基于实验分析的彬长矿区4号煤层氧化起始温度及自燃倾向性分析研究

Initial temperature and spontaneous combustion tendency of 4#coal seam oxidation in Binchang mining area based on experimental analysis

为深入研究不同起始温度条件下煤样微观孔隙及官能团分布对煤自燃的影响,分别对彬长某矿在室温、30℃、40℃、50℃、60℃起始温度条件下进行了热重分析实验、红外光谱实验以及压汞实验,得出了40℃条件下,煤样的干裂温度远高于其他温度条件下的煤样,且其增速温度也最高,40℃的煤样官能团处于一个小峰值状态,与此相对应的,40℃的煤样在压汞实验中,孔隙度也很大,表明了此温度的煤样孔隙体积越大,暴露于空气中的活性结构就愈多,煤氧复合的程度加大,氧化速率增强,放热强度增大,热量越容易聚集,其自燃性也就越强。且40℃条件下小孔中孔数量较多,其比表面积大,为氧气提供了更多的吸附点,是吸氧量增加的主力军。此外,热重实验结果表明,40℃处理的煤样吸氧的温度最高,吸氧量最多,与40℃条件下煤样的小孔中孔多相对应,从热重吸氧层面上看,40℃煤样亦是最活泼的。因此,长期处于高地温的煤样煤自燃倾向性较大,活性较强,容易促进煤的自燃进程。

In order to deeply study the influence of micro pores and functional group distribution of coal samples on coal spontaneous combustion under different initial temperatures,thermogravimetric analysis experiments,infrared spectroscopy experiments and mercury intrusion experiments were conducted at room temperature,30℃,40℃,50℃and 60℃,respectively.It was found that the dry cracking temperature of coal samples at 40℃was much higher than that at other temperatures,and its growth rate was also the highest,The functional group of the coal sample at 40℃is in a small peak state.Correspondingly,the porosity of the coal sample at 40℃in the mercury intrusion test is also large,indicating that the pore volume of the coal sample at this temperature is large,the more active structures are exposed to the air,the greater the degree of coal oxygen recombination,the greater the oxidation rate,the greater the exothermic intensity,the easier the heat is to accumulate,and the stronger its spontaneous combustion.In addition,there are many holes in the small holes at 40℃,and their specific surface area is large,providing more adsorption points for oxygen,which is the main force for the increase of oxygen uptake.The thermogravimetric experiment results show that the coal sample treated at 40℃has the highest oxygen uptake temperature and the largest oxygen uptake,which corresponds to the number of holes in the small holes of the coal sample at 40℃.From the perspective of thermogravimetric oxygen uptake,the 40℃coal sample is also the most active.Therefore,the coal sample at high temperature for a long time has a greater tendency of spontaneous combustion,strong activity,and easy to promote coal spontaneous combustion process.