# Problem with Pd from MLCC



## kilo17 (Feb 23, 2013)

Hello.... I performed the recovery of 250 grams of MLCC's exactly like the tutorial on Gold-N-Scrap. It went smoothly until the Zinc additions where I have a black precipitate with a "fluffy" gray precipitate. I have 2 sources of Zinc and tested them for cab-o-sil by putting some in HCL and there wasn't anything that didn't go into solution. If anyone has a suggestion I would appreciate it. I have tried adjusting the pH slightly with HCL additions but as soon as I do I get a positive Stannous test. Thanx in advance....Keith


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## kilo17 (Feb 24, 2013)

Well I have managed to salvage a lot of it. I ended up stirring the mixture and decanting and leaving the blacks, which I rinsed with water and then with HCL. I then added HCL to the solution to change the color and then adding Zinc and decanting and leaving the blacks. I repeated the steps several times until the Pd:Zinc ratio dropped off tremendously. Here is what I have ended up with:


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## Marcel (Feb 24, 2013)

What did you use to dissolve the Pd? 
Pic 1 shows a lot of *nickel* in your solution if I am not wrong. Remember: The least noble metal dissolved is always on top of the solution. The solution on the botton may already be precipitated Pd or Pd that has precipitated on the outside of the zinc particles, passivating them. 
That makes 3 metalls: Ni,Pd,Zn and therefore not the standard for a clean precipitation.
I have played a lot with MLCCs last year and I think there are better ways of extracting Pd. First you should sort the MLCCs and remove all that are magnetic. They contain nickel instead of Pd. If you are sceptical you could run two batches but dont mix them.
Pic 2 looks ok but murky, maybe still impurities involved.
Dont use nitric in early stages when the Pd is impure, it will make it very difficult to process if you want to wash it with HCl later. Use HCl until the very end, just when refining you could maybe use nitric, but it is not needed. Hot HCl alone dissolves Pd! 

Marcel


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## kurt (Feb 24, 2013)

Marcel said:


> First you should sort the MLCCs and remove all that are magnetic, they contain nickel instead of Pd.
> Marcel



Marcel - I have never processed any MLCCs but have a couple pounds of them that I may get to some day - I thought the electrodes on the ends of them (where they are soldered to the board) were made of nickel & the Pd was in the ceramic - so they would all be magnetic --- or am I wrong?

Kurt


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## Marcel (Feb 24, 2013)

@kurt: There is 2 types of material used in MLCCs: BME and PME = base metal electrodes and precious metal electrodes.
If an MLCC is a BM type , there will be no PMs in there. The others have silver and Pd.





It was said here in this forum that BM MLCCs also can contain silver, but that should be an exeption.
BM electrodes was introduced in the late 1990s, so MLCCs from early 1990s and 1980 most likely are made with PMs in them.
Using the magnet is an easy way to detect nickel and seperate the batches into high-yield and low yield.

The correct term for the parts where the components are soldered to the board is "terminal". The _electrodes_ are inside the capacitor.

Nice info here:
http://www.johansondielectrics.com/...aining/basics-of-ceramic-chip-capacitors.html


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## lazersteve (Feb 24, 2013)

I use Acid Peroxide on my MLCC's that contain Pd: 

0. Test a small sample for Pd before processing, not all MLCC contain Pd.
1. Remove base metals with 15% HCl.
2. Crush (optional)
3. Cover with 32%+ HCl and heat slightly in covered dish with stirring, adding a few milliliters of 35% H2O2 as need to keep the reaction going. Stop peroxide additions when only a white powder remains in the colored solution. Don't over do the peroxide additions, you only need enough to keep a gentle fizzing going.
4. Filter the solids out until only the 100% transparent liquid remains. The solution should be an orange brown to deep burgundy colored and *free of any* particulate. 
5. Slowly add aluminum foil in small strips with stirring to the solution. The aluminum will precipitate the Pd as a sponge. Aluminum does not precipitate nickel from solution.
6. Filter out the sponge and refine a second time using AP, this time precipitating with Sodium Chlorate (or chlorine gas) and ammonium chloride (or potassium chloride). 
7. Purify the colored Pd salt as see here: Purifying Pd Salts
8. Calcine the purified colored salt or reduce with hydrazine, formic acid, or your favorite reducing agent.
9. Filter the sponge out and melt under an oxy/hydrogen flame.

