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90-417: Bayswater Power Station is a bituminous (black) coal -powered thermal power station with four 660 megawatts (890,000 hp) Tokyo Shibaura Electric (Japan) steam driven turbo alternators for a combined capacity of 2,640 megawatts (3,540,000 hp). Commissioned between 1985 and 1986, the station is located 16 kilometres (10 mi) from Muswellbrook , and 28 km (17 mi) from Singleton in

180-683: A coal preparation plant . Technical and economic feasibility are evaluated based on the following: regional geological conditions; overburden characteristics; coal seam continuity, thickness, structure, quality, and depth; strength of materials above and below the seam for roof and floor conditions; topography, especially altitude and slope; climate; land ownership as it affects the availability of land for mining and access; surface drainage patterns; groundwater conditions; availability of labor and materials; coal purchaser requirements in terms of tonnage, quality, and destination; and capital investment requirements. Surface mining and deep underground mining are

270-697: A 70% increase over the 20 years since 1999. In 2018, the world production of brown coal (lignite) was 803.2 Mt, with Germany the world's largest producer at 166.3 Mt. China is most likely the second largest producer and consumer of lignite globally although specific lignite production data is not made available. Coal production has grown fastest in Asia, while Europe has declined. Since 2011, world coal production has been stable, with decreases in Europe and US offset by increases from China, Indonesia and Australia. The top coal mining nations are: Energy production from coal mining

360-446: A check on its rank classification Bituminous coal is dark brown to black, hard, but friable . It is commonly composed of thin bands of alternating bright and dull material. Though bituminous coal varies in its chemical composition, a typical composition is about 84.4% carbon, 5.4% hydrogen, 6.7% oxygen, 1.7% nitrogen, and 1.8% sulfur, on a weight basis. Its bank density (the density of a coal seam prior to breaking up during mining)

450-458: A clean coal technology. Coal mining Coal mining is the process of extracting coal from the ground or from a mine. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. In the United Kingdom and South Africa ,

540-440: A coal mine and its structures are a colliery , a coal mine is called a "pit", and above-ground mining structures are referred to as a " pit head ". In Australia , "colliery" generally refers to an underground coal mine. Coal mining has had many developments in recent years, from the early days of men tunneling, digging, and manually extracting the coal on carts to large open-cut and longwall mines. Mining at this scale requires

630-467: A coal seam occurring near the top of a ridge or hill, the entire top is removed in a series of parallel cuts. Overburden is deposited in nearby valleys and hollows. This method usually leaves the ridge and hilltops as flattened plateaus. The process is highly controversial for the drastic changes in topography, the practice of creating head-of-hollow-fills , or filling in valleys with mining debris, and for covering streams and disrupting ecosystems. Spoil

720-663: A composition of about 84.4% carbon, 5.4% hydrogen, 6.7% oxygen, 1.7% nitrogen, and 1.8% sulfur, on a weight basis. This implies that chemical processes during coalification remove most of the oxygen and much of the hydrogen, leaving carbon, a process called carbonization . During coalification, the maturing coal increases in carbon content, decreases in hydrogen and volatiles, increases in its heating value, and becomes darker and more lustrous. Chemical changes include dehydration (which removes oxygen and hydrogen as water), decarboxylation (which removes oxygen as carbon dioxide ), and demethanation (which removes hydrogen as methane ). By

810-403: A greater proportion of the coal deposit than underground methods, as more of the coal seams in the strata may be exploited. This equipment can include the following: Draglines which operate by removing the overburden, power shovels, large trucks in which transport overburden and coal, bucket wheel excavators, and conveyors. In this mining method, explosives are first used in order to break through

900-400: A high carbon content, and a low content of sulfur, phosphorus , and ash. The best unblended coking coal is high quality medium-volatile bituminous coal. However, since single coals with all the necessary properties are scarce, coking coal is usually a blend of high-volatile bituminous coal with lesser amounts of medium- and low-volatile bituminous coal. Smithing coal is bituminous coal of

990-472: A higher amount of energy per unit mass, specific energy or massic energy, and can often be obtained in areas where wood is not readily available. Though it was used historically as a domestic fuel, coal is now used mostly in industry, especially in smelting and alloy production, as well as electricity generation . Large-scale coal mining developed during the Industrial Revolution , and coal provided

