不同变质程度煤的高分辨率透射电镜分析

利用高分辨率透射电子显微镜(HRTEM)分析了三种不同变质程度煤样的结构特征。基于傅里叶-反傅里叶变换方法,并结合Matlab、Arcgis和Auto CAD软件,通过图像分析技术,获得了HRTEM照片的晶格条纹参数。结果表明,三种煤样的晶格条纹呈现不同特征,按条纹长度分别归属于1×1-8×8共计八个类型。以3×3为临界点,在1×1和2×2中,ML-8中芳香层片的比例高于DP-4和XM-3;在3×3-8×8中,ML-8中芳香层片的比例低于DP-4和XM-3。对比HRTEM和XRD参数d002发现,随着镜质组反射率的增加d002都呈现递减趋势。

High resolution TEM image analysis of coals with different metamorphic degrees

The structural characteristics of 3 coals with different metamorphic degrees were analyzed using high-resolution transmission electron microscopy (HRTEM). Applying FFT-IFFT method, in association with Matlab, Arcgis and AutoCAD softwares, the lattice fringe parameters obtained from HRTEM image were determined using image analysis. The results indicate that the lattice fringes of all the test coal samples exhibit different characteristics. These lattice fringes can be divided into 8 types (1×1-8×8 aromatic fringes) according to the fringe length distribution. Taking the 3×3 aromatic fringe as critical point, the sample ML-8 abundant in 1×1 and 2×2 aromatic fringes while short of 3×3-8×8 aromatic fringes when comparing with sample DP-4 and sample XM-3. The values of d₀₀₂ obtained from both HRTEM and XRD show a decreasing trend with increasing vitrinite reflectance.