METHOD OF MINING OF STEEPLY DIPPING DEPOSITS OF WORKING OF DEEP HORIZONS OF OPENCAST Russian patent published in 2002 - IPC

FIELD: mining; applicable in opencast mining of steeply dipping beds. SUBSTANCE: method includes mining of opencast by phases, preparation of rock mass by drilling and blasting. Opencast is mined with leading in contours of the first phase. Opencast of the first phase is worked with formation of spiral access ramp and simultaneous stripping and layer stoping of the second phase. Overburden of the first and second phases is moved to external dump. Loop system of access ramps are formed on district of the second phase, and as mining operation stepping down, after opening of mineral by the second phase, working platforms of the second phase are communicated with spiral access ramp of the first phase by temporary access roads. After completion of working of the first phase, overburden of the second phase is located to worked- out space of the first phase. For which purpose, overburden of the second phase from working platforms is hauled to spiral access ramp of the first phase, from which internal dump is filled by tiers irrespective of their height. The first tier of internal dump is located between opencast bottom and the first flight, its upper inclined platform is formed at level of the first flight of spiral access ramp. Spiral access ramp is transferred to upper platform of the first tier, and it is guarded by external and internal protective barriers. The second tier is filled on upper platform of the first tier behind internal protective barrier. The second tier is located between adjacent flight of spiral access ramp. Upper platform of the second tier is located at level of the second flight of spiral access ramp. Sequence of operations in filling of next tiers is repeated. EFFECT: reduced labor input in stripping operations, reduced expenditures for haulage of overburden rocks to dumps. 3 cl, 4 dwg