Precipitation of nanostructured calcite in a controlled multiphase process
Precipitation of nanostructured calcite in a controlled multiphase process
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DOI：
10.1016/j.jcrysgro.2009.05.017
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发表时间：
2009-07-01
影响因子：
1.8
通讯作者：
Gierycz, Pawel
中科院分区：
文献类型：
--
作者：
Kedra-Krolik, Karolina;Gierycz, Pawel
沉淀过程的进行方式对最终产品的性能及其进一步应用至关重要。在所提出的实验中，通过在Ca（OH）（2）浆料中吸收气态CO2来控制快速沉淀来制备CaCO 3粉末。这种多相反应是在一个新的旋转圆盘反应器单元中进行的，它使人们能够控制面间和面内的质量和能量传递以及反应体系中的宏观和微观混合效应。研究了氢氧化钙浓度、反应器内混合条件和圆盘表面气液界面发展对沉淀碳酸钙的影响，用动态光散射法（DLS）分析表明，随着圆盘转速和氢氧化钙浓度的增加，平均粒径减小。X射线衍射测试表明，我们已经获得了化学纯的方解石，这是最稳定的多晶型碳酸钙。扫描电子显微镜（SEM）显示了沉淀条件对菱方体方解石晶体的影响。吸附表面分析表明，高发展的比表面积（超过20米（2）克（-1））和粉末的孔隙率。(C)2009 Elsevier B. V.保留所有权利。
The way of conducting the precipitation process is crucial for the final product properties and its further applications. In the presented experiments, CaCO3 powders were produced by controlled fast precipitation through gaseous CO2 absorption in Ca(OH)(2) slurry. This multiphase reaction was conducted in a new rotating disc reactor unit, which enables one to control inter- and intra-face mass and energy transfer as well as the macro- and micro-mixing effects in the reacting system. The effect of calcium hydroxide concentration, mixing conditions in the reactor and gas-liquid interface development at discs surface on precipitated CaCO3 was investigated.The analysis with the dynamic light scattering method (DLS) showed that mean particle diameter decreases with higher rate of discs revolution speed and higher calcium hydroxide concentration. The Xray diffraction testing revealed that we have obtained a chemically pure calcite, which is the most stable polymorph of CaCO3. The scanning electron micrographs (SEM) showed the influence of precipitation conditions on rhombohedral calcite crystals. Sorptometric surface analyses reveal high development of specific surface area (over 20 m(2)g(-1)) and powders porosity. (C) 2009 Elsevier B.V. All rights reserved.