# Extraction of palladium from Russian potentiometer



## Alexander_Hun (Aug 11, 2022)

Hello!

I have collected many Russian potentiometers, the following is written about them:

The content of precious metals in the PPML-M-1 potentiometer is as follows: 2.47 grams of alloy with 80% palladium content. The practical content may differ downwards. The exact price will only be determined after the product has been disassembled.

There are many types with 20% palladium content, I have not processed palladium yet, is the process the same as for gold? What can go wrong, what should I watch out for?

Thank you

LINK

LINK2


----------



## orvi (Aug 11, 2022)

Alexander_Hun said:


> Hello!
> 
> I have collected many Russian potentiometers, the following is written about them:
> 
> ...


It could be significant to know what the rest of alloy is. Processing palladium differs from gold quite a bit. Most of the times, palladium is found alongside silver in AgPd alloys - and I assume rest of your Pd alloy will be Ag.
So you cannot use AR to dissolve it.
Most general way is to dissolve alloy in hot nitric acid, then drop the silver as silver chloride. Filter or decant silver chloride and wash it really well - it tend to lock the Pd inside the precipitate (you recognize not white but yellowish-brownish colour of ppt). Also, use just right ammount of HCL or salt water to drop the silver - PdCl2 has low solubility in water and could co-precipitate with AgCl even more.

When you obtain Ag-free solution, you will best proceed with formate reduction. You add formic acid to the Pd solution, adjust pH to 2 with sodium hydroxide or carbonate (lots of stirring necessary to break lumps of base metals hydroxides to redissolve them back) and then heat past 80°C, best to nearly simmer the solution. It takes quite a time, but you will start to clearly see CO2 bubbles arising from solution and precipitate formation, together with colour change from Pd brownish red to blue (if copper is present) or colourless (if it was just PdAg alloy). Whole process can take from half hour to few hours on heat.
In the end, test the solution with DMG for Pd presence.
Also, depending on quantity of material, you can use DMG for very quick and very effective scavenging of Pd from solution as yellow Pd-DMG salt. For nitrate solutions, it does not need to be dissolved in anything, just spoon it in and let it stirr well for half hour or so.
Filter the solution, collect the Pd-DMG precipitate and then process the silver - if there is any in solution. Incineration of the PdDMG complex is easiest way, but you will always have losses due to evaporation of superfine Pd (GOOD VENTILATION IS A MUST). It could also be redissolved in ammonia and Pd could be dropped with HCL as salt.

Be safe with PGMs, they are toxic and potent allergens. Unnoticed for very long time, until it´s too late. Proper hood, gloves, face shield and other PPE are must.

P.S.: Be careful surfing on these russian sites, they are very often full of viruses and malware.


----------



## Alexander_Hun (Oct 1, 2022)

orvi said:


> It could be significant to know what the rest of alloy is. Processing palladium differs from gold quite a bit. Most of the times, palladium is found alongside silver in AgPd alloys - and I assume rest of your Pd alloy will be Ag.
> So you cannot use AR to dissolve it.
> Most general way is to dissolve alloy in hot nitric acid, then drop the silver as silver chloride. Filter or decant silver chloride and wash it really well - it tend to lock the Pd inside the precipitate (you recognize not white but yellowish-brownish colour of ppt). Also, use just right ammount of HCL or salt water to drop the silver - PdCl2 has low solubility in water and could co-precipitate with AgCl even more.
> 
> ...


Hi!


I'm answering late, now I'm faced with something that I have to choose palladium and platinum separately. They are Russian capacitors with a fairly high content of palladium, with a little platinum.
What chemicals will I need?

Thanks!


----------



## eaglekeeper (Oct 1, 2022)

Sreetips has some excellent YouTube videos covering this topic.... *Like* and *subscribe* to his channel.


----------



## orvi (Oct 3, 2022)

Alexander_Hun said:


> Hi!
> 
> 
> I'm answering late, now I'm faced with something that I have to choose palladium and platinum separately. They are Russian capacitors with a fairly high content of palladium, with a little platinum.
> ...


Very tough material for refining. Complex matrix, lots of stubborn elements in solder, containing cadmium... Barium titanate ceramics...
Thing is how you are gonna recover the metallic fraction in the first place  efficiently. Owltech has videos covering this toppic, I very recommend to watch them.

And I strongly recommend you to just sell the alloy you get after simple treatment. If it is mixed lot, there would also be platinum ones, and you will get alloy, typically 1:3 to 3:1 Pdt - dont bother to separate Pd and Pt, sell it how you get it.
*edit: never thought that Pd: Pt without space would abbreviate like this


----------



## Alexander_Hun (Oct 3, 2022)

orvi said:


> Very tough material for refining. Complex matrix, lots of stubborn elements in solder, containing cadmium... Barium titanate ceramics...
> Thing is how you are gonna recover the metallic fraction in the first place  efficiently. Owltech has videos covering this toppic, I very recommend to watch them.
> 
> And I strongly recommend you to just sell the alloy you get after simple treatment. If it is mixed lot, there would also be platinum ones, and you will get alloy, typically 1:3 to 3:1 Pdt - dont bother to separate Pd and Pt, sell it how you get it.


