METHOD OF UNDERGROUND HYDRAULIC DEVELOPMENT OF SOLID MINERAL DEPOSITS Russian patent published in 2009 - IPC E21C45/00 

FIELD: mining.

SUBSTANCE: invention refers to underground development of mineral deposits, particularly to hydraulic excavation. The method consists in exposure of deposit by means of boreholes, in hydraulic fragmentation of rock with pressure water jet, in disintegrating and in converting fragmented mass into slurry in a working face, in transporting slurry from the working face to a pulp receiving borehole, and in lifting slurry to surface; also, prior to lifting slurry to surface it is intensively mixed; its heavy barren part (barren rock) is settled on the bottom of the washed-out cavity, thus backfilling mined space; further, light-weighted part of slurry consisting of mineral pulp is sucked off to an upper section of the cavity, wherefrom slurry (concentrated water-coal fuel) is lifted to surface and is transported directly to a consumer via pipes.

EFFECT: realisation of method in this way eliminates necessity to concentrate slurry on surface, to pile rejects and, consequently, decreases land subsidence owing to left in thickness barren rock, which serves as backfilling material of mined space in this case.