Influence of hydrolysis in sulfate process on titania pigment producing

Using industrial titanyl sulfate solution as feedstock, titania white pigment was prepared by self-generated seeded thermal hydrolysis method. The influence of some factors (such as F value, volume ratio of pre-adding water to TiOSO4, heating rate and pH of pre-adding water) on the structure and pigment properties of the as-prepared slurry metatitanic acid and titania samples were studied. The samples were characterized by XRD, particle size distribution, SEM and pigment properties test. The results show that all samples show anatase phase, and the calcined samples prepared under suitable conditions are with narrow particle size distribution and good pigment properties. All these influencing factors have great impacts on the hydrolysis velocity, nucleation rate, crystal growth rate, particle size distribution, crystal structure and pigment properties. The suitable F value is 1.73–1.93, the volume ratio of pre-adding water and TiOSO4 solution is 0.28:1, the optimum heating rate is 0.94–1.33 °C/min and pH of the pre-adding water should be at near-neutral range.