Hi!

Until then, the process would be perfect for me, a mixture of palladium and platinum, until then I just need to learn the process.


----------



## orvi (Oct 3, 2022)

Alexander_Hun said:


> Hi!
> 
> Until then, the process would be perfect for me, a mixture of palladium and platinum, until then I just need to learn the process.


I work with this material quite a bit, and I can say you that it is many times great pain to accomplish good recovery with low-end equipment. And we do have induction furnance - without it, pyrometallurgy of PGMs and stubborn ceramics is nearly impossible to do conveniently.

You can go with wet route, but for this you need to strip the resin of the capacitors either by burning them (evolving very toxic volatile CdO as yellow fumes) or stripping with solvent like DMSO. But for thick resin coated ones this is rather tedious, and you need to do it one by one with knife or pliers. Very tiring, tedious job.
Then you need to dissolve the ceramics in boiling HCL (producing very toxic barium chloride leachate you need to dispose as very toxic waste + dissolved PbCd from the solder, yummy). You will consume liters of HCL to dissolve ceramics from just one kg of caps.
And in addition, many times you obtain insoluble residue of the ceramic, which is very painful to filter after foils dissolution in AR.

Better option for easier recovery is to smelt the ceramics. But for proper decomposition of ceramics, you need to go past 1300-1400 °C to liquify titanate ceramics with suitable flux - powdered silica. There are also other options for sure, but this is very convenient. You need to shot right ammount of silica to strike an eutectic mixture, because if you add little or overadd, you obtain very viscous, non-eutectic slag which will always trap the values inside. And it is hard to resolve it with addition of literally anything - one component will tend to come out as insoluble solid, which will in turn transform to an expensive nightmare rock 

And after smelt, you obtain metallic ingot consisting of PGMs, mostly copper and solder - BiPbSnAg. Very tough to process this multicomponent dore - either in nitric (due to tin and platinum) or in AR (due to Pb and Ag forming solid chloride coating on the surface).

Very nice material in terms of PGM content, very stubborn to actually process. Every shortcut or lowering the smelt temperature will significantly lower the recovery of PGMs.

And on top of all this, you want to resolve Pt and Pd... Trust me, if you will be done with this whole torture, you wont be willing to fall into another rabbit hole without proper knowledge and equipment. Speaking as full time chemist with more than 9 years of professional lab experience.


----------



## Alexander_Hun (Oct 3, 2022)

orvi said:


> I work with this material quite a bit, and I can say you that it is many times great pain to accomplish good recovery with low-end equipment. And we do have induction furnance - without it, pyrometallurgy of PGMs and stubborn ceramics is nearly impossible to do conveniently.
> 
> You can go with wet route, but for this you need to strip the resin of the capacitors either by burning them (evolving very toxic volatile CdO as yellow fumes) or stripping with solvent like DMSO. But for thick resin coated ones this is rather tedious, and you need to do it one by one with knife or pliers. Very tiring, tedious job.
> Then you need to dissolve the ceramics in boiling HCL (producing very toxic barium chloride leachate you need to dispose as very toxic waste + dissolved PbCd from the solder, yummy). You will consume liters of HCL to dissolve ceramics from just one kg of caps.
> ...


Hi! I don't want to separate it, but I wrote it, but I have 16,000 pieces of the capacitor shown in the picture. The table reads: Platinum 0.00952
Palladium : 0.0356 grams per piece


----------



## orvi (Oct 3, 2022)

Alexander_Hun said:


> Hi! I don't want to separate it, but I wrote it, but I have 16,000 pieces of the capacitor shown in the picture. The table reads: Platinum 0.00952
> Palladium : 0.0356 grams per piece
> View attachment 52443


I don´t think you get that much from single piece of these KMs. These are palladium predominantly, but cut caps have around 40-60g Pd depending on type and year of manufacture. But these are the smallest types, where there is much much more solder and copper legs weight than for the larger pieces. 
Cut the legs from them tightly. Worthless material that will dilute PGMs evven more.

If you do not have furnance that can go past 1350 °C, do not go with smelting route. Focus on stripping the resin coating with solvent, then dissolve the solder and decompose ceramics in boiling HCL.
But bear in mind you will create liters and liters of very toxic Ba,Cd,Pb,Cu chloride waste, that NEED TO BE PROPERLY DECONTAMINED and disposed responsibly. If you pour it down the drain, you will kill all living things in sewer facility and they will investigate it for sure  If you pour it down stream of some river, every fish will turn belly up. I am not joking, this is very serious thing and you need to know the chemistry behind. 

