| Popis: |
Random mining by small coal mines left many destruction districts with a large range in Fenxi mining district. According to incomplete statistics, the destroyed areas by small coal mines amount to nearly one hundred square kilometers and have over three hundred million tons of resource reserves in Xinliu, Xinyu and Xinyang these three fields. Small coal mines tend to use outdated techniques such as replacing mining with advancement, small excavation with large stoping and room pillar mining technique, which have a stoping rate of only 10% to 25%. Some of the wellheads were not closed seamlessly, which resulted in self-combustion; some were damaged due to the mining of the lower coal seam. A serious security risk existed during the mining of the lower coal seam due to the uncertainty of gas, water and roof pressure. In addition, the destructed area by small coal mines is badly large in Shanxi Province and even the whole country which remains a huge amount of resources. The implementation of this subject is significant. |
