Palladium recovery/concentrating from mlcc's through mechanical means?

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Ian_B

Well-known member
Joined
Jul 15, 2007
Messages
148
Location
Canada
After finally being able to source Nitric acid at a somewhat reasonable price I have decided to return to this little hobby in a more laid back fashion. One of the areas I'd like to get into would be the Palladium and Silver recovery from mlcc.

I know that for mlcc's you want to find the older ones because you have a greater chance of having the caps with Palladium and Silver instead of Nickle and other base metals.

I had stumbled across this video showing a cross section of a mlcc showing the layers that the Palladium is distributed in (link below)
https://www.youtube.com/watch?v=U2k286UTZWU

It appears in that video that the Palladium metal is distributed as very thin layers on top of the ceramic kind of like the icing separating the layers of a cake. Through a little more research I found that density wise the Palladium is the metal with the highest density being 12.02 followed by Silver with 10.5. The remaining metals that I have research that can be/ are in these little guys are Copper 8.96, Nickle 8.9, Tin 7.3, & Possibly Lead 11.35 as well as other traces of other base metals. Ceramic I have found can be between 2-6 (wikipedia)

With that out of the way I was thinking of ways outside of what is well documented here on how to go at this problem the ways which are most documented are the melt first or treat with chemicals and then precipitate the Pd and Silver.

I hadn't seen any mention of mechanical methods and because of the density difference for the Palladium I was wondering about how well something like a shaker table or even miller table might work?

My idea would be to have the monolithic capacitors turned to fine powder via a ball mill and then slowly add them wet to either shaker table or miller table, then collect the concentrates.

I know this method wouldn't be the end all be all of recovery for 100% recovery but I'm wondering if it would at least be useful in helping to remove most of the unwanted base metals?(most importantly Tin) and the ceramic?

I don't currently have either of these tools available to me but thought I would start a discussion on the topic. What are your thoughts on the idea? or anything you might change/add?
 
It will not work - that is my opinion based on a simple fact that any Pd present in them is in form of a paste sandwiched in between layers of ceramic. You will have to make so fine powder of that ceramic that any shaker table would have a problem to separate that kind of material efficiently.
Smelting with lead and subsequent separation will be probably much better suited.
 
I agree with Pat on this it will not work with any decent efficiency, this material would to me appear an ideal candidate for smelting with copper and then been run through a copper cell with any values been in the slimes.
The slimes I would treat first with Hcl to remove the tin, this may dissolve some Pd so testing would be needed, then direct AR, this would create silver chloride which can be filtered out and recovered, an addition of sulfamic would reduce the lead which again could be filtered out and then cement the Pd with copper and harvest the Pd powder.
The one advantage of using the cell is you use sulphuric which is freely available leaving the hard to obtain and often expensive nitric for better uses.
I'm sure I have missed some detail or reaction so please feel free to correct my thoughts :shock: 8)
 
I would guess that the bonding material of the Pd and the ceramic is glass. Before firing, I would guess that both the ceramic greenware and the Pd thick film applied to it both contain a small amount of glass frit (maybe, 5%). When fired, the glass melts and it all fuses together. At least, that's how the traces on hybrid thick film circuits and ceramic IC packages are applied.

I would think this bonded glass would cause a problem when trying to liberate the Pd by grinding.
 
patnor1011 said:
It will not work - that is my opinion based on a simple fact that any Pd present in them is in form of a paste sandwiched in between layers of ceramic. You will have to make so fine powder of that ceramic that any shaker table would have a problem to separate that kind of material efficiently.
Smelting with lead and subsequent separation will be probably much better suited.

Yes but use a known quantity of Silver instead of Lead. No need to add another contaminant into the process. You can clean the tin off the solder joints with an HCL soak prior to melting.
 
Thank you for all of your inputs on this idea!

I might still attempt this method but if I do I would divide the starting material in half after milling it down to a homogeneous powder and process the other amount in the more conventional way of smelting with a collector metal. Then compare results to see first hand how well this idea works of mine (or doesn't) :)

Again Thank you and I'll report back on any results I come up with (or if anyone else tries please post your results)
 
anachronism said:
You don't need to bother comparing. The chemical leach doesn't get all the values.

That may very well be the case but I'd still like to see that first hand :)
 
anachronism said:
patnor1011 said:
It will not work - that is my opinion based on a simple fact that any Pd present in them is in form of a paste sandwiched in between layers of ceramic. You will have to make so fine powder of that ceramic that any shaker table would have a problem to separate that kind of material efficiently.
Smelting with lead and subsequent separation will be probably much better suited.

