Jia Xiaoliang, Wu Jiaokun, Lian Changjun, Rao Jilai
China Coal Technology and Engineering Group Chongqing Research Institute, Chongqing, China.
National Key Laboratory of Gas Disaster Detecting Preventing and Emergency Controlling, Chongqing, China.
Environ Sci Pollut Res Int. 2022 Dec;29(58):87257-87267. doi: 10.1007/s11356-022-21920-5. Epub 2022 Jul 8.
Oxygen plays a crucial role in coal spontaneous combustion (CSC), and the magnitude of oxygen concentration determines the oxidation reaction intensity of CSC. This work is aiming to investigate the contribution of oxygen concentration to CSC and to predict the spontaneous combustion stage of coal at different oxygen concentrations. Firstly, experiments on the spontaneous combustion of coal samples at six oxygen concentrations (6%, 9%, 12%, 15%, 18%, and 21%) were carried out combined with a temperature-programmed system. Then, the gas products at different temperature stages were extracted to provide detailed classification and assessment of the indicator gasses for coal spontaneous combustion at different oxygen concentrations. The results show that the oxygen concentration and the crossing point temperature (CPT) are inversely proportional. The higher the oxygen concentration, the more intense the coal-oxygen complex reaction and the greater the gas product concentration. The critical temperature of some stages in high oxygen concentration environment is lower than that in low oxygen concentration environment. The oxidation process can be slowed down by reducing the oxygen concentration as much as possible. Indicator gasses are different for different oxygen concentration environments and should be selected reasonably and optimally to match the specific environment for judging natural coal fires in order to effectively prevent coal spontaneous combustion fire disasters.
氧气在煤自燃过程中起着至关重要的作用，氧气浓度的大小决定了煤自燃的氧化反应强度。本研究旨在探究氧气浓度对煤自燃的影响，并预测不同氧气浓度下煤的自燃阶段。首先，结合程序升温系统，对六种氧气浓度（6%、9%、12%、15%、18%和21%）下的煤样自燃进行了实验。然后，提取不同温度阶段的气体产物，对不同氧气浓度下煤自燃的指标气体进行详细分类和评估。结果表明，氧气浓度与交叉点温度（CPT）成反比。氧气浓度越高，煤-氧复合反应越剧烈，气体产物浓度越大。高氧气浓度环境下某些阶段的临界温度低于低氧气浓度环境。尽可能降低氧气浓度可减缓氧化过程。不同氧气浓度环境下的指标气体不同，应合理、优化选择以匹配判断煤自然发火的特定环境，从而有效预防煤自燃火灾灾害。
