Investigation into Kinetic Relations and Operating Conditions on the Performance of Titanium Recovery Unit for Production of High-purity Titanium dioxide Nanoparticles under Sulphate Process

This study explored the impact of kinetic relations and operating conditions on the dissolution rate of titanium slug to production of TiO2 powders in the size distribution of 50-100 nm. To reach powder with 98% purity, dried and grinned titanium slag in the size distribution of 45-160 μm react with sulfuric acid based on sulphate process. The effect of operating parameters such as acid concentration, digestion temperature, digestion time, and initial particle size of dried slag is studied. By optimizing the digestion factors in dissolution process, and using sonochemical technique in dissolution reactions, the maximum extraction efficiency of TiO2 and maximum weight fraction of removed iron is obtained. Regression analysis showed that that results of shrinking core theory including control diffusion and especially control chemical reaction model applied in this study is in agreement with the experimental data. Based on the kinetic studies, the activation energy of dissolution process is determined to 38.12 kJ.mol-1 and the reaction order was assumed to be first order mechanism with respect to acid concentrations.