The Effects of Different Experimental Conditions on the Detected Results of Coal Pore Characteristics

摘要

Low-temperature nitrogen adsorption-desorption experiment based on static volumetric method is widely used to analyze the pore characteristics of coal. The pore structure of a middle rank coking coal produced in Shanxi Province, China is analyzed. The effects of different experimental conditions including degassing time, degassing temperature, sample weight, and sample particle size on the detected pore characteristics of coal are studied to obtain the best optimized experimental conditions. The results indicate that the optimal experimental conditions include degassing time of at least 8 h, degassing temperature of around 150°C, 5000.0 mg sample weight, and <0.5 mm particle size. Pore size distribution of coal samples is calculated from the adsorption branch and desorption branch isotherms by using the Barrett-Joyner-Halenda (BJH) analysis method and De Boer (DB) method. Moreover, the optimum means are obtained from the BJH method within the adsorption branch and the DB method within the desorption branch.