METHOD OF DEVELOPMENT OF CONNATE WATER FLOODED PLACERS Russian patent published in 2009 - IPC E21C41/30 E21C50/00 E02F3/88 

FIELD: mining.

SUBSTANCE: invention refers to development of connate gravel deposits of solid minerals, particularly beach deposits of shelf. The method of development of connate water-flooded placers consists in preliminary concentration of useful component of sands in a lower part of the placer by means of excitation of elastic vibration and in successive stopped excavation. A tubular casing is introduced into the placer; the height of the casing exceeds the distance from the surface to the raft of the placer, excitation of elastic vibration in placer sands is performed by means of their transmission from surface via the tubular casing. Further a compressive force onto contacting surface, covering volume of empty material, is exerted from the side of interior surface of the casing. Then lower part of placer is hydraulically excavated by means of supply of washing water through nozzles arranged at walls of the tubular casing; pulp is withdrawn through soil draw-off apertures made at walls of the tubular casing between nozzles. Also after completion of excavation of lower part of the placer, pressure onto the surface, covering volume of empty material contacting with interior surface of the casing, is dropped to zero. When the cavity of the casing has been filled to a level corresponding to a ground level, the casing is pulled off.

EFFECT: increased selective extraction.

3 dwg