You'll have a lot of work in those little buggers and a whole lot of nasty wastes, so be responsible when you go to dispose of them.

Steve


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## kilo17 (Feb 24, 2013)

Thank you for all the input, I spent a lot of time just trying to salvage what I could. I definitely like the AP idea....I definitely will properly dispose of the waste... Thank you again. Keith


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## kurt (Feb 25, 2013)

Marcel - Steve - thanks for the info - will have to go over them with a magnet & see what I have

Marcel - do you have any recovery data on what to expect from a pound of the Pd (non magnetic) MLCCs

Kurt


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## kilo17 (Mar 2, 2013)

Marcel, thank you for the info.... I have 5.5# of them and I put a magnet to them and about 0.5# were nickel... I sure am glad I didn't do the whole batch at once.... Keith


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## lazersteve (Mar 2, 2013)

Kevin,

The magnet trick is not 100% reliable as the MLCC's with Pd still use nickel in the end contacts. I would test a small sample of the magnetic ones just to be sure you are no tossing components that contain Pd.

Steve


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## kilo17 (Mar 3, 2013)

I was excited to see some fruits for my efforts (and maybe a little luck)... it's not much but it's nice to see... thanx Steve and Marcel for helping me out... keith


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## Marcel (Mar 4, 2013)

Wow, must be very clean Pd, I have never seen it so red?? Maybe Steve can say more about it, since my Pd was always greyish.
Concerning the yield: Today I have received a final analysis of 15 Kg of MLCCs. The Pd content was disappointing 0,31% only. I am still looking into it, but the batch consisted of 2Kg SMD MLCCs and 12,5 Kg THT (wired) MLCCs. 
Watch out when melting the Pd:
1. Palladium will quickly oxidize when heated under the influence of oxgen. The losses are tremendous! The Pd starts to "burn" like sparklings from iron powder. A clean process should not have oxgen involved in the gas. 
2.Molten palladium is able to dissolve carbon! I read that in a book for goldsmiths. So beware of having any carbon/organic material in your cruicible or within the process. It will make the Pd dull. I have experienced that since I took some paperfilters with Pd powder in them and melted it. No problem with gold, but the palladium became very dark and brittle. No way to remove this stuff later on.

edit: concerning the photos: is this dried Palladium(II)chlorite?


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## kilo17 (Mar 4, 2013)

That picture was taken after dropping it with Sodium Chlorate. It took a couple of tries for me to get the Ammonia Chloride concentration correct. It would precipitate and then with another crystal it would dissolve again. I ended up concentrating it more and adding a bit of 15% Ammonia Chloride and it precipitated perfectly.. Keith


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## pezosandor (Mar 10, 2013)

Steave, nice method to recover Pd. "Post by lazersteve on February 24th, 2013, 8:21 pm"

How you can get out the Ag from the MLCC whit the process?
Most case (99%) the Pd MLCC are made from alloy 70%/30% or 80%/20% Ag/Pd. 
At step 5, you cementing using Aluminum. The Ag will also drop out in the same time with the Pd ?
If this is the case, as My knowledge, with the AR I could separate the Ag from the Pd... thats clear.

Zoli


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## lazersteve (Mar 11, 2013)

Silver remains in the solids that are filtered out before adding the aluminum. Silver is not dissolved by this reaction. It can be recovered by your favorite method to extract silver. 

Steve


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## pezosandor (Mar 11, 2013)

Thank you Steve.

It s a nice work around  
Then the left over solid can be treated separately, by extracting poor silver
I'm gone receive 450Gram of brand new poor Ag/Pd MLCC, in a few day, and try the step by step process.

Kindly regards 
Zoltan


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## ericrm (Mar 12, 2013)

lazersteve said:


> I use Acid Peroxide on my MLCC's that contain Pd:
> 
> 0. Test a small sample for Pd before processing, not all MLCC contain Pd.
> 1. Remove base metals with 15% HCl.
> ...



