Research And Practice On Gas Control Technology In Dawan Coal Mine

The mining condition of Dawan coal field is complex and belongs to coal seam group mining,high gas content,high ground stress and geological structure.The gas control is hard and has seriously effect on the safe and efficient production.Therefore,it is necessary to research the gas control technology by rational mining deployment and has important significance to the safe and efficient mining of Dawan Coal Mine.This thesis takes west well gas control in Dawan Coal Mine as the research object.Based on the complex geology condition and coal seam occurrence condition,the gas occurrence law is studied based on the coal seam gas content and coal seam permeability coefficient measurement as well as industrial parameters analysis.According to the results of basic gas parameters measurement,the multivariate linear mathematical model and the single variate linear mathematical model of gas pressure and gas content of the No.9 and the No.11 coal seam are established separately for the West well of Dawan Coal Mine.The No.9 coal seam is determined as protective seam and The optimal mining sequence is the No.9,No.11,No.2,and No.7 coal seam.Based on the mining layout,the regional gas outburst prevention measures are put forward,and the arrangement of gas drainage gateways position as well as gas control scheme of mining face and adjacent layers are determined.Two "four in one" gas control technology for mine is established,and the control parameters are optimized to form an effective technical system of gas prevention and control.To verify the technical system,the gas control technology is carried out in the X10901 face based on the mining layout and entries arrangement.By the application of gas control technology,the gas drainage rate is improved,the gas emission from goaf into the mining face is reduced.and the problem of gas overrun at upper comer and return airway are solved.The gas concetration of the return airflow is controlled below 0.8%and over 510 thousand tons of coal is safely mined out.It has achieved a good economic and social benefit.