Mine fires, Coal spontaneous combustion, Oxidation inhibition, Physical-chemical inhibitory effect, Engineering (General). Civil engineering (General), TA1-2040

Inhibitors are widely used on-site due to their effective prevention. The effect of a novel compound inhibitor composed of thermosensitive hydrogel (TSH) and antioxidants (tea polyphenols (TP) and L-ascorbic acid (VC)) on coal spontaneous combustion (CSC) characteristics was studied. Its inhibitory effect was compared with that of the single component or MgCl2 by macroscopic and microscopic tests. The results show that the release of CO or CO2 from coal treated with inhibitors during temperature-programmed tests was reduced, and the crossing-point temperature of TSH-TP/VC-treated coal increased by 21.4 °C. The content of –CH2, –CH3 and oxygen-containing group in inhibitor-treated coal decreased than before, the characteristic temperature of spontaneous combustion increased significantly, and the mass gain values of coal treated with TSH-TP/VC, TSH, TP/VC or MgCl2 decreased by 0.99 %, 0.93 %, 0.87 %, 0.24 %, respectively. The inhibitory efficacy of TSH-TP/VC is superior to the effect of single component or traditional inhibitor MgCl2, and it is effective in inhibiting the entire oxidative decomposition and combustion stage of coal. TSH can effectively cover the coal body and remove the accumulated heat. At the same time, TP/VC hinders the emergence of free radicals and chelates with metal ions, thereby exhibiting a significant suppression of CSC.