Study And Application Of Comprehensive Treatment Of Coal Spontaneous Combustion Technology On Longwall Top Caving Mining Method In The Coal Seam Within Very Close Distance

As Longwall Top Caving Mining Method has lots of strongpoint, such as highefficiency, low cost, it is widely used in those years. But this method has someshortcoming, such as losing much coal, easily spontaneous combustion, and not easyto control when the coal burning and so on, coal spontaneous combustion problem ismore severity in the coal seam within very close distance. So taking effectivetreatment of coal spontaneous combustion in the coal seam within very close distanceis the key to ensure Longwall Top Caving Mining Method mine coal safely andefficiently.In this paper, taken Chaili Coal Mine as background, we take the method ofintegrating theory and technology of fire prevention and control with practice in orderto study on comprehensive treatment of coal spontaneous combustion technology onLongwall Top Caving Mining Method in the coal seam within very close distance andapplying the technology to extinguish fire on the spot.（1）Summarized the law of coal spontaneous combustion in fully-mechanizedtop caving Face in the coal seam within very close distance. Summarized the law ofprocess of coal combustion and coal spontaneous combustion in fully-mechanized topcoal caving face in the coal seam within very close distance, we came to the followingconclusions: when C₃H₆arise on the scene, the high-temperature area is at theoxidation accelerating stage and we must get rid of the fire as soon as we can; whenthe concentration of C₃H₆is more than50ppm, the high-temperature area is more than200℃，and the area would light up quickly; a quantity of abandoned coal intransportation tunnels, railway transport, open-off cut and stop line in gob of workingface in Low-part and up-part of seam No.3is inflammable area and the emphasis ofprevention and control in Fully Mechanized Top Coal Caving Mining in Low-part ofcoal Seam No.3.（2）Analyzed the fire prevention system of fully mechanized caving face in thecoal seam within very close distance in depth and perfect it. We analyzed the fireprevention system of Chaili mine and improved the technology of temperaturemeasuring in the drill hole and gas analysis, and got the conclusion that combining thetechnology of temperature measuring in the drill hole with significant gas analysis toget precise location of fire is an efficient method to detect the position of fire source.（3）Using fault tree analysis method guides the management of fire preventionand control of fully mechanized caving face. Go to the scene of fire prevention and sum up basic events relevant spontaneous combustion, and set up fault tree ofspontaneous combustion accident on Longwall Top Caving Mining Method in thecoal seam within very close distance and using the method of accident tree analysis.We come to the following conclusions: basic events relevant failures, such as isolatedfully-mechanized working face mines near the fire zone, layout of separate zoneroadway vertical,the longtime support removal of the Fully-mechanized Face and soon, may cause spontaneous combustion directly; when the tings, such as open-off cutdriving or mine in initial mining stage slowly, using too much time to install thesupport and so on, may cause the coal in pen-off cut longtime oxidize, we shouldenhance the fire prevent and control management in pen-off cut, or the coalspontaneous combustion accident may occur.（4）On field application of fire prevention system and fire prevention technologyin Fully Mechanized Caving Face in the coal seam within very close distance. Wedesigned the plan of fire prevention in Full-mechanized Caving23603mining face,and took comprehensive treatment according to fire situation and got rid of large-areaspontaneous combustion in finish line of up-part of seam No.3completely. We cameto conclusions: the key of the treatment of Large-area high-temperature spontaneouscombustion was that: taken measures, such as spraying in entry, inject nitrogen intoabandon coal area and so on,to stop the fire making progress; got the precise positionof fire source in the coal seam within very close distance by combining thetechnology of temperature measuring in the drill hole with significant gas analysis;got rid of the high-temperature hidden danger by using drilled hole expending methodto inject gel, grouting to high-temperature area by many turns.