Prevention And Control Technology Of Compound Disasters Under Complex Goaf In Yuanbaowan Coal Mine

In the early development of coal resources in China,due to the limitations of mining equipment and mining back production technology,a considerable part of mine fields adopted chamber and pillar mining or heading and pillar system,resulting in a large amount of waste of coal resources,and at the same time,a large number of coal pillars remained in the goaf after coal seam mining.With the integration of national coal resources and the expansion of coal mining in recent years,reconstruction of mines is often faced with the mining of coal seams under complicated mined-out area.However,the old kilns,chambers and columns and other complex goaf areas have long been formed,which bring a series of problems such as roof collapse,water burst,toxic gas inrush,fire and so on.Based on this background,this paper studies the composite disaster prevention and control technology of roof and gob stopping on the6105 working face of Yuanbaowan coal mine.Based on the existing data of Yuanbaowan coal mine and the actual situation of the site,this paper makes an in-depth analysis of the mining problems faced by the 6105 working face of Yuanbaowan coal mine.According to the analysis results,the three-dimensional prevention and control technology for the combined disasters of roof,water and fire in 6105 working face is proposed:(1)Before mining:Blasting and weakening roof treatment technology is adopted for roof prevention and control.Flood prevention and control adopt drilling field near stop-mining line of6105 working face and water accumulation technology in goaf of longwell working face of 4~#coal seam during exploration.Fire prevention and control adopt the technique of pressure-sharing ventilation and fire prevention technology.(2)During the mining process:The comprehensive treatment technology of roof crack caused by hydraulic fracturing is adopted for roof prevention and treatment.Flood prevention and control adopt the method of unified planning of the scheme of water release and hydraulic fracturing.The drilling field is set up in the inlet and return duct of the 6105 working face,and drawing the water accumulation in goaf of chamber and pillar of 4~#coal seam.The prevention and control of fire adopt the techniques of pressure-sharing ventilation technology,nitrogen injection technology,grouting technology,air leakage sealing technology and monitoring technology.(3)The period of final mining and withdrawal from production:Roof treatment using hydraulic fracturing weakening roof technology.Flood prevention and control adopt the method of unified planning of the scheme of water release and hydraulic fracturing.The drilling field is set up in the inlet and return duct of the 6105 working face,and drawing the water accumulation in goaf of chamber and pillar of 4~#coal seam.Fire prevention and control adopt such technologies as reasonable control of wind,reduction of residual coal,isolation of goaf,monitoring and control,nitrogen replacement,end sealing of air leakage,goaf inerting and acceleration of advance speed.After implementing the three-dimensional prevention and control technology of complex goaf under the complex goaf at the 6105 working face of Yuanbaowan coal mine,the results of field monitoring and actual production show that the effect of the three-dimensional control technology is obvious,which not only ensures the safety of workers and equipment,but also realizes the safe and efficient mining under complex goaf conditions.The research results have significant reference significance for similar projects.