METHOD FOR BOREHOLE MINING OF PERMAFROST SEDIMENTARY ROCK Russian patent published in 2007 - IPC E21C45/00 

FIELD: mining, particularly mineral mining by hydraulic borehole mining and underground accumulation reservoir construction.

SUBSTANCE: method involves uncovering productive seam 1 with borehole 2; installing water-supply 3, 4, air-supply 5 and sludge lifting 6 pipe strings in the borehole; supplying water from water pool; delivering compressed air; cutting productive seam to create underground chamber 7 by water-and-heat rock breakage and resultant hydromixture lifting to ground surface along with maintenance of predetermined water-air level 8 at productive seam roof in chamber 7 by supplied water and air flow regulation; additionally delivering heated water in borehole 2, wherein heated water rate is less or equal to volumetric flow rate of solid permafrost sedimentary rock to be cut contained in the hydromixture to be lifted. Water from water pool is supplied into underground chamber 7 under lower level of sludge-lifting pipe string 6 at flow rate equal or exceeding water flow rate in above hydromixture.

EFFECT: increased efficiency of permafrost sedimentary rock mining due to extended mining season along with relatively low power inputs.

1 dwg, 1 ex