METHOD FOR PROCESSING THE SPENT SOLUTION OF COPPER BRIGHTENING Russian patent published in 2022 - IPC C23F1/46 C23G1/36 B01D61/44 

FIELD: electroplating.

SUBSTANCE: invention relates to the field of electroplating, in particular to the processing of spent etching solution, and can be used in the manufacture of copper parts. A method for processing a spent solution of copper bright dipping containing 900-920 g/l of sulfuric acid, 410-430 g/l of nitric acid, 5-10 g/l of sodium chloride and copper salts in a dissolved and solid state is proposed. Water is added to the waste solution until the precipitate of copper salts is completely dissolved and sodium hydroxide or carbonate is added to the resulting solution to a pH of 0.5-1.0. Then the electrochemical treatment of the resulting solution is carried out in the cathode chamber of a two-chamber electrolyzer with a cation exchange membrane, with a cathode made of titanium or stainless steel and an anode made of platinized titanium or platinized niobium in a solution of 15-30 g/l of sulfuric acid, while the treatment is carried out at a cathode potential from -0.1 to -0.5 V until the solution is completely discolored.

EFFECT: complete extraction of all copper contained in the treated spent etching solution with sediment is ensured.

1 cl, 3 ex