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以黔西北青龙煤矿和小屯煤矿的构造煤和原生结构煤为研究对象,利用全自动氮吸附仪分别测得煤样的液氮等温吸解曲线。根据BJH法分别绘制了煤样的孔径分布图,对比了构造煤和原生结构煤孔隙结构对吸解特性的影响。结果表明:构造煤的BET比表面积、孔容均大于原生结构煤,构造煤的孔直径小于原生结构煤;在相同压力条件下,构造煤的解吸量与吸附量之差明显大于原生结构煤;构造煤的解吸量和解吸速度均大于原生结构煤;构造煤和原生结构煤的等温吸附线均具有Ⅱ类等温吸附线的特征;在相对压力约为0.4~0.5时,构造煤与原生结构煤解吸曲线均出现一个较大的拐点;构造煤与原生结构煤吸附与解吸均出现“滞后”现象,且构造煤脱附时很难达到吸附起始点,构造煤比原生结构煤存在更多“墨水瓶”型微孔;构造煤的微孔主要集中在2~3nm左右,原生结构煤的微孔主要集中在4 nm左右;黔西北煤的解吸空间主要集中在大于3~4 nm的微孔孔隙。
Taking the tectonic coal and primary structure coal of Qinglong coal mine and Xiaotun coal mine in northwestern Guizhou province as the research object, the isothermal absorption curves of liquid nitrogen and nitrogen of coal samples were measured by automatic nitrogen adsorber. According to the BJH method, the pore size distributions of coal samples were plotted, and the influence of pore structure of coal and primary structure coal on the absorption characteristics was compared. The results show that the BET specific surface area and pore volume of tectonic coal are larger than those of primary structure coal, and the pore diameter of tectonic coal is smaller than that of primary structure coal. Under the same pressure, the difference between desorption capacity and adsorption capacity of tectonic coal is obviously larger than that of primary structure coal. The desorption and desorption velocities of coal are higher than that of primary structure coal. The isothermal adsorption lines of tectonic coal and primary structure coal all have the characteristics of Ⅱ type isothermal adsorption line. When the relative pressure is about 0.4-0.5, the desorption curves of coal and primary structure coal Both of them show a larger inflection point. Both the structure coal and the primary structure have “lag ” phenomenon in the adsorption and desorption of coal, and it is very difficult to reach the starting point of adsorption when the coal is desorbed. The micropores of tectonic coal are mainly concentrated in about 2 ~ 3nm, while the micropores of primary structure coal are mainly concentrated in about 4 nm. The desorption space of coal in northwestern Guizhou is mainly concentrated in the micro-pores of more than 3 ~ 4 nm Hole porosity.