# Processing Ruthenium Resistors



## PlainsScrapper (Mar 2, 2014)

I just joined the forum about a week ago, and I am wondering what would be the best way to process the ruthenium and silver form the SMD resistors.
I have come up with a process and if I should modify anything to improve my yield.
1. Ruthenium contains Ag solder, so I will dissolve the solder in concentrated nitric acid to make silver nitrate (AgNO3). Then, I will use heavy gauge Cu wire to precipitate the silver onto the wire, then I will purify the powder with borax while melting.
2. Then I will crush the resistors and dissolve the powder into HCl, then precipitate the Ru with ammonium chloride.
Is there anything I missed? If so, comments would be appreciated. Note, I am still collecting the resistors, so I would like to ensure that the process will go smoothly. Thanks!


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## jimdoc (Mar 2, 2014)

PlainsScrapper said:


> I just joined the forum about a week ago, and I am wondering what would be the best way to process the ruthenium and silver form the SMD resistors.
> I have come up with a process and if I should modify anything to improve my yield.
> 1. Ruthenium contains Ag solder, so I will dissolve the solder in concentrated nitric acid to make silver nitrate (AgNO3). Then, I will use heavy gauge Cu wire to precipitate the silver onto the wire, then I will purify the powder with borax while melting.
> 2. Then I will crush the resistors and dissolve the powder into HCl, then precipitate the Ru with ammonium chloride.
> Is there anything I missed? If so, comments would be appreciated. Note, I am still collecting the resistors, so I would like to ensure that the process will go smoothly. Thanks!



Have you mastered the art of gold and platinum refining?
What makes you confident enough to move on to ruthenium?
Do you understand any of the hazards you will encounter?

Jim


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## necromancer (Mar 2, 2014)

Stay Tuned, this sounds like it's going to get interesting.............


PlainsScrapper wrote:
"I just joined the forum about a week ago, and"


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## niteliteone (Mar 2, 2014)

You might also check the cost (value) of the items you are wanting to process. (resistors)
They run a few for a penny, New :shock: 
So how many do you think you will have to process just to pay for the chemicals required to process them :?: 
Think hundreds of pounds :roll: 

I wouldn't even think of doing it without a proper fume hood with reaction scrubber to protect the neighbors from the deadly fumes you will be making. :shock:


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## PlainsScrapper (Mar 6, 2014)

Well I just realized that what I wrote was wrong. Ruthenium is immune to hydrochloric acid, and that the best method to dissolve this metal is with ordinary household bleach.  Also, I think that it is too much work for so little metal, unlike gold or silver. Also, thank you jimdoc, necromancer, and niteliteone, for all your helpful insight, and have decided to avoid this carcinogenic metal.


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## kurtak (Mar 7, 2014)

PlainsScrapper said:


> Well I just realized that what I wrote was wrong. Ruthenium is immune to hydrochloric acid, and that the best method to dissolve this metal is with ordinary household bleach.  Also, I think that it is too much work for so little metal, unlike gold or silver. Also, thank you jimdoc, necromancer, and niteliteone, for all your helpful insight, and have decided to avoid this carcinogenic metal.



PlainsScapper

bleach alone will not dissolve any of the platinum group metals -it is used along with HCL to make what we call "poor mans AR" - the bleach (chlorine) is a substitute oxidizer for nitric acid which is normally used in AR - it works slower then nitric to dissolve metal & so is used when nitric is hard or expensive to get - there are also "some" process applications where it may be a better choice --- my point being you have a lot to learn before you start asking questions here - start by spending several week searching & reading here on the forum & by all means download & read Hokes book which is a free download here on the forum - learn to use the search feature --- once you do as suggested you will be able to start asking questions we can actually help you with because you will then have a better idea of what you are talking about

Also here is a link to the resistors I believe you are talking about - the silver is not in the solder --- http://goldrefiningforum.com/phpBB3/viewtopic.php?f=34&t=9138&hilit=resistors#p86806 

Kurt


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## necromancer (Mar 7, 2014)

PlainsScrapper said:


> decided to avoid this carcinogenic metal.



that is great, we strive for safety here on the forum, just remember that taking a small amount of time to research might save you a lot of time at the doctors office.

i am sure if you cant find what you need elsewhere just asking for help & letting us know (safety may be a factor) you will get much help from many of the members here.

on this forum we have chemists, miners, refiners and more that have doing it for a great many years.


