# What did they use pd, rh os etc. for, back in the day?



## nwinther (Jun 27, 2022)

Not so much a technical question but more a historical one.
Reading online, I failed to really discover, what "they" did with the PGM's (other than Platinum) pre 1940's or so.

Gold was obviously a popular jewelry metal, as was silver (and for silverware) and I suppose Platinum was reasonablt popular to make white gold with - and post 1940 platinum (and other PGM's) became sought for in relation to industry and technology.

But what about before then? In the late 1800's or early 1900's?
Following Sreetips' videos on Silver cell filter-processing, he comes across some PGM's, mainly Pt and Pd (I suppose). Some of that may come from some of the scrap jewelry that also makes it into the silver cell, but surely some of it is from the silverware and flatware he processes.

But how did those PGM's find their way into the silverware? Is it a matter of refiners back in the day not caring if there were traces of PGM in their silver bars (from which I imagine they made their products from)?
If there was little demand for PGM's and they are (and especially were) difficult/expensive to isolate, it would make sense to just ignore it (if they even realized it was there?), and now companies and small-scale operaters such as sreetips can reap some benefits from silver-recovery/-refining.

But does anyone know of an application of the PGM's in those days (that would be "popular" enough to merit a focused production of individual PGM's)?


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## Platz (Jul 10, 2022)

They used the make furnace heating elements from platinium rhodium wire. Intrestingly over time the furnace wires would volatilise slightly at high temperature and the Pt and Rh would coat the bricks near the coils with a layer of Pt and Rh!


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## VK3NHL (Jul 11, 2022)

Platz said:


> They used the make furnace heating elements from platinium rhodium wire. Intrestingly over time the furnace wires would volatilise slightly at high temperature and the Pt and Rh would coat the bricks near the coils with a layer of Pt and Rh!


Plat/Rh is used for thermocouples in furnaces.


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## mphkdl (Jul 11, 2022)

RH is used in bearing cups of jet engines,because of high heat and wear tolerances. Also Rh in world war ll was used in cable that circled US, Atlantic and Pacific, for submarine detection. Yup from Nova Scotia ,through Panama Canal, up to Alaska .


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## stoneware (Jul 11, 2022)

Platinum and Early Photography​
Ian E. Cottington
The Johnson Matthey Group


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## Yggdrasil (Jul 12, 2022)

mphkdl said:


> RH is used in bearing cups of jet engines,because of high heat and wear tolerances. Also Rh in world war ll was used in cable that circled US, Atlantic and Pacific, for submarine detection. Yup from Nova Scotia ,through Panama Canal, up to Alaska .


I'm pretty sure those cables did not exist during WW2, which ended in 1945-46.
In the cold war on the other hand, you may be right, even if I fail to understand what Rhgodium should do in a cable other than make it next to impossible to produce. Maybe in sensors attached to the cables?
And cables through the Panama canal?? 
There is no reason what so ever for such cables there.

To me this sounds like a fairy tale.


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## nwinther (Jul 13, 2022)

mphkdl said:


> RH is used in bearing cups of jet engines,because of high heat and wear tolerances. Also Rh in world war ll was used in cable that circled US, Atlantic and Pacific, for submarine detection. Yup from Nova Scotia ,through Panama Canal, up to Alaska .


Thanks.
But what about before 1940? Like, in the early 20th century? Was it used for anything or just a trace element in platinum and silver?


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## nwinther (Jul 13, 2022)

Platz said:


> They used the make furnace heating elements from platinium rhodium wire. Intrestingly over time the furnace wires would volatilise slightly at high temperature and the Pt and Rh would coat the bricks near the coils with a layer of Pt and Rh!


Thank you for the information. These were electric furnaces, I suppose? What were their application?

And what about iridium and palladium? Any idea? Or maybe just ignored as trace elements in more important metals (Ar/Pt)?


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## nickvc (Jul 13, 2022)

Palladium was used to make white gold alloys and I believe iridium was used in arms manufacture to harden the alloys platinum main use in earlier times was in laboratory materials and for thermocouples, I’m sure there were some more used but they would be more esoteric I’m guessing .


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## Lou (Jul 13, 2022)

Os wasn't used much at all. It was basically used as the native alloy, osmiridium, for the tips of pens. That was about it. Someone made a contentious discovery (as in Mssr Matthey said he did it first before the American fellow) that cooking osmiridium with phosphorus at white heat made an material that could be cast and broken up and was harder than hell, which bode well for all sorts of applications needing really hard stuff back before carbide was discovered. 

Platinum used to be cheap and was fabricated into all sorts of chemical apparatus and stills. Having flattened out bars of it and forge welded it to itself and done all sorts of fun things with it, I'd have to say insofar as hand fabrication is concerned, platinum is the king of all metals. It can be TIG welded in air like a joke, flame welded in air like a joke, heated and annealed and beaten out into whatever. My idea of a happy retirement is a couple hundred ounces and an anvil to take out some frustration. 

Platinum rhodium alloy, as mentioned above, does have the curious tendency (as does Ir) of volatilizing at high temperature and coating the brick. I have personally seen this from the glass industry and from the crucible industry (making sapphire crystals and what not). Oxygen will slowly form PtO/RhxOy, IrO/O2 and that sublimates away from the metal. Years at high temperatures are required. Lots of interactions also occur if conditions are reducing or natural, with the formation of so called cermets between Pt and Pd and alumina, silica (especially) happening at high temperatures.


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## Platz (Jul 13, 2022)

nwinther said:


> Thank you for the information. These were electric furnaces, I suppose? What were their application?
> 
> And what about iridium and palladium? Any idea? Or maybe just ignored as trace elements in more important metals (Ar/Pt)?








The Design of Platinum-wound Electric Resistance Furnaces - technology.matthey.com







www.technology.matthey.com




This old article provides some more info on the high temperature furnace coils from the 50s. When I worked for JM there was a chap who posted articles about unusual pgm items and articles about precious metals on the internal interweb there. I will have a think if I can remember anything else interesting.


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## Platz (Jul 13, 2022)

Palladium chloride was given as a treatment for turbuclosis! I would imagine the platinum impurities were causing the side affects. It was also known to be a catalyst from Faraday and Humprey Davys work in the early 1800s. They used to use asbestos as a support routinley! The Wacker process in the 1950s was the first ever large scale homogenous catalyst plant using palladium chloride to catalyse the oxidation of alkenes to aldehydes. 
Iridium was used to make fountain pen tips, and crucibles for pure crystals formation. The refining route for iridium is complex and I doubt enough was made back then to have much of an industrial impact.


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## Alondro (Jul 13, 2022)

Osmium was used by the Wizard to make the Tin Man's heart, lol. ;]


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## nwinther (Jul 14, 2022)

Thank you all so much for your input.


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## Edlin (Jul 23, 2022)

Osmium was a catalyst used in the groundbreaking Haber process of making ammonia.


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