利用小角X射线散射技术研究煤干馏过程中的孔隙结构变化

Study on Pore Structural Changes of Coal Carbonization by Small Angle X-ray Scattering Technology

煤干馏是煤炭高效利用的重要途径之一。同步辐射小角X射线散射(Small Angle X-Ray Scattering,SAXS)技术是研究煤干馏过程中内部孔隙结构变化的常用手段。本文利用SAXS对山西余吾烟煤干馏过程(100~1200℃,温度梯度100℃)进行了表征,并对分形维数和粒径分布的变化进行了分析。结果发现煤干馏过程中,散射图像类似,具有各向同性特征,始终保持表面分形结构,且分形维数总体上呈现增大的趋势;随着煤干馏温度的升高,粒度分布发生了显著变化,充分反映了煤在不同干馏阶段的结构特征,对后续的煤炭研究具有一定的指导意义。

Coal carbonization is one of important ways to use coal efficiently.Synchrotron radiation small angle X-ray scattering(SAXS)technology is an effective method to study the change of internal pore structure during the coal carbonization.In this paper,we used SAXS to characterize Yuwu(Shanxi)bituminous coal carbonization process(100~1200℃,the temperature difference between 100°C)and analyzed the changes of fractal dimension and pore size distribution.The results indicated that the scattering image of samples was similar with each other,all of them presented isotropic characteristics and surface fractal structure during coal carbonization.The fractal dimension trended to increase on the whole.During the increase of coal carbonization temperature,the pore size distribution changed obviously.The results reflected that the structural characteristics of coal carbonization had different stages,which was of great significance for subsequent coal research.