The authoritative public forum
  for Metal Finishing since 1989
-----

Cyanides oxidations using H2O2

I want to know whether cyanides can be oxidised using hydrogen peroxide at 10,000 mg/lit. Kindly let me know reaction conditions and type of reactors to be used.

MADAN KULKARNI
- Ambarnath, Maharashtra, India
2001

---

My client used 35% solution of Hydrogen Peroxide to destroy cyanide for 20 years. A weaker solution should also work, but slower. They pumped the overflow from the brass plating bath into a tank. Then they pumped the peroxide into the tank until it stopped bubbling. It was then safe to change the pH so the copper would precipitate out of solution.

They changed the process to use bleach ⇦ bleach/sodium hypochlorite in bulk on eBay or Amazon [affil links] water, but it must be monitored continually for pH to keep HCN gas from being generated.

Richard Helzerman
- Newburgh, Indiana, United States of America
2001