Study On Water Injection Technology Of No.21 Coal Seam In Xindeng Coal Industry

In this paper,aiming at the current situation of a coal mine in Xinmi mining area where the concentration of dust is large and the effect of coal seam water injection is not ideal,the water injection of Xindeng coal mine is preliminarily studied by using fluent numerical calculation method.The wetting agent matching suitable for Xindeng coal mine is selected in the laboratory,the field effect is tested and the following factors are combined: Transportation Using the method of fluent numerical calculation and field test to study the pressure and time needed for water injection in the fully mechanized working face and driving working face,it is finally determined that the water injection pressure is about 2.5MP,and the water injection time is about 3 hours,which can achieve better water injection effect.Based on the analysis of the experimental results of surface tension,contact angle and coal dust deposition of the wetting agent compound solution,and considering the environmental protection,economy and easy to buy factors,it is determined that 0.25 kg sodium dodecyl sulfonate and 0.25 L sodium dioctyl succinate 1:1 are added to each cubic meter of water in the process of wetting agent preparation.Compared with the original coal seam water injection,the newly designed coal seam water injection technology has obvious effect on reducing the dust concentration when cutting coal in fully mechanized top coal caving face,especially the wetting of the original coal dust after water injection,which greatly reduces the production of respirable dust when cutting coal.Coal seam water injection can reduce the dust production in drilling,blasting and other processes,with obvious effect.Adding wetting agent can greatly improve the dust reduction effect of coal seam water injection,especially near the excavation head,the dust concentration is greatly reduced,and the production of respirable dust is reduced at the same time.