METHOD OF OPENCAST MINING OF STEEPLY DIPPING STRETCHED DEPOSITS Russian patent published in 2001 - IPC

FIELD: mining industry. SUBSTANCE: method may be used in mining of steeply dipping stretched deposits by opencasts whose terminal bottom is stage-shaped. The method includes working of opencast field by stages with overburden disposal to external and internal dumps. Depth of the first stage is set on horizon corresponding to stage of boundary contour of opencast meeting requirements for location of truck access ramp to final depth of opencast and minimal power capacity for mining of reserves of mineral in boundary contour. On stage from crest of bench to final position, separating platform is delimited, and it divides opencasts into part for location of internal dump and part for performance of stripping and stoping operations. Contour of internal dump is determined on opencast flank in boundary position. From internal dump contour, as mining of the first stage is realized, temporary pillars for blind haulage berms are formed in opencast part adjacent to location of internal dump, on filled flank opposite to flank of route location in direction of stretching of working zone. Upon completion of working of the first stage of opencast field, rock from lower benches of opencast to lower tiers of internal dump is delivered over haulage berms whose end part serves as a pioneer front of dump formation. For delivery of rock to middle tiers of internal dump from upper haulage berm, spiral access ramp is constructed from overburden rocks on safe distance from crest of field tier adjacent to filled flank in direction opposite to stretching of opencast working zone. EFFECT: increased capacity of sump. 5 dwg