Jing Li ¹ Lu Wang ^1* Yong D. Cao ²

• ¹ Shanxi Institute of Energey, Jinzhong, China
• ² China University of Mining and Technology, Beijing, Beijing, China

Coal-based graphite with different graphitization degree was formed as the magma intrusion. Strengthening research on the characteristics of coal-based graphite, the evolutionary features of its graphitization process, and the mechanisms of ore formation contribute significantly to the rational development and efficient utilization of coal-based graphite resources, which holds substantial economic value. In this paper, by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy, the graphite with different degrees of metamorphism has been characterized by spectroscopy to explore the evolution of macromolecular structure of organic matter during graphitization. The results show that with the deepening of metamorphism, the 002-diffraction peak of the series of samples gradually shrinks and Narrows, and the peak intensity becomes stronger, indicating that the microcrystalline structure in the graphite gradually becomes regular and ordered. As the degree of graphitization deepens, the uniformity of particle size in coal samples observed under scanning electron microscopy gradually increases, and the morphology becomes more regular, transitioning from disordered and irregular shapes to a structured large scale flake pattern. The crystallinity improves, and the massive coal particles gradually coalesce into large plate crystals, with the inter-particle pores gradually closing. The graphite structure becomes increasingly evident. The FTIR spectra show that as the degree of graphitization increases, the peak at 1581 cm -1 corresponding to C=C vibrations gradually intensify. Some inert functional groups are retained throughout the graphitization process. The pores between coal particles gradually close, and the morphology of graphite particles becomes more regular and ordered. Additionally, during the graphitization process, structures similar to carbon nanotubes may develop. Throughout the structural transformation from coal macromolecules to graphite crystals, the size of the sp 2 planar domains in single-layer graphene increases, and the lattice structure of carbon atoms gradually enlarges. These findings contribute to a comprehensive understanding of the properties and characteristics of coal-derived graphite, and can provide theoretical reference and basis for the metallogenic mechanism of coal-derived graphite and the efficient utilization of coal.