Study on the characteristics of secondary oxidation and the key reactive groups of fire area coal by different cooling rates

In order to reveal the effects of different cooling rates (slow and rapid) on the secondary oxidation characteristics of coal in coalfield fire area (primary heating to 180 °C). Simultaneous thermal analysis (TG-DSC), programmed heating and in situ Fourier transform infrared (FTIR) experiments were...

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Bibliographic Details
Main Authors: Xun Zhang, Ronghai Sun, Bing Lu, Ge Huang, Ling Qiao, Huimin Liang
Format: Article
Language:English
Published: Elsevier 2025-05-01
Series:Case Studies in Thermal Engineering
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Online Access:http://www.sciencedirect.com/science/article/pii/S2214157X25002746
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Summary:In order to reveal the effects of different cooling rates (slow and rapid) on the secondary oxidation characteristics of coal in coalfield fire area (primary heating to 180 °C). Simultaneous thermal analysis (TG-DSC), programmed heating and in situ Fourier transform infrared (FTIR) experiments were used. Thermodynamic analysis as well as Pearson and grey correlation analyses were used to analyze the low-temperature oxidation processes in raw coal and in coal from the fire area that underwent different cooling rates. The results showed that there was a significant difference of coal. The maximum cumulative heat release of raw coal was 35.942 J. The slow cooling (SC) and rapid cooling (RC) coals were only 17.188 and 23.761 J. At 200 °C, the CO production of the raw coal was 8432 ppm, and the SC and RC coals were 521 and 1166 ppm higher than it, respectively. In the correlation analysis, it was found that the key reactive groups in SC coal were -CH2 and -COOH, whereas in RC coal it was -CH2. There are two fundamental reasons for the difference: (1) SC coal accumulated more -COOH groups. (2) The -CH2 groups of RC coal are more easily oxidized than those of SC coal.
ISSN:2214-157X