METHOD OF OPEN-CUT MINING OF HORIZONTAL AND GENTLY SLOPING MINERAL SEAMS Russian patent published in 1995 - IPC

FIELD: mining methods. SUBSTANCE: method of open-cut mining of horizontal and gently sloping seams of mineral includes steps of excavating a mineral seam by substeps 2 with working the last by entires in forward and rearward directions successively from upwards to downwards and charging the rock to transport vehicles in such a way, that upon limited dimensions of an open-cut pit zone on short sides of a block to be worked cut drifts are being erected, cutting the mineral along a helical line with constant length turns and with a distance between two adjacent cutting ways, equal to two radius values of rotation of a cutter; performing first three cuts along a perimeter of the block according to flow-line technique, then along short sides of the block performing three cuts at each side according to cyclic operation; using as a parameter, determining a minimum width of the block, the radius of rotation of the cutter, and after the cut drift had be made, working the remaining width of the block cylindrically by entry of the cutter from the cut drift to a center of the block on the first zone for cutting it, then performing rotation of the cutter to a side of an opposite cut drift, entry to the second zone for cutting it in a reverse direction, performing a turning of the cutter in the initial drift and entry of the cutter to the third zone, then repeating the whole cycle; using a minimum width of the cut drift, equal to one radius of the cutter rotation and a half of its base. EFFECT: enhanced efficiency. 1 cl, 3 dwg