# Need help with Rhodium



## Anonymous (Mar 18, 2008)

If I take some ground up ore fuse it with Sodium Bisulphate then digest it in Standard Aqua Regia, then boil out the excess Nitric add alcohol, at this point I get a black precipitant of Rh. One of my questions is; what form is the Rh is it Rhodium III, Rhodium IV, or Rhodium Black? This should 99.9% pure metal right? This procedure works with Bean size material so I assume it will work with a 30g crucible size digestion.

Anyway my thinking is that because the ore is very rich in Rh I’m going after it first, then after the procedure mentioned above I would filter off the precipitant boil the digestion back down in order to remove the Alcohol and go to standard procedures for removing other precious metals. Does this look like it will work to you’ll even with the ore not being pre-washed to remove the base metals?


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## Lou (Mar 18, 2008)

It will be in its ground state, rhodium black.


What are you fusing this in? I am curious, because your black powder might be something else: contamination from your fusion vessel.

Soon I will post up a table of compatibilities for crucible material since it seems a lot of people love doing fusions :/ . 


Also, where are you getting this material from? How concentrated is this ore? 
Rhodium is exceedingly rare and there are only a couple of places where it is obtained, and even then, it is not the chief target. Even when they go after it from spent nuclear waste (rhodium only/oddly has one isotope so it's the product of nuclear decay) rods, Rh is not a major concern.


I'd be glad to help you more if you provide more details about the material. Hate to be a naysayer, but I don't think it's Rh.

Regards,
Lou


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## Anonymous (Mar 18, 2008)

What are you fusing this in? Clay Crucibles but my orginal test was fused in Pyrex Glass

Also, where are you getting this material from; Carolina Slate Belt

How concentrated is this ore; My best guess as to what this ore is is Sperrylite.

I've had a professor @ USC confirm it's existance in this area but that assay was on another ore in the same area I'm working.


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## Lou (Mar 19, 2008)

If you have that much sperrylite, God bless, I hope so. If I were you, I'd sell a pound of it to some rock shops, and use the proceeds to have a chemist separate it. 

Why mess around with PtAs2? Arsenic, as I've said, is not good to work with and disposal is a nightmare.


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## Anonymous (Mar 19, 2008)

Lou, 

I am not sure it's Sperrylite that is my best guess. Anyway look at the following please. I do know that AR will completly break down the ore from silver dollar size material.


the fuse all of that with bisulfate and then do the AR treatment on the rhodium. Precip. the Rh in solution (after removing any nitrogen oxides present) with zinc or mangesium. Rinse well with HCl and your rhodium should be pretty pure. 

Want the Zinc drop all other metals? Then there is the Pt, it would drop and not go into the HCI wash. Is this correct? 

What about Formic it should drop the Rh but it drops the Pt also but the Pt will be a yellow mud right and the Rh as Rhodium Black. Is this correct? If this is right what is the easiest way to separate this? 

What part of the Country do you live?


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## Lou (Mar 19, 2008)

It probably isn't sperrylite if you're breaking it down with acid and talking to me.


I suggest you get an assay done. You can't refine what's not there. If you already have an assay, please post up the results so that we may see them and further direct you.


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## Irons (Mar 19, 2008)

This is a very good document on the subject:

http://tinyurl.com/2raonp


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## lazersteve (Mar 19, 2008)

RW,

Welcome to the forum.

I've attached some information concerning identification and processing Rhodium. I hope it helps.

Steve


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## Anonymous (Mar 19, 2008)

How do you tell that sperrylite, I have a rock about 1/2 the size of my fist that looks like it that I found while prospecting in some glacial till deposits.

Thanks.


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## Lou (Mar 19, 2008)

If it's half the size of your fist it should weigh several (4-6) pounds.

Get it looked at by a professional mineralogist, do not harm it in any way. If you really have a *crystalline* piece of sperrylite, of such a magnificent size (normally they are no bigger than grapes at the best), it would be (to me) priceless. You could probably expect at least five times its value if it were solid platinum.


It will be a nice pretty, metallic gray, and very heavy, about as heavy as a piece of silver the same size; almost comparable to lead! If you can, do a quick density test, if it's over 8 or 9, you may have something there.


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## Anonymous (Mar 19, 2008)

It is metalic gray but almost silver looking - I though it may be a lump of
crome to be honest. It is very crystalene. It came out of a hole in northern Ohio were the glaciers from Canada ended. I find gold there most of the time and I found 2 small diamonds, well they look like diamonds and feel greasy, I did not have them tested so I could be wrong.
I do not prospect to make money - it cost me more that I could ever find - but it is fun. Find lots of fossils also.

I will find out the density, I never held a piece of lead bigger than a fishing sinker or a piece of silver that size either so I really do not now how it compares.


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## Lou (Mar 19, 2008)

Well I live up here in Northern Ohio so I'm now intensely interested!! If there's sperrylite up here, and you know where you found that, I think I found myself a new job!!


While I'd just about bet the farm that it's something stupid like galena (lead sulfide), I'm hoping for you that it's PtAs2.


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## mwren (Mar 19, 2008)

> It came out of a hole in northern Ohio were the glaciers from Canada ended.



Brecksville, Salem, or Wildcat Hollow?


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## Anonymous (Mar 20, 2008)

I do not think it is galena I have seen a lot of that stuff. Although, I tend to agree that my finding a lump of anything that would be valuable seems to be a longshot. When I get the density figured I will post.

Got it in knox County. Did not find any more there just this one piece.


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## Irons (Mar 20, 2008)

Always a good source of goodies brought down from the North.

Beware of the hanging wall. Digging into a wall of gravel is a quick way to end a career.


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## Anonymous (Mar 20, 2008)

Thanks to all of you for your help. Good hunting.


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## Anonymous (Mar 20, 2008)

Irons, I found this in a deep washout after flooding. The hole was about
6 ft deep and it was right in the bottom.

There is lots of flooding going on over there now. I am going to take some vacation days and go over when the water receeds. 

Last year after flooding I found a bar of black sand about 8 ft long and
a foot or so wide and a inch thick. Got 15 - 20 flakes per pan from that.
The ground around there was only 1 or 2 flakes per pan. Hope to find some more of these bars now that I know when and what to look for in the area. It had a covering of blond sand about 2 inches deep and was along the shore about 3 ft from the water and it was actually my kids that 
found the streak the water was to cold for them so they were playing in the sand. go figure.


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## Lino1406 (Mar 21, 2008)

Platinum will precipitate the
same way as rhodium, palladium
etc. - black. Therefore I would 
recommend to digest 1stly all 
the other PGM's as if they are there,
before doing the bisulphate melting.


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## Froggy (Mar 22, 2008)

Lou, if you go save a spot for me!! I'll bring the brew...


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