Abstract:
Controlling the oxidation rate during the latent period of spontaneous combustion plays an important role in the efficient inhibition of coal spontaneous combustion. In order to suppress coal spontaneous combustion while meeting the environmental requirements of inhibitor materials, experiments on room-temperature and low-temperature inhibition of coal spontaneous combustion using composite environmentally friendly inhibitors were conducted. Common halide salt inhibitors and composite environmentally friendly chemical inhibitors were selected for comparative analysis of gas products (CO, CO
2) and oxygen consumption during room-temperature and low-temperature oxidation of coal samples; then, Fourier transform infrared spectroscopy and electron paramagnetic resonance spectroscopy were used to analyze the changes in oxygen-containing functional groups and free radical contents of coal samples before and after treatment with the new composite environmentally friendly inhibitor. The macroscopic experimental results show that during the oxidation stage at room temperature, the cumulative production of CO and CO
2 in the coal samples treated with the new type of composite environmentally friendly inhibitor decreases more significantly. In the low-temperature oxidation stage, compared with halide salt inhibitors, the new type of composite environmentally friendly can significantly reduce the generation of CO and CO
2 in coal samples, and the oxygen consumption is the lowest. Through the microscopic test results, it can be found that the content of oxygen-containing functional groups and alkyl groups in the coal sample will significantly decrease after treatment with the new type of composite environmentally friendly inhibitor. In addition, the concentration of free radicals in the coal samples will also be significantly reduced after treatment with the new type of composite environmentally friendly inhibitor. Combining the results of macroscopic experiments and microscopic tests, it can be concluded that the new type of composite environmental-friendly inhibitor has a significantly better inhibitory effect on coal spontaneous combustion than the commonly used halide salt inhibitors. It can effectively reduce the generation of gas products and oxygen consumption during coal oxidation, and at the same time, it can effectively lower the oxidation activity of active groups in coal under normal temperature and heating conditions, revealing its potential efficacy in replacing halide salt inhibitors in preventing coal spontaneous combustion.