Study on system of prevention and control of old goaf water during coal mine re-mining

Aiming at the technical problems for the prevention and control of old goaf water, taking an integrated mine which is seriously damaged by small kiln on the same thick coal seam as an example, we develop an advanced detection-guarantee system for roadway excavation with no blind area, propose multiple geophysical exploration in combination with two types of boreholes to explore and drain water technology; take the anomalous geophysical area as the target area, the conventional borehole with the largest water outflow as the target spot, at a low elevation of the mining area, and a remote directional borehole was used to drill into the old goaf along the stable rock strata below the coal seam floor to intercept the dynamic recharge water, which increased the efficiency of roadway excavation 4 times. The “isolated island” old goaf water in the mining face was controlled through multiple geophysical exploration combined with the full-coverage exploration technology. The rich water anomaly area and geological anomaly area were discovered, which ensured the safe passage of working face through goaf area. The technology for advanced short-distance exploration, advanced estimating, roadway exploration, and dynamic old goaf water with drainage was used to comprehensively guarantee real-time, safe mining. The application of system innovates the control technology of goaf water which is destroyed by small kilns in the upper layer and disordered distribution.