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1080-423: A higher fixed carbon content is classified as anthracite, while agglomerating coal yielding less than 10,500 Btu/lb (24,400 kJ/kg) or nonagglomerating coal yielding less than 11,500 Btu/lb (26,700 kJ/kg) is classified as sub-bituminous coal. In the international market, bituminous coal is defined as coal with a vitrinite reflectance between 0.5 and 1.9. Vitrinite reflectance is also routinely measured for U.S. coal as

1170-455: A higher price than other grades of bituminous coal (thermal coal) used for heating and power generation. Within the coal mining industry, this type of coal is known for releasing the largest amounts of firedamp , a dangerous mixture of gases that can cause underground explosions. Extraction of bituminous coal demands the highest safety procedures involving attentive gas monitoring, good ventilation and vigilant site management. Bituminous coal

1260-440: A land use condition is not equal to the original use. Existing land uses (such as livestock grazing, crop and timber production) are temporarily eliminated in mining areas. High-value, intensive-land-use areas like urban and transportation systems are not usually affected by mining operations. If mineral values are sufficient, these improvements may be removed to an adjacent area. Strip mining eliminates existing vegetation, destroys

1350-440: A large dining-room table, but with hydraulic jacks for legs. After the large pillars of coal have been mined away, the mobile roof support's legs shorten and it is withdrawn to a safe area. The mine roof typically collapses once the mobile roof supports leave an area. There are six principal methods of underground mining: Coal is mined commercially in over 50 countries. 7,921 million metric tons (Mt) of coal were produced in 2019,

1440-447: A method that currently accounts for about 60 percent of world coal production. In deep mining, the room and pillar or bord and pillar method progresses along the seam, while pillars and timber are left standing to support the mine roof. Once room and pillar mines have been developed to a stopping point limited by geology, ventilation, or economics, a supplementary version of room and pillar mining, termed second mining or retreat mining ,

1530-492: A net improvement in air quality. The upgrade will increase the rated capacity of three turbines on the four generating units, increasing the capacity of each unit by 25MW whilst slightly decreasing the amount of coal consumed. Bituminous coal Bituminous coal is used primarily for electrical power generation and in the steel industry . Bituminous coal suitable for smelting iron ( coking coal or metallurgical coal ) must be low in sulfur and phosphorus . It commands

1620-452: A range of pollutant emissions, including CO , estimated at 1,600,000 kilograms (3,500,000 lb) for the year ending 30 June 2011. In 2009, the power station was the subject of "the first ever legal action aimed at curbing greenhouse gas pollution from a coal-fired power station". Environmental activist Pete Gray went to the Land and Environment Court of New South Wales , asking it to find that

1710-413: A relatively dirty fuel. The reduction in the use of bituminous coal between 1945 and 1960 is estimated to have saved at least 1,923 lives of all ages and 310 infant lives per winter month. Bituminous coal quality is improved with floatation methods, which increase the fraction of vitrinite to yield a cleaner-burning product. The bioconversion of bituminous coal to methane is being actively researched as

1800-574: A result of occupational exposures is coined occupational hearing loss . To protect miners' hearing, the US Mine Safety and Health Administration 's (MSHA) guidelines for noise place a Permissible Exposure Limit (PEL) for noise at 90 dBA time-weighted over 8 hours. A lower cutoff, 85 dBA, is set for a worker to fall into the MSHA Action Level which dictates that workers be placed into hearing conservation programs. Noise exposures vary depending on

1890-485: A surface (also called an open cast) mine. Additionally, coal seam thickness and geology are factors in the selection of a mining method. The most economical method of coal extraction for surface mines is the electric shovel or drag line. The most economical form of underground mining is the long wall, which involves using two spinning drums with carbide bits that runs along sections of the coal seam. Many coals extracted from both surface and underground mines require washing in

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1980-543: A year. This is enough power for 2 million average Australian homes and families. Carbon Monitoring for Action estimates this power station emits 19.80 million tonnes of greenhouse gases each year as a result of burning coal. In 2010 the Australian Government announced the introduction of a Carbon Pollution Reduction Scheme to help combat climate change . It is expected to impact on emissions from power stations. The National Pollutant Inventory provides details of

2070-413: Is a particular rank of coal , as determined by the amount and type of carbon present in the coal and the amount of energy it can produce when burned. It is higher in rank than sub-bituminous coal but lower in rank than anthracite . Bituminous coal is the most abundant rank of coal. Coal rank is based on several characteristics of the coal. The fixed carbon content refers to the percentage of

