Patent ID: 7858066

Claim:
A process for preparing nanocrystalline titanium dioxide, comprising the following steps: (a) forming a mixture by combining starting materials comprising (i) an aqueous titanium oxychloride, (ii) a MOH, where M is selected from the group consisting of NH 4 , Na, K, Li, and Rb, and mixtures thereof, and (iii) a solvent comprising an alcohol or an aqueous salt solution that is capable of precipitating a filtering agent and a hydrated titanium oxide in the mixture; wherein the mixture has a pH less than about 3 and a precipitate comprising the filtering agent having a formula MCl and a hydrated titanium oxide; (b) filtering the precipitate to form a filter cake; (c) calcining portions of the filter cake at a temperature greater than about 300° C. to form a calcined mixture comprising titanium dioxide, (d) removing the filtering agent from the calcined mixture, and (e) recovering nanocrystalline titanium dioxide.