Refining and melting Iridium and Platinum

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darkminos

Active member
Joined
Jul 27, 2020
Messages
29
Hi,

Newbie here. I just setting myself up as I have a substantial quantity of Ir/Pt alloy to refine.

As I'm trying to avoid spending money on equipment which will prove to be useless I wanted to ask for some advise with equipment selection as well as the refining process itself. I will address the refining process in a separate post as not to overload one thread.

First of all I'm looking to set up an oxy-hydrogen torch (from cylinder, not the tiny one for jewellers) for melting about 200g Pt and 50g Ir. Ideally I would love to melt each of them into a single ingot (or button in case of Iridium) but I think this will not be possible with using an oxy-hydrogen torch for such quantities of Ir and Pt. I'm not even sure if using an oxy-hydrogen torch on Iridium will get it to melt at all as the difference between the max flame temperature and the melting point of Iridium is only 334C and I suspect there is always some loss in the heat transfer?

But let's say the oxy-hydrogen torch will melt small quantities of Iridium (1g or so at a time), will the resulting button retain the purity obtained during the refining process or will it pull carbon and other crap out of the atmosphere and crucible? I know that ideally I should use an electrical arch furnace in a controlled atmosphere to melt Iridium, but really can't afford to spend £20k to melt 50g Iridium :lol: :?

So the questions in a nutshell:
1. Can an equal pressure oxy-hydrogen torch melt 200g of Platinum, well enough to cast it into an ingot?
2. What is the max Pt I could melt and cast in one attempt using a oxy-hydrogen torch?
3. Can an equal pressure oxy-hydrogen torch melt 50g of Iridium into a button? Or even 1g?
4. Will the oxy-hydrogen melting process substantially contaminate the Iridium?
5. Any recommendations regarding a quality torch?


Alternatively, does anyone have or know someone who has an electrical arch furnace (in the UK) I could use for a (small :wink: ) fee?

Thank you!
 
You can melt the platinum. The method Lou taught me is to use two fused silica melt dishes, one on top of the other, to make a melting chamber.

The iridium will not melt with HHO torch. You can use a TIG welder with argon shielding gas on a copper hearth, preferably water cooled. I could probably assemble something with standard copper pipe fittings that would do the job, the key is water flow to keep the copper cold. Open air is ok, but it won't be workable. It will also be very bright so plan on shade 12 or better. If there is any chance the source has osmium in it, do NOT melt it. With iridium your concern is less on the carbon uptake (still an issue) from the fuel and more on the uptake of refractory oxides from the crucible.

Most buyers would probably prefer the iridium as a sponge, as it's hard enough to dissolve in bulk without first melting it in to an alloy.

For a quality torch. Smith, Harris, Victor, all make good equipment here stateside. It's more about what brand you can source locally. I personally like Victor, but that's because that's the equipment I have, so I'm used to it. Each torch brand has a bit different "feel" to it, but most people don't notice that unless they use the equipment professionally.
 
Personally I think you may well struggle to refine this material successfully, and the materials you are aiming to dissolve are highly toxic once in solution, so you need decent equipment and fume extraction to work safely. If you want to sell the material then you may well get a better price as is because the buyers will almost certainly refine it again so all your efforts and costs could well be for nothing.
 
Thank you for the reply snoman701! I was looking at TIG welders, and my worry is that I will invest in one and not be able to complete the project, or contaminate the samples because my setup won't be clean enough. I will call around and see if people are interedted in sponge which would save me a fair amout of money and hassle on making my own arc furnice :wink:

Platinum melting - That's a cleaver pattern! I suspect I would have to drill a hole for the HHO torch in one of the fused silica melting dishes? Would you have a picture by any chance of the melting chamber?

Torches - From the Harris website I did actually read that I can use an equal pressure oxy-acetylene torch for HHO, which is fine, but was wondering if the power output varies greatly between the differen torches? Like the difference between a Benzomatic TS4000 and TS8000 that I use with my MAPP gas, or does this depend purely on the tip type/size that you use with the torch? Don't want to buy a torch which will only go as high as 2000C and waste $200, but likewise I don't want to pay $500 for a super pro torch if I don't need it.

I'm 100% sure there is no osmium in the scrap as it comes from medical grade waste.
 
nickvc said:
Personally I think you may well struggle to refine this material successfully, and the materials you are aiming to dissolve are highly toxic once in solution, so you need decent equipment and fume extraction to work safely. If you want to sell the material then you may well get a better price as is because the buyers will almost certainly refine it again so all your efforts and costs could well be for nothing.

I understand the hazards and I'm quite well equiped. I just built a fume hood with the air filtration alone costing me over $800 to handle the acidic fumes. I'm better prepared from a safety perspective than 99% of youtube refiners :lol:

Plus I do it for myself as I find the process fascinating and the knowledge I gain by doing this will also be useful in the future.
 
