# lazersteve MLCC process questions



## 924T (May 24, 2014)

After reading lazersteve's MLCC process several times, I have a few questions.



lazersteve said:


> Re: Problem with Pd from MLCC
> 
> I use Acid Peroxide on my MLCC's that contain Pd:
> 
> ...



Step #1.: Is this a heated process with the 15% HCl, and if so, is it boiling as in Samuel-a's process, or would
it be at a low enough temperature to perform this step in a food-grade plastic bucket?

Step #3.: Would air bubbling/sparging instead of the H2O2 additions yield the same results in the same amount
of elapsed time, and somewhat 'self stir' the MLCC's?

Would a stirring bar in the reaction vessel assist the process?

Is the suggested slight heat slight enough that this step could be conducted in a food-grade plastic bucket?

Step #5.: What is the purity of the Pd at this stage of the process? I'm curious to know whether it's a quantum
leap to get the Pd to .9999, or just a wee bit of a jump.

Step #6.: Rather than Sodium Chlorate, could Calcium Hypochlorite used as the Chlorine source? I can get
Calcium Hypochlorite locally, at Menard's, thus saving shipping costs and avoiding the explosion
potential of Sodium Chlorate.

If the Hypochlorite will work as the Chlorine source, should I make a solution of it, or can the pellets 
be added directly to the leachant?

Many thanks,

Mike


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## lazersteve (May 29, 2014)

924T said:


> After reading lazersteve's MLCC process several times, I have a few questions.
> 
> ...snip...
> Step #1.: Is this a heated process with the 15% HCl, and if so, is it boiling as in Samuel-a's process, or would
> it be at a low enough temperature to perform this step in a food-grade plastic bucket?


I did not heat at all. Plastic buckets will vary on the heat they can withstand depending on the thickness and type of plastic used. 
Details of Plastics Properties. Zero heat requires extended (months) soak time.


924T said:


> Step #3.: Would air bubbling/sparging instead of the H2O2 additions yield the same results in the same amount
> of elapsed time, and somewhat 'self stir' the MLCC's?


No


924T said:


> Would a stirring bar in the reaction vessel assist the process?
> 
> Is the suggested slight heat slight enough that this step could be conducted in a food-grade plastic bucket?


Yes to both.


924T said:


> Step #5.: What is the purity of the Pd at this stage of the process? I'm curious to know whether it's a quantum
> leap to get the Pd to .9999, or just a wee bit of a jump.


Purity largely depends on proper filtration, reagent purity, lab hygiene, and presence of other metals below aluminum reactivity in solution during precipitation. At this point it would not be wise to melt directly, as a few short steps down the list, you eliminate several possible contamination sources. 


924T said:


> Step #6.: Rather than Sodium Chlorate, could Calcium Hypochlorite used as the Chlorine source? I can get
> Calcium Hypochlorite locally, at Menard's, thus saving shipping costs and avoiding the explosion
> potential of Sodium Chlorate.
> 
> ...


Any source of chlorine will work. Solid contaminates in the dissolved solids should be filtered out prior to using the solution. If you add the solids without making a solution, any insoluble garbage in the solids is then added to your Pd. Garbage In = Garbage Out. Shortcuts sometimes cost you purity when working with over the counter reagents. 

Steve


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## 924T (May 30, 2014)

lazersteve, many thanks!

I think I'll skip the plastic bucket and use Pyrex, run at low heat, use a stirring bar, and use purchased bleach.

I had been wondering about contaminates from using Sodium or Calcium Hypochlorite, and you verified that
without filtering, additional complications would be caused (if I understood you correctly).

I did notice on another thread that Irons reported he'd discovered that Chlorine-free bleach from his local
grocery store appeared to be 20% concentration H2O2, so I'm going to look into that.

I have some 3ml disposable plastic pipettes coming, so those sound like they'd be perfect for adding 1-2ml
of H2O2 at a time to the AP solution. 

I also have a porcelain mortar and pestle coming, and I'm hoping it will not be destroyed by grinding MLCC's
in it. Opinions are welcome-----would I be better off with a cast Iron mortar and pestle for MLCC's?

Does grinding the MLCC's reduce the process time by roughly 80%?

