Water-preserved mining with the method named “backfilling while mining”

In view of the problems such as the shortage of filling time and filling space,the difficulty of coordination between coal mining and filling operation and so on,the new method named “backfilling while mining” was applied to water-preserved mining. In the mining of process,all the roadway in the mining block is divided into several mining stages. The work on the roadway’s mining and filling in the next stage begin when the previous stage’s work are fin- ished. With the work on all the roadway’s mining and filling finished,the filling body will substitute coal absolutely. For the purpose of the roadway’ s sides being solid coal or filling body reaching the designed strength,the roadway should be excavated alternately. The research results are applied to Wangtaipu coal mine. Field practice shows that un- der the condition of the mining rate of the whole block reaching 96. 8% ,and the surface deformation is less than the Grade I damage index,the shallow water resources will be preserved effectively. The method applies the mining pattern of “backfilling while mining” so it can realize the advantage of fast continuous mining and backfilling mining and a- chieve the work on water-preserved mining.