Think about it, read the forum, espetially waste treatment sections/threads.


----------



## Alexander_Hun (Oct 3, 2022)

orvi said:


> I don´t think you get that much from single piece of these KMs. These are palladium predominantly, but cut caps have around 40-60g Pd depending on type and year of manufacture. But these are the smallest types, where there is much much more solder and copper legs weight than for the larger pieces.
> Cut the legs from them tightly. Worthless material that will dilute PGMs evven more.
> 
> If you do not have furnance that can go past 1350 °C, do not go with smelting route. Focus on stripping the resin coating with solvent, then dissolve the solder and decompose ceramics in boiling HCL.
> ...


Hi! I also process gold, that too with a lot of chemicals. There is exhaust, a gas mask, etc... The Internet says this about this type:

Type


----------



## orvi (Oct 3, 2022)

Alexander_Hun said:


> Hi! I also process gold, that too with a lot of chemicals. There is exhaust, a gas mask, etc... The Internet says this about this type:
> 
> Type


Do not trust Internet  sometimes there are OK values, sometimes surreal numbers. Highest yield of green KMs I encountered was 70g/kg, large military green KMs H90. Weigh 10 tightly cut caps, figure weight of the one. 
Gas mask won´t help you much. And exhaust will poison your neighborhood in case you intend to incinerate them.


----------



## Alexander_Hun (Oct 3, 2022)

orvi said:


> Do not trust Internet  sometimes there are OK values, sometimes surreal numbers. Highest yield of green KMs I encountered was 70g/kg, large military green KMs H90. Weigh 10 tightly cut caps, figure weight of the one.
> Gas mask won´t help you much. And exhaust will poison your neighborhood in case you intend to incinerate them.


I appreciate the help, but there is no need to assume that everyone is irresponsible and will kill themselves and those around them. I am asking to learn, preferably as much as possible, so that in the end I can decide whether to start the process. I'm not young, I can decide what I dare to stand up for and what I prefer to neglect.


----------



## orvi (Oct 4, 2022)

Alexander_Hun said:


> I appreciate the help, but there is no need to assume that everyone is irresponsible and will kill themselves and those around them. I am asking to learn, preferably as much as possible, so that in the end I can decide whether to start the process. I'm not young, I can decide what I dare to stand up for and what I prefer to neglect.


OK.


----------



## Alexander_Hun (Thursday at 1:57 PM)

orvi said:


> I don´t think you get that much from single piece of these KMs. These are palladium predominantly, but cut caps have around 40-60g Pd depending on type and year of manufacture. But these are the smallest types, where there is much much more solder and copper legs weight than for the larger pieces.
> Cut the legs from them tightly. Worthless material that will dilute PGMs evven more.
> 
> If you do not have furnance that can go past 1350 °C, do not go with smelting route. Focus on stripping the resin coating with solvent, then dissolve the solder and decompose ceramics in boiling HCL.
> ...


Hi, if I can solve the high temperature, what is the procedure?
I've seen videos where they put silver next to it and melt it together, etc... The point is that I don't want to separate the palladium, I can take it to a company that deals with this and they can separate it.

thanks


----------



## orvi (Thursday at 2:46 PM)

Alexander_Hun said:


> Hi, if I can solve the high temperature, what is the procedure?
> I've seen videos where they put silver next to it and melt it together, etc... The point is that I don't want to separate the palladium, I can take it to a company that deals with this and they can separate it.
> 
> thanks











Processing old MLCCs - disclosed process


Also, I have traced one pattern which to this day work for me 100% - but I do not say there aren´t exceptions. Look for the colour and "metallic shine" of cracked ceramic of MLCC. I did stumbled across some MLCCs which were white in colour of ceramic - and these were just silver. All PGM...




goldrefiningforum.com





This is my post about my way of processing these capacitors. Fairly detailed I think. As I tend to write things down properly (scientific deviation  ), even if they didn´t turned good/perfect.

Silver is used to lower the melting point of the PGM alloy for better and more complete cupellation step. If you desolder the legs and solder properly, you can end up with ca 40-60% PGM alloy in the end. Rest being silver, bit of tin, and then lead and bismuth from the ceramic. That is typical.

Thing is if you can attain temperatures past 1300°C with ease (induction will do most conveniently without excessive burning of the graphite crucible), you does not need to add any collector, as there are enough metals to collect into nice little button, after some time and stirring to coalesce when molten. 

When you add more metals in, you will need to deal with these metals afterwards. That is why I like to have it all nicely concentrated, and working with less chemicals in lower volumes of liquid. Saves time and money.


