A novel nano-modified inhibitor of tert-butyl hydroquinone/sodium polyacrylate for inhibiting coal spontaneous combustion

In this study, we developed a modified antioxidant-type inhibitor (MAT-inhibitor) to address the disadvantages of the inhibitors that are currently used in coal mines, namely single effect, poor thermal stability, and low versatility. Sodium acrylate, tert-butyl hydroquinone (TBHQ), and montmorillonite were used as raw materials. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) were adopted to analyze the inhibition performance and mechanism of the MAT-inhibitor. Research indicates that the MAT-inhibitor is able to fully cover the coal surface, and has strong water absorption qualities. TBHQ in the inhibitor significantly reduces the content of methyl (-CH3), methylene (–CH2–), hydroxyl (-OH), and carboxyl groups (-COOH) in the coal radical chain reaction. In the meantime, it increases the stable ether bond content (C–O–C). After treatment with the MAT-inhibitor, the dry cracking temperature of the coal sample increased by 52.8 °C, and the maximum thermal mass loss rate decreased by 0.84%/min. This proved that the inhibitor has superior thermal stability and high inhibition performance. Therefore, regardless of the physical, chemical, and thermal stability aspects, the MAT-inhibitor can be used to control the spontaneous combustion of coal.