中国西部弱还原性煤的结构特征初步研究

PRELIMINARY STUDY ON STRUCTURAL CHARACTERISTICS OF COAL WITH WEAK REDUCTIVITY IN WEST CHINA

对中国西北地区弱还原性、高惰质组煤结构特征进行了初步研究.与同变质程度的其他成煤时代煤相比,中国西北侏罗纪弱还原性煤普遍具有较低的H/C原子比和较高的O/C原子比,同时其芳碳率和分子结构中环缩合程度相对较高.随惰质组含量增加,弱还原性煤芳碳率和平均缩合环数增高.X射线衍射(XRD)研究表明,惰质组芳环缩合程度更高,芳香层片在空间的排列更规则,相互定向的程度高于镜质组.核磁共振(13C-NMR)研究表明,惰质组分子结构中苯环取代更多,脂肪部分所占比例少.对弱还原性煤中广泛分布的惰质组组分及其分子结构特征需进行深入研究.

The structural characters of coal with weak reductibility and then higher inertinte content from West China are studied in this paper. Compared with ones with same rank but stronger and medium reductive degree from other geological ages, coals from Jurassic in Northwest China have lower H/C and higher O/C atomic ratio. On the other hand, the aromaticity and ring condensation index of these coals are relatively higher and increase with the content of inertinite, indicating their relatively weak reductibility. The result from X-ray diffraction （XRD） analysis indicates that there is higher degree of aromatization in inertinite, and the inertinite is of higher regularity and orientation in the spacial arrangement of the arene layers than vitrinite. The high-resolution solid ^13C-NMR result shows that there are less aliphatic hydrocarbon and more aromatic hydrocarbon in inertinite. It is meaningful to study deeply the structure of inertinite, especially fusinite and semifusinite in weak reductive coal in West China.