# Are Ruthenium Thick Film Resistors Worth It ?



## RLS0812 (Nov 19, 2018)

I have noticed that a lot of modern electronics have ruthenium oxide resistors.
Is it actually worth the time and money attempting to recover the metal ( $ 265 /oz ) from such small components ?
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https://i.postimg.cc/KvmmwyV5/Ruthenium-Resistor.jpg
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## Lou (Nov 19, 2018)

No one really buying low grade Ru right now...all refiners fat and happy on targets


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## Buckly (Feb 4, 2022)

I have the same question as I pick these off of mother boards, LT's, etc.


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## Elemental (Feb 4, 2022)

You could look at selling them on e-bay to other hobby refiners. If you have a good idea of how much expected metal they have per unit of weight (2 grams of metal per 100 grams of resistors (*THIS IS JUST AN EXAMPLE AND NOT A CORRECT ESTIMATE*), you can use that to set your price point.

Elemental


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## Buckly (Feb 5, 2022)

Already tried the E-Bay route with no success. That's why I asked here...


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## Dizzious (Feb 5, 2022)

Smt resistors have decent Silver content. A few years ago 999Dusan made a youtube video where he got a good Ag yield from a bunch of them.


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## orvi (Feb 5, 2022)

Dizzious said:


> Smt resistors have decent Silver content. A few years ago 999Dusan made a youtube video where he got a good Ag yield from a bunch of them.


Possible value in Ru is probably higher than silver value. But if nobody wants them, silver recovery maybe the only way how to squeeze something out of them. 
However, refining material with Ru is much more difficult and possibly very hazardous and toxic operation. For little payout.


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## samuel-a (Feb 5, 2022)

Lou said:


> No one really buying low grade Ru right now...all refiners fat and happy on targets


And paste leftovers


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## Dizzious (Feb 8, 2022)

orvi said:


> Possible value in Ru is probably higher than silver value. But if nobody wants them, silver recovery maybe the only way how to squeeze something out of them.
> However, refining material with Ru is much more difficult and possibly very hazardous and toxic operation. For little payout.


Are the hazards with Ru refining the same as with the rest of the PGMs, or more dangerous? I don't think I've ever heard of someone actually recovering Ru from e-scrap.
As for the Dusan video, it's here if anyone is interested - 
His yield comes to 25.3g per kg silver. 
AFAIK the Ru in smt resistors is under the black resin-coated part, and it looks like the resin coating was still on the resistors after he processed them. Maybe the resin protected most of the Ru from dissolving in his AR step? It makes me wonder if the trace Pt he detected was actually a tiny bit of Ru. I don't know anything about Ru though, maybe it's not soluble in AR or detectable with stannous ::


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## FrugalRefiner (Feb 8, 2022)

Dizzious said:


> AFAIK the Ru in smt resistors is under the black resin-coated part, and it looks like the resin coating was still on the resistors after he processed them.


Dizzious, please don't use text lingo here. It is against our Rules. Many of our members do not speak English so they have to rely on translators. Translators can't always handle text lingo well, so they could create a dangerous misunderstanding.

Dave


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## orvi (Feb 8, 2022)

Ruthenium could be oxidized by some chemicals and could be leached into solution mainly by alkali oxidants. It is stated that ruthenium is completely insoluble in nitric acid and also AR.
Ruthenium compounds, particulary in high oxidation states are highly toxic. RuO4 could be produced, which has boiling point of only 40°C - this is extremely hazardous. 
I worked in lab with it, and it was generated in situ from RuCl3 and oxidant as sodium periodate. Freaky stuff, everything organic in close proximity of the reaction vessel turned black...


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## Svaethger (Aug 19, 2022)

Dizzious said:


> Are the hazards with Ru refining the same as with the rest of the PGMs, or more dangerous? I don't think I've ever heard of someone actually recovering Ru from e-scrap.
> As for the Dusan video, it's here if anyone is interested -
> His yield comes to 25.3g per kg silver.
> AFAIK the Ru in smt resistors is under the black resin-coated part, and it looks like the resin coating was still on the resistors after he processed them. Maybe the resin protected most of the Ru from dissolving in his AR step? It makes me wonder if the trace Pt he detected was actually a tiny bit of Ru. I don't know anything about Ru though, maybe it's not soluble in AR or detectable with stannous ::



Dusan was very lucky to not have a serious incident with that.. HNO3, from what I’ve read, is a powerful enough oxidiser to convert RuO2 to the extremely toxic RuO4. RuO4 is very volatile and also detonates just over 100•C (108?) which makes its recovery very problematic. Certainly a no go for the hobby. 

From seeing the video I believe most of the Ru was converted to RuO4 and likely escapes into the wind.. very bad luck if anyone was downwind of that. Ruthenium is a whole other level of danger to the usual Pd, Pt, Rh.

I am looking into other options, such as conversion to Sodium ruthenate and whether the oxide will dissolve in HCl alone to produce a soluble chlororuthenic acid. There’s little info on this even in textbooks on the subject I’ve read.

Note: I am not intending on trying any of this with Ru, I’m just working on the theory.


