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Plate Nickel from Nitric Acid

We have 2 large tanks (80 gal.) each that is saturated with mostly nickel. I have tried plating using titanium and stainless steel as my anode. I am running 25 amps and all the anode is dissolved with very little plating happening. Is there a less expensive way to recover the nickel?

Joe Flederbach
Plating - Olyphant, Pennsylvania
September 9, 2008

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Hi, Joe. Nickel is difficult to plate from less than ideal solutions, and nitric acid is a strong oxidizing agent. Oxidizing is the opposite of reducing (plating out). You are trying to plate out of a solution that is designed to rapidly dissolve plating. The electricity isn't limited, so it could win, but perhaps not without destroying all the nitric acid and having the nickel precipitate.

I don't think it will work your way, but it's not inconceivable that you could add a reducing agent and sulfuric acid and slide it from nitric to sulfuric without precipitating the nickel. But I wouldn't attempt it except at small beaker [beakers on eBay or Amazon [affil links] scale. Hopefully someone else will offer encouragement.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
September 10, 2008

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I do not think that there is a cost effective way of doing it.
You could very very slowly kill the nitric acid with lye which will cause the nickel to precipitate out in a slimy gel. It will take several days to do this, as the gel is nickel hydroxide and as it drops out the nickel, you will need to add more lye. It will be slow because you do not want to use a gross excess as you will filter off the spent acid solution and then redissolve the nickel gel in sulfuric acid-again very slowly to get the pH just right and then plate out the nickel using an expensive proprietary anode that will not dissolve. Typically, titanium mesh with titanium oxides and platinum or similar.

James Watts
- Navarre, Florida
September 11, 2008

I have a client that wants to find another way to dispose of his nitric acid copper etching bath. he ask me if there is some way to remove the copper thereby possibly using his etching bath over.I think it could be plated out. Can anybody give me an answer?

Oliver Diedrich
Consultant - Naugatuck, Connecticut
September 14, 2008

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Hi, Oliver. We appended your inquiry to a thread which is similar even though it involves nickel rather than copper because I think you'll have the same problem with trying to plate out of nitric acid.

If you can find a cation resin which can resist this nitric acid, you may be able to get the copper out by ion exchange, and backwash with sulfuric acid, and plate the copper out from that. Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
September 14, 2008