METHOD FOR COMBINED MINING OF THICK ORE BODIES Russian patent published in 1995 - IPC

FIELD: mining industry. SUBSTANCE: method for combined mining of thick ore bodies includes extraction of ore by opencast mining down to design elevation of opencast bottom; preparation of drilling-and-haulage horizon on area of opencast deepening bottom of opencast; formation of common stoping district between underground and opencast areas; excavation of working trench towards slot by sections by blasting lower layer with the help of upward hole rings, and the upper layer by down hole rows of main and additional holes, with formation of spherical charges in additional holes; formation of space under overhanging rock mass by leading blasting of upward holes and blasting on it of charges of down holes; extraction of main reserves of level by adjacent trenches transverse to working trench in retreating with blasting of common sections by rings of upward holes and rows of down main and additional holes with displacement of hole rings in neighboring trenches relative to one another and overlapping of ends of counter holes; formation in process of blasting of rings of upward holes of ore receiving part of bottom in form of trenches and pillars above haulage drifts; partial drawing of ore from face area and full drawing of broken ore with lagging behind the blasting front. EFFECT: higher efficiency. 6 dwg