METHOD OF PRODUCING FINE-GRAINED CALCIUM STANNATE Russian patent published in 2025 - IPC C04B35/457 C01G19/02 C04B35/626 

FIELD: chemistry.

SUBSTANCE: invention relates to synthesis of powder oxide materials and specifically to calcium stannate, which can be used as a component when producing capacitor ceramics. To obtain fine crystalline calcium stannate, method comprises treating a mixture of calcium oxide CaO and tin dioxide SnO₂, taken in molar ratio 1.44-2.16 and mixed by multiple combined sieving through a polymer sieve with cell size of not more than 500 mcm, in the presence of sodium hydroxide NaOH, introduced into the mixture by air drying an aqueous suspension containing SnO₂ particles and dissolved NaOH, in closed reactor at temperature 400 ± 10 °C at heating rate 70 °C/h and pressure of supercritical aqueous fluid of 26.5 MPa. Product is successively washed with aqueous solution of acetic acid with concentration of 5-10 wt.%, with distilled water until neutral reaction of washing water and dried in air at temperature 70 ± 10 °C for 12 hours.

EFFECT: disclosed method enables to obtain crystalline calcium stannate powder with particle size of not more than 20 mcm while cutting the number of synthesis steps.

4 cl, 8 dwg, 8 ex