余吾矿构造煤吸附动力学特性

Adsorption Dynamics Characteristic of Tectonic Coal in Yuwu Coal Mine

针对构造煤瓦斯吸附动力学特性,以山西潞安余吾煤矿为工程背景,选取了4种不同破坏类型的构造煤样,进行了压汞测试和瓦斯等温吸附实验,获得了煤体孔隙分布特征和瓦斯吸附动力学曲线,并分析了吸附压力、吸附量及吸附速率随时间的变化规律。研究结果表明:吸附压力随吸附时长的增加而不断降低,在吸附开始的前20 min内压力急剧降低,降幅高达60%以上;随吸附时长的增加,各煤样瓦斯吸附量经历了先急剧增大再缓慢增加最后达到平衡的非线性变化过程;吸附速率曲线表明,随煤体破坏程度的增加,瓦斯吸附速率逐渐增大,吸附性增强。不同破坏类型构造煤孔隙分布差异显著,进而影响瓦斯吸附动力学特性,在煤矿瓦斯治理和煤层气开发中应予以考虑。

Aiming at the methane adsorption dynamics characteristics of tectonic coals, Yuwu Coal Mine of Lu’an Group in Shanxi Province was chosen as the engineering background. Four tectonic coal samples with different degrees of destruction were selected for high-pressure mercury intrusion porosimetry and methane isothermal adsorption experiments, and the pore distribution characteristics in coal and methane adsorption dynamics curves were obtained. The changing laws of adsorption pressure,adsorption volume and adsorption speed with time were analyzed. The research result shows that the adsorption pressure is decreased with the increase of time. At the initial 20 min of the adsorption, pressure sharply declines with the decreasing amplitude, more than 60%. As the increase of adsorption time, the methane adsorption volume experiences a nonlinear changing process: dramatical increase-slow rise-reaching equilibrium. The adsorption speed curves indicate that both the methane adsorption speed and adsorption capacity are enhanced with the increase of the degree of destruction. The pore distribution characteristics of tectonic coals with different destruction types vary a lot, further affecting the methane adsorption dynamics, which should be considered in the engineering practice for coalmine gas control and methane exploitation.