## 3 Results and Discussion
### Temperature and Damage Distribution in SM and RM
This resulted in the coal matrix suffering radial pressure and, thus, experiencing tensile damage, which is consistent with the work by [PERSON] [19] and [PERSON] et al. [48]. At 6 s, the damage areas around A0, D0, and E0 extended towards the boundaries and other pyrite particles with the temperature increasing. The damage area was located around B0 (temperature slightly lower than E0) and was connected to E0. Furthermore, the damaged areas around these four pyrite particles were interconnected with one other. This promoted the connectivity of pores and improved the ability of gas \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Time** & **Maximum-Temperature** & **Minimum-Temperature** & **Maximum-Temperature** & **Minimum-Temperature** \\  & **Pyrite in S0M** & **Pyrite in RM** & **Pyrite in RM** \\ \hline
3 & D0 & C0 & H\({}_{\text{R}}\) & J\({}_{\text{R}}\) \\
6 & D0 & C0 & A\({}_{\text{R}}\) & G\({}_{\text{R}}\) \\
9 & D0 & C0 & H\({}_{\text{R}}\) & G\({}_{\text{R}}\) \\
12 & D0 & C0 & A\({}_{\text{R}}\) & G\({}_{\text{R}}\) \\
15 & D0 & C0 & H\({}_{\text{R}}\) & G\({}_{\text{R}}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Maximum- and minimum-temperature pyrites in S0M and RM. Figure 13: Temperature comparison of pyrite molecules after 15 s for each model. seepage. In addition, the stress concentrated on the ends of the fissure, easily extending along the ends until a connection was established. Then, a fracture network was formed and able to transport gas. The temperature of the pyrite particles in RM was more uniform than in other models. There were more pyrite particles experiencing a rapid temperature increase and expansion, resulting in more damage to the coal matrix surrounding the pyrites (Figure 15). At 3 s, damage occurred around all pyrite particles, but the degree of damage varied. However, the damaged areas around A\({}_{\text{R}}\) and D\({}_{\text{R}}\) were not as serious as A\({}_{0}\) and D\({}_{0}\). The damaged areas were connected to the heating time. Finally, the damaged area connected all pyrite particles to form a fracture network, which could be used to promote gas seepage. The temperature and damage distribution in S\({}_{0}\)M, S\({}_{90}\)M, S\({}_{180}\)M, S\({}_{270}\)M, and RM were significantly different at 15 s (Figure 16). The temperature of all pyrites in S\({}_{90}\)M and S\({}_{270}\)M was the lowest, which resulted in only one pyrite (H\({}_{90}\), H\({}_{270}\)) incurring a small amount of damage. Although the average temperature of H\({}_{90}\) (42.23 \({}^{\circ}\)C) was lower than A\({}_{90}\) (45.85 \({}^{\circ}\)C) in S\({}_{90}\)M, the area around A\({}_{90}\) remained undamaged. This might have been due to H\({}_{90}\) being closer to the boundary. The coal matrix near the boundary was less constrained, which resulted in the release of stress and made fissure formation easier. In S\({}_{180}\)M, the temperature of five pyrite particles (A\({}_{180}\), D\({}_{180}\), F\({}_{180}\), G\({}_{180}\), and J\({}_{180}\)) was high enough to damage the coal matrix. In RM, damage occurred near all pyrites. The fracture network was more abundant than in all other SMs. Considering these results, rotational heating was  
Figure 14: Distribution of coal body temperature and damage in S\({}_{0}\)M.  
Figure 15: Distribution of coal body temperature and damage in RM. more conducive to the formation of fracture networks. In other words, rotational heating can be beneficial for promoting the formation of gas flow channels.