煤粉比表面积与孔径分布测定中脱气方法的实验

Experimental Study on Degassing Method for Surface Area and Pore Size Distribution Determining of Coal with Isothermal Nitrogen Adsorption

为探索一种准确测定各种煤粉比表面积与孔径分布的实验方法,采用等温氮吸附法,用抽真空法与气流吹扫法在多种脱气条件下,对一组煤粉样品进行了比表面积与孔径分布测试。发现脱气方法和脱气条件对实验结果影响较大,气流吹扫法的脱气条件较难控制,实验结果的重复性较差,误差也较大,不太合适煤粉样品的脱气处理;而抽真空法相对而言,脱气条件较好控制,实验结果的重复性较好,准确性较高,比较合适煤粉样品的脱气处理。通过实验研究,找到了用等温氮吸附法测定煤粉比表面积与孔径分布时适合煤粉的一种脱气方法与脱气条件。

In order to get an accurate method to measure the specific surface area and the distribution of pore size, the surface area and pore size property of a series of coal samples was investigated with isothermal nitrogen adsorption method under vacuum-pumping and gas sweeping and variant degassing conditions. It was observed that the degassing methods and conditions display great impact on the analysis results. The degassing condition was difficult to control and the re- peatability of experiment result was very low. However, the working condition of vacuum pumping is much better to con- trol, and the repeatability and accuracy are much higher. The suitable degassing method and operating condition for the surface structure analysis of coal with isothermal nitrogen adsorption were observed through experiment. It is significant for the accurate determination of the physical property of coal and other solid powder samples.