Experimental study on effect of mudstone on spontaneous combustion of coal

The influence of mudstone on the spontaneous combustion of coal was investigated in this study. The effects of different proportions of mudstone on the characteristic temperature, thermal effect, thermal physical parameters, and combustion characteristic index of coal were analyzed by TG-DSC experiments and thermal physical parameter test experiments. The catalytic mechanism of mudstone on the active structure of coal oxidation was obtained by Fourier transform infrared spectroscopy. The results showed that an interaction exists between coal and mudstone, and different stages had different effects. The combustion characteristic index showed a trend of an initial increase followed by a decrease. The thermal conductivity and thermal diffusivity of MY-1 samples were larger than those of raw coal samples, indicating that a small amount of mudstone had the most obvious effect on coal combustion and played a promoting role in the heat transfer of coal samples. The carbon content of mudstone was much lower than that of coal, and the content of metals and their oxides and sulfides was higher. The content of aliphatic hydrocarbons and hydroxyl groups in the samples mixed with mudstone decreased. When coal coexists with a small amount of mudstone, the risk of spontaneous combustion of coal increases.