High-temperature and high-pressure simulation of coal graphitization with SiO2 additive

Abstract

This study investigates the effect of SiO2 minerals on coal graphitization under natural conditions through high-temperature and high-pressure simulation experiment to invert the coal-based graphite formation environment.We thoroughly mixed the SiO2 additive with the sorted vitrinite in coal (from the Gemudi mining area in Guizhou province[SW China]) and then carried out high-temperature and high-pressure simulation experiment with ranging from 600 ℃ to 1 200 ℃, 1.5 GPa to 2.0 GPa.The graphitization products of the samples were analyzed by X-ray diffraction, Raman spectroscopy, and high-resolution transmission electron microscopy (HRTEM) to investigate the influence of the SiO2 additive on the process of coal graphitization.Results show that in contrast to the graphitization-promoting ability exhibited in high-temperature environments, SiO2 demonstrates a hindering effect on graphitization in high-temperature and high-pressure environments, inhibiting the growth of coal graphitization.This finding provides an hypothesis for the lower graphitization of coal in areas with strong tectonics under natural conditions.

Keywords

• coal-based graphite
• high temperature and high pressure
• sio2 additive
• graphitization