Research On Prevention And Control Technology Of Spontaneous Combustion Of Rock Burst Coal Seam In XINGAN Coal Mine

Because of the rock burst causing coal breaking,the advance speed is difficult to increas and supporting roadway with narrow coal pillar or without pillar generally using to assign the mining face,the self-ignitability of the spontaneous combustion coal seam has been exacerbated,and also the difficulty of natural fire prevention has increased significantly.To coordinate the relationship between rock burst and spontaneous combustion,reveale the spontaneous combustion rule of residual coal in large area of composite goaf,which formed by the impact breaking coal and anthracitic column mining,we carried out the following study.We determined the parameters of coal oxidation dynamics throught making spontaneous adiabatic oxidation experiments,established the mathematical model of spontaneous combustion of remnant coal to analysis the air leakage and spontaneous combustion rules in crush coal and composite goaf area,and then according to the experimental and theoretical research results,the comprehensive control measures for spontaneous combustion coal seams firing under the impact of rock burst were proposed.The results show that:The adiabatic oxidation and heating simulation system is established,carry out the adiabatic oxidation and heating experiment of coal sample by using pure oxygen.Testing the temperature,and the concentration of oxygen,and oxidation products,methane,and so on.The dynamic parameters including oxygen uptake rate,oxidation products formation rate,maximum and minimum exothermic intensity,activation energy,and shortest spontaneous combustion period and so on are analyzed,computed and calculated,according to the theory of oxidation thermal dynamics.The oxidation kinetics parameters and characteristics of 11 coal from xingan mine are clarified,that can provided the basic parameters and variables for the numerical simulation of spontaneous combustion of the crush coal and the residual coal in composite goaf.A multi-field coupling model for spontaneous combustion of crush coal is established,by using the software of COMSOL Multiphysics 5.02D,in this multi-field coupling model,the Brinkman equation(BR),material transfer equation(TDS)and heat transfer equation(HT)are effectively coupled by temperature,wind pressure and velocity,concentration.A series of numerical analysis of spontaneous combustion of crush coal is accomplished,under six different crushing states and different air pressure conditions.The range of easily spontaneous combustion porosity and area of crush coal are determined,and the relationship between air pressure difference and spontaneous combustion of broken coal is clarified,according to the distribution of spontaneous combustion temperature and oxygen concentration.A multi-field coupling numerical simulation model of spontaneous combustion and prevention and control of composite goaf is established,by using the software of COMSOL Multiphysics 5.02D,that coupled free and porous media flow field,porous media material flow,porous media heat transfer,and dilute material transfer,and total of four physical fields.Simulation study on the influence law of non-coal pillar mining and the mortar grouting and nitrogen injection on spontaneous combustion in composite goaf,analyze the distribution law of air leakage and oxidation zone.The law of spontaneous combustion of residual coal in composite goaf under the condition of non-pillar mining was determined,and the process parameters of plugging and nitrogen injection to prevent and control the spontaneous combustion in the combined goaf such as were determined.The above research work provide theoretical and technical support for the prevention and control of coal spontaneous combustion in large area composite goaf without coal pillar mining.According to field test,the adiabatic oxidation experiment and numerical simulation results,combine with the field reality,puts forward the central district 2 working face under the influence of rock bursts during excavation and mining roadway with comprehensive prevention and control technology of goaf spontaneous combustion coal pillar in Xingan 11#coal mine,used the reinforced support,note ash plugging,roadway driving along goaf roadway repair,and combining with the implementation of artificial isolation ash column with old cavity plugging and buried pipe and borehole injection nitrogen combination of comprehensive prevention and control measures.During the guarantee the mining face no impact ground pressure and spontaneous combustion accident happens,achieved the production safety,the composite impact ground pressure and spontaneous combustion disaster has been effectively controlled.There are 53 figures,20 tables,127 references in this paper.