Patent ID: 7662359

Claim:
A process for manufacturing a particulate titanium dioxide product, comprising: providing an aqueous solution of titanium oxychloride having a content of >90 g TiO 2 /l calculated as TiO 2 ; adding an amount of sulphate in the range of 1 to 5% by weight, calculated on the basis of the amount of TiO 2 in the solution, into the aqueous solution of titanium oxychloride; adding titanium dioxide particles as crystal nuclei to the aqueous solution of titanium oxychloride; precipitating hydrated titanium dioxide particles at a temperature of 50 to 100° C., the temperature being below the boiling point of the aqueous solution of titanium oxychloride and at normal pressure to obtain a precipitated hydrated titanium dioxide product; calcining the precipitated hydrated titanium dioxide product at a temperature of 100 to 500° C. to obtain a titanium dioxide product is comprised of more than 70% rutile in a crystal form.