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## eaglekeeper (Aug 19, 2022)

I don't have any experience in pyrometallurgy. But can these be smelted and use the Ag present as a collector metal, then sell as Dore?


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## Svaethger (Aug 20, 2022)

eaglekeeper said:


> I don't have any experience in pyrometallurgy. But can these be smelted and use the Ag present as a collector metal, then sell as Dore?


I haven’t seen anyone try it, but smelting with Bismuth and Silver, with Iron or carbon as a reducing agent in (10:1) in appropriate flux, then cupelling into a Ag dominant dore. Dissolution of the dore in HNO3 will get silver, and any Pt trace (as will be less than 5%), you should be left with a black powder of mainly Ru with a small amount of Ir and Re, which could be alloyed with a small amount of Cu to get a bead of Cu,Ru,Ir,Re. The mp of Ru, Ir, Re are too high (all above 2200C) to cupel the Cu off properly without an oxyacetylene torch, or two, but that could still be sellable? 

I know the majority of Pt will dissolve with the silver, not sure about the Ir. Re will dissolve in hot conc. HNO3 to form perrhenic acid HReO4, which has wildly different chemistry to what the majority of us are used to, but room temp HNO3 shouldn’t dissolve much, it would be a trace not worth recovering unless doing kilos and kilos anyway, so I wouldn’t bother. 

It’s a shame we can’t go straight to HCl/Cl2 on them as all the Ir would be dissolved as H2[IrCl6], but no way of avoiding RuO4 with any level of chlorine with RuO2  
RuO2 also catalysis the reaction of 2HCl -> H2 + Cl2, so just HCl is also not an option sadly. 

Just theoretical, but so far looks most promising to recover the Ru without any chance of RuO4 production that I am aware of.


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## eaglekeeper (Aug 20, 2022)

Svaethger thanks for the info.

Do you think the Ag dominant dore be sold as is and get paid on the PGM percentages...Thanks


(I'm still debating whether they are worth the hassle.)


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## Svaethger (Aug 20, 2022)

eaglekeeper said:


> Svaethger thanks for the info.
> 
> Do you think the Ag dominant dore be sold as is and get paid on the PGM percentages...Thanks
> 
> ...


No problem eaglekeeper,

I don’t have any experience with selling enriched dores to know, but I imagine most would only pay for the Ag, might have luck selling to someone of here who can properly process Ru though. I read somewhere the resistors should be about 2% Ag and 0.3%(+) Ru by weight, somewhere around there. 

Metalsdaily.com says Ru is currently around $19/g so if 0.3% 1kg = 3g Ru = $57, + 20g Ag roughly at 2%. 
Personally I would still dissolve the dore in nitric and redissolve the Ru powder leftover in Cu, I imagine someone would be willing to buy the Cu/Ru alloy, most likely a large markdown from spot though :/. I’ve seen a lot on this forum with people struggling to get good prices on PGM alloys in small quantities.


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## orvi (Aug 20, 2022)

Svaethger said:


> Dusan was very lucky to not have a serious incident with that.. HNO3, from what I’ve read, is a powerful enough oxidiser to convert RuO2 to the extremely toxic RuO4. RuO4 is very volatile and also detonates just over 100•C (108?) which makes its recovery very problematic. Certainly a no go for the hobby.
> 
> From seeing the video I believe most of the Ru was converted to RuO4 and likely escapes into the wind.. very bad luck if anyone was downwind of that. Ruthenium is a whole other level of danger to the usual Pd, Pt, Rh.
> 
> ...


I doubt that by processing via HNO3 or AR, ruthenium get oxidized from metallic state. NurdRage has one video on YouTube where he attempted dissolution of Ru in AR with no luck - as expected and stated in literature. I have no experience myself on trying that. Yeah, if you already have some oxidized Ru, RuO2 or something like that, it could be possible from my perspective. But if it is just Ru metal, I think acid oxidation will be at least very sluggish and hardly proceeding.

And to the selling Ru dore... I am pessimistic about the outcome. Most of the PM buyers also struggle to come with fair prices for more "valued" PGMs like PtPdRh... We had no luck with attempted sell of Ir - we also had quite a bit of it, not tens of grams - more. But we did not found buyer here willing to buy it - they didn´t make a quotation on it. So for metals like Os and Ru, I don´t know. Same as selling Ni or Co, even in few hundred kilograms ammounts - no interst from bigger guys. With mixed NiCuSnPb concentrates, even for free, nobody was willing to take them even on ton scale.

