Comparison and Application of Two types of Filling Gel to Prevent Spontaneous Combustion at the Region where Top-Coal Caves above Entry

Abstract

Abstract. Two types of gel were developed, by taking fly ash and foaming cement as aggregate, which is usually used as filling material at the region where top-coal caves above coal entry in the Jinggezhuang coal mine, and adding high molecular polymer and bio-gel as additive. Sweating rates of the two types of gel under various matching ratio and temperature were tested. And then sweating ratio and water retention ratio of the two gels were calculated, based on which, the optimized matching ratios, were determined. Viscosity indexes of the two-type gel under different ratios were tested. The optimized filling ratios of the two types of gel were determined according to the two indexes, water retention rate and the viscosity. The filling experiments were implemented and evaluated in site, the Jinggezhuang coal mine. The results show that the fly ash gel has a good achievement on preventing spontaneous combustion at the Region where Top-Coal Caves above entries. It is promising, economically and environmental friendly, and valuable in popularization in coal mines.