METHOD OF ETCHING AND REGENERATION OF PERSULFATE AMMONIUM-BASED ETCHING SOLUTION Russian patent published in 1997 - IPC

FIELD: electrochemical processes. SUBSTANCE: method includes chemical etching and electrochemical regeneration of exhausted etching solution in two-cell electrolyzer separated with cation-exchange membrane. Exhausted etching solution is introduced into anode cell of electrolyzer, whereas cathode cell is filled with cupric sulfate solution prepared via dissolving double salt $$$ precipitated from exhausted etching solution on cooling after 6-7 cycles of "etching-regeneration" process. In this case, copper is extracted to concentration 1.5-2 g/l. As anode, smooth-surface titanium is utilized. EFFECT: improved procedure. 1 tbl