东曲矿软硬煤瓦斯吸附特性对比研究

为研究不同软硬煤瓦斯吸附特性,以山西古交矿区东曲矿为研究对象,针对2组不同变质程度的软硬煤,通过高压容量法测试了其瓦斯吸附性能;同时对不同软硬煤开展了低温液氮吸附实验,分析了其孔隙结构特征,从煤体微结构层面揭示了不同软硬煤的瓦斯吸附控制机理。研究结果表明:不同软硬煤之间存在较大的吸附差异性,瓦斯吸附参数VL最大值是最小值的1.5倍;在不同软硬煤中,微孔所占比例均大于50%,煤中的孔比表面积主要由小于10 nm的微孔所贡献;构造变形作用使得煤层中的原生孔隙裂隙系统被破坏,孔隙直径减小,微孔比例增加,孔隙比表面积也在不断增大,因而,软煤较硬煤拥有更强的吸附性能。

Comparison Research on Methane Adsorption Property of Soft and Hard Coals in Dongqu Coal Mine

To investigate the methane adsorption characteristics of different soft and hard coals, Dongqu Coal Mine in Gujiao Mining Area, Shanxi Province, was selected as the research object. Aimed at two groups of soft and hard coal samples with different coalification degrees, the high pressure capacity method was adopted to measure the methane adsorption properties of these samples. Low temperature liquid nitrogen adsorption experiments were carried out for these soft and hard coal samples and their pore structural characteristics were also analyzed. On the micro structure level, the control mechanism of methane adsorption was revealed for these soft and hard coal samples. The research result shows that gas adsorption capacity differs greatly among soft and hard coals. The greatest value of Langmuir volume VLis 1.5 times of the lowest value. Among all the samples, the proportion of micropores is more than 50%, and the pore specific surface area in coal is mainly contributed by micropores(< 10 nm). The original pore/fracture systems in coal seam are destroyed by tectonic deformation, leading to the reduction of pore diameter. As a consequence, the proportion occupied by micropores increases, and the pore specific surface area is also increased. Thus, the adsorption capacity of soft coal is significantly higher than that of the corresponding hard coal.