METHOD FOR OPENCAST MINING OF INCLINED AND STEEPLY DIPPING DEPOSITS Russian patent published in 1996 - IPC

FIELD: mining. SUBSTANCE: open pit is mined by two zones adjacent in height. Upper zone with h_e height is worked with external dump by longitudinal and transverse panels with development of mining from the central part of open pit to its periphery to the deposit dip. When mining operations reach depth h_e and design contour of open pit in its end part is attained, a pit is formed by digging with curvature radius R_o of flanks on its bottom. Further on, mining is extended along strike of deposit by districts curved in plan with preservation of preset radius of flank curvature. Overburden rocks in extraction on open pit lower zone are filled into internal dump which is curved in plan and extending in the wake of mining operations. Height h_e of the upper zone of open pit is determined from expression h_e= H - h_l, m, where H is design depth of open pit; h_l is height in plan of open pit flank in its lower part. EFFECT: higher efficiency. 7 dwg