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Nickel sulfamate bath with high chloride contents

I am using nickel sulphamate bath for plating wires on continuous process. Chloride contents of my bath has increased up to 80 gms/litre due to carry over of water and chemicals from cleaning tank in my continuous process. I want to know how chloride can be reduced from my bath. and also what harm high chloride bath will do to plating on wire.

Sunil Sethia
production in charge - Kolkata, West Bengal, India
2003

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Do you mean 80 gms/liter Cl- or did you mean 80 mg/liter? Apparently it's harmless since you are telling us your real-world situation and you have not mentioned any problems :-)

Chlorides are very difficult and usually impractical to remove from process tanks, so it is very important to take measures that prevent them from getting in. Additional rinsing, or perhaps continuous recirculation of the rinsewater through a de-ionizer will capture the chlorides. You might also want to think about using some other acid activation formula in lieu of hydrochloric acid.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003

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A chloride level of 80g/l is extremely high for a sulphamate bath. It will certainly give a very tensile stressed deposit. I believe the removal of chloride is extremeley difficult, so I think you will have to dump the bath and start again. However, I would suggest you eliminate the source of chloride; if it is in the cleaning stages, use either sulfamic acid ⇦ this on eBay or Amazon [affil links] or sulfuric acid. You clearly MUST improve your rinsing and use counterflows.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
2003