palladium from nitrate solution

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Sucho

Well-known member
Joined
Mar 28, 2010
Messages
178
Location
Slovakia
Hi all !
is there any possibility to cement out palladium from a solution of various nitrates quickly and selectively?

//i will drop out Ag and Pb chlorides first using lab grade NaCl.

DMG is too expensive in a large shape and drop out Pd with Ni.
converting nitrates to chlorides is time-consuming and laborious.
cementing on copper- i think that is a good way to push out only Pd, but i have never tried this.
should i use copper cable /powder/sheet metal ? works this method well ?
 
You would want to use bar stock, pipe or sheet's. Wire will possibly break apart as it dissolves and leave small pieces in the bottom of your container and powder you might put too much and have excess left in the bottom of your container. Reprocess your material when you have it concentrated and follow the forum recomendations.
 
but there is a problem with adsorbing reduced palladium on a copper surface which causes "passivation" of copper

i have seen it before when i was cementing silver from silver nitrate solution with a small ammount of palladium nitrate.
i was thinking about using copper powder in a calculated ammount

is there any type of selective titration for palladium nitrate in a sol. of various nitrates or i have to use gravimetric determining with DMG and calculate ammount of Copper ?
 
If you have a relatively clean Pd nitrate ( ie: no other precious metals) solution you can use SMB to precipitate the Pd metal and refine it a second time for higher purity.

Steve
 
thanks Steve!

that is very useful! i will try it. hope it will drop quantitatively.

there is mainly Cu in the solution after droping Ag,Pb with Nacl...
DMG is really too expensive for large shape Pd precip.from 50 grams of DMG you have cca 22 grams of Pd.
 
Finally , i will do it with DMG in DMSO.

i have found a shop with great prices. DMG 50g - 1.9 Eur
DMSO 1L - 18.2 Eur

Thanks for all replies
 
You can forget about DMSO and spend your 18.2 Euro on different ways. DMG dissolves easily in aqueous NaOH. Use 2 moles of NaOH per mole of DMG and sufficient water to make up a solution of about 1 mole/lt NaOH. Adding this alkaline solution of DMG slowly to the nitrate solution will precipitate Pd selectively and quantitatively, without precipitation of Ni, provided the mixture will still remain acidic after addition of the alkaline precipitation agent. This can be assured by beforehand addition of an equimolar amount of nitric acid (2 moles per mole of DMG) to the nitrate
solution.
 
freechemist said:
You can forget about DMSO and spend your 18.2 Euro on different ways. DMG dissolves easily in aqueous NaOH. Use 2 moles of NaOH per mole of DMG and sufficient water to make up a solution of about 1 mole/lt NaOH. Adding this alkaline solution of DMG slowly to the nitrate solution will precipitate Pd selectively and quantitatively, without precipitation of Ni, provided the mixture will still remain acidic after addition of the alkaline precipitation agent. This can be assured by beforehand addition of an equimolar amount of nitric acid (2 moles per mole of DMG) to the nitrate
solution.

Thanks for a solution, equimolar calculations and welcome !
Great post !
 
That's going to be my next experiment when things warm up.If it works cool just want to see how voluminous it is.
 
freechemist said:
You can forget about DMSO and spend your 18.2 Euro on different ways. DMG dissolves easily in aqueous NaOH. Use 2 moles of NaOH per mole of DMG and sufficient water to make up a solution of about 1 mole/lt NaOH. Adding this alkaline solution of DMG slowly to the nitrate solution will precipitate Pd selectively and quantitatively, without precipitation of Ni, provided the mixture will still remain acidic after addition of the alkaline precipitation agent. This can be assured by beforehand addition of an equimolar amount of nitric acid (2 moles per mole of DMG) to the nitrate
solution.

Nice post!. Any suggestion to cleanly precipitate all Pt from Pt nitrate present after doing the Pd?. :?:

Is there a simple procedure to manufacture DMG at home from cheap precursors?.

I also want to learn to make Oxalic acid at home from cheap precursors. :shock:
 
DMG synthesis...// this is only my memories from organic chemistry, i dont study organic chemistry

but 2,3 diol ---oxidize ----> but 2,3 dion -----hydroxylamine---> DMG

but 2 en ---- KMnO4 dil. ----> but 2,3 diol

i dont remember temperatures and other parameters
i think synthesis of DMG at home is quite difficult.

Chemists, please correct my synthesis or suggest other procedure
Thanks
 
Forgettaboutit!

Really only useful if there's a bunch of stubborn PGMs that keep co-mingling. I prefer to use it to scavenge Pd rather than use it to remove Pd if it's the bulk constituent of the solution.

Lou
 
For quick assay of 4metals :lol: (Ag, Au, Pd, Pt) in a mixed button, I think it is a great idea. :shock:

Weight button, dissolve in AR, filter AgCl, drop Au with oxalate, filter, drop Pd with DMG, filter, drop Pt with formate, filter. Weight them all. Perhaps not the best and most accurate, but accurate enough with normal buying margins, relatively simple and fast.

If DMG could be made or purchased cheaply, I can see how it could be used in refining too, because the Pd product is quite pure and more importantly it is almost completely removed from contaminating the Pt. A nuisance like silver chloride, but no more IMO.
 
HAuCl4 said:
Is there a simple procedure to manufacture DMG at home from cheap precursors?.

I also want to learn to make Oxalic acid at home from cheap precursors. :shock:

"... of sodium formate which is dehydrated to solid formate, melted carefully at about260° C and then rapidly fused at 400° C for 5 to 10 minutes resulting in solid sodium oxalate and the evolution of hydrogen."

http://www.patentstorm.us/patents/4018875/fulltext.html

Oxalate down. DMG to go next!. :shock: :lol: 8)
 
lazersteve said:
If you have a relatively clean Pd nitrate ( ie: no other precious metals) solution you can use SMB to precipitate the Pd metal and refine it a second time for higher purity.

Steve

Correction.

I tried this yesterday and had mixed results. The result was a bright yellow powder that tested positive as a Pd salt, not a fine black powder as expected (Pd metal). I read the source literature again and noticed it said SO2 gas, not SMB so I figured the sodium ions worked to form a double salt with Pd instead of the metal as expected.

I added my SMB dry, perhaps if I had dissolved it in a little HCl first I would have had better results. I also noticed I did not get any precipitate even after the SMB fully dissolved, until I added additional water.

More to come....

Steve
 
Hello Steve,

Palladium(II) forms complex salts with sodium or potassium sulfite. The potassium salt has the composition K2Pd(SO3)2 and is commercially available from Alfa Aesar Company. With sodium sulfite Pd(II) forms a bright yellow complex salt with approaching composition corresponding to the formula Na2Pd(SO3)2x2H2O, containing about 31% Pd. As far as I know, this sodium salt is commercially available too, from Heräus Precious Metals Chemicals in Hanau (Germany). It is a bright yellow powder, only sparingly soluble in water. In excess aqueous ammonia it dissolves giving a colourless solution, probably containing the complex cation [(NH3)4Pd]2+ and sulfite as anion. Boiling the salt in excess aqueous sulfuric acid - no halides, nor nitrates may be present! - it decomposes to metallic palladium, NaHSO4, SO2 and water.

Regards, freechemist
 
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