改性高岭土抑爆剂对瓦斯煤尘复合爆炸压力的影响

瓦斯煤尘复合爆炸严重影响了煤矿的安全生产,造成了大量的生产损失与人员伤亡。研发能应用在煤矿中高湿低温等复杂环境中的抑爆剂成为了研究的难点与热点。为研发出新型改性高岭土瓦斯煤尘抑爆剂,通过插层改性的方法制备了3种改性高岭土抑爆剂,采用热重分析、扫描电镜和红外光谱分析对样品的热稳定性、表面结构以及官能团变化进行了研究。选用重庆南桐煤样,通过标准筛对煤样进行筛分,通过粒径扫描与扫描电镜观测了煤粉的粒径分布与表面形貌。使用20 L球型爆炸系统对抑制剂抑制瓦斯煤尘爆炸的特性进行了研究,探究改性后高岭土对爆炸最大压力、最大压力上升速率及爆炸峰值时间等爆炸特征参数的影响;基于粉体表征结果及抑爆数据对改性高岭土抑制作用下的瓦斯煤尘爆炸的抑爆机理进行了分析。结果表明:改性高岭土抑爆剂兼具高岭土及插层粒子的双重抑爆效果,改善了高岭土的团聚现象,同时氨基磺酸铵粒子提升了高岭土的热解与抑爆性能。对瓦斯煤尘复合爆炸的抑制性能明显优于改性前粉体,且抑爆效果随着抑制剂质量浓度增加而增大,存在临界质量浓度,试验表明,当改性高岭土与煤尘比例为2∶3,且质量浓度为0.175 g/L时,最大爆炸压力的降幅达到了32.6%,爆炸峰值时间延缓了0.45 s,展现出最佳的抑爆效果。

Influence of modified kaoline inhibitor on the explosion suppressionpressure of the methane-coal dust mixture

Gas and coal dust explosion accidents have seriously affected the safety of coal mine production,resulting in a large number of production losses and casualties.The research and development of explosion suppressants that can be used in complex environments such as high humidity and low temperature in coal mines has become a difficulty and hot research topic.In order to develop a novel type of modified kaolin methane-coal dust explosion inhibitor,three modified kaolin explosion inhibitors were prepared using the intercalation modification method,and the thermal stability of the samples was analyzed by thermogravimetric analysis,scanning electron microscopy,and infrared mass spectrometry.Surface structure and functional group changes were studied.A sample of Chongqing Nantong coal was selected,and the coal sample was sieved through a standard sieve.The particle size distribution and surface morphology of the coal powder were observed by particle size scanning and scanning electron microscope.The 20 L spherical explosion system was used to study the inhibitor’s characteristics of suppressing coal dust and gas explosions.The effects of different types and different concentrations of modified kaolin inhibitors on explosion overpressure,pressure rise rate,and time to peak pressure were explored.The results of powder characterization and explosion suppression data were used to analyze the explosion suppression mechanism of gas and coal dust explosion under the suppression effect of modified kaolin.The results show that the modified kaolin anti-explosion agent has the dual anti-explosion effects of kaolin and intercalated particles,and improves the agglomeration of kaolin.At the same time,the ammonium sulfamate particles enhance the pyrolysis and explosion suppression properties of kaolin.The suppression performance of the methane-coal dust composite explosion is obviously better than that of the powder before modification,and the explosion suppression effect increases with the increase of the inhibitor concentration,and there is a critical concentration.The experiment shows that when the ratio of modified kaolin to coal dust is 2∶3,and the volume concentration is 0.175 g/L,the maximum explosion pressure drop reaches 32.6%,the peak explosion time is delayed by 0.45 s.The explosion suppression effect is best.