terrain, to extract deposits over a large area. As each long strip is excavated, the overburden is placed in the excavation produced by the previous strip.
Contour stripping involves removing the overburden above the mineral seam near the outcrop in hilly terrain, where the mineral outcrop usually follows the contour of the land. Outcrop is a geological term referring to the appearance of Bedrock or Superficial deposits exposed at the surface of the Earth Outcrop is a geological term referring to the appearance of Bedrock or Superficial deposits exposed at the surface of the Earth Contour stripping is often followed by auger mining into the hillside, to remove more of the mineral. An auger is a device for moving material or liquid (see Archimedes' screw) by means of a rotating Helical flighting This method commonly leaves behind terraces in mountainsides.
Among others, strip mining is used to extract the oil-impregnated sand in the Athabasca Tar Sands in Alberta. The Athabasca Oil Sands (also known as the Athabasca Tar Sands) are large deposits of Bitumen, or extremely Heavy crude oil, located in northeastern Alberta (ælˈbɝtə is one of Canada's prairie provinces. It became a province on September 1 1905 It is also common in coal mining. Bucket excavators are widely used for this purpose, however, they are prone to damage and require many millions of dollars to repair.
Open-pit mining
Open-pit mining refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow. Open-pit mining, also known as opencast mining and open-cut mining and strip mining, refers to a method of extracting rock or Minerals Silver City is a town in Grant County, New Mexico, in the United States. Open-pit mining, also known as opencast mining and open-cut mining and strip mining, refers to a method of extracting rock or Minerals In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific A borrow pit, also known as a sand box is a term used in Construction and Civil engineering. Although open-pit mining is sometimes mistakenly referred to as "strip mining", the two methods are different (see above).
Mountaintop removal
Mountaintop removal mining (MTR) is a relatively new form of coal mining that involves the mass restructuring of earth in order to reach the coal seam as deep as 1,000 feet below the surface. Mountaintop removal mining ( MTR) often referred to in the industry as mountaintop mining/valley fills (MTM/VF is a form of Surface mining that involves an Mining is the extraction of valuable Minerals or other geological materials from the earth usually (but not always from an Ore body It is used where a coal seam outcrops all the way around a mountain top. Outcrop is a geological term referring to the appearance of Bedrock or Superficial deposits exposed at the surface of the Earth All the rock and soil above the coal seam are removed and the soil placed in adjacent lows such as hollows or ravines. Mountaintop removal replaces previously steep topography with a relatively level surface.
The technique has been used increasingly in recent years in the Appalachian coal fields of West Virginia, Kentucky, Virginia and Tennessee in the United States. West Virginia ( is a state in the Appalachian Upland South, and Mid-Atlantic regions of the United States, bordered by The Commonwealth of Kentucky ( is a state located in the East Central United States of America. The Commonwealth of Virginia ( is an American state Tennessee ( is a state located in the Southern United States. The United States of America —commonly referred to as the The profound changes in topography and disturbance of pre-existing ecosystems have made mountaintop removal highly controversial.
Advocates of mountaintop removal point out that once the areas are reclaimed as mandated by law, the technique provides premium flat land suitable for many uses in a region where flat land is at a premium. They also maintain that the new growth on reclaimed mountaintop mined areas is better able to support populations of game animals. [1]
Critics contend that mountaintop removal is a disastrous practice that benefits a small number of corporations at the expense of local communities and the environment. Local community is a geographically defined Community of place, a group of people living close to each other See also Nature The natural environment, commonly referred to simply as the environment, is a terminology that is comprised of all living and A U.S. Environmental Protection Agency environmental impact statement finds that streams near valley fills from mountaintop removal contain high levels of minerals in the water and decreased aquatic biodiversity. An environmental impact statement, in the United States, is a document that must be filed when the federal government takes a "major Federal action significantly Biodiversity is the variation of Life forms within a given Ecosystem, Biome or for the entire Earth. [2] The statement also estimates that 724 miles of Appalachian streams were buried by valley fills from 1985 to 2001. [2]
