Effect of potassium hydroxide on preparation of rutile TiO₂

A certain amount of potassium hydroxide was added to the hydrated titanium dioxide to study the mechanism of potassium in the system during the transition from hydrated titanium dioxide to rutile titanium dioxide, and the effect of potassium on the particle size and viscosity of hydrated titanium dioxide slurry, the aspect ratio and particle size distribution of rutile titanium dioxide. The samples were characterized by Raman spectrometer, Malvin particle size analyzer, XRD and SEM. Results showed that potassium hydroxide reacted with residual sulfuric acid in hydrated titanium dioxide system to produce potassium sulfate, which played a role in the transition from hydrated titanium dioxide to rutile titanium dioxide. The OH⁻ in potassium hydroxide will seize the H⁺ in hydrated titanium dioxide, causing the change of potential, resulting in the viscosity first increasing and then decreasing. The hydrated TiO₂ was transformed into anatase TiO₂ after calcination, and then into rutile TiO₂, a large amount of K⁺ adsorbed on the (101) facets of anatase TiO₂ hindered the migration of Ti–O crystal ions through the surface, thus affecting the aspect ratio and particle size distribution of rutile TiO₂ particles.