Experimental Verification for the Graphitization of Inertinite

Abstract

In order to explore the graphitization of inertinite, this paper conducted high-temperature thermal simulation experiments (HTT) and high-temperature high-pressure simulation experiments (HTHP) on isolated samples enriched in inertinite. X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM) were used to analyze the graphitization process of inertinite. ① Results of HTT: the graphitization of inertinite has a “threshold condition” with the temperature threshold ranging between 2100 °C and 2400 °C. Below this threshold, the d002 value of the samples remains above 0.342 nm. ② Results of HTHP: (i) External forces have a significant positive effect on the graphitization of inertinite. Compared to the HTT, the addition of external forces significantly reduces the temperature required for inertinite graphitization. (ii) Proper combinations of temperature and pressure conditions are crucial for efficiently promoting the graphitization of inertinite. Changes in pressure, either increasing or decreasing from the optimal pressure, have a suppressive effect on the graphitization of inertinite. ③ The mechanism of external forces on the graphitization of inertinite was analyzed. Shear stress promotes the rotation and orientation of aromatic layers, while static hydrostatic pressure contributes to the contraction and reduction of interlayer spacing in carbon layers.