Study And Application Of High-water Content Sealing Material For Extinguishing Coal Mine Fire

Coal spontaneous combustion is the disaster in coal mine which threatens workers'safety and property seriously, affects the social stability and hinders the sustainable development of coal industry. Continuous supply of oxygen is the necessary condition for spontaneous combustion of coal, plugging the wind and cutting off the oxygen supply to loose coal can be effective ways in combating spontaneous fire. In this paper, based on the characteristics of coal mine fire and combustion conditions, a study and application of high-water content sealing material for extinguishing coal mine fire were launched.Firstly, the main components and its proportion to prepare high-water content sealing material for extinguishing coal mine fire were studied. Superabsorbent was selected as the main component of sealing material, according to the reaction mechanism of free radical, through a large number of experiments, superabsorbent was synthesized by AA-CA dimmer, initiator and crosslinker. Through the orthogonal experiments, the optimum conditions of synthesis and technology were studied to choose the best proportion which has high absorption rate, little impact of salt and simple process The results show that the optimum conditions: the neutralization degree of AA-CA dimer was 80%, the initiator concentration was 0.025%, AA-CA:HEMA=95:5, the crosslinker concentration was 0.04%. The maximum absorbent rate of the sealing material synthesized under these conditions was up to 786g/g.Then, by adding inert powder dispersant HV into sealing material, to improve the thermal stability, moisture absorption and so on, the results showed that the best rate of dispersant and organic component was 2:1; Through the experiments about the relationship between consumption and performance of sealing material, the general dosage should be controlled at 2%. A great number of results showed that the sealing material has high-water absorption, cementing property, inhibiting property, plugging performance and other features of fire prevention and extinguishing.Finally, the high-water content sealing material was successfully used in controlling coal spontaneous combustion in Pingan mine and Huangling1# mine region. It was added less, fire resistance is good, process is simple, it solves the problems of sealing the seam leakage and lowering coal temperature. It is a good sealing material for preventing and extinguishing coal mine fire and has great application value.