Analyzing plating solution for copper and acid
Q. We have a 20 gal tank with a copper/acid mixture. We would like to test for copper content and for acid content.
Is there a simple testing method available for checking these two components, either a test kit or a methodology procedure?Wayne & Sybil DeBrusk
A. You have not provided enough information. What acid? Copper plating or copper stripping. For control or for EPA?
For about $36 you can get a subscription to Metal Finishing which includes procedures for wet chemistry testing in its Guide Book. Also has lots of vendor information. It is one of the few good deals left. Hach and a few others make some drop test equipment and solutions. With the micro titrator, Hach's is very accurate. Drop testing is an approximation or an educated guess.James Watts
- Navarre, Florida
Ed. note Nov. 6, 2017: The Metal Finishing Guidebook is now history, but you can download a copy at http://metalfinishing.epubxp.com/title/12238
A. If the acid is sulfuric acid or hydrochloric, titrate for the acid, 10cc sample, dilute to 100cc with water, Normal caustic soda to a methyl orange (yellow endpoint) or bromophenol blue (blue end).
1 ml N NaOH = 0.049 g H2SO4.
1 ml N NaOH = 0.0365 g HCl
Heavy metal content (if only Copper is present, Bingo)
10 ml sample, add 10 ml of 100 vol H2O2 and raise to the boil, heating until all oxygen is driven off, dilute to 200 ml, heat to 70 °C. Precipitate the iron using ammonia as in method 42, Then proceed as in method 43.
From Langford and Parker, "Analysis of Electroplating and Related Solutions" [linked by editor to info about book at AbeBooks].
Is this what you were looking for?
If so, I can get you the rest.
A. If you want to skip with the chemistry and just use a simple premixed test kit, contact Kocour Co. in Chicago Illinois.
Determination of Sulphuric acid in an acid copper bath using conductivity meterOctober 27, 2017
I am looking for an alternate method of determining Sulphuric acid content in an acid copper bath using conductivity meter instead of using laboratory analysis . I have seen this method being used in a company , where they measure the conductivity and use this figure to determine the sulphuric acid .
I have searched this method in google but couldn't find any solution .
Please can anybody help , this process can reduce lots of testing time.
Thanks in advance
- Ibadan, Oyo State , Nigeria
November 23, 2017
A. Hi Ajit,
It doesn't make sense sulfuric acid content in acid copper bath can be directly revealed by conductivity meter as anions like sulfate, chloride and cations like sodium, copper, etc also contribute conductance hence higher conductivity not necessary implies a higher sulfuric acid concentration.
You may analyze sulfuric acid content by acid base titration.
November 25, 2017
I agree with David. Conductivity is not going to help.
If you want a rapid analysis of a standard copper sulphate bath here is how.
Titrate with alkali to first precipitate - the copper provides its own indicator. Time about 2 minutes
Measure the density with a hydrometer, about 1 minute.
The copper content is obtained from published tables or make up standard solutions to cover the expected range and draw your own graph.
Not as accurate as a full formal analysis but fast and good enough as this bath works within wide limits
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