Study On Spontaneous Combustion Prevention Technology Of Fully Mechanized Caving Face In Small Coal Pillar Mining Island Coal Mine In Shuiliandong Mine

Shuiliandong 3803 coal mine fully mechanized face of coal pillar is a small,isolated island fully mechanized caving face,its high gas content,larger rock burst.The average thickness of the coal seam in the fully mechanized caving face is 10.4m,which belongs to the thick coal seam.The fully mechanized top coal caving process is adopted,and the amount of residual coal is large;3803 caving mining face both sides of each retain small 6.0m Pillar,Pillar burst leakage possible spontaneous combustion oxygen;With the 3803 mining face,adjacent to the mined-out area there is gas "breathing" phenomenon;In summary,the coal spontaneous combustion risk of the working face is large,and it is easy to cause secondary disasters such as gas explosion.In this paper,for the coal face of spontaneous combustion control,guarantee the safe production of fully mechanized caving face by studying the spontaneous combustion hazard warning technology.Combined with the characteristics of the fully mechanized caving face of the small coal pillar of 3803,the comprehensive index evaluation method is used to evaluate the possibility of high impact ground pressure on the surface.The main affected area is the 3803 fault and structural zone,small coal pillar and soft coal belt..Through the temperature prograrmmed experiment,it is determined that CO,R2 and C2H4 are the main indicators for the spontaneous combustion early warning of the 3803 island coal of Shuiliandong Mine,and the corresponding relationship between the gas index and the temperature range is obtained.Based on ANSYS Fluent,the seepage field in the goaf and adjacent goaf is simulated.Based on the monitoring data and the spontaneous combustion test of coal,the coal spontaneous combustion danger zone in the 3803 mining process is divided to determine the oxidation temperature of the 3803 goaf.The belt is about 40m wide on the transport side and 35m wide on the return side.By analyzing the dangerous area of the small coal pillar subjected to the impact ground pressure,the small coal pillar is crushed by the strong impact ground coal column in the range of 450?1120m from the cutting hole and 350?1300m in the return airway.Combined with the numerical simulation results and the characteristics of coal spontaneous combustion in adjacent goafs,the dangerous area is judged,and it is concluded that the two-slot floating coal in the adjacent goaf is thicker and prone to coal spontaneous combustion.According to the classification of coal spontaneous combustion danger zone and the characteristics of each zone,it can effectively prevent coal spontaneous combustion by adopting fire prevention measures such as plugging,nitrogen injection,grouting,liquid CO2 injection and air volume adjustment to ensure the safe recovery of the working face,and is an isolated island of other mining areas.Provide reference for coal spontaneous combustion prevention in the working face.