摘要
以脱铝赤泥和脱铝粉煤灰为原料，采用水热法制备硬硅钙石，考察原料配比、液固比及反应时间对硬硅钙石生成及形貌的影响。结果表明：在220℃、钙硅比为1．0时，脱铝粉煤灰掺入量的增加、液固比的提高和反应时间的延长均促进了硬硅钙石的生成。最佳反应条件为：脱铝粉煤灰加入量大于总质量40％、液固比35mL儋、反应时间9h。在该条件下获得了由直径为25～50nm，长径比大于20的硬硅钙石单晶晶须缠绕而成的球形粒子。通过扫描电镜（SEM）、透射电镜（TEM）和背散射电子图像（BSE）分析晶须生长、成球机理及粒子内部结构，证实了球形粒子的中空结构可能与反应初期形成的前驱体包裹晶态SiO_2有关。
The xonotlite was prepared by hydrothermal method using sub-molten salt red mud （SRM） and sub-molten salt fly ash （SFA） as raw materials, and the effects of ratio of raw materials, liquid-solid ratio and reaction time on the synthesis and morphology of the xonotlite were examined. The results show that the synthesis of xonotlite is promoted with the increase of doping amount of SFA incorporation, liquid-solid ratio and reaction time under the condition of 220 ℃ and n（CaO）/n（SiO_2） of 1.0. The optimal conditions are as follows： doping amount of SFA greater than 40% of the total mass, liquid-solid ratio 35 mL/g and reaction time 9 h. Under such conditions, the spherical particles are formed by the winding of xonotlite single crystal whiskers with diameter of 25-50 nm, length-diameter ratio over 20 are synthesized. The mechanisms of the growth of xonotlite whisker, formation of spherical particles and the internal structure characteristics of the spherical particles were analyzed by scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and back-scattered electron imaging （BSE）. The results show that the forming of hollow structure of the spherical particles is probably related to the wrapped crystalline state SiO_2 by precursor formed in the initial reaction stage.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2015年第2期534-544,共11页
The Chinese Journal of Nonferrous Metals
基金
国家高技术研究发展计划资助项目(2011AA060701)
关键词
硬硅钙石
脱铝赤泥
脱铝粉煤灰
晶须
球形粒子
水热反应
xonotlite
sub-molten salt red mud
sub-molten salt fly ash
whisker
spherical particle
hydrothermalreaction
