process for the production of titanium tetrachloride by gross scheuernder titandioxidteilchenaggregate dampfphasenoxidation and their use in the prevention of ansatzbildung at the same process.

摘要

A process for the production of coarse scrubbing aggregates of TiO2 particles by vapor phase oxidation of titanium tetrachloride. The particle aggregates of sizes above 0.15 mm are separated from the TiO2 fines by wet screening on a moving screen, calcined and returned to the process. In a preferred embodiment of the process, the titanium dioxide prior to calcination is admixed with 0.01 to 0.3% by weight alkaline hydroxides (related to anhydrous TiO2), hard particle aggregates of sizes between 0.2 to 2.0 mm being generated that are returned to the hot reaction mixture and used for the prevention of deposit formation on the surfaces of the heat exchanger. The process can be carried through in such a way that the quantities of coarse scrubbing TiO2 aggregates per unit of time consumed by abrasion and newly formed by sintering are equal, their percentages in recycling TiO2 thus remaining constant which simplifies the TiO2 production process.