2160-420: Is about 1346 kg/m (84 lb/ft ) while the bulk density of extracted coal is up to 833 kg/m (52 lb/ft ). Bituminous coal characteristically burns with a smoky flame and softens and swells during combustion. It gets its name from this tendency to form a softened, sticky mass when heated, which reflects the presence of bitumen (mineral tar) in the coal. Though almost all agglomerating coal

2250-446: Is accompanied by peak methane generation. This makes these bituminous coals "gassy" and precautions must be taken against methane explosions. Imidazolium -based ionic liquid solvents can reduce spontaneous combustion, which accounts for 2 to 3 percent of global annual carbon dioxide emissions. Bituminous coal was once extensively used for home heating in the US. However, bituminous coal is

2340-575: Is accomplished by drilling holes into the overburden, filling the holes with explosives, and detonating the explosive. The overburden is then removed, using large earth-moving equipment, such as draglines , shovel and trucks, excavator and trucks, or bucket-wheels and conveyors. This overburden is put into the previously mined (and now empty) strip. When all the overburden is removed, the underlying coal seam will be exposed (a 'block' of coal). This block of coal may be drilled and blasted (if hard) or otherwise loaded onto trucks or conveyors for transport to

2430-445: Is based on vitrinite reflectance. This classification divides medium rank coal (approximately equivalent to bituminous coal) into four subranks. In order of increasing rank, these are: Bituminous coal is used primarily for electrical power generation and in the manufacture of steel . Coking coal ( metallurgical coal or "met coal") is used in the manufacture of steel . A good coking coal must have excellent agglomeration properties,

2520-427: Is commonly started. Miners remove the coal in the pillars, thereby recovering as much coal from the coal seam as possible. A work area involved in pillar extraction is called a pillar section. Modern pillar sections use remote-controlled equipment, including large hydraulic mobile roof-supports, which can prevent cave-ins until the miners and their equipment have left a work area. The mobile roof supports are similar to

2610-458: Is composed mostly of nonspore algal remains. In the United States, bituminous coal is further divided into subranks based on its heating value and fixed carbon content. Thus bituminous coal is divided into high-, medium-, and low-volatile categories based on fixed carbon content, and high-volatile bituminous coal is further subdivided by energy content. ISO classification of bituminous coal

2700-418: Is dedicated to mining activities until it can be reshaped and reclaimed. If mining is allowed, resident human populations must be resettled off the mine site; economic activities, such as agriculture or hunting and gathering food and medicinal plants are interrupted. What becomes of the land surface after mining is determined by the manner in which the mining is conducted. Usually reclamation of disturbed lands to

2790-511: Is found in the Appalachian and Interior Provinces of North America. Mining is done via both surface and underground mines. Historically, the many seams scattered over rugged terrain in the Appalachians have been conducive to mining by small companies, while the great extent and gentle dip of beds further west favors very large-scale operations. The Appalachian coal is notably low in sulfur and

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2880-516: Is highly concentrated in certain jurisdictions, which also concentrates much of the social and economic impacts of the industry to these regions. The industry directly employs over seven million workers worldwide, which, in turn, creates millions of indirect jobs. In several parts of the world, producers have reached peak coal as some economies shift away from fossil fuels to address climate change. A 2020 study found that renewables jobs could feasibly be created in these geographies to replace many of

2970-479: Is mostly used to generate electricity, and 75% of annual coal production is exported, mostly to eastern Asia. In 2007, 428 million tonnes of coal was mined in Australia. In 2007, coal provided about 85% of Australia's electricity production. In the fiscal year 2008/09, 487 million tonnes of coal was mined, and 261 million tonnes was exported. In the fiscal year 2013/14, 430.9 million tonnes of coal

3060-412: Is of bituminous rank, some bituminous coal is not agglomerating. Non-agglomerating bituminous coal includes cannel coal and boghead coal . These are nonbanded and nonreflective, and break with a conchoidal fracture. Both are sapropelic , in contrast with most bituminous coal, which is humic (composed of decayed woody tissue of plants). Cannel coal is composed mostly of plant spores, while boghead coal

3150-669: Is often of metallurgical grade, while the Interior Province coal is much higher in sulfur. The belt of Carboniferous coal fields extends into central Europe, and much of this is bituminous coal. Bituminous coal fields are found in Poland and the Czech Republic, and the Polish deposits are one of the most important of that nation's natural resources. The Czech deposits have been exploited since prehistoric times. The European deposits include

