煤矸石充填体在不同参数条件下的瓦斯透气性实验研究

An experimental research on gas permeability of coal gangue backfilling body under different parameters

为研究煤矸石充填体的瓦斯透气性,根据压差法和达西定律构建了一种煤矸石充填体瓦斯透气性实验系统,并利用该系统完成了煤矸石不同级配、不同围岩压力和不同瓦斯体积分数下的透气性实验。实验结果表明:实验测定的煤矸石充填体瓦斯透气系数在区间[0.649,3.206]m2/(MPa2·d)内,属于可以抽放范围,透气性较好。在实验基础上提出了通过适当增加煤矸石充填体的粒径和工作面风量、降低煤矸石充填体承载力和充填区域瓦斯含量的方法来增大煤矸石充填体的瓦斯透气系数,从而为安全高效的保护层开采煤矸石充填应用技术提供理论指导。

In order to study the gas permeability of coal gangue backfilling body, based on the pressure-difference method and Darcy＇s law, an experimental system for measuring the gas permeability has been proposed. And a series of experiments under various particle gradation,different surrounding rock pressures and different gas concentration have been conducted by using the system. The results have shown that the gas permeability coefficients of coal gangue backfilling body measured by the experiment are in the interval of [0.649,3.206] m2/（MPa2·d）,which belong to the appropriate scope of gas drainage,and that the coal gangue backfilling body has good air penetrability. Based on the results of the experiments, the paper has put forward various methods such as appropriate increase of the grain size of coal gangue backfilling body and the ventilation quantity between working face ends, and decrease of the bearing capacity of coal gangue backfilling body and the gas concentration of packing area to increase the gas permeability of coal gangue backfilling body, and the experimental results have provided theoretical guidance for safe and highly effective gangue backfilling technology development under the circumstance of protective layer mining.