摘要
主要探究了超重力场中制备工艺条件对碳酸钙晶须断裂程度的影响规律。包括碳化温度、旋转床转速、干燥时间等因素对碳酸钙晶须断裂程度的影响,并采用SEM和XRD表征了晶须状碳酸钙的表面形貌以及晶体结构。实验结果表明:当旋转床转速一定时,较高的碳化温度有利于文石相碳酸钙晶须的生成,但随碳化温度的升高容易加剧晶须的断裂;当碳化温度一定时,旋转床转速的增加容易加剧碳酸钙晶须的断裂;在100℃下对碳酸钙晶须进行干燥,当干燥时长超过70 h时,碳酸钙晶须会出现明显的断裂,且随干燥时长的增加而加剧;在本文实验范围内:碳化温度为70℃,旋转床转速为1400 r·min^(-1),干燥时长30 h内所制备的碳酸钙晶须的长径比可达19.4,平均短径为144 nm,文石相含量为97.48%且形貌保持完整。研究结果对碳酸钙晶须的工业化生产具有一定的指导意义。
CaCO3 whiskers were synthesized by high-gravity precipitation, and the effects of reactive temperature, rotating speed of the rotating packed bed （RPB） reactor and drying time on CaCO3 whisker fracture were systematically investigated. The synthesized CaCO3 whiskers were characterized by scanning electron microscope （SEM） and X-ray diffraction （XRD）. The results show that （1） higher reaction temperature is favorable for aragonite CaCO3 whisker formation under certain rotating speeds of RPB, and it also increases whisker fracture; （2） The degree of whisker fracture exacerbates with the rise of RPB rotating speed under certain reaction temperatures; （3） obvious fracture of CaCO3 whisker occurs when the drying time exceed 70 hours at 100℃, and the fracture of whisker increases with drying time. Unbroken CaCO3 whisker with average diameter of 144 nm, average aspect ratio -19.4 and aragonite phase of 97.48% could be prepared under the following operation conditions： reactive temperature 70℃; RPB rotating speed 1400 r·min^-1; drying time less than 30 h. The results shown in this study are helpful for industrialized CaCO3 whisker production.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2016年第6期1359-1365,共7页
Journal of Chemical Engineering of Chinese Universities
基金
南宁市科技局项目(20145337)
广西大学科研基金(XGZ130963)
关键词
超重力
碳酸钙晶须
长径比
断裂
文石相
high-gravity environment
CaCO3 whisker
aspect ratio
fracture
aragonite phase
