METHOD CLEANING FLUSH WATER WHEN ELECTROPLATING WITH LEAD AND ALLOYS THEREOF Russian patent published in 2013 - IPC C25D21/20 C02F103/16 

FIELD: chemistry.

SUBSTANCE: method is realised using a trapping bath in which there is an immersed electrochemical module with an anion-exchange membrane which is fitted with a graphite anode and a cathode on which lead or alloys thereof is deposited, which is periodically returned into the coating bath. In the immersed electrochemical module, between the anion-exchange membrane and the graphite anode there is a cation-exchange membrane and an anode chamber which is filled with 10-50 g/l of sulphuric acid solution, and hydrofluoboric acid, which is returned into the coating bath, accumulates in the inter-membrane space.

EFFECT: preventing formation of highly toxic fluorine-containing wastes and return of hydrofluoboric acid from the trapping bath into the coating bath.

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