REAGENT-ELECTROLYSIS METHOD FOR REGENERATION OF COPPER-AMMONIA SOLUTION OF COPPER ETCHING Russian patent published in 2019 - IPC C23F1/46 C23F1/18 C22B15/00 C01G3/00 C25D3/22 C22B3/46 

FIELD: printing equipment.

SUBSTANCE: invention can be used in production of printed circuit boards. For recovery of spent copper-ammonia solution of copper etching, total volume of said solution is divided into two parts. In one of two pre-calculated parts of spent solution of etching copper ions of univalent and bivalent copper are reduced to a precipitation of metallic copper with periodic shaking by metal zinc, taken in form of plates, pieces, granules or powder. After decantation of precipitation of metallic copper, solution is subjected to electrolysis using cathode from titanium, stainless steel, zinc or graphite and insoluble anode from graphite, ORTA, Pt/Ti, Pt/Nb, PbO₂/Ti to remove zinc ions to a residual concentration of 0.5–5 g/l. Separated on cathode metal zinc is mechanically separated from cathode and used repeatedly. Obtained solution is mixed with the second part of the volume of spent copper-ammonia solution of copper etching, which has not undergone treatment with metal zinc. In obtained solution containing copper ions in concentration corresponding to requirements for fresh solution, ions of univalent copper are subjected to oxidation with air oxygen to ions of bivalent copper.

EFFECT: invention simplifies the process of regeneration of copper-ammonia solution of copper etching, eliminating the need to use complex equipment and reduces power consumption.

1 cl, 2 ex