Thank you for the reply snoman701! I was looking at TIG welders, and my worry is that I will invest in one and not be able to complete the project, or contaminate the samples because my setup won't be clean enough. I will call around and see if people are interested in Ir sponge which would save me a fair amout of money and hassle on making my own arc furnice :wink:

Platinum melting - That's a cleaver pattern! I suspect I would have to drill a hole for the HHO torch in one of the fused silica melting dishes? Would you have a picture by any chance of the melting chamber?

Torches - From the Harris website I did actually read that I can use an equal pressure oxy-acetylene torch for HHO, which is fine, but was wondering if the power output varies greatly between the differen torches? Like the difference between a Benzomatic TS4000 and TS8000 that I use with my MAPP gas, or does this depend purely on the tip type/size that you use with the torch? Don't want to buy a torch which will only go as high as 2000C and waste $200, but likewise I don't want to pay $500 for a super pro torch if I don't need it.

I'm 100% sure there is no osmium in the scrap as it comes from medical grade waste.

snoman701 said:
You can melt the platinum. The method Lou taught me is to use two fused silica melt dishes, one on top of the other, to make a melting chamber.

The iridium will not melt with HHO torch. You can use a TIG welder with argon shielding gas on a copper hearth, preferably water cooled. I could probably assemble something with standard copper pipe fittings that would do the job, the key is water flow to keep the copper cold. Open air is ok, but it won't be workable. It will also be very bright so plan on shade 12 or better. If there is any chance the source has osmium in it, do NOT melt it. With iridium your concern is less on the carbon uptake (still an issue) from the fuel and more on the uptake of refractory oxides from the crucible.

Most buyers would probably prefer the iridium as a sponge, as it's hard enough to dissolve in bulk without first melting it in to an alloy.

For a quality torch. Smith, Harris, Victor, all make good equipment here stateside. It's more about what brand you can source locally. I personally like Victor, but that's because that's the equipment I have, so I'm used to it. Each torch brand has a bit different "feel" to it, but most people don't notice that unless they use the equipment professionally.
 
The person who could help you most is Lou if he has the time as he handles PGMs on a daily basis, I do know that neither element are keen to go into solution especially with AR.
If you wish to experiment with refining I’d suggest starting with gold which is much easier and with less risks, starting with platinum and iridium will be very difficult but I wish you luck.
 
nickvc said:
The person who could help you most is Lou if he has the time as he handles PGMs on a daily basis, I do know that neither element are keen to go into solution especially with AR.
If you wish to experiment with refining I’d suggest starting with gold which is much easier and with less risks, starting with platinum and iridium will be very difficult but I wish you luck.

Thank you for the reply, I do have a few toz of gold which i will be refining first, but I have read and seen a lot of materials regarding gold refining and I feel quite confident now with my understanding of the process :D

With Pt it's a bit more difficult, and information regarding Ir refining is so hard to find! I just don't want to buy equipment that will be good enough for gold but not good enough for Pt... Like buying acetylene instead of hydrogen gas and then regretting it because it's too dirty and I will have to replace the fuel as well as part of the kit which can be $800... Ir is a seperate issue altogether because I know so little about it at the moment.
 
snoman701 said:
If you aren't experienced, PtIr is not a place to start.

What is the alloy from? Wires?

Yes.

EDIT:

I'm starting with gold, just want the setup to be Pt ready as not to waste money.
 
I found this Harris Heavy Duty Equal pressure Acetylene Kit which I like:

https://eu.harrisproductsgroup.com/en/Products/Equipment/Torches/Oxy-Fuel-Kits/Model-43-49-SAC.aspx

Any opinions? It's to be used with HHO as mentioned above. I suspect for melting I should be using the cutting attachment?
 
nickvc said:
Personally I think you may well struggle to refine this material successfully, and the materials you are aiming to dissolve are highly toxic once in solution, so you need decent equipment and fume extraction to work safely. If you want to sell the material then you may well get a better price as is because the buyers will almost certainly refine it again so all your efforts and costs could well be for nothing.

I have just checked the numbers as well and Ir/Pt alloy would have to be sold as a Pt alloy, in this case .800. This means not only would I lose about £2.5k of Ir because it's considered a contaminant, but also the Pt would lose value as it would be classed as .800.

So in total I would be looking at a £3.5k loss from selling as is. Personally I prefer to invest this money into the setup and refine it myself, at least I will have a £3.5k setup for future experiments! Plus Pt is dirt cheap at the moment, same as silver, I will be waiting for Pt to reach at least $1500/toz before selling so plenty of time to experiment.
 
The loss isn't nearly that high because Ir does not sell for high accountability rates like Au/Pt/Pd unless you are selling quantities of guaranteed purity.
 
snoman701 said:
The loss isn't nearly that high because Ir does not sell for high accountability rates like Au/Pt/Pd unless you are selling quantities of guaranteed purity.

Perhaps, but still the loss will be huge when selling as is. The quantities I work with justify an assay once I'm happy with the outcome.

