气肥煤与焦煤的孔隙分布规律及其吸附–解吸特征

 采用山东微山菜园矿的气肥煤和山西古交马兰矿的焦煤作为煤样，分别进行压汞试验，测定煤的孔径分布，了解各孔径段孔容、比表面积的分布规律；并且对所采集的两种煤样分别进行平衡水煤样的CH4/CO2混合气体的吸附–解吸试验，从孔隙结构方面分析深部煤层煤对瓦斯吸附的影响。研究结果表明，焦煤比气肥煤具有更为复杂的孔隙结构，具有更丰富的小孔和微孔；煤中微孔的分布决定煤的吸附能力，吸附最有效的孔隙半径是在10 nm以下；焦煤对CH4/CO2二元混合气体的吸附能力强于气肥煤的吸附能力；探讨分析CO2/CH4吸附能力的差异性是导致试验中高压阶段CH4/CO2二元混合气体吸附量小于低压时的现象发生的主要原因。研究煤的孔隙分布规律及其吸附–解吸特征，可以从微观层次揭示深部煤层煤吸附瓦斯的聚气能力，探寻煤吸附–解吸瓦斯的特征和机制，丰富煤吸附瓦斯理论，对煤与瓦斯突出的防治和煤层气资源的开发均具有重要意义。

PORE DISTRIBUTION REGULARITY AND ABSORPTION-DESORPTION CHARACTERISTICS OF GAS COAL AND COKING COAL

Hg-injection experiment was carried out with coal samples in the gas coal from Caiyuan Mine in Weishan City，Shandong Province，and the coking coal from Malan Mine in Gujiao City，Shanxi Province，to find out the distribution regularity of pore volume and specific surface area in various pore sizes. The absorption- desorption experiment on binary-component gas(CH4/CO2) was carried out with equilibrium water coal sample to analyze the influence on coal adsorbing gas in deep coal bed in the aspect of pore configuration. The results indicate that the pore configuration of the coking coal is more complicated than that of gas coal；and there are smaller and micro pores in coking coal rather than in gas coal. The absorption capacity of coal is determined by the distribution of micro pores；and the most effective absorption pore radii are below 10 nm. The absorption capacity of coking coal is stronger than that between gas coal. It is analyzed that the absorption capacity difference of gas coal and coking coal would lead to the phenomenon that absorption in high-pressure stage is less than that in low-pressure stage in the experiment. Based on the research of the pore distribution and absorption-desorption characteristics of coal，the absorption capacity of coal in deep coal bed can be revealed at micro level；and the characteristics and mechanism of absorption-desorption of coal are explored，which enriches the absorption-desorption theory of coal and is of great significance to coal and gas outburst prevention and coal-bed methane exploitation.