# Palladium in various states of process



## golddie (Jan 13, 2010)

> The palladium ammonium chloride precipitates if the solution if of the right concentration, temperature, and enough ammonium chloride is present in the solution.


Hi Steve
What is the right concentration, temperature, and enough ammonium chloride is present in the solution.


----------



## lazersteve (Jan 13, 2010)

I have not calculated the proper ratios, I merely add about twice the weight of Palladium expected in ammonium chloride and then sprinkle in the chlorate a crystal a a time until more has no further precipitation effect. Keep stirring between each tiny addition.

The completed reaction leaves you with a slightly yellow or sometimes lime green solution after filtering out the brick red palladium salt precipitate.

Steve


----------



## 61 silverman (Feb 24, 2010)

A question about the concentration of solution needed to precipitate the platinum and then palladium, I have a solution from Yellow dental crowns, I have allready precipitated the gold out using SMB, It seems that my solution is rather DILUTE, I kind of remember reading somewhere that a more concentrated solution is recomended for a GOOD precipitation of Pt and Pd.
Thanks Mark
Also what should the PH level be at before the Ammonium chloride.?


----------



## Oz (Feb 24, 2010)

If you are sure the gold is out, but your now PGM solution is dilute, I would use zinc to get the PGMs concentrated. Part of the reason for this is that if you try to evaporate it down you will find that the sodium from the SMB will wish to start crystallizing. Once you have your PGMs cemented with zinc you can then decant and put your solids into solution again being careful not to use an excess of reactants so that they stay concentrated. Proceed with the precipitation method of choice at that point.

Be aware that I have no idea what other contaminating elements you may have in solution with your PGMs but zinc will cement most elements.


----------



## lazersteve (Feb 24, 2010)

Oz has given some excellent advice as usual. 

I would like to add a note about using zinc on acidic solutions which contain dissolved SO2.

The addition of zinc to sulfurous acid (dissolved SO2 gas) solutions can result in the formation of hydrogen sulfide gas. This deadly gas has a characteristic rotten egg smell at first, but quickly dulls the sense of smell and becomes undetectable. Be sure you perform this reaction in a well ventilated area, preferably a good fume hood.

There is a great document on my website dealing with sulfur dioxide, sulfurous acid, zinc, and the formation of hydrogen sulfide gas.

The level of dissolved SO2 can be reduced by heating the solution to 100C before adding zinc.

Be safe,

Steve


----------



## 61 silverman (Mar 23, 2010)

Hi ALL , Here is a update on my palladium progress.
I know this is a small amount, and process and time involved, However it is pretty cool to be learning more all the time.. Thank's for everyones help
MARK


----------



## aflacglobal (May 22, 2011)

Meow!


----------



## Sucho (Jun 4, 2011)

i finished a palladium and silver recovery and refining from an 14,5 gram button that contains 45 % of Ag, 25% Sn, 18 % Pd, 8% Cu and Au,Fe, Ni, Bi, V under 1 %.

My steps :
1. Boiling in HNO3.(my button wasnt absolutely homogenous, areas with high content of Pd-Sn were almost insoluble in HNO3)
2. metallic residue with high content of Pd-Sn alloy with silver content about 3% was filtrated and dissolved in AR
3. Ag was precipitated as AgCl using NaCl, filtrated and washed with HCl
4. Pd(NO3)2 was mixed with a filtered AR solution of Pd and evaporated down with addition of HCl
5. 150 ml of very dark red H2PdCL6 was mixed with a sol of NH4Cl and bubbled with Cl2 gas
6. red precipitate of (NH4)2PdCl6 was filtered
7. yellow- brown supernatant was boiled for 30 minutes followed with a second precipitation of Pd salt- lime green supernatant
8. Pd salt was dissolved in aquaeous solution of NH3 - light blue solution with gelly pale yellow/orange residue(filtered, dryed and analysed- 86%Sn,12%Pd)
9. NH3 neutralised with HCL,but no yellow precipitate after cooling for 1 hour, only red-brown clear solution
10. because of no precipitation, i have added 0,5M DMG in 1M NaOH
11. yellow precipitate of chelate was filtered, dryed 
12. final button 1,24 grams 96,3% Pd, 2,1% Sn and rest traces of Fe, Ni, Au



Ammonia purification of Pd salt wasnt complete because of encasement of residue Pd salt in gelly tin compoud (tin oxide hydrate)?
if tin is present, it is important to filtrate H2PdCl6 sol properly fist with a fast paper, and second with a paper with very fine pores?
No precipitation of yellow Pd salt after neutralising ammonia with HCl even after long cooling can be caused by low concentration of Pd in sol?
As I discovered before, chelate of Pd(DMG)2 has a high sorption characteristic for colloidal particles


----------



## samuel-a (Jun 4, 2011)

Sn +HNO3 = problems !

I can't count them all and probably don't know all of them.

But, if i ware you in this case; after removal of Ag from solution, i'd cement Pd on Cu or more reactive metal and treat base metals with weak acidic solution, then move on to AR and next steps you stated.

This is how re-purification should look like :
It is very dilute btw (<0.1 Ammonium hexachloro palladate in 5ml NH3)

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


----------



## Sucho (Jun 5, 2011)

i know how it should look a like because i have done it before. dont know why it didnt precipitate.
yes you are right, tin oxide hydrate is a mess.
thanks for reply


----------

