中低变质程度煤显微组分大分子结构的XRD研究

X-ray diffraction analysis on the different macerals of several low-to-medium metamorpic grade coals

利用X-射线衍射法(X-RayDiffraction,简称XRD)对中低变质程度的不同煤显微组分(镜质组和惰质组)的大分子结构进行研究分析,计算了5种煤9个显微组分的XRD结构参数,获得了样品的结构特征及变化规律.结果表明,中低变质程度煤的物理结构具有非晶结构特征,随着煤变质程度的提高,煤中脂族结构减少,芳香结构增多,且芳核在横向上和纵向上进行芳环的缩聚反应;与镜质组相比,惰质组中芳构化程度更高,芳香层片在空间的排列更规则,相互定向程度也优于镜质组,但惰质组芳构化程度随变质程度升高的规律不如镜质组那样显著.

The structure of the different macerals of several low-to-medium metamorpic grade coals were studied by means of X-ray diffraction (XRD), and the molecular structure characteristics and parameters of the macerals were discussed.The result from XRD analysis indicates that there exists non-crystalloid physical structure in the low-to-medium metamorpic grade coals.Compared with vitrinite, there is higher degree of aromatization and higher regularity and orientation in the special arrangement of the arene layers in inertinite.With the increase of the coal metamorpic grade, the ratio of aromatic hydrocarbon increases, and condensation polymerisation of the arene cluster occurs in both the crosswise direction and the lengthwise direction, which is more obvious in vitrinite than in inertinite.