# Obtaining iridium from a polymetallic powder



## noobsk (Apr 4, 2017)

Hi, I recently acquired a mine powder, did the necessary studies in different places and detected the presence of iridium.
The composition of the powder is as follows:
IRON............... .8806
MANGANESE.......... .0906
ZINC........ .0107
TIN...... .0097
IRIDIUM... .0042
COPPER... .0042

I would like to know how to obtain the iridium and refine it, since it has been difficult for me to eliminate the iron and manganese by its great abundance. Thank you for your attention


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## Lino1406 (Apr 4, 2017)

Just for curiosity, I would try mercury, to see whether it settles down.


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## Platdigger (Apr 5, 2017)

How was the Ir detected? If it was by XRF it may not be there.
Was it by nickel sulfide fire assay? Peroxide fusion? Or?


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## Lino1406 (Apr 5, 2017)

I agree. How about Ir twin brother, osmium?


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## noobsk (Apr 5, 2017)

As it comes too iron has been very difficult the use of mercury and the method for which it was identified was by XRF, but with more than five different equipment, all metallurgical laboratory. The Osmium has not appeared


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## 4metals (Apr 5, 2017)

Lino is suggesting using mercury to cement out the precious metals in the solution. The mercury will go into solution, and due to its position on the electromotive series only precious metals will be displaced. 

I have never used mercury for cementation but in theory it makes your cemented metals cleaner than copper. It is however mercury, but for a test on a small quantity worth a try.


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## Platdigger (Apr 6, 2017)

Am I getting this right? 
You are saying this ore is 4.2 percent Ir?
In other words 84 pounds per ton?
Sorry, but I doubt it. Especially in the absence of any other pgms.


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## Lino1406 (Apr 6, 2017)

Sorry,I did not suggest cementing with mercury - nor amalgamating - iridium does not dissolve in mercury. What I meant is to use a transparent separator funnel with a minimal amount of mercury, by way of experiment and see whether something settles below - Ir of course is heavier than mercury, just to prove Ir is present (0.4 percent)


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## 4metals (Apr 6, 2017)

> What I meant is to use a transparent separator funnel with a minimal amount of mercury, by way of experiment and see whether something settles below - Ir of course is heavier than mercury, just to prove Ir is present



Well this a unique test. But the way I learn is to read, understand the concept, and approach this with an open mind. I wonder if the surface tension on the surface of the mercury pool would make a small quantity of even a more dense material float on the surface? Creating a false negative.


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## noobsk (Apr 6, 2017)

Platdigger said:


> Am I getting this right?
> You are saying this ore is 4.2 percent Ir?
> In other words 84 pounds per ton?
> Sorry, but I doubt it. Especially in the absence of any other pgms.



The percentage is 0.04% of Ir


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## anachronism (Apr 6, 2017)

so that's 40g per tonne.

with an Iridium price of $850 per Troy Oz today that's not a whole lot of return for the work you will have to do.


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## Platdigger (Apr 6, 2017)

OK then, so that means there is only 8.8 percent iron.
That doesn't make sense either. So what is the balance of the ore?


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## 4metals (Apr 6, 2017)

To convert to percent the decimal moves 2 places to the right. Iron 88% Iridium .42% A lack of other PM's makes me suspect instrument error. The 0.42% was likely less than the percent error the XRF lists.


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## g_axelsson (Apr 6, 2017)

4metals said:


> > What I meant is to use a transparent separator funnel with a minimal amount of mercury, by way of experiment and see whether something settles below - Ir of course is heavier than mercury, just to prove Ir is present
> 
> 
> 
> Well this a unique test. But the way I learn is to read, understand the concept, and approach this with an open mind. I wonder if the surface tension on the surface of the mercury pool would make a small quantity of even a more dense material float on the surface? Creating a false negative.


Most probably, surface tension is quite high for mercury, just watch how it balls up whenever some is spilled.
It would also be impossible to extract it from the other powder as solid particles seldom moves inside a powder even if it is heavier. You need to levitate it in some way, for example panning is levitating the gold and sand in water, drypanning is using air.

Göran


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## 4metals (Apr 6, 2017)

I remember panning black sands and adding mercury to amalgamate the gold and collect it that way. Gold and silver does collect in the mercury and leave the dirt behind. I did not realize that Iridium does not amalgamate in the mercury as Lino pointed out. 

One would have a better chance of this working if the pool of mercury had a large surface area and a very thin layer of ore could be tested so the pool of mercury would levitate the material. Still it would have to be heavy to fall into the mercury and pop out on the bottom of the vessel.


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## g_axelsson (Apr 6, 2017)

To levitate the material it has to be wetted by it, if it isn't wetted it will only form small balls because of the surface tension.
This phenomenon can be seen if you mix dry sand with water, small air bubbles with sand inside might sink and no matter if there is a heavy grain inside it is still lumped together with all the other grains and will move like a single particle.

Maybe levitate isn't so good term to describe what I'm trying to explain. Fluidize might describe it better. Every grain by itself, totally surrounded by the media (wetted) without excessive touching other grains. (bumping into each other is okay)

Göran


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## Lino1406 (Apr 7, 2017)

If the powder is fine enough, I would also try a magnet to separate into iron rich and iron lean phases


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## noobsk (Apr 7, 2017)

anachronism said:


> so that's 40g per tonne.
> 
> with an Iridium price of $850 per Troy Oz today that's not a whole lot of return for the work you will have to do.



Sorry, the percentage is: .44g
Yesterday I was given other metallurgical laboratory tests via wet and atomic absorption and indeed there is iridium of .44 to 2 g per kg


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## noobsk (Apr 7, 2017)

g_axelsson said:


> 4metals said:
> 
> 
> > > What I meant is to use a transparent separator funnel with a minimal amount of mercury, by way of experiment and see whether something settles below - Ir of course is heavier than mercury, just to prove Ir is present
> ...



Which way do you recommend me to levitate it? Or some chemical method to eliminate the high percentage of iron?


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## noobsk (Apr 7, 2017)

Lino1406 said:


> If the powder is fine enough, I would also try a magnet to separate into iron rich and iron lean phases


I tried a common magnet and I did not get any results, do you know of another magnet to separate iron polymetallic?


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## g_axelsson (Apr 7, 2017)

noobsk said:


> g_axelsson said:
> 
> 
> > 4metals said:
> ...


I don't, the obvious way to separate it is panning but that only works if the powder is relatively coarse and the particles are pure iron or iridium.

It almost sound like it's saw dust from cutting meteorites. If it is then it's all mixed together in an alloy and any gravimetric method will fail.

If you have access to cheap acid then dissolving the iron in sulfuric or hydrochloric acid might work. It will create a lot of waste though but concentrate the iridium.

But the real question is what it is you have? Obviously it isn't iron powder or it would have been attracted to the magnet. It has to be some compound of some sort and not metallic.

I have no experience of working with iridium so anything I write you better check with second sources.

Göran


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## Lino1406 (Apr 8, 2017)

XRF on powders is very unreliable. However only for curiosity I would make an experiment with a fine powder and mercury or panning as suggested. If the result is positive - meaning the Ir reading increased thereafter (which I doubt) we'll continue from there


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## geedigity (Apr 8, 2017)

> XRF on powders is very unreliable.



I think noobsk indicated that he was also given additional analytical results (Atomic Absorption) and concentration of Ir was confirmed to be .4 to 2 grams per kg.


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