Enhancing TiO[sub.2] Precipitation Process through the Utilization of Solution-Gas-Solid Multiphase CFD Simulation and Experiments

Ensuring uniform particle size distribution is a crucial role in the precipitation process of manufacturing white pigment. This study presents a comprehensive investigation that combines multiphase computational fluid dynamics (CFD) simulations with experimental research to effectively address the challenge of achieving uniform particle distribution during TiO[sub.2] precipitation. The objective of this study was to enhance three-phase CFD simulations involving the mixing process of TIOSO₄ solution, steam as a gas phase, and solid seed particles. By analyzing the trajectories of the seed particles using CFD, the optimal injection position for the seed particles within the mixing process was determined. Subsequently, a lab scale test and real field test were conducted based on the insights gained from the CFD simulations. The particle size distribution of two different types of seed inlets was analyzed and compared using Transmission Electron Microscopy (TEM) and Scanning Electron Microscope (SEM). The findings of this study demonstrate that the developed multiphase CFD simulation can effectively enhance the precipitation process for the production of anatase titanium dioxide particles. Additionally, using the developed multiphase CFD solver, the real physics involved in the precipitation process were identified, leading to a better understanding of the process itself. Furthermore, TiO[sub.2] particles with uniform particle size had a positive impact on the washing and bleaching processes following the precipitation process, resulting in a significant reduction in the annual defect production rate.