Numerical Modeling of Drying Behavior of Sri Lankan Kaolin

Abstract

Drying process of green ceramic bodies are complicated due to simultaneous and coupled heat and mass transfers. Dimensional variations and mechanical stresses occur within the ceramic body during drying may create defects in the final product if drying conditions are not carefully controlled. In this study, the drying behavior of Sri Lankan Kaolin was investigated. Initially, Kaolin was characterized using wet chemical analysis and X-ray diffraction to investigate structure and composition. Two batches of Kaolin with different particle size distributions were prepared using wet ball mill grinding with average particles size (D50) of $4.07\ \mu\mathrm{m}$ and $3.57\ \mu\mathrm{m}$ respectively. Green ceramic samples were obtained using extrusion process. Samples were dried in oven at 60°C and moisture variation of the green product was measured with time. Critical moisture content of the Sri Lankan Kaolin was 1.50%. Mathematical relationship was formulated to determine drying behavior of Sri Lankan Kaolin. An unsteady three-dimensional (3D) model was developed and simulated in Computational Fluid Dynamics (CFD) framework. Simulation results developed by the model were compared with data obtained by experiments conducted using Sri Lankan Kaolin. The model results were validated and comply with experiments results and R2 value was 0.9.