碳化法可控制备纳米碳酸钙研究进展

Controlled Synthesis of Nano-calcium Carbonate via Carbonization Method:A Review

随着纳米CaCO_3制备技术的发展,CaCO_3的物化特性及包括粒径及其分布、颗粒形貌和分散性在内的结构特征都得到了很好的控制,使其在涂料、填料、造纸和聚合物改性等领域应用越来越广泛.碳化法是一种以Ca(OH)_2-H_2O-CO_2为反应体系的纳米CaCO_3制备方法,是工业应用最广泛的纳米CaCO_3制备方法.立足于该法,从纳米CaCO_3的传统制备工艺出发,结合相关传质理论,介绍了近年来用于可控制备纳米CaCO_3的几种新型反应器;系统分析了Ca(OH)_2的起始浓度、CO_2分压、气体流量、温度对纳米CaCO_3成核生长过程的作用机制;介绍了碳化过程中加入添加剂对CaCO_3粒径、形貌和分散性的影响,并简述了其作用机理;针对CaCO_3可控制备过程中存在的问题提出了一些建议.

With the development of the preparation technology of nano-CaCO3, the physicoehemical properties and structure characteristics including particle size and its distribution, morphology and dispersity of CaCO3 have been well controlled, making this traditional inorganic material increasingly widely used in the field of coating, filler, paper making and polymer modification. Carbonization method is a kind of nanometer-CaCO3 preparation method with Ca（OH）2-H2O-CO2 as reaction system, which applied widely in the industrial preparation of nano-CaCO3. Focused on this method, firstly, several new reactors for the controlled synthesis procedure were introduced from the aspect of gas-liquid mass transfer enhancement, based on the traditional preparation methods of nano- CaCO3. Then, systematic analysis was taken to interpret the influence mechanism of four parameters： initial Ca（OH）2 concentration, CO2 partial pressure, the gas flow rate and temperature on the nucleation and crystal growth process of nano-CaCO3. The effects of several additives added during the carbonation process on the morphology and the dispersion of CaCO3 particles were introduced, and the mechanism of these additives was also described. Finally, some suggestions were put forward to settle the problems existing in the preparation of CaCO3.