Patent ID: 8182602

Claim:
A method of preparing a well-dispersable, rutile-structured, microcrystalline titanium dioxide product having a crystal size of less than 60 nm from a titanium dioxide starting material, the method comprising the stages: A: treating a titanium dioxide starting material to convert it into titanium dioxide so that (A1) the titanium dioxide starting material is treated with a base to have an alkaline pH value; (A2) a precipitate obtained from stage A1 is further treated with hydrochloric acid so that a final hydrochloric acid content is adjusted to 8 to 35 g/l; (A3) the precipitate obtained from stage A2 is neutralized into slurry to a pH value of 4.0 to 6.0; (A4) the neutralized slurry obtained from stage A3 is primed with a pretreatment chemical; (A5) the primed slurry obtained from stage A4 is calcinated; and B: further treating the titanium dioxide obtained from stage A to convert it into a titanium dioxide end product.