METHOD FOR DETERMINING EMISSION HAZARD IN MINE WORKINGS DURING MINING OF COAL BEDS WITH HARD-TO-COLLAPSE ROOFS Russian patent published in 2019 - IPC E21F5/00 

FIELD: mining.

SUBSTANCE: invention relates to mining and can be used for prediction of emission of coal beds with hard-to-collapse roofs during mining operations. First, for each working cut, calculating the critical value of gas release intensity, then in the mine conditions near the interfaces with the ventilation or conveyor drift, five-seven wells are drilled successively, from which 1 l of the boring mincer is sampled, determining specific intensity of gas release and weighted average radii of particles of broken coal, after which experimental dependence of specific intensity of gas release on weighted average radius of particles of coal is plotted, and the current prediction of emission danger is performed when the length of the suspending perch of the rocks of the main roof is 50–60 % of the design value of the pitch of its secondary sediments, for this, from the lava at distance of 2.5÷3.5 m from ventilation or conveyor track, that is, on the side of the above- or below-lying mined-out space, the well is drilled along the bed strike with diameter of not less than 43 mm and depth of 2.5÷3.0 m, from which is taken 1 l of drilling fines, determining weighted average radius of particles of broken coal and plotting specific intensity of gas release, after which in given well is determined depth of coal destruction zone by measuring distribution of potential of natural stationary electric field (NSEF) relative to zero electrode, volume of destruction zone is calculated, value of gas release intensity is determined for the entire destroyed volume of coal and the obtained value is compared to critical value, after which conclusion is made on emission danger of this section of coal bed.

EFFECT: improving reliability of determination of outburst hazardous sections of coal beds at extraction groove.

1 cl, 2 dwg