Letter 13051

Iron Build-up in Acid Copper Bath 

I have a 600 gal. acid copper tank, for decorative work before nickel/chrome. Copper Sulfate-28.7 oz/gal., Sulfuric Acid 10.7 oz/gal. Chloride 108.6 ppm (high). Due to water conservation it finally caught up with us. Problem is the iron has built up to 7,250 ppm (should be no more than 1,000 ppm I think). Proprietary brightener system, air agitation, phos copper nuggets, etc. Our vendor has recommended dumping. It will not hold voltage or amperage and is skip plating in the low CD. Peroxide and permanganate does not work. Does anyone know of an iron complexor at a pH of <1? I was told there is a complexor for pH >12. Help!

Bill Hemp
tech svc. w/ chemical supplier - Grand Rapids, Michigan

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