Home /
T.O.C.
FAQs
 
Good
Books
Ref.
Libr.
Advertise
Here
Help
Wanted
Current
Q&A's
Search 🔍
the Site

Chime right in! (no registration req'd)

-----

"How To Remove Zinc Contamination from Nickel Sulphate Plating Bath"




Q. Dear Sir,

We are facing problems due to Zinc in the Nickel Sulphate Solution. Kindly suggest something to sort out our problem.

Sir, Thanking You in advance.

Abhishek Goel
- Kota(Rajasthan), India
^



A. Hi Abhishek. If diecast parts fall off the racks, remove them immediately. Per The Canning Handbook, reduce the pH to 4.0; add 1 ml/l of H2O2 peroxide 130 volume; plate out at 20 ASF with vigorous agitation for 4 hours minimum. Please post further details with any additional questions. Thanks!

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



Q. Dear Sir,

We are in the business of Nickel plating in India. We have Nickel Sulphate crystals but the problem is that they contain Zinc also. Sir, we require to remove this zinc component from Nickel sulphate Electrolytically or by Precipitation method. The specification for Nickel Sulphate crystals is: Ni-19.6% Zn-1.5% Fe-0.05% Kindly suggest the process details so as to sort out our problem.

Thanking You!

Kind Regards,

Abhishek Goel(returning with a clarification)
- KOTA,RAJASTHAN, INDIA
^



A. In my opinion the best thing to do is electrolytic purification(dummying). An average current density of 0.2-0.4 A/dm2 should be enough.

Kind regards,

Sjamp van Esch
Sjamp van Esch
- Eindhoven, The Netherlands
^



A. I'm not sure that the following idea is applicable to the problem (1.5% Zn is a lot) but it might work. It would be nice to hear some feedback about a possible solution to the problem of Zn contamination in nickel baths that I worked out for a client, once, but that he decided not to implement. It did work nicely in Hull cell testing.

It's this: transfer the bath to an auxiliary tank, add nickel carbonate to the solution, and agitate it well for 4 - 6 hours. Then filter it back into the tank. The idea is that zinc carbonates and hydroxides precipitate best several pH units below nickel carbonates and hydroxides, and that the zinc will deposit out on the particles, or be removed by co-precipitation.

I've always believed that it is better to remove contaminants, either via precipitation or dummying, than to try to compensate for their effects with control additives. But then, I don't run a plating shop; it'd be nice to hear from someone who does.

dave wichern
Dave Wichern
Consultant - The Bronx, New York
^



thumbs up signHi Abhishek. While I appreciate Sjamp's and Dave's suggestion, I think we might be misleading other readers is we left your premise unchallenged --

Starting with heavily contaminated nickel sulphate crystals is not how you should do nickel plating. You should buy purer nickel plating solutions from plating process suppliers. Then you use proper nickel anode material as the source of your nickel :-)

Regards,

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



Q. Hi Ted,

What exactly the H2O2 does in the nickel sulfate bath? Please consider my lack of knowledge in chemistry.

Thanks,

Reynaldo Arrroyo
- Valencia, Calif, U.S.A.
^



A. Hi, Reynaldo. Please consider mine as well :-)

But hydrogen peroxide, H2O2, is a powerful oxidizing agent which converts to water and oxygen gas, leaving no contaminants behind. You would add it to a nickel sulphate bath for a couple reasons: to oxidize iron so that it precipitates and can be filtered out; to oxidize certain types of organic brighteners into a form from which they can more easily be carbon filtered. Exactly what peroxide does in helping to remove zinc contamination, I'm not sure.

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



August 7, 2016

Q. Can you please tell me how I can remove zinc from nickel sulphate solution (zinc 1000 ppm).

Soya khan
- jalgaon, maharashtra, india
^


August 2016

A. Hi Soya. You did not tell us what you found wrong or questionable or confusing with the answers already provided; please do not run the thread in circles, but try to keep it moving forward. Also please try to follow the forum netiquette of always spending more time on your own behalf in posing your questions than you would ask strangers to spend on your behalf. Details, please, of exactly what you are doing and why the advice from the Canning Handbook didn't help. Thanks.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
^

none
finishing.com is made possible by ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages

Q, A, or Comment on THIS thread SEARCH for Threads about ... My Topic Not Found: Start NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact    -    Privacy Policy    -    ©1995-2021 finishing.com, Pine Beach, New Jersey, USA