Palladium Complete Sequel

[lazersteve]

Aluminum works great when cementing Pd from chlorine based solutions containing nickel as the primary contaminate (eg: MLCCs dissolved in AP making a Pd + Ni chloride solution), but as Sam alluded, it has no place being used in nitric solutions due to nitric acids passivisation of the Aluminum.

When Al is used for cementing a chloride solution of Pd and Ni, you will achieve a black sediment of Pd and a bright lime green solution of Ni chloride when the cementation is complete.

Steve

 

[9kuuby9]

Thx steve!

So Al would be great for cementing Chloride based solutions and even leaving Ni in the solution. (Is their a reason for this? or does Al hate Ni that much ? :mrgreen: )
And Zn would be better in Nitrate based solutions because it does not passivate unlike Al.

A question for steve or anyone who is able to answer it ; Is it possible to convert Pd nitrate into Pd chloride? Because I really have a hard time getting Zn around here in Belgium.

 

[samuel-a]

It all come down to electronegativity,.
Al does't have enough potential to replace Ni.
Cl- would replace NO3- via simple evaporation to crystallization and adding HCl.
Search for de-NOx 'ing process

 

[mls26cwru]

Thx steve!

So Al would be great for cementing Chloride based solutions and even leaving Ni in the solution. (Is their a reason for this? or does Al hate Ni that much ? :mrgreen: )
And Zn would be better in Nitrate based solutions because it does not passivate unlike Al.

A question for steve or anyone who is able to answer it ; Is it possible to convert Pd nitrate into Pd chloride? Because I really have a hard time getting Zn around here in Belgium.

If i am remembering correctly from my chemistry days, Aluminum metal is a bit deceiving... Aluminum has an affinity for oxygen, so all aluminum actually has a 'shell' of aluminum oxide... since the metal is already oxidized, putting it into a strong oxidizer like nitric would have little effect. Hydrochloric on the other-hand is works a bit differently than nitric and will be able to attack the aluminum oxide.

just my two cents.


Mike

 

[9kuuby9]

Thx for your input mike!

 

[9kuuby9]

add 1 ml of formic acid for 4 gram of yellow salt or 0.5 ml for 1 gram of Pd metal in yellow salt i.e(1 gram yellow salt contains almost .5 gram of Pd metal)...

What concentration of Formic Acid Should I use in this case? I have 85% of Formic Acid at my disposal.

And thanks again for the help!

 

[Lou]

Don't just use straight formic acid...make it pH 6.5 with caustic and then use it. It's pretty darn quick at reduction so a dosing pump is best.

 

[9kuuby9]

Don't just use straight formic acid...make it pH 6.5 with caustic and then use it. It's pretty darn quick at reduction so a dosing pump is best.

From the description you'll have to add to the Yellow diammine salt; a certain amount of distilled water and Formic acid are added And then 25% NaOH is added in increments?

I guess everyone has his way of processing Pd :mrgreen:

Add DI water(Approx. 20 ml for 1 gram of Palladium or 10 ml for 1 gram of yellow salt) to Yellow diammine salt,then add 1 ml of formic acid for 4 gram of yellow salt or 0.5 ml for 1 gram of Pd metal in yellow salt i.e(1 gram yellow salt contains almost .5 gram of Pd metal),heat them upto to 65 C,then slowly add 6.25 M(25% NaOH solution or 250 grams NaOH per litre of water) NaOH solution such as for 1 gram metal or 2 gram yellow salt 1.7 ml of 6.25 M NaOH should be added.Suddenly after some greenish look all the yellow metal would be converted into beautiful settling Pd sponge.

Thanks Lou!

 

[RaoOvious]

What concentration of Formic Acid Should I use in this case? I have 85% of Formic Acid at my disposal.

Its fine,just observe the volumes to be added as per precious grams in salt.

One aspect is dont put all the acid at once,just give it a little sip,and when temp gets to 65 C,then add the rest & finally 25% NaOH to enhance the PH to drop it like a grain completely.

I guess everyone has his was of processing Pd

Its the same thing in essence at the end,so do it and then get satisfied as to which to put first

I saw your query today.

Good Luck

 

[9kuuby9]

Thank you for the detailed explenation! As it was, is and will be quite a journey :mrgreen:

 

[Research135]

You can O2/H2 melt the material and it will look shiny but it cannot be made into a casting. Have learned this the hard way.

It can only be vacuum melted and doing that from the sponge is a difficult proposition, as most induction melters' work coil frequencies are too low to melt anything less than bulk metal. You can do it if your customer starts with a heel made from the pure metal or alloy thereof.

Everything was going well for these guys... till they attempted to pour an ingot. Look at that thing spit and swell!.

edit: No safety goggles, no thermal clothes, no understanding, no respect... good electronics, I guess.

https://www.youtube.com/watch?v=r9sTVx_YV5A

 

[Research135]

Rao: The pictures of the processes are beautiful. And the palladium sand dropped with formate is what I've always aspired to get.

Can you see the pros and cons of just applying the sodium formate to the initial dark solution? (I understand you apply the formic acid first and then the sodium hidroxide).
I'm guessing that you are reaching for higher purity, as it purports in the books and pamphlets. The books sometimes deceive, and the pamphlets more. Try a small experiment and be amazed. Two iterations of what I've just written, and no need for ammonia, etc, handling of poisonous salts, etc, etc, etc.

In other words drop the metal from initial concentrated solution using sodium formate at pH little less than 7, temperature little less than 100 degC, wash the precipitate with DI water, re-dissolve with HCl-Cl2 or other method that avoids de-noxxing, filter (little to filter), drop again with formate, wash sponge with water. Only two beakers needed, and no handling of solid salts. 999, and sometimes 9999 product. Leave the ammonia and its salts for someone else. For ultimate purity, with a lot of work, DMG instead of second formate drop, washing the DMG compound (cumbersome), and conversion of same with... sodium formate, again.

edit: Of course I'm assuming there is no gold or platinum in your initial liquid.
edit2: Also I'm assuming that the initial solution is brought to around pH 6 and filtered, before the first formate drop.

 

[Lou]

Keep in mind that Pd precipitates round pH 6.