METHOD FOR REGENERATION OF COPPER PASSIVATION SOLUTION AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2022 - IPC C23C22/86 C25D21/16 C25F7/02 

FIELD: physical chemistry.

SUBSTANCE: group of inventions relates to a method for the regeneration of a copper passivation solution containing 80-90 g/l of chromium anhydride, 8-15 g/l of sulfuric acid and 2-5 g/l of sodium chloride, and a device for its implementation. The method includes anodic oxidation of trivalent chromium ions in the anode chamber of a two-chamber electrolyzer with an anode made of lead or platinized titanium and a cation exchange membrane and deposition of copper in a cathode chamber on a cathode made of titanium or stainless steel. Electrolysis is carried out at a cathode current density of 1-5 A/dm² and an anode current density of 0.5-2 A/dm², while the regenerated solution is circulated between the cathode and anode chambers at a rate of 1 volume of the catholyte for 15-30 hours of electrolysis. The device contains a bath 1 for passivation solution with an anode 2, which is an anode chamber, and a cathode chamber 3 immersed in it with a cation exchange membrane 5 and a cathode 4. The cathode chamber 5 is made with the possibility of placing its upper half above the level of the solution 9 in the anode chamber and is equipped with two fittings, one of which is located above the level of the solution in the anode chamber and is equipped with a control valve 6, and the second is located in the lower part of the cathode chamber 7.

EFFECT: waste-free and resource-saving process of the regeneration of copper passivation solution is provided.

2 cl, 4 dwg, 3 ex