Technology And Economic Analysis Of Zero Coal Pillar Backfill Mining In Suncun Coal Mine

In China’s coal mines,there are huge "three down" coal compactions and remaining coal pillars.How to mine them safely and efficiently is a key topic of the research.This article took Suncun Coal Mine as the background and proposed a safe,environmental and efficient zero coal pillar filling mining technology,combined with the continuous mining and continuous charging technology of Yuxing Coal Mine.It also developed efficient and fast setting environmental protection filling materials.Through laboratory test,numerical simulation and field test,the feasibility of zero coal pillar filling and mining was studied and it designed the key parameters.Through the experiment of filling material ratio,the best ratio of slurry to gangue was 1:5 and the mass concentration was 70%.The numerical simulation results showed that the zero coal pillar filling mining could effectively reduce the vertical stress of the coal pillar roadway on the working face from 14.46 MPa to 13.25 MPa,and the maximum compressive stress of the coal pillar was significantly reduced.In addition,during zero coal pillar filling and mining,the filling body could effectively support the roof and indirectly enhance the bearing capacity of the coal pillar.F urther research found that after filling the early setting backfill,the stress of the coal pillar roadway of the working face was further reduced to 13.25 MPa.Therefore,when mining with zero coal pillar,it is necessary to use early setting filling material,which can achieve the best effect of mining with zero coal pillar filling.The key parameters of zero coal pillar filling mining were designed,and the calculation methods of roadway size,filling body strength and size and bolt support parameters were obtained.Combined with the actual conditions of Suncun Coal Mine,some key parameters of the zero coal pillar filling mining test area were calculated.The roadway in the test area was 2.5m high and 5.0m wide,and the strength of the filling body is 3.0MPa.The roof is supported by Φ 20mm × 2000mm anchor bolts with row spacing of 1400mm × 1500mm;the side is supported by Φ 20mm ×2000mm anchor bolts with row spacing of 1200mm × 1500mm.The field industrial test results showed that under the influence of mining,the safety factor of the stability of the coal rock mass after zero coal pillar filling mining has increased by about 50%compared to the stability factor of the coal rock mass under normal mining conditions.The deformation of surrounding rock of some roadways was about 4%more than the initial value,and the deformation of surrounding rock was effectively controlled.According to the economic results,the cost per ton of coal in Suncun Coal Mine was reduced by 40.4 yuan under the condition of zero pillar filling mining.The safe,efficient and environmental protection zero coal pillar filling mining technology meets the requirements of scientific mining,and can realize the safe,efficient and environmental protection production of coal mine.At the same time of protecting environment effectively,it can also bring great economic benefits to coal mines,and has a strong prospect of pro motion.