Steve, on the second sentence you say that crushing is optionnal. do that mean you did it both way and came with the same yield/effiency? completely removing Pd from non crushed capacitor?

also i have tryed the magnet tricks (neodymium in my case) and 100% of my capacitor are magnetic witch make me believe that there is definitively enuf nickel in palladium capacitor to make them stick too.


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## lazersteve (Mar 12, 2013)

I have run them both ways, crushed and not crushed. The only difference I have found is that the crushed ones are leached free of values quicker. Personally, I take the slow route, set up the reaction and let it sit until all of the components have turned to powder. I add small increments of peroxide until I don't see any more bubbling. I stop adding peroxide when I do not see any more gray colored material mixed in the white sludge and all of the components are fully dissolved.


Steve


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## kilo17 (Mar 16, 2013)

Steve I have been adding small additions of 12% peroxide for 36 hours on low heat. It immediately turns orange/red and then as the reaction slows it turns green, I suspect nickel. Two questions, can bleach be used in place of the peroxide? And can aluminum be used regardless of what's used to dissolve the palladium (Nitric, Peroxide, bleach)? thanx in advance... Keith


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## kilo17 (Mar 16, 2013)

It wasn't 30 min after the last post and with the next addition it finally turned orange....


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## lazersteve (Mar 17, 2013)

You can use bleach if you like, but peroxide does not form salts (sodium chloride) like bleach will. I would not think the aluminum would be a good idea if nitric is used unless the pregnant solution is throughly denoxxed first.


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## kilo17 (Mar 17, 2013)

Thanks Steve, the reason I ask is I finished a batch of 1000 mg of MLCC's and started a second batch and calculated the amount of peroxide I needed incorrectly and ran out midway through the second batch. I wasn't sure if I should use bleach or nitric to complete the reaction. My first thought was to use Nitric Acid because I know it is used frequently with peroxide, but wasn't sure if I used bleach to finish out the reaction if I would complicate things. Keith


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## pezosandor (Apr 21, 2013)

Hello all.

Probably I got Silver in the solution 
I eliminated base metal first.
Then I heated(not boiled) in AP (As Stevie propose ) I received, a orange/brown/and red solution, the color has depended from the among of OH in the solution as expected. At filtering I accidentally diluted it, so I thought I'm gone evaporate some water from the solution.
For the night "extra", I putted it to a Ice bath, to let settle the particle, which has remind in the solution after filtering. Today morning bigger heavy whit crystals has settled on the bottom.

I decent the solution, and started to evaporate some water. As I evaporated more and more water, slightly transparent/orange /red crystals started to build up. At one point, the solution was liquid,and as I steered, and it cooled down, the hole thing started to be dense crystallized, as I heated, it has dissolved. Accidentally fully crystallized it, so I needed to dissolve the crystals. 
I was curious ... I used 30% household HCl, the crystallization started to earl, the color was orange/red, not dark red-brown as for the PdCl2 was expected. 
I thought there was something not right.
It has dissolved easily in water(maybe because it was not fully dray) or maybe because of the high concentration of HCl or maybe the household HCl contained Na, and NaCl was present in the solution -"But its impossible.".

I added some tech Nitric acid, and HCl, then diluted it with water, heat it again to evaporated some water, and to fully dissolve the crystals. 
On the bottom, clean whit crystals started to collect.. see pic.

So I think Steve's solution extract some Silver to.
Now I got a orange solution with white particles init.
I let it settle over night, let see what is happening.


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## lazersteve (Apr 21, 2013)

Did you process a small test batch first to confirm Pd was present?

The substrate layers of most ceramic capacitors is barium titanate and it can form large plate-like crystals from concentrated solutions. I do not see any evidence of Pd in the photos you posted. The white powder may be titanium dioxide. If it is silver chloride it will change to a deep purple color in bright sunlight.

