METHOD OF RECYCLING SPENT SOLUTION FROM CHEMICAL NICKEL PLATING Russian patent published in 2013 - IPC C25C7/06 C02F1/58 C25C1/08 

FIELD: chemistry.

SUBSTANCE: method involves using a double-chamber electrochemical module containing sulphuric acid solution, having two cation-exchange membranes and a lead anode in the rear chamber. Each of the chambers of the electrochemical module contains sulphuric acid solution with concentration of 50-200 g/l. Current density on the lead anode is equal to 2.5-7.5 A/dm². An indicator lead anode is placed in the front chamber, said indicator anode signalling the need to move the sulphuric acid solution from the rear chamber into the front chamber and fill the rear chamber with fresh sulphuric acid solution, wherein the surface area of the indicator anode is equal to 0.5-2% of the surface area of the main anode, and current density thereon is equal to that on the main anode.

EFFECT: method prevents decomposition of the main lead anode and minimises consumption of sulphuric acid used to prepare and replace solutions in both chambers of the module.

1 dwg, 2 ex