煤纳米孔径与分形特征的同步辐射小角散射

发布时间：2018-03-15 16:53

本文选题：小角X射线散射(SAXS)　切入点：纳米尺度　出处：《科学通报》2017年21期 　论文类型：期刊论文

【摘要】：煤是一种非均质多孔介质,孔隙结构复杂.本文利用同步辐射小角散射试验对6种不同煤阶煤样纳米尺度微孔结构(1~100 nm)进行测试,分析了煤样的Porod散射曲线、Guinier散射曲线、孔径分布、比表面积和分形特征等,探讨了煤化过程中煤中微孔隙结构的演化特征.实验表明:6种煤样Porod散射曲线均呈现正偏离现象,Guinier曲线表明煤样孔隙呈多分散系分布特征;基于最大熵理论计算得出煤样孔径分布呈"双峰"形态,随变质程度增加,煤样平均孔径和最可几孔径均呈下降趋势;煤样比表面积表现为先增大后减小又缓慢增加.测试煤样的分维数在低角q阶段呈现表面分形,在高角q阶段表现为孔分形.表面分形维数随煤阶增加呈先减小后增加而后又减小的变化趋势,孔分形维数随煤阶增加呈先减小后增加的态势,且当R_(o,max)为2.07%时达最小值.
[Abstract]:Coal is a kind of heterogeneous porous media, complex pore structure. In this paper, using synchrotron radiation small angle scattering experiments on 6 different rank coals like nano scale pore structure (1~100 nm) were tested, analyzed the Porod scattering curves of coal samples, Guinier scattering curve, pore size distribution, specific surface area and fractal characteristics. To investigate the characteristics of the evolution of the micropore structure of coal during coal. Experimental results show that the 6 kinds of coal samples Porod scattering curve showed a positive deviation, Guinier curves show that the porosity of coal samples showed polydisperse distribution; maximum entropy theory to calculate coal pore size distribution was "Shuangfeng" with the form based on the metamorphic degree of coal increased. The average pore size and size can be decreased; the coal surface area is increased first and then decreased and increased slowly. The fractal dimension of coal sample test shows surface fractal in low angle and high angle in Q stage, Q stage was divided into the hole The surface fractal dimension decreases first and then increases with the increase of coal rank. The fractal dimension of pore decreases first and then increases with the increase of coal rank. When R_ (O, max) is 2.07%, the minimum value of pore fractal dimension is reached.

【作者单位】：中国矿业大学(北京)资源与安全工程学院;中国矿业大学(北京)煤炭资源与安全开采国家重点实验室;
【基金】：国家重点研发计划(2016YFC0600708,2016YFC0801401)资助
【分类号】：P618.11;TQ531

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