3240-417: Is partially economically recoverable. Coal refuse is distinct from the byproducts of burning coal, such as fly ash . Piles of coal refuse can have significant negative environmental consequences, including the leaching of iron, manganese, and aluminum residues into waterways and acid mine drainage . The runoff can create both surface and groundwater contamination. The piles also create a fire hazard, with

3330-593: Is placed at the head of a narrow, steep-sided valley or hollow. In preparation for filling this area, vegetation and soil are removed and a rock drain constructed down the middle of the area to be filled, where a natural drainage course previously existed. When the fill is completed, this underdrain will form a continuous water runoff system from the upper end of the valley to the lower end of the fill. Typical head-of-hollow fills are graded and terraced to create permanently stable slopes. Most coal seams are too deep underground for opencast mining and require underground mining,

3420-436: Is referred to as 'overburden' and is removed in long strips. The overburden from the first strip is deposited in an area outside the planned mining area and referred to as out-of-pit dumping. Overburden from subsequent strips is deposited in the void left from mining the coal and overburden from the previous strip. This is referred to as in-pit dumping. It is often necessary to fragment the overburden by use of explosives. This

3510-515: Is removed and overburden dumped to the side. Dust, vibration, and diesel exhaust odors are created (affecting sight, sound, and smell). Residents of local communities often find such impacts disturbing or unpleasant. In case of mountaintop removal , tops are removed from mountains or hills to expose thick coal seams underneath. The soil and rock removed is deposited in nearby valleys, hollows and depressions, resulting in blocked (and contaminated) waterways. Removal of soil and rock overburden covering

3600-656: Is still common, with 4,000 new cases of black lung every year in the US (4 percent of workers annually) and 10,000 new cases every year in China (0.2 percent of workers). The use of water sprays in mining equipment reduces the risk to miners' lungs. Build-ups of a hazardous gas are known as damps, possibly from the German word Dampf which means steam or vapor: Noise is also a contributing factor to potential adverse effects on coal miners' health. Exposure to excessive noise can lead to noise-induced hearing loss . Hearing loss developed as

3690-487: Is submerged in standing water. The stagnant water excludes oxygen, creates an acidic environment, and slows decay. The dead plant material is converted to peat . Peat is mostly a mixture of cellulose , hemicellulose , and lignin that originally made up the woody tissue of the plants. Lignin has a weight composition of about 54% carbon, 6% hydrogen, and 30% oxygen, while cellulose has a weight composition of about 44% carbon, 6% hydrogen, and 49% oxygen. Bituminous coal has

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3780-435: Is used for both thermal and metallurgical coals . In New South Wales open casting for steam coal and anthracite is practiced. Surface mining accounts for around 80 percent of production in Australia, while in the US it is used for about 67 percent of production. Globally, about 40 percent of coal production involves surface mining. Strip mining exposes coal by removing earth above each coal seam. This earth to be removed

3870-562: The Coal Measures of Britain, which account for most of Britain's coal production and which are mostly bituminous coal. The Westfield coal basin is the largest in Britain. Other significant bituminous coal deposits are found through much of Europe, including France, Germany, and northern Italy. Coal deposition was interrupted by the Permian-Triassic extinction event , but resumed later in

3960-638: The Gates Formation . The Intermontane and Insular Coalfields of British Columbia also contain deposits of Cretaceous bituminous coal. As of 2009 , the countries with the greatest estimated ultimately recoverable resources of bituminous coal were the US, 161.6 Gt ; India, 99.7 Gt; China, 78.4 Gt; Australia, 51.3 Gt; South Africa, 38.7 Gt; the UK, 26.8 Gt; Germany, 25.2 Gt; Colombia, 7.8 Gt; Indonesia, 5.6 Gt; and France, 4.4 Gt As of 2018 , total world production of bituminous coal (coking coal plus other bituminous coal)

4050-516: The Hunter Region of New South Wales , Australia . Prior to September 2014 Bayswater Power Station was part of NSW Government power producer, Macquarie Generation. Macquarie Generation was acquired by AGL Energy in September 2014. The first generator was completed in 1985, and the remaining three generators progressively that same year and throughout 1986. Bayswater draws its cooling water from

4140-626: The Hunter River under water entitlements negotiated with the government of New South Wales . The Barnard River Scheme also allows Bayswater and Liddell to transfer water from the upper Manning River catchment into the Hunter River for their use. Much of the coal is supplied by overland conveyors from mines it shares with the nearby Liddell Power Station . Coal consumption is around 8 megatonnes (8,800,000 short tons) per annum and produces around 17,000 gigawatt-hours (61,000 TJ) of electricity

