Characterization of Gel Foam Containing Tea Polyphenol/Highly Absorbent Resin to Inhibit Coal Spontaneous Combustion

Gel foam is one of the effective means to prevent and control coal spontaneous combustion. To improve the inhibition effect of gel foam on coal spontaneous combustion, high absorbent resin (SAP) combined with tea polyphenol (TP) as an inhibitor agent (ST) was introduced into gel foam, and an inhibition gel foam (ST-IGF) fireproofing material was prepared. The ratio of ST-IGF was determined by one-factor test, and its foaming performance, foam stability and water retention were characterized. The inhibition effects of ST-IGF and ordinary gel foam (GF) on coal spontaneous combustion were compared by infrared spectrum analysis, programmed warming and thermogravimetric experiments. The results showed that the foam volume of ST-IGF was more than 400 mL and the half-life of precipitation was more than 12 h. The water loss of ST-IGF was 93.3%, after being heated at 100°C for 12 h. ST-IGF can reduce the rate of CO production and increase the apparent activation energy, and the inhibition rate at 100°C is 68.72%. The heat absorption and heat release of ST-IGF-treated coal (ST-IGFC) decreased by 4.02 J/g and 155.55 J/g, respectively. The peak areas of the functional groups of ST-IGFC, such as -OH, -CH2, and C = C, were reduced by 44.32%, 38.36%, and 39.83%. This study can provide a theoretical basis for the prevention and control of coal spontaneous combustion by the inhibitory gel foam.