Home – Home – Jornals – Chemistry for Sustainable Development 2020 number 1

Chemical precipitation deposition of titanium oxyhydrate TiO(OH)₂ from the solutions of titanium salts and the features of thermal decomposition of TiO(OH)2 are studied for the purpose of improving and developing an efficient technology for obtaining nanodisperse powders of titanium dioxide with the required particle size and chemical composition. The effect of the basic synthesis parameters on the size of the formed agglomerates of titanium oxyhydrate is established. A method of the heterogeneous synthesis of titanium oxyhydrate using calcium hydroxide is proposed. The effect of the porosity of the crystalline precipitant (calcium hydroxide) on the disperse characteristics of the resulting product is studied. It is shown that a decrease in the average size of pores in calcium hydroxide causes a proportional decrease in the average size of the aggregated particles of titanium dioxide. Under the conditions of different methods of drying (convective, radiation and microwave), the kinetic regularities of the dehydration of titanium oxyhydrate are investigated. The effect of the temperature of titanium oxyhydrate dehydration on the size and crystalline structure of titanium dioxide powders is evaluated. To prevent agglomeration of the formed nanoparticles of titanium dioxide, it is proposed to add ammonium carbonate before the final stage of drying. Relying on the results of the studies, a technology of the synthesis of fine titanium dioxide particles with the concentration of the major component ≥98 mass % is developed.