Study on the Effect and Mechanism of Original Moisture on Coal Spontaneous Combustion

Xiaoyuan LIU; Yulong ZHANG; Xiaoyu ZHANG; Junfeng WANG; Chunshan ZHOU

doi:10.16355/j.cnki.issn1007-9432tyut.2021.03.004

Taiyuan Ligong Daxue xuebao (May 2021)

Study on the Effect and Mechanism of Original Moisture on Coal Spontaneous Combustion

Xiaoyuan LIU,
Yulong ZHANG,
Xiaoyu ZHANG,
Junfeng WANG,
Chunshan ZHOU

Affiliations

Xiaoyuan LIU: College of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan 030024, China
Yulong ZHANG: College of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan 030024, China
Xiaoyu ZHANG: College of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan 030024, China
Junfeng WANG: College of Mining and Technology, Taiyuan University of Technology, Taiyuan 030024, China
Chunshan ZHOU: College of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan 030024, China

DOI: https://doi.org/10.16355/j.cnki.issn1007-9432tyut.2021.03.004
Journal volume & issue: Vol. 52, no. 3
pp. 350 – 359

Abstract

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Lignite coal samples with different water contents were prepared by drying lignite raw coal. The process of coal spontaneous combustion was simulated in a temperature programmed oxidation device. The change of active functional groups of oxidized coal samples in the process of coal spontaneous combustion was measured by in-situ Fourier transform infrared spectrometry. At the same time, the change law of microscopic specific surface area and mass in the process of coal spontaneous combustion was characterized by nitrogen adsorption and thermal analysis, and the influence mechanism of original water on coal spontaneous combustion was discussed. The influence mechanism of original moisture on coal spontaneous combustion process mainly shows four stages: in the slow oxidation stage, the external water mainly plays a physical inhibition on coal oxidation, and the continuous volatilization of external water causes the decrease of coal mass and the content of hydroxyl and carboxylic acid components. In the accelerated oxidation stage, water in coal begins to directly participate in reaction, and plays a chemical role in promoting coal oxidation. The content of carboxyl compounds begins to increase significantly, and the inhibition of original moisture on coal oxidation is gradually reduced. In the rapid oxidation stage, the original moisture in coal body is basically removed, and the pore structure of coal body continues to collapse and break during inherent water removal process, resulting in new active sites, which shows a delayed promotion effect on coal oxidation reaction process. The internal water mainly affects the formation and decomposition of intermediate complexes and the release of gas. When coal temperature reaches 180 ℃, the effect of original moisture on coal oxidation reaction is weak, and the spontaneous combustion characteristics of coal tend to be consistent.

Published in Taiyuan Ligong Daxue xuebao

ISSN: 1007-9432 (Print)
Publisher: Editorial Office of Journal of Taiyuan University of Technology
Country of publisher: China
LCC subjects: Technology: Chemical technology: Chemical engineering; Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials
Website: https://tyutjournal.tyut.edu.cn/english.html

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