METHOD OF UNDERGROUND MINING OF KIMBERLITE PIPE BURIED UNDER SEDIMENTARY ROCKS IN PERMAFROST ZONE Russian patent published in 2001 - IPC

FIELD: mining, particularly, technology of ore underground mining; applicable of kimberlite pipes located in permafrost zones and covered with sedimentary rocks with high ice content and swampy day surface. SUBSTANCE: method includes laying of layer of foam hardening heat-insulating material to preserve frozen mass in pipe mining; drilling from day surface of spiral working from which sets of holes are drilled; separation of frozen mass above kimberlite pipe into blocks by explosive charges installed in holes; excavation of chambers in kimberlite pipe on contact with covering rocks; caving of pillars between chambers together with separation of frozen sedimentary rocks into blocks; working of the second stage by technology of sublevel caving with partial drawing of ore. After ore breakage at the second stage, stored ore is drawn by technology of simultaneous dosed vibration drawing. EFFECT: high safety in deposit mining, reduced losses and impoverishment, and increased mining productivity. 18 dwg