Rhodium.... your views

The topic is Rhodium. Rhodium as we know is Pgm or platinum group metal. It has similar traits of other Platinum type metals, it's luster is silvery white with darker hue in undertones ,it has a high heat resistant and acid resistant. It is also light weight, of the lightest if not the lightest (least dense ) of the pgm. And is also rigid.
OK that being said and the current facts of Rhodium, it is known amongst buyers and sellers that it is sold as a sponge.

My question for discussion is why? Why sell it as a sponge?
And second part, have any formed Rhodium into a bar? If so what method did you use.?

I have a method I'm currently working on and could use some positive feedback on the topic.

I would have to say when it comes to PGMs our resident expert is Lou so my advice is to hope he chimes in and if he does listen very carefully.

Rhodium sponge is easier to dissolve than a solid bar. It makes it easier to work with.

Göran

As a sponge it is easy to make a distillate and utilize it for plating purposes., and a variety of other uses.
But transportation of a fine powder compared to a solid bar? I would prefer a solid bar, just think of the nightmare of spilling a jar of fine rhodium dust while in transit.
I've been told that many find it difficult to work into bars, I guess that's just a matter of opinion.
Sellers should beware sending rhodium or pgm in dust form across international boarders require s customs ... At least going to Canada. So seller don't just send your pgm to refiners... They would likely rob you and tell you a lie after. But hey they are still a few honest ones out there.

Hi Indigo,

Any luck with your new method of precipitating Rhodium. I am very interested. I have a lot of it in my stock pot.

Kindest Regards!

Hi,
Rhodium is also found in scrap catalytic converters with Platin, Palladium. They are found in honeycomb part of the catalytics and reason to found PGM is cleaning harmful gases like NOx, hydrocarbons etc. Do you get the Rhodium from there?
How do you make it bars? It needs high temperature, do you use arc furnace for that?and then solid bar is %95 purity Rh?

Thanks,
Regards

Even though rhodium has dropped in price lately, it is still a very expensive metal. I have been fairly successful at separating PGM's but the precipitation of rhodium is still something that I haven't quite mastered. I receive rhodium from my costumers because there is no easily accessible markets that are willing to pay more than 50% of spot. This sample came to me from a regular costumer who happens to be a broker. I have received the metal in wire form all other times except this time. The content as sent to me, which was obtained through hand held XRF gave a ratio of 84% platinum and 16% rhodium. After searching for this alloy with these percentages, I could find nothing that resembled it. I am guessing that it is the more common 90%/10% Pt/Rh alloy. The national refinery that I deal with only offered 90% on the Pt and 50% on the Rh. It left me scrambling trying to find a better percentage. I finally found a reputable buyer from a member of the forum and my facebook group that has offered 85% and 75% respectively. It is hitting the ol' dusty trail in the morning.

75% of what price index?

Lou said:

75% of what price index?

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Spot price, I hope. At least that is what I agreed to.

I’m asking which one. Heraeus, BASF (Engelhard), and Johnson Matthey each have their own index. Sometimes they agree, sometimes they do not.

Right now JM is 14350, Kitco bid says 13100. So if you are getting Kitco Bid, vs JM vs

Meh, Lou beat me to it.

Lou said:

I’m asking which one. Heraeus, BASF (Engelhard), and Johnson Matthey each have their own index. Sometimes they agree, sometimes they do not.

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Hmm, I've been a little behind and was ready to leave to send it out. Now I am wondering. I still have the metal as of right now. I'll try and contact him and get that index nailed down before it actually leaves. Good thing there's not a fedex store closer to home or it would already be there.
Thanks.

Lou said:

I’m asking which one. Heraeus, BASF (Engelhard), and Johnson Matthey each have their own index. Sometimes they agree, sometimes they do not.

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I heard back before actually sending. He uses Kitco and spot was $13,000 this morning.

Nicely made bar of something that darn hard to melt. If you made that, really nice work Geo!!

Lou said:

Nicely made bar of something that darn hard to melt. If you made that, really nice work Geo!!

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Thank you. Homemade induction furnace. Closed graphite crucible coated with Satanite.

What is Satanite?

Edit:
I googled it it is refractory cement

I am looking for thin foils of Rh as calibration objects. If anyone has something like that, please PM me. I only need small pieces (10mm diameter), however.
@Geo: Can you plate Rh onto another metal, let's say copper? I could use well plated Rh(at least 8 ym) on round copper pieces for the same purpose as well.

Marcel said:

I am looking for thin foils of Rh as calibration objects. If anyone has something like that, please PM me. I only need small pieces (10mm diameter), however.
@Geo: Can you plate Rh onto another metal, let's say copper? I could use well plated Rh(at least 8 ym) on round copper pieces for the same purpose as well.

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It would need a nickel "strike" as a barrier metal between the copper and the rhodium. Nickel acetate is a good plating electrolyte for plating a nickel barrier.
https://en.wikipedia.org/wiki/Nickel(II)_acetate