Refining MLCC´s for Palladium and Silver !

[Yggdrasil]

I'm familiar with the process of converting silver chloride to silver oxide. I have successfully performed it many times now. I was just wondering why not cement on copper instead of dropping silver chloride with HCL? But I think I know the answer. It's so you can next instead cement the Pd, if any, via copper cementation. Am I correct? And what do you mean I have milled and dissolved in nitric? Me? Have I milled? No. Have I dissolved in nitric? Yes, but the mlccs are not much dissolved much at all. So all are in the same shape more or less. But I'm currently working on a test batch of 20g. So this is me studying more. I'm learning the process on a small sample size as directed by forum members. Read, research forum, ask questions, videos. My research has shown me that sample sizes are the way to go. So thats what I'm doing. I've spent all day reading this stuff. Which can be quite difficult to a non chemistry mind or background. So terms and base knowledge I'm gathering as I learn. But I've been studying literally all day.

Well if you have not crushed/milled them into dust, almost all the values are still in there.
And it is time to read Orvis post regarding MLCCs or Kurtaks.

If you just convert to Silver Oxide then you are only half way, you need to convert the Oxide to elemental Silver, before you are finished.

And, Yes the reason to convert to Silver Chloride is to separate the Ag and Pd.
But there is still drag down so one need to clean/wash the Silver Chloride thoroughly.
Then cement out the Pd, this has to be done with aggressive stirring.

 

[Rreyes097]

Well if you have not crushed/milled them into dust, almost all the values are still in there.
And it is time to read Orvis post regarding MLCCs or Kurtaks.

If you just convert to Silver Oxide then you are only half way, you need to convert the Oxide to elemental Silver, before you are finished.

And, Yes the reason to convert to Silver Chloride is to separate the Ag and Pd.
But there is still drag down so one need to clean/wash the Silver Chloride thoroughly.
Then cement out the Pd, this has to be done with aggressive stirring.

I've been reading all that. And I've also read that crushed or milling isn't necessary. Because the leeching will get to it. But again that's why I'm doing a sample sized run. To learn the proper process for what I'm trying to accomplish. Which is I think just to go for the silver.

 

[Yggdrasil]

I've been reading all that. And I've also read that crushed or milling isn't necessary. Because the leeching will get to it. But again that's why I'm doing a sample sized run. To learn the proper process for what I'm trying to accomplish. Which is I think just to go for the silver.

Then you should know that that is completely depending on the composition of the ceramics.
Older will more likely decompose than newer.

So if the MLCCs are whole, they are not leached, if they smoulder to powder they may be.

And often HCl are better for attacking the Ceramics than Nitric.

That is the reason Orvi and Kurt are advocating the smelting route.

That route also starts with milling unless you have access to the beauties Orvi showed in his thread

 

[kurtak]

So if the MLCCs are whole, they are not leached,

This is absolutely correct

Kurt

 

[kurtak]

And I've also read that crushed or milling isn't necessary. Because the leeching will get to it

It may not be necessary to mill them - BUT - if you don't run the leaching process to the point that the ceramic turns to an ultra fine ceramic mud you have NOT leached all the Ag/Pd out of the ceramic

The Ag/Pd is layered/sintered in the ceramic - as the leaching dissolves the Ag/Pd the ceramic falls apart into ultra fine ceramic particles - leaving you with an ultra fine clay like mud

That mud is impossible to filter !!!!

Therefore you have to wash it with water (to get the leach values out) let the ceramic settle (that can take a day or more) - decant the wash - AND - you have to do multiple washes (3 or MORE) & even then you will never get all the values washed out - there will always be at least "traces" left behind

This results in VERY diluted solutions which means lots of evaporation is needed before going to recovery of the values from the leach/washing process

At every step of trying to leach MLCCs you are likely to lose at least some values

LOTS of chem waste - time wasted & values lost in leaching MLCCs

Smelting = MUCH less time MUCH less chem waste & MUCH better recovery

For what it is worth

Kurt

 

[kurtak]

Also - for what it is worth - I am still working with Lars100 "trying" to get his values back from the 33kg of MLCCs he leached --- that has been an on going "daily" project for 7 months now

We are now "finally" to a point of working on the recovery of the values from the leach - AND - we have no idea of how much values have been left behind in the ceramic mud &/or other waste