So if you know about some Ir buyers, I am more than willing to talk about it


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## Svaethger (Aug 20, 2022)

orvi said:


> I doubt that by processing via HNO3 or AR, ruthenium get oxidized from metallic state. NurdRage has one video on YouTube where he attempted dissolution of Ru in AR with no luck - as expected and stated in literature. I have no experience myself on trying that. Yeah, if you already have some oxidized Ru, RuO2 or something like that, it could be possible from my perspective. But if it is just Ru metal, I think acid oxidation will be at least very sluggish and hardly proceeding.
> 
> And to the selling Ru dore... I am pessimistic about the outcome. Most of the PM buyers also struggle to come with fair prices for more "valued" PGMs like PtPdRh... We had no luck with attempted sell of Ir - we also had quite a bit of it, not tens of grams - more. But we did not found buyer here willing to buy it - they didn´t make a quotation on it. So for metals like Os and Ru, I don´t know. Same as selling Ni or Co, even in few hundred kilograms ammounts - no interst from bigger guys. With mixed NiCuSnPb concentrates, even for free, nobody was willing to take them even on ton scale.
> 
> So if you know about some Ir buyers, I am more than willing to talk about it


Hi orvi,

A few years back I bought a 1.8g bead of 99.98% Ir from eBay, I’m sure I’m not the only one who would want such an item, so it could be worth making some 1-2g beads and trying to eBay them as a test? I’ve looked since out of curiosity to whether there’s anymore and didn’t seen anything over 0.4g on multiple occasions, so 1-2g may arouse some interest on there. 

The density of that metal.. I’ve had a lot of fun blowing friends minds over how a thing so small can be so heavy, a lot of fun haha.


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## Svaethger (Aug 20, 2022)

Is anyone aware of whether small amounts of Ir or Ru would follow the potential small amount of Pt into solution with the silver? I can’t say I have any experience with that and the literature rarely even mentions the Pt following the silver into solution with HNO3, let alone Ir or Ru. 
To mention again this procedure I’ve talked about is just theoretical.


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## eaglekeeper (Aug 20, 2022)

orvi said:


> I doubt that by processing via HNO3 or AR, ruthenium get oxidized from metallic state. NurdRage has one video on YouTube where he attempted dissolution of Ru in AR with no luck - as expected and stated in literature. I have no experience myself on trying that. Yeah, if you already have some oxidized Ru, RuO2 or something like that, it could be possible from my perspective. But if it is just Ru metal, I think acid oxidation will be at least very sluggish and hardly proceeding.
> 
> And to the selling Ru dore... I am pessimistic about the outcome. Most of the PM buyers also struggle to come with fair prices for more "valued" PGMs like PtPdRh... We had no luck with attempted sell of Ir - we also had quite a bit of it, not tens of grams - more. But we did not found buyer here willing to buy it - they didn´t make a quotation on it. So for metals like Os and Ru, I don´t know. Same as selling Ni or Co, even in few hundred kilograms ammounts - no interst from bigger guys. With mixed NiCuSnPb concentrates, even for free, nobody was willing to take them even on ton scale.
> 
> So if you know about some Ir buyers, I am more than willing to talk about it


Thanks.... more info to think about if they are worth it.

For those that haven't seen it.


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## orvi (Aug 21, 2022)

Svaethger said:


> Is anyone aware of whether small amounts of Ir or Ru would follow the potential small amount of Pt into solution with the silver? I can’t say I have any experience with that and the literature rarely even mentions the Pt following the silver into solution with HNO3, let alone Ir or Ru.
> To mention again this procedure I’ve talked about is just theoretical.


Yeah, I leaned it myself when doing experiments on parting PtPdRh mixtures. Pt is also soluble in plain nitric, and so is Rh, if they are finely divided. They all react with acid, but Pt and Rh much much slower than Pd. They quickly reach equilibrium point, where they stop dissolving (maybe it has something with stability of Pt nitrate salts in solution). If present alloyed in something, that is completely different story. As far as I know, Ir and Ru are more resistant to acid attack. But this may be too general, and there could be some exceptions. 
As you say, not a lot of chemistry of PGMs is known for general public. Lots of secret research has been done in private companies and refineries regarding mainly separation of them.


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## Hombressino (Aug 22, 2022)

orvi said:


> I doubt that by processing via HNO3 or AR, ruthenium get oxidized from metallic state... Yeah, if you already have some oxidized Ru, RuO2 or something like that, it could be possible...


Generally true, but I believe Svaethger meant RuO2 in the sentence _"From seeing the video I believe most of the Ru was converted to RuO4 and likely escapes into the wind.."_ Ruthenimu in Thick Film Resistors is already in RuO2 form, as far as I know.


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## Svaethger (Aug 22, 2022)

Hombressino said:


> Generally true, but I believe Svaethger meant RuO2 in the sentence _"From seeing the video I believe most of the Ru was converted to RuO4 and likely escapes into the wind.."_ Ruthenimu in Thick Film Resistors is already in RuO2 form, as far as I know.


Yeah, to clarify, I meant the Ru in the resistors is already RuO2, not metallic, and both HNO3 and Cl2 will oxidise RuO2 further into RuO4, which is very volatile. RuO2 will also reduce HCl to Cl2, so that’s not a good option either. As the RuO4 is volatile, I believe dusan evaporated most of his Ru as RuO4 and that’s why he couldn’t recover any, either way to where it went, his method with resistors was quite frankly suicidal in this regard and should not be replicated.


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## kurtak (Aug 22, 2022)

Svaethger said:


> quite frankly *suicidal* in this regard and should not be replicated.


 And the bottom line is --- *JUST DON"T DO IT*

Kind of like adding acid to cyanide - *JUST DON"T DO IT*

Kurt


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