湖南新化煤系石墨结构演化及其热反应行为

Investigation on structural evolution and thermal reaction of coal-based graphite from Xinhua County, Hunan Province

  • 摘要: 为了探究煤系石墨形成过程中结构演化及不同石墨化程度无烟煤和石墨的热反应行为,选取湖南新化系列变质程度无烟煤和煤系石墨为研究对象,通过X射线衍射(XRD)和高分辨率透射电子显微镜(HRTEM)对其结构进行表征,并结合程序控制升温法(TPO)分析不同变质程度无烟煤和煤系石墨的热反应行为。结果表明,随变质程度的增加,碳结构由无烟煤中的无定形态转变成石墨的三维有序C原子点阵。系列石墨化煤是由多种有序度不同的碳结构相组成,体现了其结构非均质性,碳结构相含量及分布随变质程度而逐渐变化,石墨化程度最高的煤系石墨中主要为石墨微晶集合体,但依旧含有结构缺陷。无烟煤和煤系石墨中碳结构的多相性和不均匀分布是影响其热反应行为的重要原因。

     

    Abstract: To investigate the structural evolution and thermal reaction of coal-based graphite with different graphitization, the anthracite and coal-based graphite from Xinhua County, Hunan were analyzed by X-ray diffraction (XRD), high resolution transformation electron microscope(HRTEM), and temperature programmed oxidation (TPO). The results show that carbon structure transformed from the amorphous anthracite to three dimensionally ordered graphite as graphitization degree increases. The coal-based graphite samples with different graphitization degree are composed of multi carbon phases, suggesting a heterogeneous nature of coal-based graphite, and ordered carbon phases were common in higher rank samples, however, defects can still be detected in most metamorphosed coal-based graphite. The multi carbon phases co-exist and inhomogeneous distribution have important impact on the thermal reaction of coal-based graphite.

     

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