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Sub-bituminous
Sub-bituminous coal is a lower grade of coal that contains 35–45% carbon. The properties of this type are between those of lignite, the lowest grade of coal, and those of bituminous coal, the second-highest grade of coal. Sub-bituminous coal is primarily used as a fuel for fossil fuel power station, steam-electric power generation. Properties Sub-bituminous coals may be dull, dark brown to black, soft and crumbly at the lower end of the range, to bright jet (lignite), jet-black, Mohs scale of mineral hardness, hard, and relatively strong at the upper end. They contain 15-30% inherent moisture by weight and are non-coking (undergo little swelling upon heating). The heat content of sub-bituminous coals range from 8300 to 11,500 British Thermal Unit, BTu/Pound (mass), lb or 19.3 to 26.7 Mega-, MJoule, J/kilogram, kg. Their relatively low density and high water content renders some types of sub-bituminous coals susceptible to Spontaneous combustion (combustion), spontaneous com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bituminous Coal
Bituminous coal, or black coal, is a type of coal containing a tar-like substance called bitumen or asphalt. Its coloration can be black or sometimes dark brown; often there are well-defined bands of bright and dull material within the coal seam, seams. It is typically hard but friable. Its quality is Coal analysis#Coal classification by rank, ranked higher than lignite and sub-bituminous coal, but lesser than anthracite. It is the most abundant rank of coal, with deposits found around the world, often in rocks of Carboniferous age. Bituminous coal is formed from sub-bituminous coal that is buried deeply enough to be heated to or higher. 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 a higher price than other grades of bituminous coal (thermal coal) used for heating and power generation. Within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SUB-BITUMINOUS COAL LIKE THE PIECE JOHN REDDING IS HOLDING LIES UNDER THE SURFACE OF SOME 25,000 SQUARE MILES OF
Sub-bituminous coal is a lower grade of coal that contains 35–45% carbon. The properties of this type are between those of lignite, the lowest grade of coal, and those of bituminous coal, the second-highest grade of coal. Sub-bituminous coal is primarily used as a fuel for steam-electric power generation. Properties Sub-bituminous coals may be dull, dark brown to black, soft and crumbly at the lower end of the range, to bright jet-black, hard, and relatively strong at the upper end. They contain 15-30% inherent moisture by weight and are non-coking (undergo little swelling upon heating). The heat content of sub-bituminous coals range from 8300 to 11,500 BTu/ lb or 19.3 to 26.7 M J/ kg. Their relatively low density and high water content renders some types of sub-bituminous coals susceptible to spontaneous combustion if not packed densely during storage in order to exclude free air flow. Reserves A major source of sub-bituminous coal in the United States is the Powde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is a type of fossil fuel, formed when dead plant matter decays into peat which is converted into coal by the heat and pressure of deep burial over millions of years. Vast deposits of coal originate in former wetlands called coal forests that covered much of the Earth's tropical land areas during the late Carboniferous (Pennsylvanian (geology), Pennsylvanian) and Permian times. Coal is used primarily as a fuel. While coal has been known and used for thousands of years, its usage was limited until the Industrial Revolution. With the invention of the steam engine, coal consumption increased. In 2020, coal supplied about a quarter of the world's primary energy and over a third of its Electricity generation, electricity. Some iron and steel-maki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal In The United States
Coal mining is an industry in transition in the United States. Production in 2019 was down 40% from the peak production of in 2008. Employment of 43,000 coal miners is down from a peak of 883,000 in 1923. Generation of electricity is the largest user of coal, being used to produce 50% of electric power in 2005 and 27% in 2018. The U.S. is a net exporter of coal. U.S. coal exports, for which Europe is the largest customer, peaked in 2012. In 2015, the U.S. exported 7.0 percent of mined coal. According to the U.S. Energy Information Administration (EIA), in 2015, Wyoming, West Virginia, Kentucky, Illinois, and Pennsylvania produced about , representing 71% of total coal production in the United States. In 2015, four publicly traded U.S. coal companies filed for Chapter 11 bankruptcy protection, including Patriot Coal Corporation, Walter Energy, and the fourth-largest Alpha Natural Resources. By January 2016, more than 25% of coal production was in bankruptcy in the Unite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Powder River Basin
The Powder River Basin is a geologic structural basin in southeast Montana and northeast Wyoming, about east to west and north to south, known for its extensive coal reserves. The former hunting grounds of the Oglala Lakota, the area is very sparsely populated and is known for its rolling grasslands and semiarid climate. The basin is both a topographic drainage and geologic structural basin, drained by the Powder River, after which it is named, Cheyenne River, Tongue River, Bighorn River, Little Missouri River, Platte River, and their tributaries. The major cities in the area include Gillette and Sheridan, Wyoming and Hardin, Montana. In 2007, the region produced 436 million short tons (396 million tonnes) of coal, more than twice the production of second-place West Virginia, and more than the entire Appalachian region. The Powder River Basin is the largest coal-producing region in the United States. The region includes the Black Thunder Coal Mine, the most product ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal Mining
Coal mining is the process of resource extraction, extracting coal from the ground or from a mine. Coal is valued for its Energy value of coal, energy content and since the 1880s has been widely used to Electricity generation, 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, 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-pit mining, open-cut and Longwall mining, longwall mines. Mining at this scale requires the use of Dragline excavator, draglines, trucks, conveyors, hydraulic jacks, and shearers. The coal mining industry has a long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lignite
Lignite (derived from Latin ''lignum'' meaning 'wood'), often referred to as brown coal, is a soft, brown, combustible sedimentary rock formed from naturally compressed peat. It has a carbon content around 25–35% and is considered the lowest rank of coal due to its relatively low heat content. When removed from the ground, it contains a very high amount of moisture, which partially explains its low carbon content. Lignite is mined all around the world and is used almost exclusively as a fuel for steam-electric power generation. Lignite combustion produces less heat for the amount of carbon dioxide and sulfur released than other ranks of coal. As a result, lignite is the most harmful coal to human health. Depending on the source, various toxic heavy metals, including naturally occurring radioactive materials, may be present in lignite and left over in the coal fly ash produced from its combustion, further increasing health risks. Characteristics Lignite is brownish-bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mohs Scale Of Mineral Hardness
The Mohs scale ( ) of mineral hardness is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by the German geologist and mineralogist Friedrich Mohs, in his book (English: Attempt at an elementary method for the natural-historical determination and recognition of fossils); it is one of several definitions of hardness in materials science, some of which are more quantitative. The method of comparing hardness by observing which minerals can scratch others is of great antiquity, having been mentioned by Theophrastus in his treatise ''On Stones'', , followed by Pliny the Elder in his ''Naturalis Historia'', . The Mohs scale is useful for identification of minerals in the field, but is not an accurate predictor of how well materials endure in an industrial setting. Reference minerals The Mohs scale of mineral hardness is based on the ability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weight
In science and engineering, the weight of an object is a quantity associated with the gravitational force exerted on the object by other objects in its environment, although there is some variation and debate as to the exact definition. Some standard textbooks define weight as a Euclidean vector, vector quantity, the gravitational force acting on the object. Others define weight as a scalar quantity, the magnitude of the gravitational force. Yet others define it as the magnitude of the reaction (physics), reaction force exerted on a body by mechanisms that counteract the effects of gravity: the weight is the quantity that is measured by, for example, a spring scale. Thus, in a state of free fall, the weight would be zero. In this sense of weight, terrestrial objects can be weightless: so if one ignores Drag (physics), air resistance, one could say the legendary apple falling from the tree, on its way to meet the ground near Isaac Newton, was weightless. The unit of measurement fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
