# PtIr10 or PtRh10



## teclu (Oct 30, 2009)

Hello everybody,


How can I determine if the alloying element is Ir or Rh?
The material is in the form of rivets with different geometric sections and therefore, to determine the density of the alloy I can not make accurate measurements (volume).

...AR?


Thanks in advance!

teclu


----------



## butcher (Oct 30, 2009)

Here are few clues from my notes, as I have very little experience here I hesitate to go further, I do have some chemistry notes of how to test these , but the chemistry gets very intense.

HNO3 will disolve copper and metals above copper in EMF series, it will disolve Ag and Pd,(if much silver may carry PGM's)

Aqua regia will disolve most all base metals,(refinining we eliminate them before use). cold aqua regia will attack Gold,Pd, but wont hardly touch platinum,boiling aqua regia will slowly disolve Pt.

Rh,Ir,Os,Ru, not attacked by acids or by Aqua regia to any extent.(usually smelted).
EMF series,which metal will displace another in solution, or plate to other etc.
for those who need this:
PGM= platinum group metals
Au= gold
Cu=copper
Ag=silver
Pd=palladium
Pt=platinum
Rh=rhodium
Ir=iridium
Os=osmium
Ru=ruthenium

Lou has vast expierience with PGM's, check his posts, you will probably find your answer's there.

hope this helps.


----------



## teclu (Oct 30, 2009)

Butcher, thank you sir!


I hope that mister Lou or anybody with more experience will read this post.

teclu


----------



## Oz (Oct 30, 2009)

Butcher,

I will be the first to admit that I do not know the exact ordering of the 6 platinum group metals in the electromotive series of elements, but how did copper end up between gold and silver? This makes me wonder where you got your list.


----------



## butcher (Oct 30, 2009)

Oz that was not an order of series of metals, I was trying to give a name to the metal for my abbreviation's for those who may be new, or not know them, sorry Oz for the misunderstanding, I dont know series for the PGM's either. have never run across them listed in the series, besides platinum.


----------



## Oz (Oct 30, 2009)

My bad. 

I saw the EMF and thought that was what you were referencing with the list.


----------



## butcher (Oct 31, 2009)

lasersteve has a post on testing Rhodium, 

editted out confusion :lol:


----------



## Lou (Nov 1, 2009)

The easiest way to tell is in a mechanical fashion: the alloy containing rhodium is less stiff and rolls much more easily than the platinum-iridium alloy. This would require known platinum-iridium alloy.


The other method to tell is to make a thin foil or shaving of the material (make sure it is free of organics--they can ruin the test) and heat in a test tube with concentrated sulfuric acid until white fumes escape. These white fumes are extremely dangerous, so do this in a fume hood or in a very good draft!! This is one of the methods that our very own lazersteve has used and was my recommendation to him based on him wanting a fairly nondestructive test for rhodium vis a vis its sulfate.


----------



## Irons (Nov 1, 2009)

Lou said:


> The easiest way to tell is in a mechanical fashion: the alloy containing rhodium is less stiff and rolls much more easily than the platinum-iridium alloy. This would require known platinum-iridium alloy.
> 
> 
> The other method to tell is to make a thin foil or shaving of the material (make sure it is free of organics--they can ruin the test) and heat in a test tube until white fumes escape. These white fumes are extremely dangerous, so do this in a fume hood or in a very good draft!! This is one of the methods that our very own lazersteve has used and was my recommendation to him based on him wanting a fairly nondestructive test for rhodium vis a vis its sulfate.


I think you forgot the sulfuric acid. 8)


----------



## lazersteve (Nov 1, 2009)

Here's a positive test result of the concentrated sulfuric acid Rhodium test:







Steve


----------



## teclu (Nov 2, 2009)

Then concentrated sulfuric acid reacts/attack with the platinum rhodium alloys? ex PtRh10 or PtRh30
... cold, hot or boiling?

teclu


----------



## lazersteve (Nov 2, 2009)

The test result was obtained from residual material after AR extraction of Platinum and Palladium from catalytic converters.

The acid is boiled. Be very cautious as hot acid is very dangerous.

Steve


----------



## teclu (Nov 2, 2009)

Steve,thank you sir!

I hope I understood.

Lou, also thank you sir!

teclu


----------



## Lou (Nov 4, 2009)

Yes, I forgot sulfuric acid in there. The post is now edited for it.


----------



## skippy (Feb 22, 2010)

I've searched the forum, and I couldn't find any information whether the fuming sulfuric acid treatment works effectively as a recovery method for rhodium, or is it more of a test? Anybody know?


----------



## lazersteve (Feb 22, 2010)

skippy said:


> I've searched the forum, and I couldn't find any information whether the fuming sulfuric acid treatment works effectively as a recovery method for rhodium, or is it more of a test? Anybody know?



Considering the amount of Rh one is likely to encounter in our refining efforts sulfuric acid is a viable method of putting Rhodium into solution. Complete digestion is seldom, if ever, achieved. 

I have also posted some other methods that I found on the internet for larger amounts. These other methods are also only partially effective at putting Rh into solution. 

In my opinion for powdered, wash coat, or plated Rhodium, the best method of recovery by far is gas phase extraction. I intend to demonstrate this process in video format once the weather warms up here.

Steve


----------



## skippy (Feb 22, 2010)

> In my opinion for powdered, wash coat, or plated Rhodium, the best method of recovery by far is gas phase extraction. I intend to demonstrate this process in video format once the weather warms up here.



Waiting for it to warm up? Don't you live in Florida? Put on some long pants if you are cold :lol: 

Anyhow I put in an order for your PGM DVD and I'm looking forward to watching it - I'd probably pay $25 for your upcoming one too if thats an incentive for you to put on a windbreaker and brave the elements to make the new video.


----------

