Complex cyanides and wastewater treatment

Our facility uses potassium stannate and copper cyanide to get tin-over-copper plating. Can this produce a complex cyanide that is resistant to destruction by chlorination?

This is a fairly easy complex to destruct with normal alkaline chlorination techniques, as long as your setpoints are correct on both your pH and your ORP - and your probes are calibrated!

If your having a problem with this process, it may be contaminants that exist in the process bath itself that are giving you high numbers. Nickel (from stainless steel corrosion), iron, and other metals will form more difficult to break complexes if present. A good analysis of your bath for other metals would be advisable to give you a baseline to work from.