Yes but use a known quantity of Silver instead of Lead. No need to add another contaminant into the process. You can clean the tin off the solder joints with an HCL soak prior to melting.

Jon,
that may be little problematic in my opinion. My observation is that HCl not only dissolved solder points but actually disintegrated whole body. I was left with strange rectangle whitish foils floating around and some mud on the bottom. I did not investigate further these foils as at that time I was doing just RAM sticks but they may do have value in them. Most of what was in MLCC like silver and palladium was probably on the bottom but Pd being so fine probably dissolved in HCl too. That is why I think smelting may be the best idea to concentrate value. When used with lead it will help oxidize and get rid of tin, nickel and lead can be absorbed in bone ash crucibles so at the end only good stuff should remain.
I do have over 10 kilograms of them so I can bring some or all of them over and we can figure out something next time I see you.
 
That sounds like a plan. Maybe I'm doing something different with the HCl but I've only ever had them in HCL for a relatively short while to dissolve the solder.
 
It can be. Perhaps short exposure deal with just tin, nickel and copper. In my case, they were there few days. Anyway, I do have plenty to play with. :mrgreen:
 
anachronism said:
You WANT to see values being lost? Be my guest. :lol:

What are you on about? what sort of help is this comment giving? Yes I'm just going to have the material that runs off the shaker table or miller table go off and down the drain/ into the soil/ be thrown out... :roll: :lol: I never once said that the material from the mechanical and then chemical process wouldn't be saved for analysis (or processing with a collector metal) later. Nothing is going to be lost, first hand knowledge is going to be gained.
 
Well, Ian to be honest, you did not say that before. As it was mentioned Pd if present is in form of paste which is comprised of such small particles that I will have serious doubts that they can be separated in any shaker or miller table.
So if you really are going to save all material you intend to experiment with then perhaps no value will be lost apart from time. Which is a real value itself.
 
Ian_B said:
anachronism said:
You WANT to see values being lost? Be my guest. :lol:

What are you on about? what sort of help is this comment giving? Yes I'm just going to have the material that runs off the shaker table or miller table go off and down the drain/ into the soil/ be thrown out... :roll: :lol: I never once said that the material from the mechanical and then chemical process wouldn't be saved for analysis (or processing with a collector metal) later. Nothing is going to be lost, first hand knowledge is going to be gained.
I think it is a quite good answer. Since no one have tried your way and no one seems to think it would work (me included) it is just pointing out that you would probably just waste your time and money.

The density of the barium titanate is 6.
https://en.wikipedia.org/wiki/Barium_titanate

Not every post is directed to the original poster, it can also be directed to anyone else reading the same thread.
About one in ten comes back to report how the experiment turned out, I've seen a lot of threads like this. Someone comes with a new revolutionizing method that no one believes in, saying they will test it and then never reports back. To drive home the point that it's a waste of money and time in our view is beneficiary to the next person considering this method if you don't come back and report the result of this experiment.

In my view the particle size would need to be so small that it would never settle and then a shaker table is useless. The difference in density is also so small that it would complicate the process. Since the powder would take long time to settle it would work extremely slow as you can't put a lot of material through the table and the water speed needs to be extremely slow too.

Göran
 
Ian_B said:
anachronism said:
You WANT to see values being lost? Be my guest. :lol:

What are you on about? what sort of help is this comment giving? Yes I'm just going to have the material that runs off the shaker table or miller table go off and down the drain/ into the soil/ be thrown out... :roll: :lol: I never once said that the material from the mechanical and then chemical process wouldn't be saved for analysis (or processing with a collector metal) later. Nothing is going to be lost, first hand knowledge is going to be gained.
I think it is a quite good answer. Since no one have tried your way and no one seems to think it would work (me included) it is just pointing out that you would probably just waste your time and money.

The density of the barium titanate is 6.
https://en.wikipedia.org/wiki/Barium_titanate

Not every post is directed to the original poster, it can also be directed to anyone else reading the same thread.
About one in ten comes back to report how the experiment turned out, I've seen a lot of threads like this. Someone comes with a new revolutionizing method that no one believes in, saying they will test it and then never reports back (me included). To drive home the point that it's a waste of money and time in our view is beneficiary to the next person considering this method if you don't come back and report the result of this experiment.
And if you report success then we will be corrected.