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## Platdigger (Mar 7, 2014)

Kurt, evidently bleach will dissolve ruthenium, and if made more alkaline, then even better.


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## Irons (Mar 7, 2014)

Platdigger said:


> Kurt, evidently bleach will dissolve ruthenium, and if made more alkaline, then even better.



Bleach and Hydrogen Peroxide under Vacuum. Ruthenium is extremely toxic. I have worked with it in the past and prefer not to in the future.

Ruthenium poisoning is something you will never forget. It will make you fear for your life.


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## Marcel (Mar 8, 2014)

The amount of ruthenium is rather small in resistors, only some very old types had traceable amounts in them. But if you collect SMD resistors from recent electronics it is very unlike, that you will find detectable amounts of it. So apart from teh dangers that were mentioned here, I doubt that the hunt for ruthenium is somewhat profitable at all.


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## bmgold2 (Mar 8, 2014)

Marcel said:


> The amount of ruthenium is rather small in resistors, only some very old types had traceable amounts in them. But if you collect SMD resistors from recent electronics it is very unlike, that you will find detectable amounts of it. So apart from teh dangers that were mentioned here, I doubt that the hunt for ruthenium is somewhat profitable at all.



What do you consider recent electronics? Everything I have been able to find about the SMD resistors has shown that the most common types DO contain ruthenium oxide. Since the quantity of these parts would have to be a lot to be worth processing, even a tiny amount of ruthenium per part could be dangerous.

In this link, SMD resistor discussions, there are some links about these resistors and the possible danger. I've been avoiding processing these parts due to the possible ruthenium.


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## 924T (May 5, 2014)

Ah, Ruthenium.

I've never met it, and already I don't like it!

I've got some MLCC's that are mixed with SMD resistors, and I'm keenly interested in getting the resistors
out of the mix, so that I can experiment with processing the capacitors, safely.

How can this be achieved?

I searched on the internet, and the only specific gravity figures I've come across so far show the SMD
resistors to have a SG of around 1.5, and the MLCC's to have a SG of around 2.25-2.5.

I'm not sure that's enough of a Specific Gravity differential to separate them with a wave table.

And, unfortunately, the resistors I'm dealing with, being all from XP and newer equipment, are just as
magnetic as the MLCC's, so I can't separate them with magnetism.

I found a thread on the forum that revealed that Ruthenium is bad news when exposed to high heat
or strong acids, so that rules out incineration or pyrolysis, and also boiling in HCl or Aqua Regia.

So, I'm stumped at this point.

Has anyone done this (separating SMD resistors from MLCC's) successfully?

I'm open to any/all thoughts/ideas on this, because it's definitely not worth the time it would take to
sit at a graphics light table and manually sort them out.

Cheers,

Mike


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## Irons (May 5, 2014)

At less than $100 US per Troy Oz, Ruthenium is not worth bothering with unless it is a byproduct of refining PGMs. Even then, it's recovery is due, in part because it interferes with the recovery and purification of other PGMs. Osmium is another of the same ilk.


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## Irons (May 5, 2014)

924T said:


> Ah, Ruthenium.
> 
> I've never met it, and already I don't like it!
> 
> ...


I don't think incineration would be a problem. In the Metallic State, It's very inert and likely to be just part of the insolubles left over after Digestion of the other Elements.


