Changes and Migration of Coal-Derived Minerals on the Graphitization Process of Anthracite

Abstract

It is unclear that the changes and migration of coal-derived minerals on the graphitization process of coal. The Taixi anthracite is the study sample of the changes and migration mechanisms of coal-derived minerals during graphitization. Raw coal and different temperature-treated products were collected and analyzed by X-ray diffraction (XRD) to reflect the variation trends of the crystal structure and functional groups with temperature. To analyze the microstructure and mineral composition of the samples in experimental and industrial ultrahigh-temperature graphitization furnaces, a series of experiments were performed using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS). The results showed that temperature played a crucial role in the changes and migration of minerals during the graphitization of anthracite. As the temperature rose, cracks appeared from the surface to the inside of anthracite and minerals gradually changed and migrated from the inside of the anthracite to the cracks in the form of gas or liquid. At ultrahigh temperatures, only a small amount of silicon remains in the system as a catalyst, and most of the elements escaped in the form of oxides.