METHOD OF PRODUCING HIGHLY PURE FINE-CRYSTAL BARIUM TITANATE Russian patent published in 2020 - IPC B01J3/00 C30B29/32 C04B35/468 C01G23/04 C01F11/02 

FIELD: technological processes.

SUBSTANCE: invention relates to synthesis of fine-grained barium titanate used for making ceramic capacitors. Method comprises treatment of a mixture of titanium dioxide and barium-containing reagent in a medium based on water vapor at high temperature and pressure, wherein the barium-containing reagent used is barium nitrate monohydrate Ba(NO₂)₂⋅H₂O and treatment of reagents is carried out in medium of mixture of water vapor and ammonia; mixture of powders of monohydrate of barium nitride and titanium oxide is taken in molar ratio [Ba(NO₂)₂⋅H₂O]/TiO₂ from 1.0 to 1.3; in reaction space, mole ratio of NH₄OH/H₂O=1/5; thermal treatment of mixture of reagents with steam containing ammonia is carried out for 1 to 16 hours under isothermal conditions at temperature selected in range from 250 to 400 °C with heating rate in range of 50–100 °C/h and water vapor pressure from 3.98 to 26.1 MPa. Reaction of reagents by steam reacts at molar ratio NH₄OH/[Ba(NO₂)₂⋅H₂O]=2.0–3.2. Obtained product is washed with aqueous solution of acetic acid with concentration of 5 wt%, with distilled water till pH=7 of washing water and dried in air at temperature of 70 °C to consistency of mass.

EFFECT: invention enables to obtain fine-grained titanate with average crystal size of 0,2–2 mcm with content of basic substance higher than 99,98 %.

3 cl, 6 dwg, 2 tbl, 4 ex