I'm getting a lot of "don't do it" on this forum, instead of a helping hand on how to do it correctly and safely.... To be honest I'm a bit disappointed that no one can even point me at a book if they don't want to share their experience or methods....
 
You are getting a lot of "don't do this" because it's unsafe and you clearly have no clue what you are doing.

There's like a grand total of 20 people in the WORLD that refine iridium.

There is no "iridium refining for dummies" book.

Platinum refining carries it's own set of risks. You clearly don't know what you are doing, and haven't done your own due diligence, so expecting other people to lay it all out there for you is a bit selfish on your part.

Your other posts such as "where do I source nitric in the uk" further suggest that you are a complete beginner at all chemical processing. So the extreme care necessary in handling not only the pregnant solutions but also the waste solutions, and responsibility to appropriately decontaminate working areas and simply the background knowledge needed to not make a boneheaded mistake are all working against you.
 
These alloys are not cheap to produce so try someone like Johnson Matthey who produces them and see if they offer a better price. There are other producers of industrial PMs so try them all.
 
snoman701 said:
You are getting a lot of "don't do this" because it's unsafe and you clearly have no clue what you are doing.

There's like a grand total of 20 people in the WORLD that refine iridium.

There is no "iridium refining for dummies" book.

Platinum refining carries it's own set of risks. You clearly don't know what you are doing, and haven't done your own due diligence, so expecting other people to lay it all out there for you is a bit selfish on your part.

Your other posts such as "where do I source nitric in the uk" further suggest that you are a complete beginner at all chemical processing. So the extreme care necessary in handling not only the pregnant solutions but also the waste solutions, and responsibility to appropriately decontaminate working areas and simply the background knowledge needed to not make a boneheaded mistake are all working against you.

"lay it all out there for you" - Like asking for a book? Seriously? That's laying it out for me? That's selfish? Just pause for 1 second and think about what you said, because I can't believe someone just told me that asking for a book is being selfish. Unbelievable.

Yes I'm a beginner in chemical processing and as I mentioned many times before I'm not touching it until I'm satisfied with my understanding of the process. What's so hard to understand?

"where do I source nitric in the uk" - That's not my post, just updated the thread with my experience and that it is in fact possible to obtain a licence for anyone else who might be interested (You know, being HELPFUL to the community). In the US you can probably buy HNO3 in Walmart, but over here it's strictly regulated.

Have a great day.
 
I'm not trying to be a jerk....but I don't think you've done your homework.

I wasn't kidding when I said 20 people worldwide. It's a very small group of people that handle the isolation and refinement of the lesser known PGM's.

A google search of "iridium refinement" gives this.

https://www.technology.matthey.com/article/52/3/186-197/

From there, you can start pulling the sources they give you.

You honestly will not get any free rides with iridium processing.

You can figure out Pt refinement quite well on this forum. Pd, somewhat. Everything else, snippets. Starting with Gilchrist is never a bad idea.
 
Simply put, what you are asking, is not written in books. It's written in journal articles, and most of the time it's not specifically related to the separation science. It's more broadly written as underlying chemical characteristics of not only the parent element, but it's various chemical compounds. You have to develop all of this fundamental knowledge, so that you can connect the dots as to how to first get it in to solution, then isolate it, then bring it back to pure elemental state.

With gold, silver and platinum; the financial incentive, ease of processing and availability of material is such that it's been explained well enough that the average idiot such as myself can figure it out. When you start talking about the other five platinum group metals however, much remains as proprietary secrets.
 
snoman701 said:
Simply put, what you are asking, is not written in books. It's written in journal articles, and most of the time it's not specifically related to the separation science. It's more broadly written as underlying chemical characteristics of not only the parent element, but it's various chemical compounds. You have to develop all of this fundamental knowledge, so that you can connect the dots as to how to first get it in to solution, then isolate it, then bring it back to pure elemental state.

With gold, silver and platinum; the financial incentive, ease of processing and availability of material is such that it's been explained well enough that the average idiot such as myself can figure it out. When you start talking about the other five platinum group metals however, much remains as proprietary secrets.

Now that's a more useful reply 👍 I do struggle to find an "easy" step by step instruction for Ir refining, but I think there are some fairly easy processes burried inside more general PGM books. I have found a book which explains Ir refining and some articles but read those only briefly, I will purchase the book as not all pages are available...

https://books.google.co.uk/books?id=GibosO9NKWwC&pg=PA1243&source=gbs_selected_pages&cad=3#v=onepage&q=1767&f=false

You can have a look on page 1768 for a process flow chart.

Just to stress it again, I won't touch it until I have a clear process written down for what I'm trying to achieve and all the safety measures are in place. Gold comes first (which has to be handled carefully as well, I know). In the end I might decide not to do it after all and just melt it down into a bar, but I'm far from accepting this result at the moment 😉

And who knows, maybe there will be one day 21 people in the world who can refine Ir!
 
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