So we will have go back & test/assay all of that to see if it is worth going back to - to chase (because values are always left behind with leaching)

It is one thing to leach 1Kg MLCCs - but 33kg - what a mess !!!!!!!!!

if Lars had smelted those MLCCs he (we) would have been 6 months ago - had better recovery - used MUCH less chem - with MUCH less chem waste

The problem --- Lars (before coming to this forum) watched some "back yard hacks" leach MLCCs & followed the advice of those "back yard hack" - not realizing (at the time) just how bad the advice to leach MLCCs really is

IMO - even small batches should be smelted

Again - for what it is worth

Kurt

 

[kurtak]

But again that's why I'm doing a sample sized run. To learn the proper process for what I'm trying to accomplish.

Per the bold print - if you really want to learn the "proper process" - learn to smelt !!!!!

Leaching a small sample will give you results without to much problem/mess - BUT - that will most certainly lead you to believe - cool - now I can move up to leaching bigger batches - that will most certainly result in nothing other then bigger problems/messes

In other words - leaching (MLCCs) is a case where bigger is absolutely not better --- in fact - the bigger you go - the WORSE it gets !!!!

Which is I think just to go for the silver.

If you are going to go after the values in MLCCs - why in the world you go after "just the silver --- the real value is the Pd

Current silver value = 68 cents per gram

Current palladium value = $58.26 per gram

Kurt

 

[Rreyes097]

Per the bold print - if you really want to learn the "proper process" - learn to smelt !!!!!

Leaching a small sample will give you results without to much problem/mess - BUT - that will most certainly lead you to believe - cool - now I can move up to leaching bigger batches - that will most certainly result in nothing other then bigger problems/messes

In other words - leaching (MLCCs) is a case where bigger is absolutely not better --- in fact - the bigger you go - the WORSE it gets !!!!


If you are going to go after the values in MLCCs - why in the world you go after "just the silver --- the real value is the Pd

Current silver value = 68 cents per gram

Current palladium value = $58.26 per gram

Kurt

Because most of what I'm told I have( magnetic) has or most likely has no palladium. Gave me something to think about there.

 

[Geo]

Converting the silver to silver chloride is not just to chase the silver. It is actually part of the process of chasing the Pd. In a nitrate solution, both silver and Pd are in liquid form. If you cement on copper from here, you will still have silver and palladium mixed. If you add chlorine, the silver will turn into a solid (AgCl2) and will settle out or be filtered leaving palladium in solution effectively separating the two metals. The silver and it's recovery is secondary to the recovery of the Pd.

 

[Rreyes097]

Ok so I'll research smelting. But I'm not sure I have the proper equipment.

 

[orvi]

Ok so I'll research smelting. But I'm not sure I have the proper equipment.

Wet-leaching MLCCs is doable, Owltech has great video about it on YouTube. But overall process is far from nice and efficient. And also it is necessary to point out that unless the caps arent from the "good" ceramic material - namely barium titanate ceramics or other favourable types, they doesn´t even disintegrate in acids AT ALL. So nothing is achieved by this step in some cases.

Most likely, modern types are composites of titanates with alumina or zirconia, some wild niobium additives and other stuff. Acid attacks only leachable parts, leaving ultrafine TiO2, Al2O3 and ZrO2, which aren´t filterable and clog any filter, worse than metastannic acid. And decantation is a process where certain proportion of values is still trapped in the mud. So you need to repeat the process numerous times - insanely increasing volume of the solution = creating buckets and buckets of waste to be dealt with... Not nice.

Question is, do you want to continue with refining in the future ? I mean, serious refining. If your answer is yes, then invest in proper equipment. As probably all members here know, I am strong advocate for induction furnance. Small types going up to 7-8kW of real heating power are relatively cheap, selling under 800 bucks on Aliexpress. Despite the fact they are genuinely Chinese machines, they run nicely, and I never had any problem with them (actually we have two, one large 35kW one). And we abused them A LOT.

