Study on mechanism of influence of low temperature freeze-thaw cycle on spontaneous combustion characteristics of coal gangue
In order to investigate the influence of the number of freeze-thaw cycles (freeze-thaw) on the spontaneous combustion characteristics of coal gangue, this study simulated the alpine environment and examined the spontaneous combustion characteristics of coal gangue after undergoing multiple freeze-th...
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Elsevier
2025-09-01
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| Series: | Case Studies in Thermal Engineering |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214157X25009645 |
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| author | Xun Zhang Ning Ma Bing Lu Fengwei Dai Ge Huang Huimin Liang Chen Yu |
| author_facet | Xun Zhang Ning Ma Bing Lu Fengwei Dai Ge Huang Huimin Liang Chen Yu |
| author_sort | Xun Zhang |
| collection | DOAJ |
| description | In order to investigate the influence of the number of freeze-thaw cycles (freeze-thaw) on the spontaneous combustion characteristics of coal gangue, this study simulated the alpine environment and examined the spontaneous combustion characteristics of coal gangue after undergoing multiple freeze-thaw cycles. The evolution of the macro-oxidative exothermic properties and microstructural characteristics of the gangue during the freeze-thaw cycles were analyzed by X-ray diffraction (XRD), low-temperature N2 adsorption (LTNA), programmed temperature-expanded oxidation (PTO), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR), and other experimental means. The results showed that the freeze-thaw cycle significantly promoted the spontaneous combustion effect of gangue, and the effect showed an increasing and then decreasing trend with the increase in the number of cycles, and reached the maximum in the fourth freeze-thaw cycle. The mineral composition of the gangue changed significantly during the freeze-thaw cycle, and the pyrite content decreased by 5.5 %. The apparent activation energy decreased to the lowest in the fourth freeze-thaw cycle, which was only 0.79 times of the untreated sample, while the exothermic amount also reached the peak, which was about 1.71 times of the untreated sample. In addition, -CH3, C=O, and -OH contents firstly increased and then decreased with the number of freeze-thaw cycles, and all of them reached a great value at the fourth freeze-thaw cycle. Further analysis showed that the freeze-thaw cycle caused nonlinear changes in the spontaneous combustion effect of coal gangue by regulating the mineral composition, pore structure, and FeS2 reaction of the gangue, which was shown to be enhanced at the beginning of the cycle and weakened with the increase in the number of cycles. |
| format | Article |
| id | doaj-art-9b8a9f79dca34c92a70ac6220fea4980 |
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| issn | 2214-157X |
| language | English |
| publishDate | 2025-09-01 |
| publisher | Elsevier |
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| series | Case Studies in Thermal Engineering |
| spelling | doaj-art-9b8a9f79dca34c92a70ac6220fea49802025-08-20T02:38:51ZengElsevierCase Studies in Thermal Engineering2214-157X2025-09-017310670410.1016/j.csite.2025.106704Study on mechanism of influence of low temperature freeze-thaw cycle on spontaneous combustion characteristics of coal gangueXun Zhang0Ning Ma1Bing Lu2Fengwei Dai3Ge Huang4Huimin Liang5Chen Yu6College of Mining, Liaoning Technical University, Fuxin, Liaoning, 123000, China; Institute of Safety Engineering and Technology, Liaoning Technical University, Fuxin, Liaoning, 123000, ChinaCollege of Mining, Liaoning Technical University, Fuxin, Liaoning, 123000, China; Corresponding author.College of Mining, Liaoning Technical University, Fuxin, Liaoning, 123000, ChinaCollege of Safety Science & Engineering, Liaoning Technical University, Fuxin, Liaoning, 123000, ChinaCollege of Safety Science & Engineering, Liaoning Technical University, Fuxin, Liaoning, 123000, ChinaCollege of Mining, Liaoning Technical University, Fuxin, Liaoning, 123000, ChinaCollege of Mining, Liaoning Technical University, Fuxin, Liaoning, 123000, ChinaIn order to investigate the influence of the number of freeze-thaw cycles (freeze-thaw) on the spontaneous combustion characteristics of coal gangue, this study simulated the alpine environment and examined the spontaneous combustion characteristics of coal gangue after undergoing multiple freeze-thaw cycles. The evolution of the macro-oxidative exothermic properties and microstructural characteristics of the gangue during the freeze-thaw cycles were analyzed by X-ray diffraction (XRD), low-temperature N2 adsorption (LTNA), programmed temperature-expanded oxidation (PTO), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR), and other experimental means. The results showed that the freeze-thaw cycle significantly promoted the spontaneous combustion effect of gangue, and the effect showed an increasing and then decreasing trend with the increase in the number of cycles, and reached the maximum in the fourth freeze-thaw cycle. The mineral composition of the gangue changed significantly during the freeze-thaw cycle, and the pyrite content decreased by 5.5 %. The apparent activation energy decreased to the lowest in the fourth freeze-thaw cycle, which was only 0.79 times of the untreated sample, while the exothermic amount also reached the peak, which was about 1.71 times of the untreated sample. In addition, -CH3, C=O, and -OH contents firstly increased and then decreased with the number of freeze-thaw cycles, and all of them reached a great value at the fourth freeze-thaw cycle. Further analysis showed that the freeze-thaw cycle caused nonlinear changes in the spontaneous combustion effect of coal gangue by regulating the mineral composition, pore structure, and FeS2 reaction of the gangue, which was shown to be enhanced at the beginning of the cycle and weakened with the increase in the number of cycles.http://www.sciencedirect.com/science/article/pii/S2214157X25009645Freeze-thaw cyclesSpontaneous combustion of coal ganguePore structureOxidation characteristicsActive functional groups |
| spellingShingle | Xun Zhang Ning Ma Bing Lu Fengwei Dai Ge Huang Huimin Liang Chen Yu Study on mechanism of influence of low temperature freeze-thaw cycle on spontaneous combustion characteristics of coal gangue Case Studies in Thermal Engineering Freeze-thaw cycles Spontaneous combustion of coal gangue Pore structure Oxidation characteristics Active functional groups |
| title | Study on mechanism of influence of low temperature freeze-thaw cycle on spontaneous combustion characteristics of coal gangue |
| title_full | Study on mechanism of influence of low temperature freeze-thaw cycle on spontaneous combustion characteristics of coal gangue |
| title_fullStr | Study on mechanism of influence of low temperature freeze-thaw cycle on spontaneous combustion characteristics of coal gangue |
| title_full_unstemmed | Study on mechanism of influence of low temperature freeze-thaw cycle on spontaneous combustion characteristics of coal gangue |
| title_short | Study on mechanism of influence of low temperature freeze-thaw cycle on spontaneous combustion characteristics of coal gangue |
| title_sort | study on mechanism of influence of low temperature freeze thaw cycle on spontaneous combustion characteristics of coal gangue |
| topic | Freeze-thaw cycles Spontaneous combustion of coal gangue Pore structure Oxidation characteristics Active functional groups |
| url | http://www.sciencedirect.com/science/article/pii/S2214157X25009645 |
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