中低阶煤孔隙结构特征的氮吸附法和压汞法联合分析

(1.西安科技大学 安全科学与工程学院,陕西 西安 710054; 2.西安科技大学 西部矿井开采及灾害防治教育部重点实验室,陕西 西安 710054)

氮吸附法; 压汞法; 联孔分布; 全孔径; 中低阶煤

Joint analysis of pore structure characteristics of middle and low rank coal with nitrogen adsorption and mercury intrusion method
LIN Hai-fei1,2,BU Jing-ting1,2,YAN Min1,2,BAI Yang1,2

(1.College of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.Key Laboratory of Western Mine Exploitation and Hazard Prevention,Ministry of Education,Xi'an University of Science and Technology,Xi'an 710054,China)

nitrogen adsorption method; mercury intrusion method; joint pore distribution; full-aperture; middle and low rank coal

DOI: 10.13800/j.cnki.xakjdxxb.2019.0101

备注

为进一步分析中低阶煤孔隙结构特征,选取新疆矿区4个典型煤样,通过低温氮吸附法和压汞法测试了煤样的孔隙参数,得到2种测试方法下孔隙比表面积及孔隙体积分布,提出2种测试方法的全孔径段孔隙联孔原则:首先在不超过各自测试范围的前提下,测试微孔孔隙特征以氮吸附法为主,中孔及大孔孔隙特征主要以压汞法为主,联孔位置在过渡孔段; 2种方法在同一孔隙直径处比表面积增量或孔隙体积增量差值最小处即为联孔段。分析了实验煤样全孔径段的孔隙特征,研究结果表明:采用氮吸附法和压汞法对煤样全孔径段孔隙结构分析的联孔位置,对于低阶煤为50~60 nm,中阶煤为85~90 nm,均位于过渡孔段; 全孔径段孔隙比表面积占比,低阶煤以微孔为主,中阶煤受微孔和过渡孔共同作用; 中低阶煤的全孔径段孔隙体积占比均以中大孔为主。

In order to further analyze the pore structure characteristics of middle and low rank coal,4 typical coal samples in Xinjiang mining area were selected.The pore parameters of coal samples were tested with low temperature nitrogen adsorption and mercury intrusion method.The pore specific surface area and pore volume distribution were obtained.The pore connection principle of full-aperture with two testing methods was put forward.Firstly,under the premise of not exceeding the test range,the pore characteristics of micropore is determined by nitrogen adsorption,the pore characteristics of mesopore and macropore is determined by mercury injection,and the location of the connection position is in the transition pore section.The two methods are linked pore segments where the difference between specific surface area increment and pore volume increment is minimum at the same pore diameter.The pore characteristics of full-aperture of coal samples was analyzed.The results show that for the pore structure analysis with nitrogen adsorption method and mercury intrusion method,the pore connection position of low rank coal is 50~60 nm,and the pore connection position of middle rank coal is 85~90 nm,which are located in the transition pore section.For the proportion of pore specific surface area of full-aperture,the low rank coal is mainly micropore,and the middle rank coal is affected by micropore and transition pore.For the proportion of pore volume of full-aperture,the middle and low rank coal are mainly mesopore and macropore.