Controlled vapor phase oxidation of titanium tetrachloride to manufacture titanium dioxide

摘要

A process for controlling the formation of TiO2 particles in a multi-stage vapor-phase oxidation reactor wherein the process includes the steps of limiting the fraction of TiCl4 converted into TiO2 in the reaction stream of a first or intermediate stage of the reactor under conditions that control the mean residence time distribution of the reacting mass. By running the reaction in this manner, the growth of TiO2 particles produced is so controlled that after subsequent standard finishing steps (e.g. milling) the fraction of particles having an average size of less than 0.5 mum is reduced or minimized.