Cyanide Disposal

[Andrew Campbell]

I am trying to find out a way to safely dispose of cyanide residues
after I have done some mineral processing testwork. The amount
of CN being added is about 120ppm.

The most promising thing i have found is to use hydrogen peroxide
with a basic environment.

Secondly whats the easiest way to tell when you have decomposed all
the CN?

Could you mail me directly as I read my mail regularly, news
occasionally.

[ProChem2]

Cheapest way is bleach.
John Carmody ProC...@aol.com

[Michael A Kay]

If you are going to give information on handling dangerous materials,
please give enough to avoid creating possibly lethal hazards.

Cyanide can be destroyed with common household bleach, but at all times
the pH must be kept above 9 or 10. The usual way to destroy small
quantities of cyanide, such as are used in zinc testing kits or
other chemical reactions, is to add sodium hydroxide to maintain a
pH greater than 9 and add an equivalent volume of household chlorine
bleach. Let stand overnight and dispose of down the drain as long as there
are no other components that would prohibit such disposal.

Michael Kay, ScD, CHMM
Certified Hazardous Materials Manager