Experimental Study On Fire Prevention And Extinguishing Performance Of Mine High Water Capsule Material

China is rich in coal resources,but at the same time,the accidents and disasters in coal mines are also very serious,and the most important thing in coal mine disasters is the pHenomenon of spontaneous coal seam fires.With the improvement of coal mine safety requirements,the problem of spontaneous combustion of coal seams in coal mines has gradually changed to a treatment method that focuses on prevention and combines prevention and control,which puts forward higher requirements for mine fire-fighting materials.In this paper,by investigating the current fire-fighting materials and combining the spontaneous combustion mechanism of coal,a high-water capsule fire-fighting material is developed based on sodium alginate and light calcium carbonate,and gluconolactone as a slow-release agent.Taking the initial setting time and water holding capacity of gaoshui capsule as the optimization index,the selection of different use conditions was determined:when better fluidity and slower molding speed were needed,the proportion of gaoshui capsule was 2%SA+0.5%PCC+1%GDL,and the molding time was 4.5min;When more water holding capacity and faster molding speed are needed,high water capsules with the ratio of 2.5%SA+1%PCC+1%GDL and molding time of 2.5 min can be selected.By testing the effects of temperature and pH on high-water capsules,it is determined that the optimal conditions for preparing high-water capsules are temperature lower than 40? and pH 6-7.Through the thermal stability test and the sealing and cementing experiment,it is proved that the high water capsule has good heat resistance and plugging effect,and has the ability to adhere to the coal body.Through temperature-programming experiments and thermogravimetric experiments,it is found that the high-water capsules reduce the concentration of the iconic gas and can delay the characteristic temperature point and increase the activation energy of coal oxidation,indicating that the high-water capsules can effectively inhibit the spontaneous combustion process of coal in the low temperature stage.Infrared spectroscopy experiments are used to study the micro-resistance mechanism of high-water capsules.The results show that high-water capsules mainly suppress coal spontaneous combustion by reducing the activity of Ar-C-O-,-COO-,-CH3,-CH2 and-OH in coal.Finally,the fire extinguishing performance of the high-water capsule was tested through small-scale fire-extinguishing experiments and medium-scale fire-extinguishing experiments.The results showed that the high-water capsules can effectively extinguish coal fires and can be used as coal fire extinguishing materials.