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

Influence of NH4F concentration on the conditions of separation of Ti(IV) and Fe(III) salts by fractional hydrolysis under the action of ammonia in the system (NH4)2TiF6-(NH4)3FeF6-NH4F-H2O was studied. The coprecipitation of (NH4)3TiO2F5 and (NH4)3FeF6 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 NH4F 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 TiO2 with a whiteness above 92%.