REGENERATION OF HYDROCHLORIC COPPER-CHLORIDE SOLUTION OF COPPER ETCHING BY MEMBRANE ELECTROLYTIC CELLS Russian patent published in 2019 - IPC C23F1/46 C25C1/12 C23G1/36 C25B9/18 C25B11/10 C25B11/16 

FIELD: chemistry.

SUBSTANCE: invention relates to electrochemistry. For electrochemical regeneration by membrane electrolysis of hydrochloric of copper-chloride or hydrochloric copper-ammonium-chloride solution of copper etching in cathode space, separated with cation-exchange membrane, membrane electrolysis cell, where copper etching solution is located, is carried out cathode process of electrochemical reduction of copper ions to copper metal. An anode space contains a solution of sulfuric acid with an insoluble anode. Process of electrochemical reduction of copper ions to metallic copper is carried out either by successive treatment of etching solution of copper on two cathodes located in cathode space of one membrane electrolytic cells: two- or three-chamber, or treatment of copper etching solution on cathode in cathode space in series in two membrane electrolytic cells: two- or three-chamber. In a two-chamber electrolysis cell, concentration of sulfuric acid in anode space is equal to 1–3 n, insoluble anode – lead dioxide on titanium substrate, i_a=1–25 A/dm². In a three-chamber electrolysis cell with two cation-exchange membranes, concentration of sulfuric acid in average and anode space is equal to 1–3 n, insoluble anode – platinised titanium or niobium, i_a=5–10 A/dm². Copper ions electrochemical reduction process is carried out in series on two cathodes of titanium or graphite at i_c=1–15 A/dm². After reduction of total concentration of copper ions in copper etching solution to values corresponding to fresh copper etching solution, univalent copper ions are oxidized with air oxygen to bivalent copper ions.

EFFECT: disclosed is regeneration of hydrochloric copper-chloride solution of copper etching by membrane electrolytic cells.

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