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topic 37685

Rhodium refining

A discussion started in 2005 but continuing through 2019


Q. Dear Sir,
I have collected a container of used rhodium plating solution about 21 liters and l want to use it again, what will I do?


Angelito R. Dazo
plating Shop - Phillippines

Rhodium Plating System


A. Hi, Angelito. I assume you believe that there is still some rhodium left in this plating solution that you want to use again, so it has intrinsic metal value -- but that it is now either too weak or too contaminated for successful use as a plating bath?

Unfortunately, it is not trivial to purify and then rebuild a precious metal plating solution, and 21 liters is a large amount. You haven't told us yet what you believe is wrong with the solution, nor what knowledge you possess and what equipment & instrumentation is available. Personally, I think you should contact a rhodium plating solution supplier and see if you can simply trade in the 21 liters of weak and used plating solution for a smaller quantity of fresh and properly purified solution. But good luck.

Ted Mooney, Teds signature
Ted Mooney, P.E. - Pine Beach, New Jersey
Striving to live Aloha


A. Your letter title is rhodium refining.

I guess, you just want to recover the rhodium metal from the spent solution?

To give you an idea, this is how I used to do it.

1. From the color of the solution I make a judgement whether it's rich in rhodium or not.

2. I use zinc powder in small increments to precipitate the metal, constantly agitating the solution. Without instrumentation you have to make a judgement when enough zinc powder is added through color changes.

3. Decant the spent solution, filter the precipitate, wash until neutral to pH paper.

4. Transfer precipitate to another container, dissolve excess zinc with 10% sulfuric acid. You may do this several times with hot solution.

If you want to make rhodium sulfate, this is the fun part: then you have to use molten salts.

Good luck,

H. Solidum
- Philadelphia, Pennsylvania, USA

May 20, 2008


April 4, 2011

Q. hi sir,
I'm prateek luthra from India (delhi). I have a query that I have a batch of 10 grams of rhodium which is in the black powder form, which is precipitated by the zinc powder as you further told above. Now the problem occurs when I mix the rhodium with potassium bi-sulphate & sodium chloride. It's only half rhodium and it also contains other particles like iron, lead and zinc. Now what would be the next part of making rhodium pure? Can anyone help me?


April 7, 2011

Q. hi sir,
This is prateek from india i have solution of rhodium which is diluted with potasium bi-sulfate and sodium chloride in HCl and water. How can I precipitate only the rhodium metal which I can use to make rhodium sulphate?
regards, Regards,

PRATEEK LUTHRA [returning]

June 5, 2008

Q. How to refine and re-use rhodium bath please suggest me I will wait for your reply.

Samrath Sojitra
jewellery - Mumbai, Maharastra, India

sidebar June 16, 2008

Q. Dear Sir/Madam,
I am Mr. Mitesh From India (Mumbai), I just want to know what's the exact procedure for recovery of rhodium from spent solution with good purity.
Thanking You,
Yours Faithfully


June 17, 2008

thumbs up sign Hi, Mitesh. You've asked the same question that H Solidum already answered for us with significant detail. Could you please try to recast your question by asking for clarification on any step in his procedure that is confusing you? Thanks.


Ted Mooney, Teds signature
Ted Mooney, P.E. - Pine Beach, New Jersey
Striving to live Aloha

October 17, 2011

A. You can recover your Rhodium from the used plating solution. See youtube.

Shant Aghyarian
- Dallas Texas

November 9, 2008

Q. Dear Sir:
I would like to know what metal was this blood red color precipitate that I was able to process this afternoon? Because when I smelted it goes directly inside the Crucible penetrating almost half, unlike the black precipitate that just stays above with the borax. And what is also this Black precipitate that turned into Silver Gray Metal but not shiny in appearance?
Sir, can you please give me a step by step procedure in the recovery of PGM thru Iodine or any other cheaper chemicals until its refining?
Thank you very much for your time!

Respectfully Yours,

Franklin H. Pag-Ong
silver gray ore mines - Tagbilaran city, Philippines

February 22, 2013

Q. Dear sir,

Please tell me how can I increase the reaction rate for sulfonation of rhodium? Meaning, what type of catalyst should I use to decrease the condensation time? Awaiting for your hopeful reply.


Hardik Rank
- Surat, Gujarat, India

December 7, 2014

Q. Hello,
I want to refine the precious metals from super alloys.
I have complete know-how about refining the precious metals, but the problem is that in this job there is so much Nickel in the base metal.

Ibrahim ibrahim
- Dubai , UAE

May 2019

Dear Readers: This isn't some sort of United Nations funded charity site where consultants are standing by to volunteer expert assistance :-) Rather, this is a mutual help public forum where participants who want help must give help as well. It simply doesn't work if you don't take the time to do that :-(


Ted Mooney, Teds signature
Ted Mooney, P.E. - Pine Beach, New Jersey
Striving to live Aloha

How to Refine Rhodium and Separate from Gold

November 20, 2016

Q. Hi, greetings to you all.
My problem is that I have some gold which has some rhodium. How can I isolate the rhodium from the gold.

ali sadeghi

May 24, 2019

Q. I took a litre of Spent Rhodium solution for refining. I added Caustic to Make pH neutral and then I kept for settling .After settling I removed Clean solution And filtered PPT through bag. After ppt I received red-ish Powder. If I have to make pure rhodium solution what will be my final part to do. To dissolve with which chemicals? Please suggest me.

wasim kazi
HKE pvt ltd - Mumbai Maharshtra India

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