# Pt in nitric



## teclu (Sep 7, 2009)

Hello everybody,


I have to process ceramic capacitors with Pt, Pd, Ag and I think these steps after nitric treatment(1:1, HNO3 70% ): silver chloride and then cement Pt, Pd on Copper.

Questions: Is sure that Pt dissolves in the presence of Ag?...To test, I put 100 mg of pure platinum wire from thermocouple tip R(Pt-PtRh13, ) and 500 mg of pure Ag(wire), but after about 7 hours silver was dissolved and Pt untouched!!!...What color is the solution of dissolved platinum in nitric?

By the way Pd and Ag in nitrate solution, which cemented the first on the copper?... if I used NaCl for Ag the AgCl is very delicate to filtration, traces of AgCl remain with Pd in nitrate solution and to cementation the Pd nitrate appears gray in color, not black.


Thanks in advance!

teclu


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## scrapman1077 (Sep 7, 2009)

Pt will NOT be affected buy nitric, only AR


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## Lou (Sep 7, 2009)

Teclu,

Why don't you try that again, this time melt 500 mg of platinum with a gram of silver and tell me what happens. :lol: 


If you put silver and platinum wire together into the same beaker and add nitric, you're left with platinum wire in a silver nitrate solution. Alloy the two and you will find it is a different story...

If you want your most of the Pt back, add HCl to the solution, just enough to precipitate all the silver, then boil it, filter it, and rinse with hot, dilute nitric acid, and then add HCl and boil until the nitric is gone to get chloroplatinic acid.


Louis


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## goldsilverpro (Sep 7, 2009)

The Pt and Ag must be *ALLOYED* in order for the Pt to dissolve. You require at least 10 times as much Ag as Pt in order for this to happen. All of the Pt won't dissolve. As you increase the Ag/Pt ratio, the greater the percentage of Pt that will dissolve.

This Ag alloying method is used primarily to remove Pt from Au/Pt assay beads. It has to be repeated several times. It never works 100%.


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## teclu (Sep 7, 2009)

Lou and GSP thank you gentlemen,

I understand, then return to the capacitors: in 1kg of capacitors without legs are aprox. 25-30 grams Pt, aprox. 50-60 grams Pd and aprox. 50 grams Ag...them below

http://i43.tinypic.com/2h4kbw4.jpg

As I thought, after crushing and nitric treatment Pt will most likely remain undissolved now, the same question:

Pd and Ag in nitrate solution, which cemented the first on the copper?... if I used NaCl for Ag the AgCl is very delicate to filtration, traces of AgCl remain with Pd in nitrate solution and to cementation the Pd nitrate appears gray in color, not black.
Can I melt PdNO3(black powder)?... which is the purity?

teclu


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## Palladium (Sep 7, 2009)

teclu said:


> Pd and Ag in nitrate solution, which cemented the first on the copper?... if I used NaCl for Ag the AgCl is very delicate to filtration, traces of AgCl remain with Pd in nitrate solution and to cementation the Pd nitrate appears gray in color, not black.
> Can I melt PdNO3(black powder)?... which is the purity?
> 
> teclu




http://goldrefiningforum.com/phpBB3/viewtopic.php?f=39&t=63&p=487&hilit=activity+metal+series#p487


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## Platdigger (Sep 8, 2009)

Teclu, the problem I have heard made mention of with precipitating silver as it's chloride in the presence of palladium is that the volumous silver chloride precip, could drag down and trap some pd.

Not as an atempt to answer your question, but to pose another question to the forum.......
What if, the solution (of ag and pd in nitric) was diluted and free nitric amount kept minimal...
and if,.....the pd in solution was cemented to silver metal, as a first step?


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## Lou (Sep 8, 2009)

Quite frankly, I doubt that these capacitors have that value in them.

Assuming they did, I think it would be wise to solvate everything below platinum in nitric acid. Precipitate the silver with HCl, filter and rinse the AgCl with HCl until it runs clear--doing so will ensure that the palladium is removed, as it very strongly colors a solution yellow, even showing up when in the 10 ppm range (that is, 10 mg/L, an acceptable ''loss''). Just make sure the HCl is somewhat dilute, if it is concentrated, with it will go some of your AgCl. Your palladium solution should be boiled (a mauve precipitate will form, if palladium is concentrated), and added to more concentrated HCl. Boil that down again, and add some 3M HCl, evaporate to a syrup, and then add saturated ammonium chloride with a few crystals off sodium chlorate. It will precipitate out as a brick red mud, and more will come as you ice bath it.

Get the platinum only AFTER the base metals are removed.


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## teclu (Sep 8, 2009)

Palladium said:


> teclu said:
> 
> 
> > Pd and Ag in nitrate solution, which cemented the first on the copper?... if I used NaCl for Ag the AgCl is very delicate to filtration, traces of AgCl remain with Pd in nitrate solution and to cementation the Pd nitrate appears gray in color, not black.
> ...




Thanks Palladium for your help in the way of recovery of palladium.

teclu




Platdigger said:


> Teclu, the problem I have heard made mention of with precipitating silver as it's chloride in the presence of palladium is that the volumous silver chloride precip, could drag down and trap some pd.
> 
> Not as an atempt to answer your question, but to pose another question to the forum.......
> What if, the solution (of ag and pd in nitric) was diluted and free nitric amount kept minimal...
> and if,.....the pd in solution was cemented to silver metal, as a first step?



Platdigger hello,

You absolutely right, that I think is happening, the silver chloride is voluminous and very annoying for me everytime and everywhere.

teclu





Lou said:


> Quite frankly, I doubt that these capacitors have that value in them.
> 
> Assuming they did, I think it would be wise to solvate everything below platinum in nitric acid. Precipitate the silver with HCl, filter and rinse the AgCl with HCl until it runs clear--doing so will ensure that the palladium is removed, as it very strongly colors a solution yellow, even showing up when in the 10 ppm range (that is, 10 mg/L, an acceptable ''loss''). Just make sure the HCl is somewhat dilute, if it is concentrated, with it will go some of your AgCl. Your palladium solution should be boiled (a mauve precipitate will form, if palladium is concentrated), and added to more concentrated HCl. Boil that down again, and add some 3M HCl, evaporate to a syrup, and then add saturated ammonium chloride with a few crystals off sodium chlorate. It will precipitate out as a brick red mud, and more will come as you ice bath it.
> 
> Get the platinum only AFTER the base metals are removed.




Lou, thanks you sir

Yes, this is the way that I thought, but frankly, it was better if I could avoid AgCl.

teclu


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## Pen Cen (Jun 23, 2022)

teclu said:


> Hello everybody,
> 
> 
> I have to process ceramic capacitors with Pt, Pd, Ag and I think these steps after nitric treatment(1:1, HNO3 70% ): silver chloride and then cement Pt, Pd on Copper.
> ...


Pt in alloy can dissolve in HNO3 ! I try it million times!!!!!!! when I ICP the solution the Pt was present!! I do it for million times !!!! so if you have for example Cu 90% and Pt 10%; some of your Pt will dissolve in your HNO3 solution.


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