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-? However, in so%e %nst_anres ctngre suitagle quality coal 1s gear the surface, the <br />overburden hay be removed Wit "t a combihatton of dozers ziad scrap@rs, Lhe over- <br />_W <br />wquLI, ct?eo be hayLed to, a stockpile. at pla'--ed qn mined-out areas for evon- <br />tu91 tegrad%ng and rstobsoiling. <br />The pr'inc:ipie mining methoq u3ed at Trapper is d4+-1i.ae mirlink, tii.e., [pining in <br />sttips parallel rq rYte gown hill dib of the goal aeeas, Each pit is adjacent and <br />patall,el to the previ,au% one. Pit 'widths vary according, to the specific site. <br />Tybic§lly, leach Cltt is initiated near the coal outcrop snd woakeq down thg hill <br />until th@ dipping coal becomes Coo deep to re;over ecogomically• on occasion, <br />th§ alit may be worked lip @he hill. When mare tl)§n one seam is recov6red, the <br />patting is temyved in owie of Sevsral methods, 'whin partings up to ten feet thick <br />are r-mooed with a loz?-r, batkhoe or siniilyr §9ulpmgn[, Thickfir par{iqs qre <br />removed Witli a drggline, Rart:ink myy be ktri,ppgd up-dip or down-dip depending on <br />the p§rticular situation. Strike-line: mining may be Performed in3tead of the <br />present dip--line mining metbod ik geologic conditiPns allow. <br />Th° tbp of the uncovered co41 is cleaned with ?-quipment such as a fronr-end <br />loedet•, nworor graders of rybber I_irad dozer. Ve Goal i% then either, ripped with <br />a dozer 4r <1ri.Lled with a (wiq-m§sted coal drill arld theft blasted. F1ole spacings <br />vaYy d.eprtndLng on coal thickn@ss, <br />Thu h<)1e3 are loathed with Ali-F? or other blhsting agents and stehamed with drill <br />cuttings, 'The blasr circuit is then completed end the blast is initiated {refer <br />to Secti6n ).4). <br />Large 6at,khUes or trust enfl loaders ace Vsed to load thN coal into haul trucks. <br />The cpal haulers transport the coal frym the pit to the power plant's grizzly or <br />a coal. stockpile, The coal haulers exit the pit via an inclihed ramp and enter <br />onto the haUl road system that coongcts egch pit to the power plant's grizzly and <br />the cUal stpckpil@s. At a lacer date, a conveyor system may replace part of this <br />truck haul. <br /> <br />3-14 <br />Ftc.VISED FEB 13 `81