Effects of Heating Rate on Pigment Properties of Rutile TiO₂

Using industrial metatitanic acid as raw material,rutile TiO₂ was prepared via bleaching,washing,salt treatment and calcination.The effects of heating rate on the crystal structure and pigment properties of titanium dioxide particles were investigated.The samples were characterized by XRD,SEM,laser particle size analysis and pigment properties test.The results show that the heating rate has a significant effect on the phase transition,surface morphology,particle size and distribution,and pigment properties of the titanium dioxide particles.A faster heating rate can promote the phase transition and particle growth of titanium dioxide,but it causes sintering and leads to a larger particle size and a wider size distribution.At the optimum heating rate of 1.2 ℃/min,titanium dioxide having a particle size of 252 nm with the narrowest particle size distribution,a better sphericity and the best pigment performances can be obtained.