预氧化煤复燃行为演化特征及微观动力学机制  

Evolution characteristics and microscopic dynamics mechanism of recrudescence behaviors of pre-oxidized coal

作　　者：郭志国 张俊 郑彪华[1] 高懿伟 赵宇 GUO Zhiguo;ZHANG Jun;ZHENG Biaohua;GAO Yiwei;ZHAO Yu(School of Resources and Environment Engineering,Jiangxi University of Science and Technology,Ganzhou,Jiangxi 341000,China)

机构地区：[1]江西理工大学资源与环境工程学院,江西赣州341000

出　　处：《安全与环境学报》2023年第8期2644-2652,共9页Journal of Safety and Environment

基　　金：国家自然科学基金青年基金项目(51904120);江西省教育厅科学技术青年项目(GJJ180473)。

摘　　要：为探究不同预氧化程度煤的复燃行为演变特征及微观机制,采用程序升温试验、红外光谱测试和电子自旋测试对不同预氧化程度煤样进行宏观复燃特性与微观结构特征研究,测定复燃过程自燃特性参数以及活性基团与自由基的变化规律。结果表明,不同预氧化程度的煤在复燃过程中,耗氧速率和标志性气体(CO、CO_(2))产生率均低于原煤,表观活化能则均高于原煤,且预氧化至90℃煤的自燃特性参数相较于其他不同预氧化程度煤更接近于原煤;说明预氧化至临界温度的煤体自燃倾向性更高。其微观动力学机制是由于不同预氧化程度(60℃、90℃、120℃、150℃、180℃、210℃)煤中还原性官能团数量,其中—OH伸缩振动峰面积分别为10.37、10.92、9.85、9.58、9.42、8.94,脂肪族—CH伸缩振动峰面积分别为4.77、5.22、4.85、4.68、4.22、3.94,烷链—CH_(2),—CH_(3)峰面积分别为12.37、13.02、12.25、11.58、10.42、9.94,均小于原煤(分别为11.58、7.28、14.08),氧化煤较原煤与氧的结合能力减弱,而不同预氧化程度煤复燃过程自由基浓度平均增长率(分别为0.42、0.49、0.37、0.27、0.21、0.18)亦均低于原煤(0.74),氧化煤的氧化性相较原煤下降,且预氧化至90℃的煤还原性官能团数量与复燃过程自由基浓度平均增长率更接近于原煤,从而揭示了预氧化至临界温度时的煤比其他预氧化程度的煤更易复燃的内在原因。To research the evolution characteristics of resurgence behaviors and microscopic dynamics mechanism of coal with different pre-oxidation degrees,a study on coal samples macro resurgence characteristics and microstructure characteristics with different pre-oxidation degrees was carried out by using temperature-programmed experiment,infrared spectra,and electron spin testing,and the change rule of spontaneous combustion characteristic parameters,reactive group,and free radicals during the resurgence process was determined.The results show that during the recrudescence of coals with different pre-oxidation degrees,the oxygen consumption rate and production rate of landmark gases(CO,CO_(2))are lower than that of raw coal,while apparent activation energy is higher than that of raw coal.and spontaneous combustion characteristic parameters of coals with pre-oxidation to 90℃are closer to raw coal than other coals with different pre-oxidation degrees,indicating that coal pre-oxidized to the critical temperature has a higher tendency to spontaneous combustion.The micro-dynamic mechanism is that the number of reductive functional groups in coals is with different pre-oxidation degrees(60℃,90℃,120℃,150℃,180℃,210℃),the areas of—OH stretching vibration peaks are 10.37,10.92,9.85,9.58,9.42 and 8.94 respectively,the areas of aliphatic CH stretching vibration peaks are 4.77,5.22,4.85,4.68,4.22 and 3.94 respectively,and the areas of alkane chain CH_(2) and—CH_(3) peaks are 12.37,13.02,12.25,11.58,10.42 and 9.94 respectively.Both of them are smaller than raw coal(11.58,7.28,and 14.08 respectively),and the binding capacity of oxidized coal with oxygen is weaker than that of raw coal.The average growth rate of free radical concentration in the recrudescence process of coal with different pre-oxidation degrees(0.42,0.49,0.37,0.27,0.21,and 0.18 respectively)is also lower than that of raw coal(0.74),and the oxidizability of oxidized coal is lower than that of raw coal.The average growth rate of reductive functional gr

关 键 词：安全工程 氧化煤复燃 表观活化能 活性基团 自由基 

分 类 号：X932[环境科学与工程—安全科学]