Jia Baoshan, Chai Zihao, Zhao Wanting, Wu Xian
College of Safety Science and Engineering, Liaoning Technical University, Fuxin, Liaoning, China.
Key Laboratory of Mine Thermodynamic Disaster & Control of Ministry of Education, Liaoning Technical University, Huludao, Liaoning, China.
PLoS One. 2025 Jan 7;20(1):e0316705. doi: 10.1371/journal.pone.0316705. eCollection 2025.
To investigate the impact of the oxidation temperature and variations in airflow conditions on coal spontaneous combustion characteristics, pre-oxidized coal samples were prepared using a programmed temperature rise method. Synchronous thermal analysis experiments and Fourier transform infrared spectroscopy were conducted to explore changes in the thermal effects and functional group content of the coal samples, respectively. The results indicate that variations in pre-oxidation conditions primarily in fluence the activation temperature and maximum weight loss temperature of the coal samples, while exerting a lesser impact on the critical temperature and ignition point. Variations in air volume conditions predominantly affect the content of Ar-C-O- and -CH2 & -CH3 in the oxygen-containing functional group region. The trend of the average activation energy within a conversion rate range of 0.2 to 0.6 of pre-oxidized coal samples changing with the increased of pre-oxidation temperature under the air flow conditions of 25mL/min and 50mL/min is consistent, but opposite to that under the air flow conditions of 100mL/min and 200mL/min. Compared to raw coal, under an airflow rate of 50 mL/min and when oxidized to 110°C, the coal sample exhibits an increase in the content of OH…OH, accompanied by reductions in the critical temperature, activation temperature, ignition point, and maximum weight loss temperature to varying degrees, thereby rendering it more susceptible to oxidative spontaneous combustion.
为研究氧化温度和气流条件变化对煤自燃特性的影响，采用程序升温法制备了预氧化煤样。分别进行了同步热分析实验和傅里叶变换红外光谱分析，以探究煤样热效应和官能团含量的变化。结果表明，预氧化条件的变化主要影响煤样的活化温度和最大失重温度，而对临界温度和着火点的影响较小。风量条件的变化主要影响含氧官能团区域中Ar-C-O-和-CH2&-CH3的含量。在25mL/min和50mL/min的气流条件下，预氧化煤样转化率在0.2至0.6范围内的平均活化能随预氧化温度升高的变化趋势一致，但与100mL/min和200mL/min气流条件下的变化趋势相反。与原煤相比，在50mL/min的气流速率下氧化至110°C时，煤样中OH…OH含量增加，同时临界温度、活化温度、着火点和最大失重温度均有不同程度降低，从而使其更易发生氧化自燃。