4230-685: The Middle Triassic . Extensive bituminous coal deposits of Permian age are found in Siberia, east Asia, and Australia. These include the Minusinsky coal basin in Siberia, the Queensland , Bowen , and Sydney Basins in Australia, and the extensive bituminous coal reserves of China. A second peak in coal deposition began in the Cretaceous , though most of this is lower rank coal rather than bituminous. In

4320-440: The global energy economy . The major coal producing countries, though, such as China , Indonesia, India and Australia , have not reached peak production, with production increases replacing falls in Europe and the United States and proposed mines under development. The coal mining industry employs almost 2.7 million workers. The History of coal mining goes back thousands of years, with early mines documented in ancient China,

4410-400: The 1860s onward. By the late 20th century, coal was, for the most part, replaced in domestic as well as industrial and transportation usage by oil , natural gas or electricity produced from oil, gas, nuclear power or renewable energy sources. By 2010, coal produced over a fourth of the world's energy. Coal extraction methods vary depending on whether the mine is an underground mine or

4500-469: The Earth's geologic history. Vast deposits of coal formed in wetlands —called coal forests —that covered much of the Earth's tropical land areas during the late Carboniferous ( Pennsylvanian ) and Permian times. Bituminous coal is predominantly Carboniferous in age. Most bituminous coal in the United States is between 100 and 300 million years old. Vast deposits of bituminous coal of Pennsylvanian age

4590-573: The Roman Empire and other early historical economies. It became important in the Industrial Revolution of the 19th and 20th centuries, when it was primarily used to power steam engines, heat buildings and generate electricity. Coal mining continues as an important economic activity today, but has begun to decline due to the strong contribution coal plays in global warming and environmental issues, which result in decreasing demand and in some geographies, peak coal . Compared to wood fuels , coal yields

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4680-787: The U.S., Examples include the Sago Mine disaster of 2006, and the 2007 mine accident in Utah 's Crandall Canyon Mine , where nine miners were killed and six entombed. In the decade 2005–2014, US coal mining fatalities averaged 28 per year. The most fatalities during the 2005–2014 decade were 48 in 2010, the year of the Upper Big Branch Mine disaster in West Virginia, which killed 29 miners. Chronic lung diseases, such as pneumoconiosis (black lung) were once common in miners, leading to reduced life expectancy . In some mining countries black lung

4770-608: The US 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. But according to the Bureau of Labor Statistics , even in 2006, mining remained the second most dangerous occupation in America, when measured by fatality rate . These numbers, however, include all mining activities, and oil and gas mining contribute to

4860-676: The United States, Cretaceous bituminous coals occur in Wyoming, Colorado and New Mexico. In Canada, the Western Canada Sedimentary Basin of Alberta and British Columbia hosts major deposits of bituminous coal that formed in swamps along the western margin of the Western Interior Seaway . They range in age from latest Jurassic or earliest Cretaceous in the Mist Mountain Formation , to Late Cretaceous in

4950-413: The coal is. It is determined by how much of the carbon has condensed to an aromatic form from the heat and pressure of deep burial. In the United States, bituminous coal is defined as agglomerating coal yielding at least 10,500 Btu /lb (24,400 kJ/kg) of energy on combustion (on a moist, mineral-matter-free basis), with a fixed carbon content less than 86% (on a dry, mineral-matter-free basis.) Coal with

5040-581: The coal mining jobs as part of a just transition ; however, renewable energy was not suitable in some of the geographies with high concentrations of miners, such as in China, which is far and away the leading coal-mining nation. Coal refuse (also described as coal waste, rock, slag, coal tailings, waste material, rock bank, culm, boney, or gob ) is the material left over from coal mining, usually as tailings piles or spoil tips . For every tonne of hard coal generated by mining, 400 kg (880 lb) of waste material remains, which includes some lost coal that

5130-497: The coal preparation (or wash) plant. Once this strip is empty of coal, the process is repeated with a new strip being created next to it. This method is most suitable for areas with flat terrain. Equipment to be used depends on geological conditions. For example, to remove overburden that is loose or unconsolidated, a bucket wheel excavator might be the most productive. The life of some area mines may be more than 50 years. The contour mining method consists of removing overburden from

