Processing Ruthenium Resistors

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!

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!

Click to expand...

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

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


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

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:

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.

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.

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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

PlainsScrapper said:

decided to avoid this carcinogenic metal.

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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.

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

Platdigger said:

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

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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.

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.

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.

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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.

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

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.

924T said:

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

Click to expand...

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.

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.

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

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.

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

RuO2 can be dissolved in alkalis.

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.

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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.

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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?

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