Practically ALL your casual melting can be done in an induction furnance. It is very energy effective heating device = proportion of heat used vs. necessary to attain the required temperature is very nice, compared to indirect heating techniques like using gas torch or gas furnance. With induction, your temperature limit is practically sublimation point of carbon = using graphite crucibles allow you to go sanely to like 2000°C. Then it burns too quickly in the air

So not only for copper, gold and silver. Palladium and platinum like a piece of cake. Even rhodium is nicely melted, when you insert the magnesia crucible inside the graphite one to prevent carbides formation. I do not say this is proper melting technique for these metals (and for Pd certainly isn´t), but much easier and "better" than bleeding with handheld oxy-acetylene, spitting half of the charge around the melt dish, even if you try to not to.

Think about it and I would suggest to give it a shot. 7kW is a LOT of power to be concentrated to one small crucible, so melting IS FAST. Ordinary melting of silver to 0,5-1kg ingots is done in order of minutes. Consistently, predictably, no metal contamination from the tip of the torch... Quite a lot of advantages

 

[Rreyes097]

Wet-leaching MLCCs is doable, Owltech has great video about it on YouTube. But overall process is far from nice and efficient. And also it is necessary to point out that unless the caps arent from the "good" ceramic material - namely barium titanate ceramics or other favourable types, they doesn´t even disintegrate in acids AT ALL. So nothing is achieved by this step in some cases.

Most likely, modern types are composites of titanates with alumina or zirconia, some wild niobium additives and other stuff. Acid attacks only leachable parts, leaving ultrafine TiO2, Al2O3 and ZrO2, which aren´t filterable and clog any filter, worse than metastannic acid. And decantation is a process where certain proportion of values is still trapped in the mud. So you need to repeat the process numerous times - insanely increasing volume of the solution = creating buckets and buckets of waste to be dealt with... Not nice.

Question is, do you want to continue with refining in the future ? I mean, serious refining. If your answer is yes, then invest in proper equipment. As probably all members here know, I am strong advocate for induction furnance. Small types going up to 7-8kW of real heating power are relatively cheap, selling under 800 bucks on Aliexpress. Despite the fact they are genuinely Chinese machines, they run nicely, and I never had any problem with them (actually we have two, one large 35kW one). And we abused them A LOT.

Practically ALL your casual melting can be done in an induction furnance. It is very energy effective heating device = proportion of heat used vs. necessary to attain the required temperature is very nice, compared to indirect heating techniques like using gas torch or gas furnance. With induction, your temperature limit is practically sublimation point of carbon = using graphite crucibles allow you to go sanely to like 2000°C. Then it burns too quickly in the air

So not only for copper, gold and silver. Palladium and platinum like a piece of cake. Even rhodium is nicely melted, when you insert the magnesia crucible inside the graphite one to prevent carbides formation. I do not say this is proper melting technique for these metals (and for Pd certainly isn´t), but much easier and "better" than bleeding with handheld oxy-acetylene, spitting half of the charge around the melt dish, even if you try to not to.

Think about it and I would suggest to give it a shot. 7kW is a LOT of power to be concentrated to one small crucible, so melting IS FAST. Ordinary melting of silver to 0,5-1kg ingots is done in order of minutes. Consistently, predictably, no metal contamination from the tip of the torch... Quite a lot of advantages

Wow lots to think about. I do intend to continue refining. And I have invested lots into the hobby. But money is right now so any money I put back into it needs to be made from it. With the mlccs I was just trying to learn the process. And while trying to learn said process I've encountered this ceramic and it's incredible power to lock up the filter. So I'm seeing the smelting as probably the way to go but now I have to learn and research a whole another aspect of refining. Would a electric furnace be enough? Until I can invest in all the equipment I need?

 

[orvi]

Wow lots to think about. I do intend to continue refining. And I have invested lots into the hobby. But money is right now so any money I put back into it needs to be made from it. With the mlccs I was just trying to learn the process. And while trying to learn said process I've encountered this ceramic and it's incredible power to lock up the filter. So I'm seeing the smelting as probably the way to go but now I have to learn and research a whole another aspect of refining. Would a electric furnace be enough? Until I can invest in all the equipment I need?

Practically speaking, kind of. Electric can´t go to that high temperatures, and past 1300-1400°C, most of the wiring simply erode and brake too quickly. You need to be able to re-wire the furnance, adding cost of the quality wiring, which isn´t cheap. So you will be kind of able to smelt the MLCCs, but not able to eg melt final refined palladium or platinum in it, or pyrometallurgically refine the Pd (which is the easiest way for rough cleaning).

 

[kurtak]

Would a electric furnace be enough?

