Experimental Research on Heat Transfer and Strength Analysis of Backfill with Ice Grains in Deep Mines

Abstract

In deep mines, two urgent problems are a high temperature thermal environment and solid waste. Filling the goaf with slurry mixed with ice grains is an effective way to solve these two problems simultaneously. The thermal property and mechanical property of the ice-added backfill have a great influence on the cooling effect in the deep mine. In this study, an experimental facility for measuring the temperature distribution of ice-added backfill slurry was established, and the temperature of backfill slurry with different proportions was measured. Then, the thermal properties of temperature distribution and cooling capacity and the mechanical property of uniaxial compressive strength of the backfill specimens were analyzed, and the results indicated the following: firstly, the cooling capacity of ice-added backfill specimens is negatively related with the slurry concentration C and is positively related with the ice-water ratio Ω; secondly, the strength of backfill specimens is affected by the slurry concentration C and ice-water ratio Ω by a contrary law compared to the cooling capacity; thirdly, ice-added backfill slurry with an ice-water ratio Ω of 1:1 has the best mechanical property after solidification. The effects of the slurry concentration and ice-water ratio on the thermal and mechanical properties were analyzed, and the results indicated that the optimum proportion of ice-added backfill slurry is a slurry concentration of 74% and an ice-water ratio of 1:1 in the present research range. This study is significant for the deep mine cooling method with ice-added backfill.