In common with other methods of coal mining, processing the coal mined by mountaintop removal generates waste slurry (also called coal sludge), which is usually stored behind a dam on-site. Many coal slurry impoundments in West Virginia exceed 500 million gallons in volume, and some, including the Brushy Fork impoundment in Raleigh County, exceed 7 billion gallons. A coal slurry impoundment consists of solid and liquid Waste and is a By-product of the Coal mining and preparation processes Raleigh County, founded in 1850 is located in the US state of West Virginia. [3] Such impoundments can be hundreds of feet high and be in close proximity to schools or private residences. [4] The most controversial sludge dam at present sits 400 yards above Marsh Fork Elementary School. The sludge pond is permitted to hold 2. 8 billion gallons of toxic sludge, and is 21 times larger than the pond which killed 125 people in the Buffalo Creek Flood. The Buffalo Creek Flood was an incident that occurred on February 26, 1972 when a Coal Slurry impoundment Dam #3 on a hillside [5]
Kentucky's Martin County Sludge Spill occurred after midnight on October 11, 2000 when a coal sludge impoundment broke through into an underground mine below, propelling 306 million gallons of sludge down two tributaries of the Tug Fork River. The Martin County Sludge Spill was an accident that occurred after midnight on October 11, 2000 when a coal sludge impoundment owned by Massey Energy Events 1138 - A massive earthquake struck Aleppo, Syria. 1531 - Huldrych Zwingli is killed 2000 ( MM) was a Leap year that started on Saturday of the Common Era, in accordance with the Gregorian calendar. The Tug Fork is a Tributary of the Big Sandy River, 154 mi (248 km long in southwestern West Virginia, southwestern Virginia The spill polluted hundreds of miles of waterways, contaminated the water supply for over 27,000 residents, and killed all aquatic life in Coldwater Fork and Wolf Creek.
Blasting at a mountaintop removal mine expels coal dust and fly-rock into the air, which can then disturb or settle onto private property nearby. Coal dust is a fine powdered form of Coal, which is created by the crushing grinding or pulverizing of coal This dust contains sulfur compounds, which corrodes structures and tombstones and is a health hazard. [6]
Although MTR sites are usually reclaimed after mining is complete, reclamation has traditionally focused on stabilizing rock and controlling erosion, but not reforesting the area with trees. Secondary, or second-growth, forest is a Forest or Woodland area which has re-grown after a major disturbance such as Fire, Insect [7] Quick-growing, non-native grasses, planted to quickly provide vegetation on a site, compete with tree seedlings, and trees have difficulty establishing root systems in compacted backfill. An introduced species (also known as naturalized species or exotic species) is an Organism that is not indigenous to a given location but Grass is the common word that generally describes Monocotyledonous green Plants The family Gramineae ( Poaceae) are the "true grasses" and include [2] Consequently, biodiversity suffers in a region of the United States with numerous endemic species. Biodiversity is the variation of Life forms within a given Ecosystem, Biome or for the entire Earth. Endemism is the Ecological state of being unique to a place Endemic species are not naturally found elsewhere [8] Erosion also increases, which can intensify flooding. Erosion is the carrying away or displacement of solids ( Sediment, Soil, rock and other particles usually by the agents of currents such as wind A flood is an overflow of an expanse of water that submerges land a deluge In the Eastern United States, the Appalachian Regional Reforestation Initiative works to promote the use of trees in mining reclamation. [9]
Dredging
Dredging is a method often used to bring up underwater mineral deposits. Dredging is an Excavation activity or operation usually carried out at least partly underwater in shallow seas or Fresh water areas with the purpose of Although dredging is usually employed to clear or enlarge waterways for boats, it can also recover significant amounts of underwater minerals relatively efficiently and cheaply. A waterway is any navigable Body of water. These include Rivers Lakes Seas Oceans and Canals In order for a waterway
Highwall Mining
Highwall mining is another form of surface mining that evolved from auger mining. In highwall mining, the coal seam is penetrated by a continuous miner propelled by a hydraulic Pushbeam Transfer Mechanism (PTM). A typical cycle includes sumping (pushing forward) and shearing (raising or lowering the cutterhead boom to cut the entire height of the coal seam). As the coal recovery cycle continues, the cutterhead is progressively pushed into the coal seam for 20 feet. Then, the Pushbeam Transfer Mechanism (PTM) automatically inserts a 20-foot long rectangular pushbeam into the center section of the machine between the powerhead and the cutterhead. The pushbeams system can penetrate nearly 1000 feet or 305 meters into the coal seam. Some highwall mining systems use augers enclosed inside the pushbeams that prevent the mined coal from being contaminated by rock debris during the conveyance process. Using a video imaging and/or a gamma detector, the operator can see and guide the continuous miner's progress. Highwall mining can produce thousands of tons of clean coal in contour-strip operations with narrow benches, previously mined areas, or trench mine applications.
