METHOD FOR OBTAINING DOUBLE ZIRCONIUM-SODIUM MOLYBDATE Russian patent published in 2022 - IPC C01G39/00 

FIELD: chemical industry.

SUBSTANCE: invention relates to the field of chemical industry, in particular to the production of inorganic compounds - zirconium-sodium molybdates with a scheelite structure, which can be used as optical matrices in the manufacture of phosphors for LEDs of various spectral ranges, as well as the basis for obtaining ionic conductors. A method for obtaining double zirconium-sodium molybdate of the composition Na_xZr(MoO₄)_y, x=2 or 4, y=0.5x+2, includes calcining a complex sodium, zirconium and molybdenum formate obtained by reacting concentrated formic acid in a solution with salts of the corresponding metals at a ratio, mol.: ammonium hexamolybdate: basic zirconium carbonate: sodium carbonate: formic acid = 0.43-0.57:1:1-2:23.9-26.3. The mentioned salts in the form of crystalline powders are pre-dissolved, and ammonium hexamolybdate is dissolved in water at a temperature of 80-100° С at a ratio, mol.: (NH₄)₆[Mo₇O₂₄] 4H₂O : H₂O = 0.0043-0.0057:2.5 -2.8, basic zirconium carbonate is dissolved at a temperature of 80-100°С in 19.7-20.15% nitric acid at a ratio, mol.: Zr(OH)₂CO₃⋅5H₂O: 19.7-20.15 % HNO₃ = 1:8-9.2, and sodium carbonate is dissolved at a temperature of 50-60°С in water at a ratio, mol.: NaCO₃: Н₂О = 1:97-110. The resulting solutions are drained and evaporated until the volume is reduced by 3-4 times. The calcination is carried out in three stages: stage I - at a temperature of 300-320°С for 3-4 hours, stage II - at a temperature of 400-420°С for 3-4 hours with remixing and pressing under a pressure of 50-60 bar after the end of stage II, stage III - at a temperature of 450-500°С for 14-15 hours.

EFFECT: method makes it possible to obtain double zirconium-sodium molybdate while reducing the duration of the process along with improving the quality of the final product by obtaining the final product in the form of a fine powder.

1 cl, 2 dwg, 3 ex