----------



## Alexander_Hun (Thursday at 3:57 PM)

orvi said:


> Processing old MLCCs - disclosed process
> 
> 
> Also, I have traced one pattern which to this day work for me 100% - but I do not say there aren´t exceptions. Look for the colour and "metallic shine" of cracked ceramic of MLCC. I did stumbled across some MLCCs which were white in colour of ceramic - and these were just silver. All PGM...
> ...


I understand, thanks, I plan to melt the thing with an oxygen propane mixture. So if there is enough capacitor, there is no need to add extra metal? I'll solder his legs off in front of him.


----------



## orvi (Thursday at 4:12 PM)

Alexander_Hun said:


> I understand, thanks, I plan to melt the thing with an oxygen propane mixture. So if there is enough capacitor, there is no need to add extra metal? I'll solder his legs off in front of him.


Note that at these high temperatures, you will find the resulting slag very corrosive to the ordinary clay crucibles, not to mention silica dishes - do not use quartz dishes. I don´t know if the clay crucibles are capable to withstand such temperatures without structural disintegration.
Practically only solutions for this are either graphite or MgO (and even MgO would be attacked to some extent, but nowhere near silica or clay).

With oxypropane, hard to say how difficult it would be and how much of the crucible would burn out. How much of them you have ? If max 100-200g, that would be OK. But more, it can be difficult to melt whole lot with one oxypropane, altough high power burner could be capable of this chore. 

Try smaller sample, say 20-30g to observe how it will go. And use crucible of appropriate size to collect metal bead - if too large crucible would be used, metal coalesce badly and there are many small beads instead of one - tedious to get them cleanly separated.


----------



## Alexander_Hun (Thursday at 4:29 PM)

orvi said:


> Note that at these high temperatures, you will find the resulting slag very corrosive to the ordinary clay crucibles, not to mention silica dishes - do not use quartz dishes. I don´t know if the clay crucibles are capable to withstand such temperatures without structural disintegration.
> Practically only solutions for this are either graphite or MgO (and even MgO would be attacked to some extent, but nowhere near silica or clay).
> 
> With oxypropane, hard to say how difficult it would be and how much of the crucible would burn out. How much of them you have ? If max 100-200g, that would be OK. But more, it can be difficult to melt whole lot with one oxypropane, altough high power burner could be capable of this chore.
> ...


OK thanks, it says oxygen propane flame temperature 2200 degrees, I have a regular large industrial oxygen bottle and a large industrial flame welder.
Since the metal is thin on the ceramic, don't you have to worry about me vaporizing it with high heat? I will make 100 pieces as a sample, there are 8,000 of them, they are quite small, but there is a picture of them above in the post. In principle, these are of very good quality.


----------



## orvi (Thursday at 4:36 PM)

Yeah, you will obviously need to hit it with flame inside the crucible. From outside, you will just bore a hole to the side  graphite burns quite quickly at these high temperatures. Start lightly to cake the top, and only if it all start to liquify at the top, approach closer with the flame. Your intention is nevertheless heat the whole container, not only superheat one little spot on top of the charge. 

Be careful and try not to overheat the tip of the burner - welding burners aren´t built for such intense radiating heat from all sides - I seen tips melted few times, and flashbacking the flame pretty terribly, shattering whole weakened tip of the burner to tidbits. Insulate crucible well with mineral wool to speed up the preheat.


----------



## Alexander_Hun (Thursday at 4:41 PM)

orvi said:


> Yeah, you will obviously need to hit it with flame inside the crucible. From outside, you will just bore a hole to the side  graphite burns quite quickly at these high temperatures. Start lightly to cake the top, and only if it all start to liquify at the top, approach closer with the flame. Your intention is nevertheless heat the whole container, not only superheat one little spot on top of the charge.
> 
> Be careful and try not to overheat the tip of the burner - welding burners aren´t built for such intense radiating heat from all sides - I seen tips melted few times, and flashbacking the flame pretty terribly, shattering whole weakened tip of the burner to tidbits. Insulate crucible well with mineral wool to speed up the preheat.


Thanks, the capacitors don't have to be ground then? Can I remove the legs and bake?


----------



## orvi (Thursday at 4:46 PM)

yes. incinerate the varnish, or strip it with solvent, then desolder legs, put them into crucible, add measured ammount of silica and bake it slowly to temperature.


----------



## Alexander_Hun (Thursday at 4:56 PM)

orvi said:


> yes. incinerate the varnish, or strip it with solvent, then desolder legs, put them into crucible, add measured ammount of silica and bake it slowly to temperature.


Silica? What role does it play in the process?


----------



## orvi (Yesterday at 12:09 AM)

Alexander_Hun said:


> Silica? What role does it play in the process?


Read that post


----------

