METHOD FOR UNDERWATER PLACER DEPOSIT DEVELOPMENT Russian patent published in 2008 - IPC E21C50/00 

FIELD: mining, particularly to develop deposits in shelf adjoining shore line.

SUBSTANCE: method involves forming enveloping structure made as closed barrier, which surrounds placer deposit area, extending from bedrock to water surface; separating space inside enveloping structure in at least two chambers; introducing excavation equipment for placer material mining inside chambers after enveloping structure forming; mining placer material in the first chamber; excavating placer material in the next chambers with tails stacking in previous chamber up to level of not less than water area bottom; removing enveloping structure chambers from the goaf side of mining area adjoining chambers from which placer material is excavated and forming thereof in immediate proximity to chambers from mining propagation side.

EFFECT: increased mining completeness, provision of inner enveloping structure cavity dimension independence of placer deposit thickness in capping rock presence.

5 cl, 4 dwg