Process for the preparation of very pure titanium dioxide

US5468463A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Kai Butje · Duisburg, DE
• Jurgen Kischkewitz · Ratingen, DE

Key dates

• Filing date: Jul 29, 1994
• Grant date: Nov 21, 1995
• Expiry date: Jul 29, 2014

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/80
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A process for the preparation of very pure titanium dioxide by reacting titanium tetrahalides with sulphuric acid, hydrolysis the titanyl sulphate solution obtained and calcining the hydrolysate is disclosed wherein the reaction between titanium tetrahalide and aqueous 20-40% by weight strength sulphuric acid is performed in such a way that crystallisation of titanyl sulphate does not take place, the hydrogen halide is separated, the solution is optionally concentrated and filtered and then the ratio by weight of sulphuric acid to titanium dioxide is adjusted to between 1.7 and 2.0 and the titanium dioxide concentration is adjusted to between 250 and 300 g/l, the solution is hydrolyzed and the resulting titanium oxide hydrate is filtered off and calcined to give Futile or anatase.