5220-549: The coal reaches temperatures above about 235 °C (455 °F), bitumen breaks down ( debituminization ) and the coal matures to anthracite. Coal deposits are widely distributed worldwide, and range in age from the Devonian (about 360 to 420 million years ago) to Neogene deposits just a few million years old. However, 90% of all coal beds were deposited in the Carboniferous and Permian periods , which represent just 2% of

5310-857: The coal resource may cause burial and loss of topsoil, exposes parent material, and creates large infertile wastelands. Soil disturbance and associated compaction result in conditions conducive to erosion. Soil removal from the area to be surface-mined alters or destroys many natural soil characteristics, and reduces its biodiversity and productivity for agriculture. Soil structure may be disturbed by pulverization or aggregate breakdown. Top 10 hard and brown coal producers in 2012 were (in million metric tons): China 3,621, United States 922, India 629, Australia 432, Indonesia 410, Russia 351, South Africa 261, Germany 196, Poland 144, and Kazakhstan 122. Coal has been mined in every state of Australia, but mainly in Queensland, New South Wales and Victoria. It

5400-445: The coal that is neither moisture, nor ash, nor volatile matter. When evaluated on a dry, mineral-matter-free basis, the fixed carbon content is the fraction of the coal that is not volatile organic matter. An agglomerating coal is a coal that softens when heated, forming a hard, gray, porous coke that resists crushing. Vitrinite reflectance is a measure of how reflective a polished surface of an average particle of vitrinite in

5490-429: The developed world. Modern coal mining in the US has an average 23 deaths per year due to mine accidents (2001–2020). However, in lesser developed countries and some developing countries, many miners continue to die annually, either through direct accidents in coal mines or through adverse health consequences from working under poor conditions. China , in particular, has the highest number of coal mining related deaths in

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5580-455: The disruptive activities of blasting, ripping, and excavating coal. Stripping of overburden eliminates and destroys archeological and historic features, unless they are removed beforehand. The removal of vegetative cover and activities associated with the construction of haul roads, stockpiling of topsoil, displacement of overburden and hauling of soil and coal increase the quantity of dust around mining operations. Dust degrades air quality in

5670-571: The fatalities occurring in the first half of the 20th century. 3,242 died in 1907, the worst year ever; in 2020 there were five. Open cut hazards are principally mine wall failures and vehicle collisions; underground mining hazards include suffocation, gas poisoning, roof collapse, rock burst , outbursts , and gas explosions. Firedamp explosions can trigger the far more dangerous coal dust explosions, which can engulf an entire mine. Most of these risks are greatly reduced in modern mines, and multiple fatality incidents are now rare in most parts of

5760-457: The genetic soil profile, displaces or destroys wildlife and habitat, alters current land uses, and to some extent permanently changes the general topography of the area mined. Adverse impacts on geological features of human interest may occur in a coal strip mine. Geomorphic and geophysical features and outstanding scenic resources may be sacrificed by indiscriminate mining. Paleontological, cultural, and other historic values may be endangered due to

5850-569: The highest quality, as free of ash and sulfur as possible, used to manufacture coke for use by blacksmiths . Coking coal commands a higher price than coal used for energy production. As of 2020 , coking coal in the U.S. sold for about $ 127/ short ton , compared with $ 50.05/short ton for bituminous coal generally. The cost of coking coal is about 3.5 times as high as the cost of coal used for electrical power (which includes lower ranks of coal, such sub-bituminous coal and lignite , as well as noncoking bituminous coal.) Bituminous coal which lacks

5940-450: The immediate area, has an adverse impact on vegetative life, and constitutes health and safety hazards for mine workers and nearby residents. Surface mining disrupts virtually all aesthetic elements of the landscape. Alteration of land forms often imposes unfamiliar and discontinuous configurations. New linear patterns appear as material is extracted and waste piles are developed. Different colors and textures are exposed as vegetative cover

6030-552: The main source of primary energy for industry and transportation in industrial areas from the 18th century to the 1950s. Coal remains an important energy source. Coal is also mined today on a large scale by open pit methods wherever the coal strata strike the surface or are relatively shallow. Britain developed the main techniques of underground coal mining from the late 18th century onward, with further progress being driven by 19th-century and early 20th-century progress. However, oil and gas were increasingly used as alternatives from

6120-404: The majority of fatalities. Coal mining resulted in 47 fatalities that year. One study, though, has suggested that hazards of modern mining are now more accretive with workers facing long-term health impacts, such as sleep deprivation, that build up over time. Strip mining severely alters the landscape, which reduces the value of the natural environment in the surrounding land. The land surface

