贫煤孔隙特征及其对瓦斯解吸的影响

Porosity Characters of Lean Coal and It's Influence for Methane Desorption

为了研究贫煤孔结构特征对瓦斯解吸规律的影响, 采用低温液氮吸附法针对5 个贫煤煤样的纳米级（〈100nm） 孔隙结构进行了分析.同时根据瓦斯解吸实验, 将实验结果与煤的孔隙结构特征相结合, 分析纳米级孔隙结构对煤体瓦斯解吸的影响.结果表明 贫煤的小孔（10-100nm） 和微孔（〈10nm） 发育, 微孔主要占据了孔隙的比表面积, 决定瓦斯解吸特性, 在相同平衡压力条件下, 瓦斯解吸量随比表面积的增加而增加, 呈现出较好的线性关系; 孔比表面积是影响解吸量的主要因素, 而孔容与瓦斯解吸量的关系不明显.研究结果对煤矿瓦斯涌出量预测具有重要意义.

In order to study the influence that porosity character of lean coal to methane desorption law, then nanoscale （〈100 nm）porosity structure of five lean coal sample were analyzed by low temperature liquid nitrogen adsorption. According methane desorptionexperiment at the same time, the influence that nanoscale porosity structure to coal methane desorption was analyzed based experimentalresults and coal porosity characters. The results showed that the samll pore （10 ~100nm） and micro pore （〈10nm） developed inlean coal, micro pores principal occupied specific surface area of porosity, and methane desorption was decided by it. Under the samebalance pressure situation, methane desorption amount increases with specific surface area increases, present a preferable linear relation.Porosity specific surface area is the main factor that influenced desorption, but the relation between pore volume and methane desorptionwas unconspicuous. The results could referenced for coal mine methane emission quantity.