煤—水双资源矿井
Coal-water double-resources mine
本质安全型矿井
intrinsically safe coal mine
intrinsically safe mine
大井矿冶遗址
the Dajing site of mining and smelting
低温矿井水
low temperature mine water
高产高效矿井
High output and high profit mine
high yield and high efficiency mine field
High Output and High Efficiency Mine
高铁高锰矿井水
mine water with high concentration of iron and manganese