Evolution patterns of coal micro-structure in environments with different temperatures and oxygen conditions
Evolution patterns of coal micro-structure in environments with different temperatures and oxygen conditions
复制标题
不同温度和氧气环境下煤微观结构的演化规律
DOI：
10.1016/j.fuel.2019.116425
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发表时间：
2020-02-01
期刊：
影响因子：
7.4
通讯作者：
Fu, Dong
中科院分区：
文献类型：
--
作者：
Pan, Rong-kun;Li, Cong;Fu, Dong
深部煤层在开采前处于高温高应力状态。开采后，煤体暴露于氧气中，氧化反应导致氧化煤体显微结构发生显著变化。为了了解这种变化过程，本文采用X射线衍射（XRD）和傅里叶变换红外光谱（FTIR）对高温瓦斯作用下的煤体进行了测试。对比分析了煤在不同温度和氧气条件下氧化显微结构的演化规律。结果表明，在有氧气的环境中，随着温度的升高，煤大分子晶格的堆积高度（L-c）总体呈增加趋势，并具有自修复能力。在氧化过程中，煤分子结构演变的空间排列是可逆的。在无氧环境中，羟基（-OH）峰高和峰面积超过有氧环境中的那些，这表明-OH基团促进煤的氧化。高温断裂作用下煤中官能团不断发生变化，氧化作用产生新的官能团。
Before mining, a deep coal seam exists in a state with a high formation temperature and high stress. After mining, the coal body is exposed to oxygen, and the oxidation reaction results in significant changes in the micro-structure of the oxidized coal body. To understand the change process, in this paper, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy are employed to test a coal body subjected to flow of hot gas. The evolution patterns of the coal oxidation micro-structure under different temperatures and oxygen conditions are compared and analysed. The results show that in an environment with oxygen, as the temperature increases, the stacking height (L-c) of the coal macromolecular lattice follows an overall increasing trend and has a self-repair capability. During oxidation, the spatial arrangement of the evolution of the coal molecular structure is reversible. In an environment without oxygen, the hydroxyl (-OH) peak height and peak area exceed those of an environment with oxygen, which suggests that the -OH group facilitates coal oxidation. Coal functional groups under high-temperature fracture polymerize constantly, and oxidation produces new functional groups.