A Very Old Cadmium Plating Bath
What should we do with a plating bath that is a least 20 years old and has a cyanide cadmium solution that is emitting a strong ammonia smell?
Q. Our plating bath is a least 20 years old, and the cyanide cadmium solution is emitting a strong ammonia smell. I would like to remove the ammonia, but I am not sure how to do this. The bath currently contains 13 oz/gal of carbonate and does not have any brighteners. The last time we tried to freeze out the carbonate the bath did not plate very well. Do you have any suggestions for what should be done with this bath? D.V.
A. A 20-year-old cadmium plating bath probably qualifies for some sort of record. I would seriously consider replacing the bath at this time and starting fresh. You did not say how large the bath is, and I realize the cost of disposing of plating waste containing cyanide is not inexpensive. Depending on how much cadmium plating you do, this would make the most sense. If you do very little cadmium plating however, you might try to find another plating shop in you area that handles cadmium and “farm it out” to them.