34 G L O SSA R Y into shuttle cars in a continuous operation Of t en these machines are highly automated and can be operated by remote control Accounts for about 45 percent of US under gr ound c oal production conventional mining A deep mining method that includes inserting explosives in a coal seam blast ing the seam and removing the coal onto a convey or or shuttle car Accounts for less than 5 percent of total underground coal production core The sample of rock obtained through the use of a hollow drilling bit which cuts and retains a sec tion of the rock penetrated usually to determine the interior composition or the hidden condition deep mine An underground mine demonstrated reserves Coal deposits that are potentially minable on an economic basis with ex isting technology The US has an estimated 481 billion tons of demonstrated reserves deposit A natural occurrence or accumulation of mineral material coal iron ore oil or gas dragline A large excavating machine used in the surface mining process to remove overburden see overburden The dragline has a large bucket sus pended from the end of a huge boom which may be 275 feet long or larger The bucket is suspended by cables and capable of scooping up huge amounts of overburden as it is dragged across the excavation area The dragline which can walk on huge pon toonlike feet is one of the largest landbased ma chines in the world drift mine A coal mine entered directly through a horizontal opening drilled into the side of a hill or mountain This mining method is used in hilly or mountainous areas electrostatic precipitator An electrical device used in removing particles see fy ash from combustion gases prior to release from a power plants stack excavator A large number of poweroperated dig ging and loading machines used increasingly in openpit mining and quarrying exploration The search for coal mineral or ore by geological surveys prospecting GPS or sat ellit e location or use of tunnels drifts or boreholes face The exposed area of a coalbed from which coal is extracted fotation Separating miner als from other materials by foating away materials of lower specifc grav ity while heavier materials sink fuidizedbed combustion A clean coal technolo gy process to remove sulfur from coal combustion as well as limit the formation of nitrogen oxides The process involves suspending crushed coal and limestone in the bottom of a boiler by an upward stream of hot air While the coal is burned in this liquidlike mixture sulfur from combustion gases combines with the limestone to form a solid com pound recovered with the ash fy ash The fnely divided particles of ash entrained in gases resulting from the combustion of fuel At coalfred power plants fy ash is captured by spe cial equipment usually either electrostatic pre cipitators or baghouses Fly ash and other forms of coal ash are useful byproducts about 25 mil lion tons are used each year in major concrete en gineering projects such as highway construction formation Any rock unit conspicuously diferent from adjacent rock units fossil fuel Fuel such as coal crude oil or natural gas formed from the fossil remains of organic ma terial Frasch sulfur deposit Native sulfur mined by the Frasch hot water process in which superheated water is forced into the sulfur deposit for the pur pose of melting the sulfur The molten sulfur is then pumped to the surface gasifcation Any of various processes by which coal is turned into low medium or highBtu gas General Mining Law The primary statute that gov erns the right to mine locatable minerals on unap propriated public domain lands Though enacted in 1872 it has been amended many times