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Coal played an important role in industry in the 19th and 20th century. The predecessor of the European Union, the European Coal and Steel Community, was based on the trading of this commodity. [73] Coal continues to arrive on beaches around the world from both natural erosion of exposed coal seams and windswept spills from cargo ships.
[1] [2] The most common types include coal, lignite, oil shale, or black shale. [2] The organic material may be disseminated throughout the rock giving it a uniform dark color, and/or it may be present as discrete occurrences of tar, bitumen, asphalt, petroleum, coal or carbonaceous material.
Yet it is the twelfth most common element there. In the rock of the lithosphere, carbon commonly occurs as carbonate minerals containing calcium or magnesium. It is also found as fossil fuels in coal and petroleum and gas. Native forms of carbon are much rarer, requiring pressure to form. Pure carbon exists as graphite or diamond. [1]
The most common oxidation state of carbon in inorganic compounds is +4, while +2 is found in carbon monoxide and transition metal carbonyl complexes. The largest sources of inorganic carbon are limestones, dolomites and carbon dioxide, but significant quantities occur in organic deposits of coal, peat, oil, and methane clathrates.
Coal rank is based on several characteristics of the coal. The fixed carbon content refers to the percentage of 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. [4]
Anthracite is processed into different sizes by what is commonly referred to as a breaker. The large coal is raised from the mine and passed through breakers with toothed rolls to reduce the lumps to smaller pieces. The smaller pieces are separated into different sizes by a system of graduated sieves, placed in descending order. [19]
The organic matter has an atomic ratio of hydrogen to carbon of about 1.5 – approximately the same as that of crude oil and four to five times higher than coals. The organic matter in oil shales forms a complex macromolecular structure which is insoluble in common organic solvents. [1] [10] It is mixed with varied amounts of mineral matter ...
This gives information on the carbon, hydrogen and nitrogen composition of the coal, and determines the type of coal: lignite, bituminous coal, or anthracite. Macerals found in kerogen source rocks are often observed under the microscope to determine the kerogen maturity of the sedimentary formations. This is a vital component of oil and gas ...