METHOD FOR PRODUCING ANATASE TITANIUM DIOXIDE WITH HIGH WEATHER RESISTANCE Russian patent published in 2022 - IPC C09C1/36 C09C3/06 C09C3/04 C09C3/08 C09C3/12 C01G23/08 

FIELD: chemistry.

SUBSTANCE: invention relates to the field of technology for producing titanium dioxide, namely, to a method for producing anatase titanium dioxide with high weather resistance. Proposed is a method for producing anatase titanium dioxide with high weather resistance, including the following stages: stage S101: a mineral is subjected to acid splitting, deposition and filtration, crystallisation and removal of green vitriol, then concentrated resulting in a concentrated titanium solution, which undergoes hydrolysis and a first water-washing, producing a suspension of hydrated titanium dioxide after the first washing; the resulting the suspension is bleached; the bleached hydrated titanium dioxide undergoes a second water-washing; the filtered deposits after the second washing are transferred to the suspension production tank, the suspension produced therein is transferred to the salt treatment tank. Stage S102: the resulting suspension is diluted, heated with vapour and held, then subjected to surface treatment with inorganic compounds, namely: the suspension is diluted with desalinated water to a concentration of 220 to 250 g/l and heated to a temperature of 80 to 90 °C. A diluted solution of phosphoric acid is added to the suspension while constantly stirring, holding for 30 minutes; the mass concentration of said diluted solution of phosphoric acid is 100 to 110 g/l, the volume of the addition as calculated for the content of P₂O₅ in TiO₂ is 0.2 to 0.4%. A solution of potassium hydroxide is added to the suspension while constantly stirring, and the pH is brought to the limit value from 7.5 to 8.0, holding for 30 minutes. A solution of sodium silicate is added to the suspension while constantly stirring, holding for 60 minutes. Diluted sulphuric acid is added to the suspension while constantly stirring, and the pH is brought to the limit value from 7.0 to 7.5, holding for 30 minutes. Solutions of aluminium sulphate and potassium hydroxide are added simultaneously in a single stream while constantly stirring, the pH is maintained in the range from 6.0 to 7.0, holding for 60 minutes. The pH is brought to the limit value from 6.0 to 6.5, holding for 30 minutes, producing a sinter. Stage S103: the sinter is transferred to a frame filter press for a third washing with desalinated water in order to ensure a specific conductivity of 200 to 300 mcS/cm, the third washing results in a deposit. Stage S104: the deposit after the third washing is transferred into a rotating furnace for calcining, the crystallisation temperature herein is maintained within the range of 700 to 800 °C, coarse anatase titanium dioxide is thus produced. Stage S105: the resulting coarse anatase titanium dioxide is crushed on a roll press, resulting in a fine-fraction powder, D50 in the range of 0.3 to 0.4 mcm. Stage S106: the titanium dioxide powder is transferred into a steam grinder in order to apply an organic shell, while simultaneously grinding with a gas jet, resulting in finished titanium dioxide.

EFFECT: possibility of producing anatase titanium dioxide with high weather resistance.

7 cl, 1 dwg, 1 tbl, 5 ex