6210-461: The method of extraction. For example, a study has found that among surface coal mine operations, dragline equipment produced the loudest sound at a range of 88–112 dBA. Within longwall sections, stageloaders used to transport coal from the mining face and shearers used for extraction represent some of the highest noise exposures. Auxiliary fans (up to 120 dBA), continuous mining machines (up to 109 dBA), and roof bolters (up to 103 dBA) represent some of

6300-465: The mining workforce. in 2015 US coal mines had 65,971 employees, the lowest figure since EIA began collecting data in 1978. However, a 2016 study reported that a relatively minor investment would allow most coal workers to retrain for the solar energy industry. Coal mining has been a very dangerous activity and the list of historical coal mining disasters is long. In the U.S., 104,895 coal miners were killed in mine accidents since 1900, 90 percent of

6390-552: The nature of the original plant material, nor the length of burial is nearly as important. The temperature range for maturation of bituminous coal is from 85 to 235 °C (185 to 455 °F). The bitumen that characterizes bituminous coal forms under approximately the same conditions at which petroleum is formed in petroleum source rocks. Bituminization is accompanied by peak methane generation in medium to low volatile bituminous coal. This makes these bituminous coals "gassy" and precautions must be taken against methane explosions. If

6480-469: The noisiest equipment within continuous mining sections. Exposures to noise exceeding 90 dBA can lead to adverse effects on workers' hearing. The use of administrative controls and engineering controls can be used to reduce noise exposures. Improvements in mining methods (e.g. longwall mining), hazardous gas monitoring (such as safety-lamps or more modern electronic gas monitors), gas drainage, electrical equipment , and ventilation have reduced many of

6570-585: The open pit methods, due to thickness of the seam 20–25 metres (60–90 feet). Coals occurring below 90 m (300 ft) are usually deep mined. However, there are open pit mining operations working on coal seams up to 300–460 metres (1,000–1,500 feet) below ground level, for instance Tagebau Hambach in Germany. When coal seams are near the surface, it may be economical to extract the coal using open-cut , also referred to as open-cast, open-pit, mountaintop removal or strip, mining methods. Opencast coal mining recovers

6660-421: The operation reaches a predetermined stripping ratio (tons of overburden/tons of coal), it is not profitable to continue. Depending on the equipment available, it may not be technically feasible to exceed a certain height of highwall. At this point, it is possible to produce more coal with the augering method in which spiral drills bore tunnels into a highwall laterally from the bench to extract coal without removing

6750-408: The overburden. Mountaintop coal mining is a surface mining practice involving removal of mountaintops to expose coal seams, and disposing of associated mining overburden in adjacent "valley fills." Valley fills occur in steep terrain where there are limited disposal alternatives. Mountaintop removal mining combines area and contour strip mining methods. In areas with rolling or steep terrain with

6840-425: The potential to spontaneously ignite. Because most coal refuse harbors toxic components, it is not easily reclaimed by replanting with plants like beach grasses. The use of sophisticated sensing equipment to monitor air quality is common and has replaced the use of small animals such as canaries, often referred to as " miner's canaries ". In the United States, the increase in technology has significantly decreased

6930-522: The power station had been "wilfully or negligently disposing of waste [...] by emitting carbon dioxide into the atmosphere in a manner that has harmed or is likely to harm the environment in contravention of section 115(1) of the Protection of the Environment Operations Act 1997", and sought an injunction against the station. The case, Gray and Anor v Macquarie Generation , was ongoing at

7020-665: The qualities required for use as metallurgical coal is graded as thermal coal. This is used primarily for electrical power generation. The ideal thermal coal is easily ignited but has a high heat content. Bituminous coal is used for the production of activated carbon . The coal is first coked, removing volatiles, then steam treated to activate it. Chemical processes for activating coke produced from bituminous coal have also been investigated. Like other ranks of coal, bituminous coal forms from thick accumulations of dead plant material that are buried faster than they can decay. This usually takes place in peat bogs , where falling plant debris

7110-399: The risks of rock falls, explosions, and unhealthy air quality. Gases released during the mining process can be recovered to generate electricity and improve worker safety with gas engines . Another innovation in recent years is the use of closed circuit escape respirators , respirators that contain oxygen for situations where mine ventilation is compromised. Statistical analyses performed by

