Synergistic acceleration effect of coal spontaneous combustion caused by moisture and associated pyrite. (15th November 2021)

• Record Type: Journal Article
• Authors: Wang, Caiping; Lv, Chunhui; Bai, Zujin; Deng, Jun; Kang, Furu; Xiao, Yang; Shu, Chi-Min
• Is Part Of: Fuel. Volume 304(2021)
• Publication Date: 2021-11-15
• Subjects: Internal effects -- In situ Fourier transform infrared spectroscopy -- Correlation analyses -- Apparent activation energy -- Oxidation reaction; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2021.121458
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Key critical points of moisture and pyrite that affect CSC are grasped. Thermodynamic process in coal with water and associated pyrite is described. Key active groups for inducing exotherm of coal oxidation are determined. Mechanism of active groups in inducing coal spontaneous combustion is revealed. Abstract: The water and pyrite contents of coal may cause coal self-heating, followed by coal spontaneous combustion (CSC) under appropriate conditions. To determine the internal effects of water and associated pyrite on active group–induced CSC, coal samples with different water and pyrite content were analysed through Fourier transform infrared spectroscopy (FTIR), in situ FTIR, microcalorimetry (C80), kinetic analysis, and Grey and Pearson correlation analyses. The results indicated that the synergistic effect of a water content of 10%–15% and pyrite content of 2%–4% promotes the generation of class IV and III hydrogen atoms and free hydroxyl groups. Class IV and III hydrogen atoms and free hydroxyl groups had the highest correlation with apparent activation energy and were positively correlated. The oxidation reaction between water and pyrite released a large amount of heat and promoted the formation of class IV and III hydrogen atoms as well as free hydroxyl groups, which further induced a decrease in the apparent activation energy before enhancing the exothermic oxidation, eventually leading to CSC.