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## MarcoP (Aug 16, 2014)

While reading about the possibility of processing MLCC and SMD resistors together I come across this thread, and after reading http://en.m.wikipedia.org/wiki/Ruthenium I come to agree with Irons:



> Osmium, ruthenium, rhodium and iridium can be separated from platinum and gold and base metals by their insolubility in aqua regia, leaving a solid residue.


As long is kept away from ammonium, should it be safe?


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## MarcoP (Aug 17, 2014)

Further reading and soon found out that thick film SMD resistors contains RuO2, not Ru, which instead cannot stand in any acid. My intention was to clean each motherboard from the few inductors and other very tiny SMD components, sand bath and sieve. This way I would have had in my hands only MLCC and SMD resistors to process together, saving me a lot of time.

I wasn't interested in recovering Ru, just avoiding it, but I do was interested in the little Ag and Pt in them to mix with Ag and Pd coming from MLCCs.


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## kjavanb123 (Aug 17, 2014)

I have always been curios why grinding followed by gravity separation never been discussed or mentioned as a processing methods for ICs or SMDs? Since you do not deal with chemicals.

Regards
Kevin


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## Lou (Aug 17, 2014)

RuO2 can be dissolved in alkalis.


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## MarcoP (Aug 18, 2014)

kjavanb123 said:


> I have always been curios why grinding followed by gravity separation never been discussed or mentioned as a processing methods for ICs or SMDs? Since you do not deal with chemicals.


ICs and SMDs will have base metals legs/frames/welding joints, plastics, ceramic and values stored in micron-sized wirings and layers, some trapped in epoxy.
Grinding will literally pulverize the micron-sized values and shred down chunks of other values with or without being still attached to base metals by any means.
Values will end up everywhere and even still trapped in epoxy. You will be using more acids to process load more materials and still end up loosing some values.
This has been already discussed in other threads  however something to *note *is that RuO2 is found in SMD thick film resistors in dust-powder form and by grinding them you will free this as highly toxic dust into the air for you and your neighbors to breath.

ICs and other SMDs are best processed separately for better yelds. SMD tick film resistors are best to be avoided due to Ruthenium Oxide presence.



Lou said:


> RuO2 can be dissolved in alkalis.


My main concern now is how to reach the RuO2 powder without using any acid (normally used to remove base metals) or oxidizers that would change it into RuO4.
Probably incineration in a closed system with ammonium scrubber and a series of ammonium washes/incineration for solids could be something to think about, but again high heat is to avoid with RuO2 so not even incineration would work?


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## kjavanb123 (Aug 18, 2014)

I was thinking using multi mesh classifier screens, then gravity separation each sieve sizes separately. I am going to run a sample soon and post results.

I have seen posts that members used grinders to pulverize ICs then use panning to successfuly get the gold bonding wires, so it might be working with SMDs.

Thanks
Kevin


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## Rougemillenial (Dec 16, 2016)

kurtak said:


> PlainsScrapper said:
> 
> 
> > Well I just realized that what I wrote was wrong. Ruthenium is immune to hydrochloric acid, and that the best method to dissolve this metal is with ordinary household bleach.  Also, I think that it is too much work for so little metal, unlike gold or silver. Also, thank you jimdoc, necromancer, and niteliteone, for all your helpful insight, and have decided to avoid this carcinogenic metal.
> ...


Ok. That idea of using poor mans AR to dissolve ruthenium is really bad. One, the temperature increase will easily cause the detonation of the RuO4. In theory the RuO4 would be reduced with the hydrochloric acid to form Ru+4 ions though it would have to be kept at below-10C in order to prevent a runaway reaction. Attempting the two reactions at once is probably is asking for trouble. Cutting corners to save steps could end up with a long time spent at the doctor's office. One word of warning with ruthenium is that ruthenium is carcinogenic. Those who wish to refine ruthenium really should invest in a glove box kind of like what they use in the NNL in Scotland. That's really your only way to ensure your safety. My recommendation would be to crush the SMDs up and fire them under say litharge to collect the metal to the bottom. Then cuple it like they do in fire assays. Then the bead remaining can be sold or refined. the reason for the fire assay is to remove ceramic which would adsorb the ruthenium ions in solution. Also once the ceramics are removed and it's a metal bead it can be dissolved under far more controlled conditions if you wish to refine it. Another reason is that the ruthenium in the SMD's is not elemental. It's Ru+4 oxide which unlike Ru+8 ions is a black solid instead of an explosive liquid more toxic than cyanide. Hope this helps. Sincerely, Rougemillenial


