基于衍射图谱低角度信息的煤化程度分析

Analysis of coalification degree based on low angle information of diffraction pattern

基于煤炭的衍射图谱,判断其煤化程度的常规方法是计算002峰峰高与半高宽的比值。探讨了九种不同变质程度煤的衍射图谱信息,在应用该方法进行煤化程度的比较分析后,认为该方法对中低变质程度煤的判定较为可靠,但对高阶煤有所欠缺。另外,通过布拉格方程计算,认为煤样衍射图谱低角度区(3°~10°)反映的是煤中直径为(0.884~2.94)nm的微孔信息,其衍射强度对应煤中的孔隙率。因此,结合孔隙率随煤化程度变化的规律,提出了一种全新的表征煤化程度的函数。新函数可综合煤样衍射图谱中的低角度区与002峰的信息,判定煤化程度。结果表明:该函数对于煤化程度的表征更加可行、可靠和精确。

According to the diffraction pattern of coal, the conventional judging method for coalification degree is to calculate the ratio of 002 peak height and FWHM. In this paper, the diffraction patterns of nine kinds of coal were discussed and calculated. It is proved that this method is more reliable for the judgment of medium and low metamorphic grade coal, but it has deficiency for high rank coal. In addition, low-angle region （3°~ 10°） of the diffraction pattern of coal, which is calculated by Bragg equation, reflects the micropore information with diameter within 0. 884 ~ 2. 94nm, and its diffraction intensity corresponds to the porosity in coal. Therefore, the function of coalification degree is proposed according to the regulation of porosity variation with the coalification degree. It can integrate coal information in the low- angle diffraction patterns and 002 peak to determine the coalification degree. The results show that this function is more feasible, reliable and accurate for characterization of coalification degree.