METHOD OF ELECTRIC OXIDATION OF CERIUM IONS (III) Russian patent published in 2018 - IPC C25B1/00 C01F17/00 C25B9/08 

FIELD: technological processes.

SUBSTANCE: invention relates to a method for the electro-oxidation of cerium (III) ions, including the treatment of an initial solution containing cerium (III) ions, in an electrolyzer with an anode and cathode installed in it, separated by a porous nanostructured ceramic diaphragm into an anode and cathode chambers, each of which has an input and output, the input and output of each chamber is equipped with circulation circuits, the supply of the initial solution to the anode chamber of the electrolyzer, the supply of an auxiliary electrolyte to the cathode and the conduct of electrolysis while maintaining the required temperature and pressure. Method is characterized by the fact that the diaphragm is made of aluminum oxide grains, surrounded by particles of zirconium dioxide, as the electrolyte in the process using the initial solution containing: cerium nitrate from 100 to 200 g/l, lanthanide nitrate from 0 to 200 g/l and from 30 to 100 g/l of nitric acid, while in the cathode chamber of the electrolyzer serves either an auxiliary electrolyte, which is not a concentration of nitric acid less than 30 g/l, or the original solution, and the process is conducted while maintaining the turbulent flow of the electrolyte in the cathode and anode chambers or while maintaining the turbulent flow of the electrolyte in the anode chambers and laminar flow in the cathode, however, the turbulent flow of electrolyte in the anode chamber is maintained at a Reynolds number of 3,000–71,000; while maintaining anolyte temperature 50–55 °C and catholyte temperature 20–25 °C and the excess pressure in the cathode chamber with respect to the anode, the pressure drop across the diaphragm is maintained within 1.2⋅10⁵÷2⋅10⁵ Pa when the ratio of the areas of the anode and cathode is (3–5):1 and the ratio of the volume of the anode chamber and the volume of the cathode chamber is (8–10):1; electrolysis is carried out at a step change in the anodic current density from 3.5–7.0 A/dm² within 60–90 minutes followed by a decrease in the current density of 1.5–2.0 times every 20–40 minutes, and when the anode current density is 0.5 A/dm² the process continues for another 30–40 minutes.

EFFECT: using the proposed method allows to reduce energy consumption and increase the current efficiency of Ce⁴⁺ ions, and also reduces the time of receipt of a unit of finished products.

1 cl, 7 ex, 1 dwg