Recovery is much better than augering, but the mapping of areas that have been developed by a highwall miner are not mapped as rigorously as deep mined areas. Very little spoil is displaced in contrast with mountain top removal, however a lot of capital is required to operate & own a highwall miner.
Mapping of the outcrop as well as data derived from core holes & samples taken during the bench making process are taken into account to best project the panels that the Highwall miner will cut. Obstacles that could be potentially damaged by subsidence & the natural contour of the Highwall are taken into account, and an Surveyor points the Highwall miner in a line mostly perpendicular to the Highwall. Parallel lines represent the panels cut into the mountain (Up to 1000' deep), because changing the Azimuth during the mining process results in missing a portion of the coal seam.
Environmental and health issues
The large impact of surface mining on the topography, vegetation, and water resources has made it highly controversial.
Surface mining is subject to state and federal reclamation requirements, but adequacy of the requirements is a constant source of contention. Land reclamation is either of two distinct practices One involves creating new land from sea- or riverbeds the other refers to restoring an area to a more natural state (such as after Unless reclaimed, surface mining can leave behind large areas of infertile waste rock (i. e. it generates 75% of industrial waste in Spain).
In the United States, the Surface Mining Control and Reclamation Act of 1977 mandates reclamation of surface coal mines. The Surface Mining Control and Reclamation Act of 1977 (SMCRA is the primary federal law that regulates the environmental effects of Coal mining in the United States See Reclaim for other uses Reclamation is the process of reclaiming something from loss or from a less useful condition Reclamation for non-coal mines, is regulated by state and local laws, which may vary widely.
Human health
Surface mining creates problems for the human health: gases, dust in suspension, noises and vibrations from the machines and explosions, that can create lung or nervous diseases. Dust is a general name for minute Solid particles with Diameters less than 500 micrometers.
References
- ^ J. S. Gardner and P Sainato, Mountaintop mining and sustainable development in Appalachia, Mining Engineering, March 2007, p. 48-55.
- ^ a b c U. S. Environmental Protection Agency (2005-10-25). Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. Events 1147 - The Portuguese, under Afonso I, and Crusaders from England and Flanders conquer Lisbon after a Mountaintop Mining/Valley Fills in Appalachia: Final Programmatic Environmental Impact Statement. Retrieved on 2006-08-20. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 636 - Battle of Yarmouk: Arab forces led by Khalid ibn al-Walid take control of Syria and Palestine
- ^ Brian Vanneman (2004). Tearing Up Appalachia. Sierra Club. Retrieved on 2006-09-04. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 476 - Romulus Augustus, last emperor of the Western Roman Empire, is deposed when Odoacer proclaims himself
- ^ Marsh Fork Elementary, Massey Energy's Shumate Coal Sludge Impoundment and Goals Coal Prep Plant. Retrieved on 2006-07-31. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 30 BC - Battle of Alexandria: Mark Antony achieves a minor victory over Octavian 's forces but most of his army subsequently
- ^ West Virginia Division of Culture and History – Buffalo Creek.
- ^ Jessica Tzerman. "Blast Rites", Grist, 2006-08-03. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 8 - Roman Empire General Tiberius defeats Dalmatians on the river Bathinus. Retrieved on September 4. Events 476 - Romulus Augustus, last emperor of the Western Roman Empire, is deposed when Odoacer proclaims himself
- ^ Appalachian Regional Reforestation Initiative Forest Reclamation Advisory. Office of Surface Mining and Reclamation. Retrieved on 2007-07-11. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 911 - Signing of the Treaty of Saint-Clair-sur-Epte between Charles the Simple and Rollo of Normandy.
- ^ Biology: Plants, Animals, & Habitats - We live in a hot spot of biodiversity. Apalachicola Region Resources on the Web. Retrieved on 2006-09-18. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 96 - Nerva is proclaimed Roman Emperor after Domitian is assassinated
- ^ Appalachian Regional Reforestation Initiative. Retrieved on 2006-09-05. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1590 - Alexander Farnese 's army forces Henry IV of France to raise the siege of Paris.
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