METHOD FOR WORKED-OUT PIT AND CAVING AREA RECLAMATION IN PERMAFROST ZONES Russian patent published in 2008 - IPC E21C41/32 

FIELD: mining, particularly to recover surface and reclaim worked-out pits.

SUBSTANCE: method involves filling worked-out space with ice-rock filler made as ice prism frozen by water sprinkling method in cold season with the use of negative frozen rock temperatures; covering ice prism with loosened overburden layer having thickness exceeding seasonal ground thawing depth. Voids located under pit bottom or under caving areas are preliminarily suppressed. Heat-insulation material layer is laid on pit bottom or on caving area bottom and heat-insulation material is covered with water-tight film. System including vertical and inclined wells, as well as horizontal tunnels is built over the film in several stages so that the wells and tunnels are communicated with each other. The wells and tunnels have solid walls and uniformly penetrate worked-out space. The tunnels and wells are opened in ground surface and have lids frozen in ice prism. The lids are opened in cold season and closed in warm season.

EFFECT: increased reclamation efficiency.

3 cl, 2 dwg