In my view the particle size would need to be so small that it would never settle and then a shaker table is useless. The difference in density is also so small that it would complicate the process. Since the powder would take long time to settle it would work extremely slow as you can't put a lot of material through the table and the water speed needs to be extremely slow too.

To add about the discussion about HCl and MLCC:s, I had about 145g of MLCC:s soaking for weeks in HCl and some of them broke down into foil while some barium titanate recrystallized into small yellow crystals.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=51&t=18564

Göran
 
g_axelsson said:
[
I think it is a quite good answer. Since no one have tried your way and no one seems to think it would work (me included) it is just pointing out that you would probably just waste your time and money.

The density of the barium titanate is 6.
https://en.wikipedia.org/wiki/Barium_titanate

Not every post is directed to the original poster, it can also be directed to anyone else reading the same thread.
About one in ten comes back to report how the experiment turned out, I've seen a lot of threads like this. Someone comes with a new revolutionizing method that no one believes in, saying they will test it and then never reports back (me included). To drive home the point that it's a waste of money and time in our view is beneficiary to the next person considering this method if you don't come back and report the result of this experiment.
And if you report success then we will be corrected.

In my view the particle size would need to be so small that it would never settle and then a shaker table is useless. The difference in density is also so small that it would complicate the process. Since the powder would take long time to settle it would work extremely slow as you can't put a lot of material through the table and the water speed needs to be extremely slow too.

To add about the discussion about HCl and MLCC:s, I had about 145g of MLCC:s soaking for weeks in HCl and some of them broke down into foil while some barium titanate recrystallized into small yellow crystals.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=51&t=18564

Göran

Hello Goran, I completely understand what you are saying but again anachronism comment stating that if I WANT (Capitalized for emphasis on his part) to see my values being lost that I could be his guest with a laughing emoticon serves zero purpose to better the thread and only serves as a belittlement towards my personal comment that I want to experiment to see for myself first hand. His opinion was made perfectly clear in the posts prior to this one. If I am wrong in how I feel then I apologize however that's how that post came off to me in my opinion.

You generally have multiple buckets under a shaker table to collect the waste from the concentrates, and usually from what I have seen of miller tables you have them set up in a closed loop for the water with a basin under to collect the material that washes away so again no material would be lost.

Yes you're right some might consider the experiment a waste of my time, but this is a hobby and at the end of the day isn't every hobby just a waste of time? is reading a book a waste of time? some may say so and some may say not because they are learning something new... I'm of the same thought process If I experiment with this for myself then I am learning something new, if it doesn't work oh well. I'm still going to have the material I'm not planning on processing a metric ton of material either, it would only be maybe 200 grams divided in half with the first being processed in a more conventional way (after being turned to powder and mixed homogeneously). the other hundred grams after testing out the process I laid forward in my original would either treated wet, or smelt or send a sample of the concentrates with a sample from the "waste" off for assay to see how well a mechanical process might work.

I can tell you one thing though, I have wasted my time and money on much worse things in life (and I'm sure everyone else has also ) than the cost of some HCL and Nitric and a day or two of time for an experimental run of 200 grams of Mlcc's.

Again thank you for all of your thought processes and opinions.
 
Well if you ask for advice from people, and then decide and state that you're not going to follow it, your responses can range from people getting totally butthurt through to not answering or helping. You're perfectly entitled to ignore or refute advice. I'm perfectly entitled to make light of the situation rather than get annoyed.

Your being so annoyed about my not getting annoyed is a more than a bit daft - can we just move on? 8)
 
nickvc said:
I agree with Pat on this it will not work with any decent efficiency, this material would to me appear an ideal candidate for smelting with copper and then been run through a copper cell with any values been in the slimes.
The slimes I would treat first with Hcl to remove the tin, this may dissolve some Pd so testing would be needed, then direct AR, this would create silver chloride which can be filtered out and recovered, an addition of sulfamic would reduce the lead which again could be filtered out and then cement the Pd with copper and harvest the Pd powder.
The one advantage of using the cell is you use sulphuric which is freely available leaving the hard to obtain and often expensive nitric for better uses.
I'm sure I have missed some detail or reaction so please feel free to correct my thoughts :shock: 8)
I agree with pat as well. Umar (gold recovery) was on the right track with that one in his three part series on recovering metals from MLCC’s. Granted the third part of his series could’ve seen major improvements but pt 1 and 2 were pretty much spot on. Though it’s certainly possible to substitute lead for copper and cuplation for copper electrorefining if lead is something you want to avoid working with too much.
 
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