Nie Baisheng, Yan Hongwei, Liu Peijun, Chen Zongyu, Peng Chao, Wang Xiaotong, Yin Feifei, Gong Jie, Wei Yueying, Lin Shuangshuang, Gao Qiang, Cao Mingwei
State Key Laboratory Coal Resources and Safe Mining, School of Emergency Management and Safety Engineering, China University of Mining & Technology, Beijing, 100083, People's Republic of China.
State Key Laboratory of Coal Disaster Dynamics and Control, School of Resources and Safety Engineering, Chongqing University, Chongqing, 400044, People's Republic of China.
Environ Sci Pollut Res Int. 2023 Jan;30(3):8269-8279. doi: 10.1007/s11356-022-22824-0. Epub 2022 Sep 2.
Coal spontaneous combustion (CSC) is a major disaster threatening coal mine safety; therefore, the investigation of coal spontaneous combustion and oxidation characteristics has been a hot topic in the long term. In this paper, the experimental temperature programmed system is used to carry out the simulation experiment of coal spontaneous combustion and oxidation of three kinds of coal with different metamorphic degrees under three oxygen concentrations (9%, 15%, 21%). The effects of metamorphic degree and oxygen concentration on coal oxidation characteristics were analyzed, and the variation laws of crossing point temperature, three characteristic point temperature, and apparent activation energy were qualitatively discussed. Finally, coal oxidation reaction stages were evaluated and divided. The results show that the concentrations of CO and CH are negatively correlated with the degree of deterioration but increase with the increase of oxygen concentration. High metamorphic coal corresponds to high crossing point temperature (CPT). The average error between the CPT value calculated from the BM empirical correlation and the experimental data is very small, which is 6.42%. The higher the metamorphic degree of coal, the higher the three characteristic temperature points (critical temperature, xerochasy temperature, and activity temperature). The oxidation process of the three coal samples is divided into four stages: surface oxidation, oxidation self-heating, accelerated oxidation, and deep oxidation. The apparent activation energy of each stage exhibits significant variability, with varying patterns displayed with the degree of metamorphism.
煤炭自燃是威胁煤矿安全的重大灾害；因此，长期以来对煤炭自燃及氧化特性的研究一直是热点话题。本文利用实验程序升温系统，对三种不同变质程度的煤在三种氧气浓度（9%、15%、21%）下进行煤炭自燃及氧化模拟实验。分析了变质程度和氧气浓度对煤氧化特性的影响，并定性讨论了交叉点温度、三个特征点温度及表观活化能的变化规律。最后对煤氧化反应阶段进行了评估和划分。结果表明，CO和CH的浓度与变质程度呈负相关，但随氧气浓度的增加而升高。高变质煤对应较高的交叉点温度（CPT）。由BM经验关联式计算得到的CPT值与实验数据的平均误差很小，为6.42%。煤的变质程度越高，三个特征温度点（临界温度、干裂温度和活性温度）越高。三种煤样的氧化过程分为四个阶段：表面氧化、氧化自热、加速氧化和深度氧化。各阶段的表观活化能表现出显著的变化性，且随变质程度呈现不同的变化规律。
