METHOD FOR PRESERVING PREPARATORY MINES IN LOW-STABILITY ROCK SOLIDS Russian patent published in 2004 - IPC

FIELD: mining industry.

SUBSTANCE: method includes determining convergence of preparatory mine before start of its driving, leaving in soil of preparatory mine during its driving of coal pack having power equal to mine convergence, and full extraction of this coal pack in case of equality in lowering of ceiling and raising of soil, during extraction of first adjacent coal column on the side of cleaning face(lava). In the mine a portion of pack is left having rectangular cross-section with width of no more than 0.5 of mine width with greater share of ceiling lowering in total convergence, or trapezoid shape with slant of side edge no less than angle of coal inner friction - with greater share of soil swelling in total convergence.

EFFECT: higher reliability level and no need for maintenance of mine for its operation in second use.

4 dwg