Effect of Important Precipitation Process Parameters on the Redispersion Process and the Micromechanical Properties of Precipitated Silica
Effect of Important Precipitation Process Parameters on the Redispersion Process and the Micromechanical Properties of Precipitated Silica
复制标题
重要沉淀工艺参数对沉淀二氧化硅再分散过程和微观力学性能的影响
DOI：
10.1002/ceat.200900023
复制
发表时间：
2009
影响因子：
2.1
通讯作者：
A. Kwade
中科院分区：
文献类型：
--
作者：
C. Schilde;T. Gothsch;Kerstin Quarch;M. Kind;A. Kwade
在过去，通过沉淀法大规模生产高质量产品和特种化学品的重要性迅速增加。在工业中，通常生产较大的集料，为了生产具有所需性能的胶体系统，沉淀颗粒的或多或少的强烈分散是必要的。最大压痕力、塑性和弹性变形能、强度等微观力学性能可以提供产品和分散过程效率的信息。一般情况下，温度作为半间歇沉淀过程中最重要的参数之一，会改变sio2的结构、初生粒径、团聚体粒径以及团聚体中初生颗粒的相互作用。沉淀二氧化硅在搅拌介质磨和溶解剂中的分散表明，沉淀温度越高，产品细度越高，因此团聚体的强度越小。造成这种影响的原因是随着析出温度的升高，初生颗粒尺寸增大，固相键减少。由于较高的应力强度，搅拌介质磨中的产品细度比溶解机中的产品细度要高得多。原则上，随着颗粒强度和最大压痕力的减小，可达到的最大产品细度和分散过程的能量效率增加。除最大压痕力外，可获得的最大产品细度和分散过程的能量效率随塑性和弹性变形能商的增加而增加。
In the past, the importance of the industrial mass production of high-quality products and specialty chemicals by precipitation increased rapidly. In the industry, usually larger aggregates are produced and in order to produce colloidal systems with the desired properties, a more or less intense dispersion of the precipitated particles is necessary. The micromechanical properties such as the maximum indentation force, the plastic and elastic deformation energy, and the strength can give information on the product and the efficiency of the dispersion process. Generally, the temperature, as one of the most important parameters of the semi-batch precipitation process of silica, was varied in order to change the structure, the primary particle size, the aggregate size, and the primary particle interactions in the aggregates. Dispersion of the precipitated silica in a stirred media mill and a dissolver show that the higher the precipitation temperature, the higher is the product fineness and, thus, the smaller is the strength of the aggregates. The reason for this effect is the increase of the primary particle size and the decrease of the solid bonds with increasing precipitation temperature. Because of higher stress intensities, the product fineness in a stirred media mill is considerably higher than in the dissolver. In principal, the maximum achievable product fineness and the energy efficiency of the dispersion process increase with decreasing particle strength and maximum indentation force. Besides the maximum indentation force, the maximum achievable product fineness and the energy efficiency of the dispersion process increase with increasing quotient of plastic and elastic deformation energy.