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## Lou (Dec 16, 2016)

I agree that Ru isn't worth the time or the risk for the hobbyist. Especially @ $40/oz in the pure form at present market conditions. 

And yes, it's immune to pretty much every aqueous solvent but hypochlorite. AR won't touch the pure stuff, even as powder. Mix it with other PGMs and some synergism happens and it will dissolve to varying degrees. The danger with the NaOCl digestion is when it is acidified because bleach often contains chlorate (especially when it gets heated) and that makes chlorine when added to HCl. Off then comes the RuO4 as a distillate. That usually gets collected in KOH traps. The whole "explosion" thing is due to chlorine dioxide produced from the chlorate acidification--in clean apparatus, the RuO4 can be redistilled in a current of air without decomposition. 

I don't know how carcinogenic it is (never saw any IARC studies or listing, so please enlighten me if you have references) but I would treat any soluble metallic compound with great care.


FYI rougemillenial, Ru/Os/Ir/Rh have really poor solubilities in lead. Ir and Os probably the worst, in fact one can prepare pretty nice Os, Ir and alloys of the two from recrystallizing in molten lead! 

Here's a great link to some Ru chemistry:

http://woelen.homescience.net/science/chem/exps/ruthenium/index.html

The ruthenium (IV) oxide present in the escrap does not dissolve well in bleach. It has to be prereduced back to metal first.


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## PlainsScrapper (Dec 18, 2016)

Lou said:


> I agree that Ru isn't worth the time or the risk for the hobbyist. Especially @ $40/oz in the pure form at present market conditions.
> 
> And yes, it's immune to pretty much every aqueous solvent but hypochlorite. AR won't touch the pure stuff, even as powder. Mix it with other PGMs and some synergism happens and it will dissolve to varying degrees. The danger with the NaOCl digestion is when it is acidified because bleach often contains chlorate (especially when it gets heated) and that makes chlorine when added to HCl. Off then comes the RuO4 as a distillate. That usually gets collected in KOH traps. The whole "explosion" thing is due to chlorine dioxide produced from the chlorate acidification--in clean apparatus, the RuO4 can be redistilled in a current of air without decomposition.
> 
> ...





Rougemillenial said:


> kurtak said:
> 
> 
> > PlainsScrapper said:
> ...



I understand what both of you mean. Way too much trouble for me to deal with it. I found out about this component on youtube, so I just hope other people on youtube that know about the ruthenium in surface mount resistors not process them, as the danger is just too great for most people to be worth the end product. Both of your comments are greatly appreciated.


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## Rougemillenial (Feb 12, 2017)

ruthenium is an interesting metal. though, if I needed ruthenium for something I'd probably just buy it. unless you have large quantities and the equipment/ experience to make the process doable which means that your garage isn't the place, I would not suggest trying it. I wouldn't go the bleach route either way. i'd probably use 200C lye solution under pressure to dissolve ceramics, tin, zinc, etc. then dissolve iron, copper, nickel etc. in HCL/H2O2. then you're left with rhenium, platinum, ruthenium, gold, silver, rhodium among other things. then use aqua regia to dissolve the gold, rhenium, and platinum. then dissolve the rhodium with molten sodium bisulfate as rhodium sulfate. then oxidize the ruthenium dioxide to sodium ruthenate using molten sodium peroxide.


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