METHOD FOR RE-DEVELOPMENT OF GRAVEL DEPOSITS Russian patent published in 2012 - IPC E21C41/30 

FIELD: mining.

SUBSTANCE: method includes backfill in worked-out area of small-grain dump and further backfill of pebble dump on its surface using mined rock removed upon processing of solid placer and consequent extraction of material from dump removing particles of gold. Before re-processing of dump works for coarsening of gold particles sizes are performed. Before backfill of pebble dump silt-settling tank is formed in near-bedrock part of small-grain dump, for which purpose a barrier is formed on bedrock surface from water-proof, covering perimeter small-grain dump. After backfill of pebble fraction on surface of small-grain dump, dump is exposed during the time interval required for flushing of dump space by non-ramming water flows, then the dump is frozen preferably in two stages. Upon extraction of material from the dump its volume located above volume of silt-settling tank is removed without flushing. In order to flush volume of the dump by non-ramming water flows, natural water-borne sediments and/or forced feed of water to the dump surface is used. During formation of water-proof barrier water-proof film material is used in addition.

EFFECT: higher gold extraction efficiency during re-development of gravel deposits.

5 cl, 3 dwg