# thin palladium plating



## Anonymous (Oct 22, 2008)

I have plastic with I think is thin palladium foil on it, my question is will
diluted AR work to remove it? I want to process small batches at a time and the amount of metal per plastic area is a very small ratio. I think if I used normal strength acids I would be wasting a lot of acid because of the large volume needed to get only a small amount of metal.

Jim

I just noticed, I made the subject "think" ha, ha, boy I'm loosing it. It should be Thin palladium foil.

That has been corrected. 

Harold


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## Lou (Oct 22, 2008)

Dilute aqua regia should remove it quite easily and is a better option than using nitric acid.


Lou


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## Anonymous (Oct 22, 2008)

Thanks Lou, I did not know if AR worked or not when diluted.

Jim


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## Harold_V (Oct 23, 2008)

Use the AR warm and it will dissolve with a vengeance, even diluted. 

Harold


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## Lino1406 (Oct 25, 2008)

Do you think it's palladium?


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## Anonymous (Oct 25, 2008)

Lino, I haven't tested it yet, but it looks like palladium. It is actually conductors in some tester. I have just been so busy working I haven't worked it. I have a pd coin and the metal looks exactly the same. I know that is not proof, but I will know soon enough.

Jim


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## Lino1406 (Oct 25, 2008)

Great!


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## Lino1406 (Oct 25, 2008)

What below the palladium


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## Anonymous (Oct 25, 2008)

Lino, I think it is just pd on plastic, the plastic is thin and goe trought the side of the tester with a seal to keep moisture of chemicals? from going into the electronics compartment. I scrapped the pd it is really thin plating and does not apprear to be anthing under.

It is raining so I am going to try and do a few of these today.
I do not expect much of a yield, but I have a 12" * 12" box full of them.
May yeild a couple of grams if it is in fact pd. I have never actually seen
pt I am hoping it is not that because I do not know how to process pt.
I thaught it may be al, but I have seen litteral tons of that in my life and does not look like it.

Jim


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## Harold_V (Oct 25, 2008)

From your description, my mind goes quickly to nickel instead of palladium. Have you eliminated it as one of the possibilities?

Harold


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## Lino1406 (Oct 25, 2008)

Usually is using metallization, where
a very little amount of palladium can
be involved, later copper (or copper 
directly), then nickel, then everything else
Another possibility vaporizing metal (any) directly


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## Anonymous (Oct 25, 2008)

We will know soon. I have 8 pieces in a test tube now, the solution is dilute with no heat. 

Will the stannous test confirm pd, I do not have any of the other stuff I have seen referrenced for test PGM group.

thanks.

Jim


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## Lino1406 (Oct 25, 2008)

with Ni =brown
Pd=green


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## Harold_V (Oct 25, 2008)

james122964 said:


> We will know soon. I have 8 pieces in a test tube now, the solution is dilute with no heat.
> 
> Will the stannous test confirm pd, I do not have any of the other stuff I have seen referrenced for test PGM group.


Palladium yields a dark brown solution. Nickel yields a green/blue solution. If you have both present, your solution may be a dark green color. It may or may not be conclusive without testing. 

Testing with DMG is an excellent way to go for both metals. A drop of DMG in palladium will yield a huge volume of canary yellow precipitate. 

A drop of ammonium hydroxide and a drop of DMG will yield a beautiful pink color if you have nickel. 

I like a spot plate for testing, where a drop of the unknown solution is placed in a cavity for testing. My comments reflect that process. 

Stannous chloride has no reaction with nickel----and the reaction with palladium can be wide-spread. A green/blue reaction through a dark brown/black reaction isn't unheard of. Often you may even confuse palladium with gold, although you won't find a purple stain with palladium, unlike gold. The number of reactions you can achieve with palladium make it almost mandatory to have DMG so you can sort the differences, particularly when you have multiple types of values in solution. 

Condition of stannous chloride, free acid present and the level of concentration all play a big role in the reactions you get with stannous chloride, particularly with palladium.

Harold


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## Anonymous (Oct 26, 2008)

initial results, test pieces in HCL - no aparent reaction.
test pieces in HCL + KNO3 - dissolved rather easily.
There appears to be some kind of clear layer over the metal strips as only the ends reacted quickly, the rest is slowly dissappearing.

My solution is a straw color right now.

Have to get tin solder in the morning to make stannous and give time for rest of sample to go into solution.

Jim


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## Anonymous (Oct 27, 2008)

Harold is there a common name or item that is DMG or a substitue.
If I buy DMG can I use it to precip my(if I have any) palladium?

I kinda screwed up because I reached in with a pair of needle nose pliers and got some iron in my solution.

thanks.

Jim


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## Lou (Oct 27, 2008)

You do NOT want to precipitate with DMG. It is a very flocculent, voluminous precipitate that will be misery to filter.


Just a word of caution.


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## Anonymous (Oct 27, 2008)

What would I use to precip pd? Not concerned with being pure at this time because I just want to learn the process. 

I got some 95tin today will make the stannous test on wed when I get off work early.

Question, what color should I see for pd with the stannous? should I neutralize before testing? I only have 10ml of solution since I only did 8 1 inch pieces for the test.

My solution has a tiny amount of iron from pulling out the plastic with needle noise pliers, I only did this once but I could instantly see that I messed up, thaught I was quicker than the acid :lol: Will the tiny amount of iron mess up my stannous results?

