Low-temperature oxidation characteristics of compacted broken coal and macroscopic cause analysis

doi:10.16265/j.cnki.issn1003-3033.2019.09.012

Abstract

Abstract: In order to identify the effects of stress loading on the oxidation process of broken coal, firstly, using self-designed experimental devices, low-temperature oxidation experiments of compacted broken coal were conducted under different stress loading. Secondly, the oxygen consumption rate, CO and C₂H₄gas generation characteristics were analyzed based on the test data. Finally, variation causes of coal oxidation under different stress loading states were analyzed. Results show that,while at the same temperature, the oxygen consumption intensity and generation amount of CO and C₂H₄will increase with the increase of axial loading strength, and the C₂H₄ occurrence temperature was advanced, with the increase of axial pressure, the oxidation activity of coal samples will be enhanced which contributes to the occurrence of low temperature oxidation and spontaneous combustion of coal, it was also found that the increases of fractal dimension, the specific surface area and the thermal conductivity coefficient are the causes for oxidation behavior variance of compacted broken coal.

Key words: compacted broken coal, goaf, stress recover, low-temperature oxidation, spontaneous combustion of coal

CLC Number:

X936

CHU Tingxiang, HAN Xuefeng, YU Minggao. Low-temperature oxidation characteristics of compacted broken coal and macroscopic cause analysis[J]. China Safety Science Journal, 2019, 29(9): 77-83.

References

[1] 鲜学福,王宏图,姜德义,等.我国煤矿矿井防灭火技术研究综述[J].中国工程科学,2001,3(12): 28-32.
XIAN Xuefu, WANG Hongtu, JIANG Deyi, et al. The summarization of the investigation on coal mine fire prevention &fire extinguishing techniques in China [J]. Engineering Science, 2001, 3(12): 28-32.
[2] 何满潮,谢和平,彭苏萍,等.深部开采岩体力学研究[J].岩石力学与工程学报,2005,24(16): 2 803-2 813.
HE Manchao, XIE Heping, PENG Suping, et al. Study on rock mechanics in deep mining engineering [J].Chinese Journal of Rock Mechanics and Engineering, 2005, 24(16): 2 803-2 813.
[3] 周福宝.瓦斯与煤自燃共存研究(I):致灾机理[J]. 煤炭学报,2012, 37(5): 843-849.
ZHOU Fubao, Study on the coexistence of gas and coal spontaneous combustion (I): disaster mechanism [J]. Journal of China Coal Society, 2012, 37 (5): 843-849.
[4] 钱鸣高,徐家林.覆岩采动裂隙分布的“O”形圈特征研究[J].煤炭学报,1998,23(5): 466-469.
QIAN Minggao, XU Jialin. Study on the “O-shape”circle distribution characteristics of mining-induced fractures in the overlaying strata [J]. Journal of China Coal Society, 1998, 23(5): 466-469.
[5] KING H, WHITTAKER B. A review of current knowledge on roadway behavior, especially the problems on which further information is required[C]. Proceedings of the Symposium on Strata Control in Roadway,1971: 73-90.
[6] CONROY J. Influence of elevated atmospheric CO₂concentrations on plant nutrition [J]. Australian Journal of Botany, 1992, 40(5): 445-456.
[7] YAVUZ H. An estimation method for cover pressure re-establishment distance and pressure distribution in the goaf of longwall coal mines [J]. International Journal of Rock Mechanics & Mining Sciences, 2004,41(2):193-205.
[8] 徐连满,潘一山,李忠华,等.深部开采覆岩应力变化规律模拟试验研究[J].中国地质灾害与防治学报,2011,22(3): 61-66.
XU Lianman, PAN Yishan, LI Zhonghua, et al. Similarity simulation experiment of deformation of deep mining-induced overburden stress[J].The Chinese Journal of Geological Hazard and Control, 2011,22(3): 61-66.
[9] PAPPAS D M, MARK C. Behavior of simulated longwall gob material[R].Washington: United States Department of the Interior Bureau of Mines, 1993.
[10] 缪协兴,茅献彪,胡光伟,等.岩石(煤)的碎胀与压实特性研究[J].试验力学,1997,12(3): 394-399.
MIAO Xiexing,MAO Xianbiao,HU Guangwei, et al. Research on broken expand and press solid characteristics of rocks and coals [J]. Journal of Experimental Mechanics, 1997, 12(3): 394-399.
[11] 李树刚,钱鸣高.综放采空区冒落特征及瓦斯流态[J].矿山压力与顶板管理,1997,3(4): 76-78.
LI Shugang, QIAN Minggao. Features of fallen rock and methane flow characteristics in gob of fully-mechanized working-face with top-coal caving ground [J].Pressure and Strata Control, 1997, 3(4): 76-78.
[12] 梁军,刘汉龙,高玉峰.堆石蠕变机理分析与颗粒破碎特性研究[J].岩土力学,2003,24(3): 479- 483.
LIANG Jun, LIU Hanlong, GAO Yufeng. Greepmechanism and breakage behavior of rockfill [J]. Rock and Soil Mechanics, 2003, 24(3): 479-483.
[13] TYLER S W, WHEATCRAFT S W. Fractal scaling of soil particle size distributions: analysis and limitations [J]. Soil Science Society of America Journal,1992,56:363-369.
[14] 谢和平.分形-岩石力学导论[M]. 北京:科学出版社,1996: 62-86.
[15] 李增华. 煤炭自燃的自由基反应机理[J].中国矿业大学学报,1996,25(3): 111-114.
LI Zenghua. Mechanism of free radical reactions in spontaneous combustion of coal[J].Journal of China University of Mining &Technology,1996,25(3): 111 - 114.