METHOD OF FORMATION OF OPENCAST NONMINING FLANK IN ARGILLACEOUS ROCKS Russian patent published in 2003 - IPC

FIELD: mining industry; applicable in mineral opencast mining. SUBSTANCE: method includes layer excavation of rocks by benches, alternate bringing of working benches up to design contour of opencast and haulage of overburden rocks to external dumps. In rock excavation, the crest of the first bench is combined with crest of opencast design contour. Slopes of the first and subsequent benches are left at working angles. Left between benches of adjacent levels are safety berms of such sizes that margin of stability of opencast flame in argillaceous rocks with resulting slope angle of inclination meets the requirements of its short-time stability. Filled on berm located on boundary of hard rocks and argillaceous rocks, and on berms remaining between benches of adjacent levels is internal dump of hard rocks in one or several tiers with such volume that margin of opencast plank slope stability with said internal dump will correspond to requirements for prolonged stability of opencast flank slopes. Filling of internal dump may be started with filling of hard rocks on berms of safety bank. EFFECT: reduced expenditures for formation of opencast nonmining flank in loose and argillaceous rocks and reduced probability of development of deformations in argillaceous rocks with their intensive waterflooding. 2 cl, 4 dwg, 1 tbl, 1 ex