Steve


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## pezosandor (Apr 22, 2013)

Hello Stieve 

The MLCC was band new, and with Pd/Ag inner electrodes.
I collected some silver chloride from the first settling after filtering, and put-it on sunlight, and it turned do pure metal.
So there is Pd in it. 
I have built a gas washer , and put it between the Vakum pump and the filter flask.
Now the 1-1,5l liquid witch was in the Gas washer contained 15-20 gram of baking soda (NaHCO3) to reduce and protect the vacuum pump from the chlorine gas.
The sucing tube has dropped of, and some Liquid has got in to the solution. witch I had tray to evaporate.
And so the history has begone 

Yesterday evening I added some more nitric acid, not much, and this is Wat I received after settling it for the night:


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## pezosandor (Apr 22, 2013)

This is how its looks like when it heated to 78-80C, at evaporation state.
http://upload.wikimedia.org/wikiped...achloropalladate_ions_in_aqueous_solution.jpgPicture of Palladium chloride from wiki:

I thinking about to tray to Cement the Pd with Zinc.


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## kilo17 (Apr 24, 2013)

Here is the final product after purifying the Pd powder twice by the method outlined by Steve and Lou... thanx guys...
First picture is the before shot, second picture is after the second time purifying.


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## lazersteve (Apr 24, 2013)

Looks good. 

Remember the left over solution needs to be tested for Pd, if positive acidify slightly and any remaining Pd cemented or scavenged with DMG.

Keep your ammonia containing wastes separate from your other wastes. 

Steve


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## johnny309 (Apr 28, 2013)

@Marcel

Concerning the yield: Today I have received a final analysis of 15 Kg of MLCCs. The Pd content was disappointing 0,31% only. I am still looking into it, but the batch consisted of 2Kg SMD MLCCs and 12,5 Kg THT (wired) MLCCs. 


Still from UMICORE....if I may guess right......
Remember what Harold said...:"the refiner is the last liar"

I got a similar experience with Safina....well the branch here involving silver ......dissapointing....from 125 grams of cemented silver,after melt the result was 91 grams......of a purity of 92%......and they charge for the melt 18 euros
Guess what....at this rates....my grandmother moves better.....

Below are the picture of cemented silver...
Any opinion on that ?


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## johnny309 (Sep 2, 2013)

No one...?


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## samuel-a (Sep 2, 2013)

Johnny

It is hard to tell just from a picture...
I've seen before Ag powder that looks much like clean, 9999 Ag out of the AgCl process, but after inciniration + melt was 80% and assayed at lower than 90%.
I've also seens fluffy red colored silver powder that looks more like copper than Silver, but was 999 Silver.
It happens... Looks can be quite deceiving in our profession.


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## chlaurite (Sep 2, 2013)

Marcel said:


> and 12,5 Kg THT (wired) MLCCs.


Wait... _Wired_ MLCCs?

I thought _all_ MLCCs came in surface-mount form? What do these look like in wired form? A Google search shows a few examples of the yellow ones called that, but those have a distinct polarity, which (AFAIK) MLCCs do not...


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## johnny309 (Sep 3, 2013)

@chlaurite......this is mlcc with leads...... http://www.avx.com/docs/masterpubs/mclc.pdf

@samuel-a .....the silver was treated with HNO3(relay points...mostly Ag-Ni alloy)...and cemented on copper for two days( so no Ag-Cl involved)....wash with DI water....and the product well dried.


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## Ahmedelkhateeb (Jun 6, 2014)

lazersteve said:


> I use Acid Peroxide on my MLCC's that contain Pd:
> 
> 0. Test a small sample for Pd before processing, not all MLCC contain Pd.
> 1. Remove base metals with 15% HCl.
> ...



Hello every one
First thing sorry about my language because my mother language is arabic
Second,
Dear steve
I want some demonstration
U said preciptate with sodium chlorate and ammonium chloride .
What i want to know
How much of the first and second?,
I add both together or one follow one? And if one follow one what is the first and what is the conditions?
I hope understand me
Sorry again about my language
Special thx for steve
And thx all


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## lazersteve (Jun 11, 2014)

Hoke covers precipitation of Pd from solution using chlorate in great detail. 

You can download a free copy of Hokes book from the Guided Tour Link below.

Steve


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