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Spent Nickel Strike

The shop I'm working in has been treating a nickel strike that we no longer use a few gallons at a time. Considering there is something like $10,000 worth of nickel metal in this tanks it seems sad to me that we are just using waste treatment chemical and turning into hazardous waste. So my question is does anybody know of a service that takes spent nickel solution for free?

Jay Dee
Lab Tech - Kent, Michigan
November 24, 2010

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Years ago, there was a firm in LA that would take some nickel solutions. You might check with stainless steel foundries to see if they would take it in what form--IE: hydroxide or crystals (dry) form.

Also, years ago, it was not a haz waste IF it was a raw material for another process. A big savings on shipping costs and paperwork.

James Watts
- Navarre, Florida
First of two simultaneous responses -- November 26, 2010

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Second of two simultaneous responses -- November 28, 2010

My sense is that you could find someone to take it away for less than a comparable corrosive material that did not have recyclable Ni. Not for free, though.

I'd look into two things:

1) Raise pH to 8+ with sodium hydroxide, then add sodium hydrosulfite [on eBay or Amazon] to precipitate a Ni rich sludge. This would not be corrosive, and would likely be reduced in volume by 90+%. The remaining liquid would probably not be legally dischargable, but could be made so by treatment with DTC, or similar chemical.

Disadvantage: There would be significant work involved. Also, sodium hydrosulfite isn't cheap.

2) Raise the pH to 11+ with ammonium hydroxide, then plate the Ni out. I have seen this method used to treat spent electroless Ni baths, which also contain chloride. (The pH adjustment seems to inhibit chlorine generation, which is why you can't plate it out as is.) I am not sure that it would work on your problem but I think it's worth a look.

Disadvantage: The ammonium hydroxide is very fume-y. And, I doubt that you could plate the Ni out down to the point where you could discharge the liquid as is. All that ammonia [on eBay or Amazon] would make conventional treatment of it difficult.

Your first step is to talk to the disposal/recycle people and get some cost numbers.

Dave Wichern
Consultant - The Bronx, New York