在某些特定条件下,先采下部煤层,后采上部煤层的上行开采法,不仅在安全技术上是可行的,而且能取得较好的经济效益。我矿二号井曾于1978年10月至1985年4月在火成岩侵蚀严重的西四采区采用了先采下部9层煤,后采上部7层煤天然焦层的方法,从采空区上方安全地采出15万吨天然焦,获得了较好的效果。 Under certain conditions, the mining of the lower coal seam and the upper mining method of the upper coal seam after the first mining is not only feasible in safety technology, but also achieves better economic benefits. I mine in the second well from October 1978 to April 1985 in the serious igneous rock Xisi Mining adopted the first nine lower coal mining, after the upper part of the seven natural coal coke method adopted from the goaf Above the safety of mining 150,000 tons of natural coke, get better results.