METHOD OF BOREHOLE MINING OF THICK UNDERGROUND FORMATIONS Russian patent published in 2002 - IPC

FIELD: hydraulic borehole mining of placer deposits within wide range of mining and geological conditions. SUBSTANCE: method includes opening of formation by borehole through its entire thickness and formation working by a chamber coaxial to borehole with formation of connectors in the chamber to separate it into compartments in height. Connectors are formed by leaving pillars of mineral. Formation is worked in ascending order with filling of worked-out spaces after full working and solidification of fill mass adjacent to external surface of compartment, preferably with location on said area of hardening materials. In this case, after completion of filling of compartment worked-out space, connector is broken and its material is withdrawn. Besides, formations are worked with staggering chambers so that external surfaces of worked chambers form closed surface. Volume of formation located between worked chambers are mined without use of hardening materials. Filling of worked-out space of each compartment is carried out successively by alternating filling of incoherent fill material with formation of zones with use of hardening material. EFFECT: stability of chamber sides for period of its full working. 3 cl, 4 dwg