Research On Pressure Released Mining And Technology Of Gas Governance In Pan2Mine Of3Coal

Mine gas disasters are increasingly serious, especially gas outburst and explosionaccident. Coal mine gas control becomes the crucial problem of coal mine safety. For the prevention and treatment of multi coal seams mining and gas outburst, mining of first layer of unloading pressure and anti-reflection effect to eliminate the adjacent coal seams of coal and gas outburst hazard is economical effective and regional outburst prevention measure. Due to the high coal gas content and the prominent danger of huainan pan4coal, first of all, mining the3coal seam without gas outburst danger so that can make4coal unloading and reduce the gas outburst danger.By theoretical analysis, software simulation and field trials after extraction of first layer of the coal unloading rock mass stress distribution on the protective layer mining conditions, coal bed expansion deformation characteristics and fractured, coal seam permeability variation and seam permeability coefficient to optimization algorithm to carry out a systematic study. Numerical simulation was used to study the influence of initial mining on coal and rock stress distribution, vertical displacement on coal strata, expansion deformation, etc.; the paper makes measurement analysis of the working face mining engineering of unloading layer gas pressure, expansion deformation, permeability change rule and the effect of pressure relief gas extraction through actual.The engineering practice of first layer mining of pan2mine indicates that pressure relief layer of pressure relief effect is very ideal. The expansion of the actual measurement of pressure relief layer4coal seam deformation rates up to18.68%o.4coal seam permeability coefficient is0.054m2/MPa2·d. after coal seam mining,4coal seam permeability coefficient is31.95m2/MPa2-d, permeability has increased592times. Relief gas extraction for pressure relief lay by floor roadway network format wear layer drilling gas extraction technology finds that gas extraction rate of4coal seam within the scope of protection is as high as64.1%.Also the residual gas pressure relief layer is2.21m3/t, and the residual gas pressure dropped to0.16MPa. It indicates that pressure relief layer has obtained good pressure relief gas drainage effect and the gas content of coal of4coal seam within the scope of protected has got substantially reduce. It has already eliminated the outburst danger and can ensure the safety of pressure relief layer drilling.