Preparation of high-purity titanium salts from the system (NH4)2TiF6-(NH4)3FeF6-NH4F-H2O

Influence of NH 4 F concentration on the conditions of separation of Ti(IV) and Fe(III) salts by fractional hydrolysis under the action of ammonia in the system (NH 4 ) 2 TiF 6 -(NH 4 ) 3 FeF 6 -NH 4 F-H 2 O was studied. The coprecipitation of (NH 4 ) 3 TiO 2 F 5 and (NH 4 ) 3 FeF 6 as a result of crystallochemical substitution of Fe +3 for Ti +4 makes it possible to reduce the content of Fe(III) salts in the system. After separation of a precipitate containing up to 25% of Ti from solutions with NH 4 F concentrations from 10.6 to 22.3% and subsequent hydrolysis, the remaining titanium precipitates. The precipitate is annealed up to 800°C in the presence of water vapor to form TiO 2 with a whiteness above 92%.