Effect of Delamination on Physico-Chemical Properties of Kaolin

Abstract

To provide the quality required for its use, raw kaolin must be subjected to certain processing procedures like delamination which is applied to the layered structure materials. The aim of this research is to determine the possibility of performing delamination in the extruder and to estimate the effects of this process on the physico-chemical properties of kaolin. The results showed that delamination can be efficiently realized in the extruder by shearing densely packed layers under the influence of friction force and added Na2CO3 electrolyte. The crystal structure of the system was thus disrupted. This was confirmed by the Hinckley index (HI) decrease and by the dilatometric characteristics changes during heating. The particle size was reduced and, furthermore, new adsorption centers were formed, which led to an increase in the total cation exchange capacity (CEC). The plasticity of kaolin decreased with the increasing delamination degree, as well as the amount of water required for plastic processing, which is favorable in drying ceramic products.