Study of inflatable temperature–sensitive hydrogel to prevent the coal spontaneous combustion

Abstract

A serious of inflatable temperature–sensitive hydrogel (HPMC–CS–EM) were prepared to prevent coal spontaneous combustion (CSC). Through performance tests, it was found that gel of 50 mPa∙s HPMC had good fluidity, the addition of EM can increase the water loss in the early pyrolysis stage. A50, B50 prepared by 50 mPa∙s HPMC and 0 %, 0.5 % EM had good performance which were suitable for the prevention of CSC. The inhibition of A50, B50 on CSC was tested by means of paramagnetic resonance spectroscopy and thermogravimetry. Inhibition experiments revealed that more water and hydrocarbon gas were released from B50 gel, thereby significantly reducing the concentration and amount of free radicals, the maximum water loss rate temperature and the dry crack temperature. The more carbon residue of A50 gel made it have better inhibition effect in the slow oxidation stage. The average apparent activation energy was obtained by the combination of universal integral and differential at multiple heating rates, indicating that these two gels remarkably reduced the tendency of CSC.