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 two adjacent closed structures, which surround placer deposit area, extending from bedrock to water surface with the use of plates having vertical edges to be releasably connected with that of at least two adjacent ones so that one plate is used as structure partitioning wall, wherein enclosing structure creation is carried out by serial plate insertion up to bedrock with simultaneous plate edge connection with each other; introducing excavation equipment for placer material mining inside structures after enveloping structure forming; mining placer material in the first structure; excavating placer material in the next structures with tails stacking in previous structure up to level of not less than water area bottom; creating next enclosing structures by serial plate removal so that one plate side touches massif surrounding excavation area and another side thereof is in contact with filling massif including tails or both plate sides touch filling massif; serially inserting removed plates in deposit up to bedrock along with plate edge connection with that of plates adjoining enclosing structures to be developed. New enclosing structures are created from mining propagation side.

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

6 cl, 4 dwg