| 摘要 |
PURPOSE:To regenerate a plating soln. contg. iron as ferrous ions with a simple apparatus when ferric ions accumulate in the plating soln., by pouring the plating soln. into a reduction tank having a soluble electrode and by supplying electric current to reduce the ferric ions to ferrous ions. CONSTITUTION:When an electroplating soln. contg. Fe as Fe<2+> ions is used for plating, Fe<3+> ions accumulate in the soln. by partial oxidation during plating and the plating capacity is deteriorated. The used plating soln. is poured from the upper chamber of a storage tank 14 into an electrolytic reduction tank 12 wherein a pair of electrodes 20 are placed and a soluble Fe electrode is used as at least the anode. DC is then supplied from a rectifier 24 at <=10A/dm<2> current density to reduce Fe<3+> ions in the plating soln. to Fe<2+> ions. AC may be supplied between the electrodes at <=20A/dm<2> current density to dissolve Fe deposited on the cathode while acting as the anode. The plating soln. is regenerated by reducing Fe<3+> ions to Fe<2+> ions without using an ion exchange membrane or an insoluble electrode of Pt of the like and the regenerated plating soln. is stored once in the lower chamber of the tank 14 and fed to a plating cell.
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