Coal Geology Bureau of Ningxia Hui Autonomous Region
State Key Laboratory of Pollution Control and Recycling Research, Nanjing University
International Research Center for Earth Critical Zone Science and Technology, Nanjing University
College of Geology and Environment, Xi’an University of Science and Technology

以宁夏宁东、贺兰山、宁南和香山等四大煤田不同矿区典型煤样为研究对象,采用X射线衍射、拉曼光谱和傅里叶红外光谱对煤结构进行表征,结合分峰拟合来获取煤结构参数及变化规律。结果表明:低-中煤阶煤光学性质是各向同性的,芳香层片尺寸较小,任意取向;随着煤级的增加,芳香层间距d002值以最快的速率减小,延展度La则加快增长,在Rmax大于2.0%后,d002值变化幅度减缓与堆砌度Lc值增大相对应;在d002<0.3480nm,拉曼参数ID1/IG、AD1/AD1+G开始线性减小,煤的分子结构中芳香层片尺寸增大,定向性增强,光学性质在平行和垂直于芳香层片方向上呈现各向异性,结构有序化程度增大;随着煤化程度的增高,红外光谱显示脂肪结构含量较低,芳香结构吸收带显著,芳香度参数迅速增大,脂肪烃侧链快速脱落,生烃潜力参数‘A’变小;贺兰山煤田和香山煤田煤叠加了岩浆热作用,变质温度较高,导致芳香环缩合程度增强,芳香烃类物质增多。研究结果对煤的结构演化与煤炭清洁高效利用有一定指导意义。

With the typical coal samples taken as the research objects from different mining areas of Ningdong, Helanshan, Ningnan and Xiangshan in Ningxia Hui Autonomous Region, the coal structure was characterized by X -ray diffraction, Raman spectroscopy and Fourier transform infrared spectrosco- py, and the coal structure parameters and variation rules were obtained by peak fitting. The results show that the optical properties of low-medium rank coal are isotropic, the aromatic layer size is small, and the orientation is arbitrary. With the increase of coal rank, the d value of aromatic layer spacing de- creases at the fastest rate, and the ductility L increases rapidly. When R is greater than 2. 0% , the change of d value slows down, which corresponds to the increase of stacking degree L value. At d < 0. 348 0 nm, the Raman parameters I / I and A / A began to decrease linearly, the size of aro- matic lamellae in the molecular structure of coal increased, the orientation increased, the optical proper- ties showed anisotropy in the direction of parallel and perpendicular to the aromatic lamellae, and the degree of structural ordering increased. With the increase of coalification degree, the infrared spectrum shows that the fat structure content is low, the aromatic structure absorption band is significant, the aro- maticity parameter increases rapidly, the aliphatic hydrocarbon side chain falls off rapidly, and the hy- drocarbon generation potential parameter‘ A’ becomes smaller. The coal of Helanshan coalfield and Xiangshan coalfield is superimposed by magmatic heat, and the metamorphic temperature is higher, which leads to the enhancement of aromatic ring condensation and the increase of aromatic hydrocar- bons. The research results provide certain guidance for the structural evolution of coal and the clean and efficient utilization of coal.

宁夏回族自治区重点研发计划项目(2021BEG02015);宁夏回族自治区非常规天然气勘查开发创新团队项目(2022BSB03105)

夏炎,许睿,路学忠,等.宁夏煤的分子结构演化特征[J].西安科技大学学报,2024,44(5):924-933.

XIA Yan, XU Rui, LU Xuezhong, et al. Molecular structure evolution characteristics of coals in Ningxia Hui Autonomous Region[ J] .Journal of Xi’an University of Science and Technology, 2024, 44( 5) : 924- 933.