Revolutionary Gas Pre-Drainage Technology Boosts Safety in Outburst Mines.
Gas pre-drainage technology with boreholes drilled along the mining seam in an outburst mine can improve gas drainage by 40% using large diameter boreholes. Borehole gas drainage concentration is higher at drilling sites than in gateways, and sealing depth should be at least 5m. Two directional gas drainage boreholes should cover the entire coal mining face, with gateway borehole depth limited to 100m.