If you are talking about electric furnace like this --------

https://www.vevor.com/melting-furna...c1af1e957fe7351f6a5c1&utm_content=Ad group #1
NO !!! --- they are ok for melting "pure" metals (but even then I do not recommend them - waste of money IMO)

They DO NOT work at all for smelting - the FIRST time you have a flux boil over (which IS going to happen) it destroys the heating elements

Edit to add; - they get hot enough to melt silver - barely hot enough (though they will) to melt gold - NOT hot enough to melt copper

If you are going to smelt you need ether a propane fired or induction furnace

Kurt

 

[orvi]

If you are talking about electric furnace like this --------

https://www.vevor.com/melting-furna...c1af1e957fe7351f6a5c1&utm_content=Ad group #1
NO !!! --- they are ok for melting "pure" metals (but even then I do not recommend them - waste of money IMO)

They DO NOT work at all for smelting - the FIRST time you have a flux boil over (which IS going to happen) it destroys the heating elements

Edit to add; - they get hot enough to melt silver - barely hot enough (though they will) to melt gold - NOT hot enough to melt copper

If you are going to smelt you need ether a propane fired or induction furnace

Kurt

As long as you want to obviate the correct solution to the problem, you will find yourself in even bigger mess correct greatly apply to the field of refining.

Induction has also one advantage - whole machine is practically separated from the place where you melt, coil being separated from the whole machine = you can nicely insulate the machine box from the heat produced = for sane power output rating, it never suffer from heat generated during melting or smelting. Folded aluminium foil mostly being completely enough to do the job perfectly.

If some boil-over DO occur in induction, you will likely just melt your insulation mineral wool with molten flux. In extreme case coil could possibly be damaged. But anyway, that is few bucks for new copper pipe nothing major. And by the way, it never occured to me to damage coil in a way I would need to replace it. Some coils we use are in service for more than 4-5 years - working hard over those years

 

[Rreyes097]

Practically speaking, kind of. Electric can´t go to that high temperatures, and past 1300-1400°C, most of the wiring simply erode and brake too quickly. You need to be able to re-wire the furnance, adding cost of the quality wiring, which isn´t cheap. So you will be kind of able to smelt the MLCCs, but not able to eg melt final refined palladium or platinum in it, or pyrometallurgically refine the Pd (which is the easiest way for rough cleaning).

Mine goes to 2000°Fv how much is that in centigrade? Either way it sounds like it's not hot enough.

 

[orvi]

Mine goes to 2000°Fv how much is that in centigrade? Either way it sounds like it's not hot enough.

Yup, you are right. Barely enough to melt gold. 2000F is around 1090 °C. You need to go more to the range of 1400-1500°C. That is around 2500F and more. Electric tabletop furnance does not gonna make it

 

[Rreyes097]

As long as you want to obviate the correct solution to the problem, you will find yourself in even bigger mess correct greatly apply to the field of refining.

Induction has also one advantage - whole machine is practically separated from the place where you melt, coil being separated from the whole machine = you can nicely insulate the machine box from the heat produced = for sane power output rating, it never suffer from heat generated during melting or smelting. Folded aluminium foil mostly being completely enough to do the job perfectly.

If some boil-over DO occur in induction, you will likely just melt your insulation mineral wool with molten flux. In extreme case coil could possibly be damaged. But anyway, that is few bucks for new copper pipe nothing major. And by the way, it never occured to me to damage coil in a way I would need to replace it. Some coils we use are in service for more than 4-5 years - working hard over those years

My electric furnace burnt it's heating element within the first 2 to 3 months. So yes I know first hand that they are cheap.

 

[Rreyes097]

Yup, you are right. Barely enough to melt gold. 2000F is around 1090 °C. You need to go more to the range of 1400-1500°C. That is around 2500F and more. Electric tabletop furnance does not gonna make it

Yeah I realized that when I went to melt some gold and it only got hot enough by adding another torch. but I'm not it about to buy a new one right now. I just lost my job because of not enough work to be had. So I got laid off.

 

[orvi]

My electric furnace burnt it's heating element within the first 2 to 3 months. So yes I know first hand that they are cheap.

That is why I am advocating for permanent solution to much of the pyro-work. Reliable, robust, effective and able to melt anything you will likely encounter, even vaporize carbon if you feel like it