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

FIELD: borehole mining of placer deposits in wide range of mining and geological conditions. SUBSTANCE: method includes tapping of thick underground formations by boreholes through entire thickness of formation and its working with chamber coaxial to borehole with formation in chamber of connectors separating the chamber in height into compartments. Connectors are formed by leaving mineral pillars. Working of formation is carried out in ascending order, with filling of worked-out space of compartments after their complete extraction. IN so doing, before completion of process of filling of compartment, applied to connector overlapping the compartment is supporting force, for instance, by formation under connector of layer from nonbound particles of material with positive buoyancy. After completion of filling of worked-out space, connector is broken and its material is withdrawn. In addition, particles of material with positive buoyancy are not introduced at the stage of breakage of connector into water, supplied to column of hydraulic monitor unit. EFFECT: ensured stability of chamber sides during period of chamber full working. 2 cl, 2 dwg