Research Of The Spontaneous Combustion Characteristic And Prevention Technology Of Complex Mining Coal Seam In Hegang Mining Area

In Hegang mining area,Complex geological conditions,coal seam thickness,large dip Angle,more easy spontaneous combustion of coal seam mining and shallow buried factors lead spontaneous combustion problem to outstanding,and governance is difficult.So,Aimed at spontaneous combustion hazards that the complicated condition of Hegang mining area coal seam mining facing,I use theoretical analysis?experimental research?numerical simulation and field measurement to have coal spontaneous combustion characteristics and comprehensive prevention and control technology research.The main research results are as follows:Using the method of combining thermal analysis technology and the theory of activation energy,to determinate Hegang mining area coal seam spontaneous combustion tendency,the results show:ignition activation energy of the main working bed is between 73.92?109.79 kJ/mol.All coal have spontaneous combustion tendency,Including I class easy spontaneous combustion of coal seam for more than 80%.Build coal spontaneous combustion gas product simulation experiment device,complete the analysis optimization of each index gases,determine CO?Ci2H4?C2H4/C2H6 as Hegang mining area coal seam spontaneous combustion prediction index.Based on the fluid dynamics?mass transfer heat transfer theory and coal and oxygen compound theory,combining with actual conditions of Hegang mining area,the paper establish the complex conditions of mining coal seam spontaneous combustion mathematical model and give the methods for determining key parameters such as intensity of Oxygen release from coal combustion?porosity distribution of coal and rock under the influence of coal seam dip angle?residual coal thickness.According to the complicated mining conditions of Hegang,such as close coal seam,shallow burial rich coal seam and large inclination thick coal seam,the spontaneous combustion danger zone is divided and the spontaneous combustion law is analyzed.In the condition of large-angle thick coal seam mining,the spontaneous combustion's danger area of the goaf is in "L"shape,and the maximum temperature is 69 ? in the middle of the mined-out area.Under the conditions of close coal seam mining,the upper goaf's spontaneous combustion's danger zone is concentrated at the inlet and near the stop line and the maximum temperature is up to 50 ?.The upper goaf is affected by the upper coal caving and the maximum temperature is 60 ?.Spontaneous combustion's risk is greater.Under the condition of mining in the shallow coal seam,the residual coal body and the remaining coal in the goaf are in the high oxygen concentration air leakage environment,there is no obvious asphyxiation zone,and there are large temperature hidden trouble,residual coal mining's highest temperature was 64 ? and the vacant region's highest temperature is 57 ?.The fire prevention and extinguishing system of grouting,injecting nitrogen and spraying inhibitor in goaf of complex condition was established.The numerical simulation was conducted to analyze the grouting diffusion law of mined-out area.With the index of the coverage of oxide belt and the presence of running slurry,the reasonable position of grouting under different inclination conditions was given,and the best grouting The location is 45m away from the working surface;The influence of nitrogen injection location and nitrogen injection on the distribution of spontaneous combustion "three zones" in goaf was studied.The reasonable nitrogen injection location was from the working face 30 50m and nitrogen injection is 540?720m3/min.The inhibition mechanism of the coordination agent of the inhibitor was analyzed,and the MgCl2 solution with concentration of 15%was selected as the index of the change of activation energy of the coal sample under the effect of the inhibitor.The comprehensive prevention and control of multi-area spontaneous combustion fire in complex condition coal seam with the combination of roadway filling and sealing,coal drilling and water injection grouting in working face,grouting in old road detection grouting and ground crack backfilling and sealing.