Thanks again,

Mike


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## YELLOWBEARD (Jun 6, 2014)

Hi,

Thanks for everything lazersteve. I wondered If you could comment on why the aluminum does not precipitate the other metals, like nickel. Is it the ph? 

Also, you gave a color range of the starting solution. Could you comment about the solution color after the pd has been precipitated?
How do you tell if you have dropped it all? Is there an obvious color change or do you test with stannous as you add aluminum strips?

Thanks again.


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## solar_plasma (Jun 6, 2014)

> I wondered If you could comment on why the aluminum does not precipitate the other metals, like nickel.



I am pretty sure this has been explained somewhere, but though I wondered as long as I stay here, I never found it. To me this is quite not as trivial as it sounds. Would be really nice, if anyone would explain it shortly. Just some keywords or links, pleeease.


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## Lou (Jun 6, 2014)

Aluminum will NOT precipitate nickel in noncomplexing (i.e. no chlorides) media.

This means aluminum foil will dissolve and give nickel metal which will contaminate the palladium, *if* done in an HCl medium.


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## solar_plasma (Jun 6, 2014)

Thank you, Lou, I think, now I know, what I have to look for and found some details about what you mentioned in article 2.1.2 in Hollemann/Wiberg Inorganic chemistry (those pages are not displayed in google books).


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## YELLOWBEARD (Jun 6, 2014)

Lou said:


> Aluminum will precipitate nickel in noncomplexing (i.e. no chlorides) media.
> 
> This means aluminum foil will dissolve and give nickel metal which will contaminate the palladium, if done in an HCl medium.



I think Lou means unless done in an HCL medium. Thanks.


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## necromancer (Jun 6, 2014)

solar_plasma said:


> Thank you, Lou, I think, now I know, what I have to look for and found some details about what you mentioned in article 2.1.2 in Hollemann/Wiberg Inorganic chemistry (those pages are not displayed in google books).



Dr. A.F. Holleman Inorganic chemistry 1908, 3rd Edition (i do think its the complete book, errata corrected)
https://archive.org/stream/atextbookinorga01hollgoog#page/n538/mode/2up

online reading only, does this help ?
if not i can keep looking


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## lazersteve (Jun 11, 2014)

I have dissolved MLCC in acid peroxide, filtered the resulting burgundy solution free of particulate, and treated with Aluminum foil. 

The nickel remains in solution (pale bright green color) and the palladium XRFs as over 99%. The left over solution tests negative for Pd to DMG and stannous chloride.

If you have MLCC's that contain Au and/or Pt the Aluminum will precipitate these metals along with the Pd. 

Any other base metals besides nickel (below Al in the activity series chart) in the pregnant solution will also come down with the values. For this reason it is important to know your starting material by testing samples before using this process. 

Mixed precious metal precipitates can be separated as describe in Hoke and numerous places across the forum.

Steve


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## YELLOWBEARD (Jun 13, 2014)

Thanks lazersteve.

I tried a small sample run of this process. At the end, I added the aluminum, stirred a couple times, and let it sit overnight. in the morning, It had turned to a gel. 

How do you cope with that or avoid it? Did I add too much aluminum? Or, do you dilute this and then filter? 
As the aluminum seems to be causing the gel, Is there a reason that aluminum is chosen to initiate the precipitation, or could something like zinc be used?


The Pd did seem to fall out as I have flakes of a black precipitate. Appreciate any help.


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## freechemist (Jun 15, 2014)

You should use more acid (HCl) and/or less aluminum. The acid in your solution has dissolved a lot of aluminum, such that HCl-concentration became lower and lower, until gelatinous aluminum hydroxide began to form. Addition of more HCl with stirring until pH is 1 or even lower should redissolve the gel.


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## Mauriq11 (Jul 25, 2014)

Tengo un problema, al agregar el zinc en la solución, el prcipitado no es negro sino blanco amarillento. Una pregunta sera lo mismo usar zinc metalico? que usar oxido de zinc?. Espero me puedan ayudar estoy estancado en este proceso. Gracias.


I have a problem, adding the zinc in the solution, the prcipitado is not black but yellowish white. Questions will be the same using metallic zinc? to use zinc oxide?. I hope you can help me I'm stuck in this process. Thank you.


