Home /
T.O.C.
FAQs
 
Good
Books
Ref.
Libr.
Advertise
Here
Help
Wanted
Current
Q&A's
Search 🔍
the Site
pub Where the world gathers for
plating, anodizing, & finishing Q&As since 1989





-----

Copper plating: Anode consumption Q&A's





January 30, 2012

Q. We are using titanium anode baskets of rectangular shape 2100 mm * 400 mm * 100 mm & 1730 mm * 400 mm * 100 mm in our cyanide copper plating electrolyte having volume of 11000 liters each (strike and plating bath). The anode baskets are wrapped with ss mesh to avoid the small pieces of copper falling inside the tank. We are plating copper of 6 microns on the steel strips using copper cyanide potassium cyanide along with rochelle salts. Ours is continuous line operation. From last couple of months we are facing problem that our line speed has been reduced because the ss mesh has a black coating. We thought of current leakage, increased the free cyanide concentration, increased Rochelle concentrations also. Since it's a continuous line operation we are not having enough line stoppages. At present at every week or once in 15 days we remove anode baskets top up the black smuts and run the line.
My question about the above problem: is it because of titanium anode baskets which are very old?

Maybe the baskets inside wall broken due to which current flow may not be proper? We are using 19 mm copper rod cut into small pieces of 4" long; or is it because of metal contamination?
Please answer me. My line speed earlier was 29 to 30 feet/minute. Now I am running with 16 to 17 feet/min

Keshav Prasad
working as a consultant - VADODARA, GUJRAT, INDIA



January 31, 2012

A. I do not plate copper, but I would never cover a titanium basket with stainless steel.
I do not like dissimilar metals. You have Ti, SS, and Cu. It will be a confused battery.
If you are going to use Ti baskets, why not use a fine Ti mesh or very small expanded Ti?

I thought that plain steel was normally used for alkaline baths.

You do not mention your carbonate level.

My text books say that you should be using OFHC copper for anode material.

James Watts
- Navarre, Florida



February 2, 2012

A. ANODES POLARISED:- LACK OF FREE CYANIDE
ANODES BLACK:- METALLIC CONTAMINATION (LEAD) DUMMYING AT 1 A/DM SQ.

ajay raina
Ajay Raina
Ludhiana, Punjab, India



February 3, 2012

A. I think you are not using the correct anodes for your cyanide copper electrolyte. You have to use "electrolytic copper anode" specially designed for cyanide copper. If you use "phosphorous copper anode", designed for acid copper electrolyte, you will have this black/brown deposit on your anodes ;)

Francois Pignon
- France




Sacrificial anode consumption in electroplating on copper

May 20, 2015

Q. Dear all, we are an electrical panel board manufacturing company. We do electroplating on copper for our panels. To calculate the consumption of anodes I am looking for a formula. We use copper strips of different size in the plating bath for approx. 30 mins @ 50 A. How can I get the anode usage? Our anode size is 600 height x 200 width x 8 thickness (mm).
Looking forward to get a solution by experts
Thanks
Lijo

Lijo John
material planning - Kuwait



May 2015

Hi Lijo. Although I'm a little bit unsure about whether you are electrodepositing copper onto some other metal or are electrodepositing some other metal onto copper, the basic situation is the same. There are two different calculation approaches, and you can use each to serve as a check on the other:

1). Plating tanks can run for years in a state of approximate equilibrium, which means that the amount of anode consumed equals the amount of metal deposited onto the parts, otherwise the bath would either quickly build up in metal or starve. So just calculate how much metal you put on your parts, and that's how much metal you'll use in your anodes.

2). Faraday's Law says that the electrons you move from the anode to the cathode through your rectifier force an equivalent number of atoms to oxidize & dissolve at the anode and be reduced onto the cathode. 96485 ampere-seconds moves one equivalent weight. So 30 minutes @ 50 A = 90000 ampere-seconds, which moves about .93 equivalent weights. Give us the plating solution you are using and we can estimate the weight of metal you are electrodepositing and dissolving from the anodes.

Regards,

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



May 21, 2015

Dear Sir,
I am very much delighted and thankful for your advice. Furthermore we are electroplating another metal onto copper to prevent corrosion of copper bars in electrical panels.
We apply only a thin layer of plating on copper bars and plating thickness is approximately 5-7 microns. Hence I am unsure about your first opinion. In 2014 our copper consumption is 50,502KGS whereas our anode consumption is only 500KGS.
Since we have copper strips of various length I would like to get an idea of how much anode required to plate one m2 of copper area so that I can use for various sizes.
Once again thanks for your time and efforts for the industry,
Regards,
Lijo

Lijo John
- Subhan Kuwait



May 2015

Hello again, Lijo. It's very hard to proceed in the abstract. If we don't know whether you are electrodepositing silver, or tin, or something else, and whether it's an acid or alkali bath, we can't give you the atomic weight or the oxidation state or the density factors you would need to proceed with a Faraday's Law calculation. All we can tell you in the abstract, once again, is that you'll deposit .93 equivalent weights of that metal if you plate for 30 minutes @ 50 A.

Likewise, if you know the total surface area of the parts you plate, and you know the thickness, you can calculate the volume of metal plated onto the cathode and dissolved off the anodes, but you can't calculate the weight until you know what metal you are plating, and its density.

A general rule of thumb for a lot of types of plating is that you should have about twice as much surface area in the anode as the cathode. If you are doing silver plating, yes, you must track the anode usage; it's not fair to you or your employees to have such a valuable material go missing without proper accounting.

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 -or- Start a 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    -    ©1995-2023 finishing.com, Pine Beach, New Jersey, USA