02
2019-12
Water conservancy punching hole making technology-beneficial mining drilling technology
Hydraulic punching refers to the method of using the water jet jetted by the drilling rig to flush out coal and methane in the outburst coal seam or induce controllable small outburst, so as to cause the coal body to relieve pressure, discharge methane and eliminate the danger of mining outburst.
2019-12-02
22
2019-11
22
2019-11
21
2019-11
19
2019-11
19
2019-11