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## solar_plasma (Jul 25, 2014)

More detailed information is needed. Please explain your process.

To me it sounds like too little acid/too high pH. But without knowing more about your process, this is just guessing.


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## Mauriq11 (Jul 25, 2014)

Bien gracias, someter los capacitopres en Hcl y H2o2 el resultado es satisfactorio, la solucion color purpura resultante es filtrada y el precipitado fue lavado con agua, tambien lo separe para llevarlo a dilucion en agua regia. Tal como se explica en el apartado de refinacion de MLCC, resulta una solucion color verde amarillenta; filtre el precipitado color blanco amarillento para llevar a calentamiento la solucion filtrada y agregue Zinc pero solo precipita una sal blanca amarillenta.
El ph de esta solucion es de 1 y pues no me ha resultado el precipitado negro o gris como mencionan, pero me indica existencia de paladio la solucion de SnCl. No agregue Zinc hasta aclarar pues solo fueron 10 gramos.

Well thanks, submit capacitopres in H2o2 Hcl and the result is satisfactory, the resulting color purple solution is filtered and the precipitate was washed with water, also put asunder to carry dilution in aqua regia. As explained in the section of MLCC refining, is a yellowish green solution; strain the yellowish white precipitate to carry heat and add the filtered solution but only Zinc precipitated a yellowish white salt.
The pH of this solution is 1 and it has not turned me black or gray precipitate as mentioned, but it indicates the existence of palladium solution of SnCl. Do not add Zinc to clarify it was only 10 grams.


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## lazersteve (Jul 25, 2014)

I'm not sure if I'm losing something in the translation, but is sounds to me like you are using zinc oxide instead of metallic zinc. You need to use metallic zinc. I prefer using metallic Aluminum when working with clean *palladium *solutions that contain traces of *nickel*.

The color of the solution after dissolving the palladium and before adding metallic zinc/aluminum should be dark burgundy (like red wine) to blood red. The pH of the solution should remain acidic during the zinc additions. It is sometimes advisable to neutralize the solution with soda ash to a pH between 4 and 5 to save on the amount of metal required to complete the precipitation process. Excess acid (very low pH) consumes more base metal. 

I also noticed that you mentioned using AR to extract the palladium. In my experiments referenced above I used HCl (32%) + H2O2 (35%) to extract the palladium. Cover the capacitor powder with HCl and add peroxide in small amounts as need to extract the palladium. Gentle heating and stirring speeds this step. If you are using AR, then you should be sure to denoxx the solution before proceeding to metallic zinc after proper filtration. 

Stannous chloride testing palladium solutions can be inconclusive, especially when several other base metals are in the solution. For this reason you should always test for palladium using DMG. 

Steve


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## Mauriq11 (Jul 26, 2014)

Gracias a Solar_Plasma y Lazersteve por su apoyo y ayuda en este paso, Mil gracias a estas increibles personas, pues seguire en este proceso para el refinado del Pd, espero seguir contando con su apoyo de su indudable experiencia.
Un gran aprecio desde México.


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## goldsilverpro (Jul 26, 2014)

Mauriq11 said:


> Gracias a Solar_Plasma y Lazersteve por su apoyo y ayuda en este paso, Mil gracias a estas increibles personas, pues seguire en este proceso para el refinado del Pd, espero seguir contando con su apoyo de su indudable experiencia.
> Un gran aprecio desde México.



No more Spanish!

In your other posts, you wrote in Spanish and translated in English, of which you sound well-versed. This time only Spanish. This is an English language forum. If you want to stick around, NO MORE SPANISH.


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## Mauriq11 (Aug 4, 2014)

Hello, here again asking for your help in the process: After precipitation with zinc, resulting in a black precipitate. I decided to dilute HNO3; Resulting in a clear orange solution with a dark gray precipitate which subjected it in AP BECOMING white suspect is silver chloride.

A solution I add orange Hcl or NaCl in small samples and is a white precipitate, which will also assume AgCl. To remove the nitric acid Palladium have to Denoxx but I can also add Sodium Hydroxide in solution and precipitate down as White Pd. This result makes me doubt the first precipitate can also be Pd.

I will appreciate your help or your opinion. Thanks in advance.


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