Search results
Results From The WOW.Com Content Network
It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the highest ranking of coals. The Coal Region of Northeastern Pennsylvania in the United States has the largest known deposits of anthracite coal in the world with an estimated reserve of seven billion short tons. [2]
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]
In the ASTM system, any coal with more than 69% fixed carbon is classified by its content of carbon and volatiles. Coal with less than 69% fixed carbon is classified by its heating value. Volatiles and carbon are on a dry mineral free base; heating value is based on the moisture content as mined, but without any free water.
For bituminous coal, the elemental composition on a dry, ash-free basis of 84.4% carbon, 5.4% hydrogen, 6.7% oxygen, 1.7% nitrogen, and 1.8% sulfur, on a weight basis. [40] This composition reflects partly the composition of the precursor plants. The second main fraction of coal is ash, an undesirable, noncombustable mixture of inorganic minerals.
Coke is the non-volatile residue of the decomposition, the cemented-together carbon and mineral residue of the original coal particles in the form of a hard and somewhat glassy solid. [citation needed] Additional byproducts of the coking are coal tar pitch, ammonia (NH 3), hydrogen sulphide (H 2 S), pyridine, hydrogen cyanide and carbon based ...
Carbon can be produced in stars at least as massive as the Sun by fusion of three helium-4 nuclei: 4 He + 4 He + 4 He --> 12 C. This is the triple alpha process.In stars as massive as the Sun, carbon-12 is also converted to carbon-13 and then onto nitrogen-14 by fusion with protons.
Carbon is a constituent (about 12% by mass) of the very large masses of carbonate rock (limestone, dolomite, marble, and others). Coal is very rich in carbon (anthracite contains 92–98%) [64] and is the largest commercial source of mineral carbon, accounting for 4,000 gigatonnes or 80% of fossil fuel. [65]
This is achieved by remelting pig iron, often along with substantial quantities of steel and scrap iron, removing undesirable contaminants, adding alloys, and adjusting the carbon content. Ductile iron can also be produced using certain high purity grades of pig iron; depending on the grade of ductile iron being produced, the pig irons chosen ...