Thanks
Jim

Also, although the amount is tiny per test lead, I am getting them by the box full.


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## Anonymous (Oct 27, 2008)

Harold, I think incernating the plastic would be great, i just do not know how to keep the fine metal from being blown away with the ash from the plastic, I tried burning one and it made long stringy carbon filiments that floated way and the metal is so thin on these I think it might float way with it.

Jim


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## lazersteve (Oct 27, 2008)

James,

Check my Rough Guide tot he Forum, you'll see a photo of a positive Pd swab.

Solutions of Pd are a deep red brown color when concentrated and more of a yellow color when diluted.

I have a video on my website in the Pd section for precipitating Pd.

Steve


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## Harold_V (Oct 28, 2008)

james122964 said:


> Harold, I think incernating the plastic would be great, i just do not know how to keep the fine metal from being blown away with the ash from the plastic, I tried burning one and it made long stringy carbon filiments that floated way and the metal is so thin on these I think it might float way with it.
> 
> Jim


I would avoid incinerating plastic unless I had no other alternative. In this case, a rinse in sodium hydroxide to kill oils and to remove the protective layer, then direct dissolution of the plating would be the answer, assuming you have palladium. The stripped plastic would be easy to separate from the solution. Note that I rarely suggest you not incinerate. 

Lou is right with his advice using DMG to precipitate palladium. I have done it, and still have a small vial of the salt---but it's a complete nuisance to handle. A trace of palladium will make a huge amount of precipitate, and it's sticky and hard to handle. When it is calcined, it reduces to almost nothing. 

DMG is an excellent test for palladium because of the comments, above. If it's present in the least, you'll see a yellow precipitate. 

From a solution that has had the nitric acid expelled, add ammonium chloride, which will precipitate platinum if it's present in great enough quantity. If there is none, you then heat the solution to just below a boil, then introduce crystals of sodium chlorate and stir. There will be evolution of gasses, and eventually you'll see the crimson red particles of palladium forming. Your solution will shift color as the palladium comes down. Do read Hoke for more information. She addresses the process very well. 

Remember----platinum and palladium do NOT precipitate well, if at all, from dilute solutions. Keep your solutions as concentrated as you can if you want good recovery. Traces in solutions are best recovered in the stock pot, where they can accumulate for later recovery. 

Harold

edit: added comments


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## Harold_V (Oct 28, 2008)

james122964 said:


> Harold is there a common name or item that is DMG or a substitue.


Lou may have to address this question. 

DMG is dimethylglyoxime, a compound that is available from chemical supply houses. I do not know where it might be used outside of testing for palladium. It is a strange, white powder, difficult to dissolve in water. Others have commented that it readily dissolves in alcohol----which I'd recommend if you make a solution. Hoke provides information regards concentration. 

Harold


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## Anonymous (Nov 2, 2008)

I made some stannous test solution with 95/5 tin/antimony solder, it turned out gray. I tried to use it but i could not tell if the result was from the stuff floating in the testing solution. I left it in a bottle to settle, hopefully better results afterwards.

I also think I have to boil down and concentrate the solution that I am testing for content.

just wanted to know that with the solder, the stannous is following normal
reaction an will be useable.

thanks


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## Harold_V (Nov 2, 2008)

james122964 said:


> I made some stannous test solution with 95/5 tin/antimony solder, it turned out gray. I tried to use it but i could not tell if the result was from the stuff floating in the testing solution. I left it in a bottle to settle, hopefully better results afterwards.


I can't address this issue because I always made my solution from crystals. When fresh, it was clear, with a hint of yellow. As it aged, it turned milky, and slightly more yellow. If you have a gray solution, something surely is wrong. 



> I also think I have to boil down and concentrate the solution that I am testing for content.


Palladium, unlike some metals, yields a very dark solution. The slightest trace would be a nice yellow color, which quickly turns dark brown as it is concentrated. You should get a reaction from even a dilute solution with stannous chloride, but the test with DMG will be totally conclusive. 



> just wanted to know that with the solder, the stannous is following normal reaction an will be useable.


As I stated, I have my doubts. Something isn't right----I just don't know what it is. Could be the traces of antimony are so finely divided that they are in suspension in the solution. That might explain the gray color. 

If you don't get a reaction with the unknown solution, test the stannous against a known solution (a gold standard, for example). It's the way you insure your stannous chloride is functional. Anyone that refines should have a couple ounces of gold standard solution on hand. Think 50 milliliters for you metric guys. Keep it stoppered and it will last a long time. 

If any of this is not clear, you really should read Hoke on testing. 

Harold


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## Anonymous (Nov 3, 2008)

Thanks,
I have read the Hoke download. I just could not figure why my stannous was grey. I is out the workshop, settling I hope. I will know tomorrow when I go back out there.

Jim


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## Lou (Nov 3, 2008)

That is the antimony reacting and then hydrolyzing. Filtering it will solve this problem. 

Really though, pure tin isn't hard to find, and 50g of tin powder or wire will keep you many years!


Lou


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## Lino1406 (Nov 3, 2008)

No palladium there


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## Anonymous (Nov 3, 2008)

I got a lite red/purple reaction that eventually dissappeared? 
oh, well.


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