Purifying Palladium Salt extracted with DMG

Here is a short video I made showing the process I used to purify the impure palladium salt extracted with DMG from my silver nitrate electrolyte.

This is my first time doing this so I hope I got it right.

Any critique would be welcomed - I have not burned the product yet.

I'll make another video when I burn the Pd salt in a quartz dish.

kadriver

[youtube]http://www.youtube.com/watch?v=btvN9KIghHc[/youtube]

I goofed the title - misspelling the word "Purifying"

If one of the moderators could change the word "Purifting" to "Purifying" in the title on this post then it would be greatly appreciated!

Might help someone who is trying to use the search block.

kadriver

Nice thanks

Thanks for sharing!

You're really mastering Pd refining

Very instructive. Thank you for sharing.

Kevin,

Suggestion: just digest the DMG in aqua regia, dilute, filter off any AgCl that might have been entrained in the filter, then treat as per normal.

Best,

kadriver said:

I goofed the title - misspelling the word "Purifying"

If one of the moderators could change the word "Purifting" to "Purifying" in the title on this post then it would be greatly appreciated!

Might help someone who is trying to use the search block.

kadriver

Click to expand...

I think you can edit the title yourself. Give it a try.

Jim

I got it for him


Also, Kevin...Pd is one of those metals that it is inadvisable to calcine, especially in quartz. It forms palladium silicides which embrittle the metal.

Lou said:

I got it for him


Also, Kevin...Pd is one of those metals that it is inadvisable to calcine, especially in quartz. It forms palladium silicides which embrittle the metal.

Click to expand...

From the Chart I can tell that Pd2Si only forms in a hydrogen environment with a temperature of 1100°C and Calcination takes place at around 550°C.

I still might be wrong since I do not have as much knowledge in platinum refining as you do; And If I even read the Chart Correctly.

Thanks for the Chart it really does have some valuable information in it; I guess the catalytic properties of platinum metals makes is much more harder to refine :mrgreen:

It happens as low as 550*C in quartz under H2.

In vacuo, it occurs over 1000C.


Cheers,

Lou said:

It happens as low as 550*C in quartz under H2.

In vacuo, it occurs over 1000C.


Cheers,

Click to expand...

That explains it all :mrgreen:

@Lou

Suggestion: just digest the DMG in aqua regia, dilute, filter off any AgCl that might have been entrained in the filter, then treat as per normal.

Click to expand...

First time I read this: Digest the yellow palladium-DMG in AR? How is that done, does it take heat and much time or will it easily digest? And then treat as if you had dissolved palladium directly in AR?

Lou said:

Kevin,

Suggestion: just digest the DMG in aqua regia, dilute, filter off any AgCl that might have been entrained in the filter, then treat as per normal.

Best,

Click to expand...

Lou,

I was wondering about this because the appearance of the yellow precipitate, once it dried, did not look very clean.

As I was doing the experiment I mused that even after rinsing the DMG Pd salt with plenty of distilled water that some silver would still be in the Pd salt.

I didn't know if the ammonia dissolutions would remove the silver or not - judging by the appearance, I would guess that there is some silver chloride in with the Pd.

Thanks for the tip, I'll dissolve the impure yellow Pd salt in AR, then filter out the silver chloride.

I would guess that it would be a matter of course to treat any Pd recovered with DMG with AR and filter to ensure purity.

kadriver

solar_plasma said:

@Lou

Suggestion: just digest the DMG in aqua regia, dilute, filter off any AgCl that might have been entrained in the filter, then treat as per normal.

Click to expand...

First time I read this: Digest the yellow palladium-DMG in AR? How is that done, does it take heat and much time or will it easily digest? And then treat as if you had dissolved palladium directly in AR?

Click to expand...

solar_plasma,

I think the Pd salt that I recovered from the ammonia with HCl could be dissolved in nitric acid only.

By using AR instead of just nitric acid, it will ensure that any silver will precipitate out as silver chloride.

Then the silver chloride can be removed by filtering the resulting solution over and over through the same filter paper until the solution is crystal clear.

I have dissolved other Pd salts in AR. I put the Pd salt in a covered beaker then added concentrated HCl on low heat. Then added nitric acid in small doses until it all dissolved.

kadriver

I think the Pd salt that I recovered from the ammonia with HCl could be dissolved in nitric acid only.

By using AR instead of just nitric acid, it will ensure that any silver will precipitate out as silver chloride.

Then the silver chloride can be removed by filtering the resulting solution over and over through the same filter paper until the solution is crystal clear.

I have dissolved other Pd salts in AR. I put the Pd salt in a covered beaker then added concentrated HCl on low heat. Then added nitric acid in small doses until it all dissolved.

kadriver

Click to expand...

Yes, I got that, I just wondered about the Pd-DMG salt, since I thought DMG would precipitate Pd also from AR. But when you guys now tell, that Pd-DMG complex as well can be dissolved again in AR, it seems to depend on the acid concentration?

solar_plasma said:

Yes, I got that, I just wondered about the Pd-DMG salt, since I thought DMG would precipitate Pd also from AR. But when you guys now tell, that Pd-DMG complex as well can be dissolved again in AR, it seems to depend on the acid concentration?

Click to expand...

Wouldn't this be similar to Re-disolving gold precipitated with SMB with a second treatment of AR ???

The way I see it the DMG that "pushed" palladium out of solution is still in that solution and not a part of the precipitated palladium recovered from that solution.
Similar to the gold we precipitate with SMB and the Silver we precipitate with copper.

I hope I got this correct. Brain good not function today.

niteliteone said:

solar_plasma said:

Yes, I got that, I just wondered about the Pd-DMG salt, since I thought DMG would precipitate Pd also from AR. But when you guys now tell, that Pd-DMG complex as well can be dissolved again in AR, it seems to depend on the acid concentration?

Click to expand...

Wouldn't this be similar to Re-disolving gold precipitated with SMB with a second treatment of AR ???

The way I see it the DMG that "pushed" palladium out of solution is still in that solution and not a part of the precipitated palladium recovered from that solution.
Similar to the gold we precipitate with SMB and the Silver we precipitate with copper.

I hope I got this correct. Brain good not function today.

Click to expand...

It's a different reaction. When you precipitate gold with SMB, the gold is reduced by the SO₂. Only electrons are exchanged between the gold and SO₂. Metallic gold is the result. Silver cementation is a somewhat different reaction, but the result is the same with an exchange of electrons between the copper and silver, the result being metallic silver.

When you precipitate palladium with DMG, the DMG chemically combines with the palladium, so it is part of the precipitate. If you use HCl to precipitate your silver instead of cementing it with copper, you'll have a similar result as the Cl^- ion combines with the Ag⁺ ion to for solid AgCl. In both cases the precipitant doesn't push the target cation out of solution, it combines with it.

Dave

In laymen's terms then, Gold and silver are pushed out of solution and palladium "Bonds" with the DMG to come out of solution ???

You could say that.

Reduction of gold with sulfite is just that, a reduction. Precipitation as the PdDMG complex occurs with no valence change.

I am not a big believer in the ammonia treatment of Pd-DMG.

If you must recover via DMG, oxidize away the organic ligand with aqua regia. Then you can proceed as normal. Just trying to dissolve in ammonia is wasteful of reagent, plus, where does the DMG go from the complex. What makes you so certain that you'll get the diammine and not your DMG back?