Anthracite latter in two or three sizes, all three being above in (38 mm) size on round-hole screens. High grade (HG) and ultra high grade (UHG) anthracite are the highest grades of anthracite coal. They are the purest forms of coal, having the highest degree of coalification, the highest carbon count and energy content and the fewest impurities (moisture, ash and volatiles). High grade and ultra high grade anthracite are harder than standard grade anthracite, and have a higher relative density. An example of a chemical formula for high-grade anthracite would be CHONS, representing 94% carbon. UHG anthracite typically has a
Coal power in the United States facilities hold the noncombustible ingredients of coal and the ash trapped by equipment designed to reduce air pollution. Byproducts of coal plants have been linked to acid rain. 86 coal powered plants have a capacity of 107.1 GW, or 9.9% of total U.S. electric capacity, they emitted 5,389,592 tons of SO in 2006 – which represents 28.6% of U.S. SO emissions from all sources. Emissions from electricity generation account for the largest share of U.S. greenhouse gases, 38.9% of U.S. production of carbon dioxide in 2006 (with transportation emissions close behind, at 31%). Although coal power only accounted for 49%