XU Y L, WU J D,LI M J,et al. Spontaneous combustion behavior of crushed coal at different preoxidation temperatures under uniaxial compression[J]. Journal of Henan Polytechnic University(Natural Science) , 2025, 44(1): 10-17.

doi: 10.16186/j.cnki.1673-9787.2022050064

Received: 2022/05/19

Revised: 2023/04/07

Published: 2025/01/02

Spontaneous combustion behavior of crushed coal at different preoxidation temperatures under uniaxial compression

XU Yongliang1,2,3, WU Jindong2,LI Minjie2,ZHANG Jian2,3, WANG Wen4

1. School of Safety Science and Engineering， Changzhou University， Changzhou  213164， Jiangsu， China; 2. College of Safety Science and Engineering， Henan Polytechnic University， Jiaozuo  454000， Henan， China; 3. Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization， Jiaozuo  454000， Henan， China; 4. School of Energy Science and Engineering， Henan Polytechnic University， Jiaozuo  454000， Henan， China

Abstract: Objectives To study the spontaneous combustion characteristics of crushed coal at different pre-oxidation temperatures under various stress conditions， Methods a uniaxial compression device equipped with a temperature-programmed oxidation device （UCTP） was used to analyze the characteristic parameters such as oxygen consumption rate， characteristic temperature points， gas production， and activation energy changes during the oxidation process. Results The experimental results showed that uniaxial compression enhanced the oxidation characteristics of the coal samples， as evidenced by the increase in oxygen consumption rate， the higher concentration of CO and C₂H₄ gases， the forward shift of characteristic temperature points， and the decrease in activation energy. When the uniaxial compression was 0 MPa and 4 MPa， the oxidation characteristics of the pre-oxidized 70 ℃ coal samples were the strongest. At 8 MPa， the increase in pre-oxidation temperature led to a decrease in the oxidation characteristics of the coal samples. Combining the changes in oxygen consumption rate， index gases， and activation energy， it was found that the spontaneous combustion tendency of pre-oxidized 70 ℃ coal was higher and more prone to reignition. Conclusions （1） The spontaneous combustion characteristics of coal samples with different pre-oxidation temperatures behaved consistently under the influence of axial pressure. Specifically， uniaxial compression enhanced the oxidation characteristics of the coal， making it more likely to reignite and progress to the rapid oxidation stage. （2） The effects of pre-oxidation temperature on coal’s spontaneous combustion characteristics under different axial pressures varied. Increasing the pre-oxidation temperature reduced the coal’s oxidation characteristics， indicating that higher pre-oxidation temperatures weakened the oxidation properties of the coal under high axial pressure.

Key words: uniaxial compression; oxygen consumption rate; characteristic temperature point; index gases; apparent activation energy; propensity for spontaneous combustion