7200-565: The seam in a pattern following the contours along a ridge or around the hillside. This method is most commonly used in areas with rolling to steep terrain. It was once common to deposit the spoil on the downslope side of the bench thus created, but this method of spoil disposal consumed much additional land and created severe landslide and erosion problems. To alleviate these problems, a variety of methods were devised to use freshly cut overburden to refill mined-out areas. These haul-back or lateral movement methods generally consist of an initial cut with

7290-432: The spoil deposited downslope or at some other site and spoil from the second cut refilling the first. A ridge of undisturbed natural material 15 to 20 ft (5 to 6 m) wide is often intentionally left at the outer edge of the mined area. This barrier adds stability to the reclaimed slope by preventing spoil from slumping or sliding downhill. The limitations of contour strip mining are both economic and technical. When

7380-399: The structural element of graphite . This is accompanied by an increase in vitrinite reflectance, used to assess coal rank. During coalification, the pressure of burial reduces the volume of the original peat by a factor of 30 as it is converted to coal. However, the increase in rank of maturing coal mostly reflects the maximum temperature the coal reaches. Neither the maximum pressure, nor

7470-476: The surface or overburden, of the mining area. The overburden is then removed by draglines or by shovel and truck. Once the coal seam is exposed, it is drilled, fractured and thoroughly mined in strips. The coal is then loaded onto large trucks or conveyors for transport to either the coal preparation plant or directly to where it will be used. Most open cast mines in the United States extract bituminous coal . In Canada, Australia, and South Africa, open cast mining

7560-611: The time of Gray's death from cancer in April 2011. In December 2018, a proposed upgrade to the Bayswater Power Station was approved to be completed around the same time as the proposed closure of the Liddell Power Station in 2022. Both are owned by AGL Energy and consume coal from the same mine. The upgrade approval did not impose tighter air emission controls, however AGL claimed that the closure of Liddell would result in

7650-659: The time the coal reaches bituminous rank, most dehydration and decarboxylation has already taken place, and maturation of bituminous coal is characterized by demethanation. During coalification at bituminous rank, coal approaches its maximum heating value and begins to lose most of its volatile content. As carbonization proceeds, aliphatic compounds (carbon compounds characterized by chains of carbon atoms) are replaced by aromatic compounds (carbon compounds characterized by rings of carbon atoms) and aromatic rings begin to fuse into polyaromatic compounds (linked rings of carbon atoms). The structure increasingly resembles graphene ,

7740-524: The two basic methods of mining. The choice of mining method depends primarily on depth, density, overburden, and thickness of the coal seam; seams relatively close to the surface, at depths less than approximately 55 m (180 ft), are usually surface mined. Coal that occurs at depths of 55 to 90 m (180 to 300 ft) are usually deep mined, but in some cases surface mining techniques can be used. For example, some western U.S. coal that occur at depths in excess of 60 m (200 ft) are mined by

7830-452: The use of draglines , trucks, conveyors , hydraulic jacks , and shearers. The coal mining industry has a long history of significant negative environmental impacts on local ecosystems, health impacts on local communities and workers, and contributes heavily to the global environmental crises, such as poor air quality and climate change . For these reasons, coal has been one of the first fossil fuels to be phased out of various parts of

7920-441: The world, with official statistics claiming that 6,027 deaths occurred in 2004. To compare, 28 deaths were reported in the U.S. in the same year. Coal production in China is twice that in the US, while the number of coal miners is around 50 times that of the US, making deaths in coal mines in China 4 times as common per worker (108 times as common per unit output) as in the US. Mine disasters have still occurred in recent years in

8010-445: Was 6.220 Gt. The leading producer is China, with India and the United States a distant second and third. U.S. production of bituminous coal was 238 million short tons in 2020 and represented 44% of all U.S. coal production. Bituminous coal is mined in 18 states, but the five states of West Virginia, Pennsylvania, Illinois, Kentucky, and Indiana produce 74% of U.S. coal. Maturation of bituminous coal at medium and low volatile subrank

8100-531: Was mined, and 375.1 million tonnes was exported. In 2013/14, coal provided about 69% of Australia's electricity production. In 2013, Australia was the world's fifth-largest coal producer, after China, the United States, India, and Indonesia. However, in terms of proportion of production exported, Australia is the world's second largest coal exporter, as it exports roughly 73% of its coal production. Indonesia exports about 87% of its coal production. A court in Australia has cited climate change in ruling against

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