系列富硅铝矿石水热晶化法合成纳米莫来石复相粉体的研究  

The preparation of mullite nanocomposites powders from silicon-aluminiumbearing minerals through hydrothermal crystallization

作　　者：童玲欣[1] 李金洪[1] 刘芳[1] 林志祥[1] 

机构地区：[1]中国地质大学矿物岩石材料国家专业实验室,北京100083

出　　处：《岩石矿物学杂志》2011年第6期994-1000,共7页Acta Petrologica et Mineralogica

基　　金：教育部新世纪优秀人才支持计划资助项目(NCET-08-0828);中国地质调查项目资助项目(1212011120323)

摘　　要：分别以粉煤灰、煤矸石、红柱石千枚岩、油页岩渣等富硅铝矿石为原料,经过除杂、煅烧活化后,利用水热晶化法制备出纳米莫来石复相粉体。采用X射线粉末衍射(XRD)、透射电子显微镜(TEM)、能量色散X射线荧光光谱分析(EDX)和选区电子衍射(SAED)等手段研究了复相粉体的物相组成与显微结构,并用魔角旋转核磁(MAS^NMR)分析水热晶化反应机理。结果表明:经过一定温度煅烧活化后,当NaOH溶液浓度为2~3 mol/L、搅拌温度80~90℃、恒温3 h、液固比为10 mL/g时,上述四种原料均可制得以莫来石为主晶相的纳米复相粉体,其中以煤矸石、红柱石千枚岩、油页岩渣为原料制备的晶体均为结晶良好的柱状晶,平均长度分别为50、300和150 nm,平均长径比分别为4、3.5和3.75;以粉煤灰为原料制备的晶体主要呈现棒状、针状和纤维状,其棒状晶长度约30~80 nm、直径约4.5~30 nm。Mullite nanocomposites powders were successfully synthesized from high-aluminium coal fly ash,coal gangue,andalusite-sericite phyllite and oil shale slag through the hydrothermal crystallization process after the removal of the residual carbon,deferrization or calcination.The phase constitution and microstructure of the synthesized mullite nanocomposites powders were investigated by X-ray diffraction（XRD）,transmission electron microscopy（TEM）,selected area electron diffraction（SAED） and energy-dispersive X-ray（EDX）.Moreover,the reaction mechanism was analyzed according to MAS-NMR results.The experimental results show that mullite nanocomposites powders can be prepared from any silicon-aluminium-bearing minerals at 80~90℃ for 3 h with NaOH concentration of 2~4 mol/L and L/S ratio（liquid/solid ratio in mass） of 10 mL/g.Mullite nanocomposites which are synthesized from coal gangue,andalusite-sericite phyllite and oil shale slag are mainly existent as whole puncheon-shaped crystals,whose average lengths are 50 nm,300 nm and 150 nm,and whose average aspect ratios are 4,3.5 and 3.75,respectively.Otherwise,when coal fly ash is used as the raw material,mullite nanocomposites are mainly rod-like,acicular and fibroid in shape with the length in the range of 30~80 nm and the diameter in the range of 4.5~30 nm.MAS-NMR analysis indicates that the nano-size mullite grows around the central atoms Al,Si of the O4 tetrahedron and the growth unit Al-4 is existent in this process definitely.

关 键 词：纳米莫来石 粉煤灰 煤矸石 红柱石千枚岩 油页岩渣 水热晶化法 

分 类 号：P579[天文地球—矿物学]