PROCEDURE FOR DEVELOPMENT OF PLACERS Russian patent published in 2010 - IPC E21C45/00 

FIELD: mining.

SUBSTANCE: invention refers to mineral resource industry, particularly to development of placers of minerals including alluvial placers of valuable minerals and noble metals including gold, silver, platinum etc. The procedure includes making vertical borehole and drilling boreholes into zone of gravel product deposits which are washed out with hydro-monitors. Produced pulp is directed to the vertical borehole. The vertical borehole is drilled facilitating entry into underground mine working constructed below the placers in a zone of stable rock. Directional upward boreholes are drilled into the zone of placers from the said mine workings. The vertical and directional upward boreholes are cased with a through filter pipe and filter strings; also hydro-monitors are installed in the filter strings of directional upward boreholes. Screw or helical hollow pipe is axially transferred and rotated for cleaning a filter part inside the through filter string of the vertical borehole and for control of pulp flow from the placer. Flush fluid coming via pointed perforation in screw or helical hollow pipe is supplied along whole length of the filter part of the through filter string.

EFFECT: maximal complete development of placer and continuous extraction of mineral.

1 dwg