Effects of oxygen concentration and heating rate on coal spontaneous combustion characteristics

• Published in: Journal of thermal analysis and calorimetry Vol. 148; no. 11; pp. 4949 - 4958
• Main Authors: Zhao, Jia-Rong, Xiao, Yang, Zhong, Kai-Qi, Li, Qing-Wei, Zhai, Xiao-Wei
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.06.2023; Springer; Springer Nature B.V
• Subjects: Activation energy; Analysis; Analytical Chemistry; Chemistry; Chemistry and Materials Science; Coal; Coal mines; Combustion; Heat transmission; Heating rate; Inorganic Chemistry; Measurement Science and Instrumentation; Oxygen; Physical Chemistry; Polymer Sciences; Spontaneous combustion; Characteristic temperature; Reaction mechanism; Kinetic model; Coal spontaneous combustion; Apparent activation energy
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-023-12041-3

Coal spontaneous combustion (CSC), as the central cause of coal fire disasters, gravely threatens the safety and efficiency of coalmine production. We take Huating long flame coal as an example and use simultaneous thermal analyzer to investigate how oxygen concentration and heating rate effects CSC characteristics. The reaction process, variation of characteristic temperature, and heat flow were studied. Besides, the kinetic model and parameters were calculated through Šatava and Ozawa methods. The results indicated that the curve peaks of TG and DSC moved to lower temperatures and the characteristic temperatures gradually decreased when the oxygen concentration changed from 3 to 21%. On the contrary, the curve peaks of TG and DSC moved to higher temperature region and the characteristic temperatures increased as the heating rate rose. The most probable mechanism function of Huating long flame is determined to be Avrami–Erofeev equation ( n  = 3) by calculation. When oxygen concentration is 3% or 21%, CSC showed larger tendency. The higher the heating rate, the larger the apparent activation energy, and harder to occur CSC. These findings provide a basis for discovering the formation and evolution mechanism of coal fires.