Metal finishing Q&As since 1989

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Barrel finishing of jewelry

Is potassium cyanide of use in barrel finishing of jewelry? if so how much is used for a barrel of 50 liters ? any additions req'd & precautions?

Thanks,

Veera Raghavan
- Bangalore, Karnataka, India
2004

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2004

Mr Veera Raghavan,

It is likely you are asking about the Mechanical tumbling of unfinished jewelry. It is unclear from our letter so we will do our best in view of the info provided.

Potassium cyanide is a certified carcinogen and can cause death within seconds. The CPCB at Delhi, and the Karnataka Pollution Control board have very clear guidelines on the use of cyanides in industry. Therefore you would do well to drop this Potassium cyanide route to barrel tumble polishing of jewelry.

As you have not described the jewelry you wish to polish please be guided by the following:

1) raw brass/Copper artificial jewelry can be vibratory finished .
2) Pure gold lower karat jewelry is either polished chemically in Peroxide based solutions or is vibratory finished.
3) White metal, or lower purity Silver jewelry is vibratory finished.

There may be the odd user of Potassium cyanide which is today considered outdated and positively dangerous. The Pollution law in India has serious words for its breach.

We strongly suggest moving away from the Pot Cyanide route, even academically.

Regards

Asif Nurie [deceased]
- New Delhi, India
With deep regret we sadly advise that Asif passed away on Jan 24, 2016