QUARRY DEVELOPMENT METHOD Russian patent published in 1998 - IPC

FIELD: mining industry. SUBSTANCE: this can be used in opencast mining of mineral deposits which are made up of uniform and nonuniform rock mass, and particularly in mining vertically dipping ore bodies. According to method, quarry field is developed by stages. Development is started from excavating rock mass in layer-by-layer procedure. Then, performed is formation of intermediate and final sides of quarry at resulting angle. Benches are formed at stage and final contours. Adjacent benches are conjugated. Created are horizontal protective berms of constant width and inclined transportation berms with formation of route of spiral configuration. Formed are sites for adjoining inclined transportation berms to horizontal berms. At each stage contour before building of current pair of adjacent descents, formed is section of horizontal protective berm with vertical angle of repose between lower edge of above-lying bench and line of back slope. Width and length of berm section in this case is equal to half width of descent and to length of two lower-lying descents. Rotary excavator is used to form concentrically located dual benches with vertical angle of repose. Also formed is vertical side slope of inclined transportation berm. Built is horizontal protective berm under each two adjacent descents. This is carried out at successive reduction of its width from maximal value at level of upper mark of above-lying descent to level of lower mark of lower-lying descent. Width of berm under adjoining site remains constant. Made at level of adjoining site is protective berm of width which is equal to half width of transportation berm. Application of method helps reduce amount of overburden removal operations, cuts operating cost, ensures independent performing of mining work at every stage. EFFECT: higher efficiency.