构造煤瓦斯解吸特征及对煤与瓦斯突出的影响

Gas Desorption Characteristics of Tectonic Coal and Its Influence on Coal and Gas Outburst

通过改进的煤样瓦斯解吸装置,精确测定了不同平衡压力下构造煤与原生煤的恒温瓦斯解吸量与解吸速度数据,分析了构造煤的瓦斯解吸特征。实验结果表明:构造煤的瓦斯解吸量具有明显的分段特征,其初期瓦斯解吸量更大,第1 min内瓦斯解吸量可达120 min总解吸量的31.55%～38.07%,远高于同条件原生煤的10.94%～14.24%;构造煤的初始解吸速度可达10.11～15.75 mL/(g·min),是同条件下原生煤的的1.72～2.32倍,构造煤的初期解吸特征主要由第1 min内的解吸特性控制。通过现场数据分析了钻屑瓦斯解吸指标K_1随构造煤平均厚度变化情况,两者呈线性关系且显著正相关,说明在构造煤发育区域煤与瓦斯突出危险性显著增加。

Through the improved coal sample gas desorption device,the constant temperature gas desorption quantity and desorption velocity data of tectonic coal and primary coal under different equilibrium pressure are accurately measured,and the gas desorption characteristics of tectonic coal are analyzed.The experimental results show that the gas desorption curve of tectonic coal has obvious sectional characteristics compared with that of the primary structural coal.In the first 1 minute,the gas desorption amount of tectonic coal can reach 31.55%to 38.07%of the total desorption amount in 120 minutes,which is much higher than that of the primary coal under the same condition(10.94%to 14.24%).The initial desorption of tectonic coal can reach 10.11 mL/(g·min)to 15.75 mL/(g·min),which is 1.72 to 2.32 times faster than primary structural coal.Therefore,the initial desorption characteristics of tectonic coal are mainly controlled by the desorption characteristics in the first 1 minute.The relationship between the desorption index of drill cuttings K1 and the average thickness of tectonic coal is analyzed,and the relationship between them is linear and significantly positive,indicating that the risk of coal and gas outburst increases significantly in the area where tectonic coal is developed.