METHOD OF TITANIUM DIOXIDE OBTAINMENT UTILISING AQUEOUS FLUORIDE SOLUTION Russian patent published in 2010 - IPC C01G23/53 C09C1/36 C22B3/04 C01G49/06 

FIELD: chemistry.

SUBSTANCE: method of titanium dioxide obtainment involves stages of (a) iron-containing titanium ore processing by aqueous solution of NH₄F and/or NH₄HF₂; (b) filtration of obtained water suspension with further separation of solid sediment and aqueous solution containing titanium salts; (c) hydrolysis of the aqueous solution obtained; (d) filtration and pyrohydrolysis of solid sediment. Hydrolysis involves first stage at pH 7.0-8.5 and second stage at pH 10.0-13.0. Suspension obtained at the fist hydrolysis (c) stage is filtered to obtain aqueous solution containing titanium salt (NH₄)₂TiF₆ with (NH₄)₃FeF₆ concentration under 0.01 wt %, and sludge fraction containing ammonia oxyfluorotitanate and (NH₄)₃FeF₆. Aqueous solution undergoes second hydrolysis (c) stage to obtain water suspension. Pyrohydrolysis involves first stage at maximum temperature of 450°C and second stage at maximum temperature of 1000°C.

EFFECT: waste-free obtainment of titanium dioxide resistant to UV radiation and not requiring additional grinding, reduction of power consumption.

22 cl, 1 dwg