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  for Metal Finishing since 1989
  

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Treatment of Waste Solutions

2001

I am a chemist working in the electroplating industry. I am interested in the treatment of both rinse and process solutions. The treatment of complexed cyanide (cadmium & Iron)solutions and chrome VI solutions.

I would like to communicate to someone who is treating such solutions so we can be of help to each other.

I would appreciate any ideas.

Bernard Irving
- United Kingdom

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It is a common practice to treat diluted cyanide solutions with a strong hypochlorite (bleach) solution ⇦ bleach/sodium hypochlorite in bulk on eBay or Amazon [affil links] . Cyanide is transformed to a cyanate in this reaction. However, if iron is present then the process becomes more complicated. Details about this process has been discussed in some letters previously published in finishing.com.

As for hex chrome solutions, you may obtain more information from a company called Rohm & Haas. They sell specific resins for extracting hex chrome ions and also a chemical called "Kolene" for transforming hex chrome to a neutral complex.

Ajit Menon
- Alden, New York
2001