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Ferricyanide Removal / Destruction for disposal

Due to the regulations on the ferricyanide in the Alodine 1200s the company I work for has switched over to Alodine 600. However, this means that I must dispose of the 1200s and it's dragout, before doing this I must neutralize the ferricyanide within the 1200s. I am planning on neutralizing the ferricyanide with 1.5 lb of zinc sulphate ⇦this on eBay or Amazon [affil links] per 0.1% of. Does anyone know a titration to find out the % of ferricyanide within the 1200s? Or is there a better method for removing the ferricyanide?

Benjamin Curto
- Ponderay, Idaho, USA
2000

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2000

That sounds like it should work fine. I'd suggest the following:

1) Reduce the ferricyanide to ferrocyanide with sodium metabisulfite first.

2) The lowest levels obtainable with this technique result when the iron cyanides are precipitated at pH 6 - 7, then the residual zinc and other metals removed in a second step.

3) If manganese is not regulated in your area, it may be substituted for the zinc and simplify the treatment process.

Good Luck,

Dave Wichern
Consultant - The Bronx, New York