应用高分辨率透射电镜研究煤显微组分的结构

应用高分辨率透射电镜研究变质系列镜质体和丝质体以及热解碳的物理结构特征表明,随煤级增高,镜质体的基本结构单元(BSU)的平均长度及缩聚芳香层平均环数NC呈增加的趋势;衍射环数增多,环的弥散程度减小,最终出现弧状;表明镜质体的BSU在变质过程中长大,定向性增强,VRo,max=6.50％是阶跃点,当VRo,max>6.50％,BSU突然定向排列。获得了很难获得的低煤化烟煤(VRo,max=0.66％)的高分辨图像,它的BSU尺寸小,无序排列。对丝质体和热解碳高分辨图像的首次研究发现,前者有序性差,随煤级演化的速度较镜质体慢,后者有序性好。

THE APPLICATION OF HIGH-RESOLUTION TRANSMISSION ELECTRON MICROSCOPY TO STUDY THE STRUCTURES OF COAL MACERALS

The authors studied the physical structures of a metamorphic series of vitrinites, fusinites and pyrolytic carbon by applying high-resolution transmission electron microscopy (HRTEM). The results show that with an increase in coal rank, the average length (L) of the basic structural unit (BSU) and the average number of condensed aromatic rings of vitrinites increase, the number of diffraction circles goes up, and the degree of circle diffusion decreases, so resulting in arc-like. This indicates that the BSU of vitrinite might grow and get more oriented in the process of metamorphism. It is found that the point with VRo,max=6. 50%, marks a step change and that when VRo,max>6. 50% the BSU became oriented apparently. The high-resolution image of fusinites and pyrolitic carbon were firstly studied by HRTEM. The structural order oflusinites is less and its evolution is slower than that of vitrinites. The structural order of pyrolytic carbon is better.