# Dropping palladium from an HNO3 and NaCl mix



## Trypanosoma (Jan 6, 2017)

Hello there friends

I got nitric acid in which there is Pd dissolved that I'm trying to drop.
Turns out some refiners I know, recovered silver from jewelry scrap containing Ag and Pd. They were going to throw away the water since they didn't know how to recover the Pd. The used NaCl to cement the silver.
I did my homework and researched about the process, I read Hooke's book and studied before I came up with a plan.
Right now I'm evaporating the solution (I'm careful it doesn't boil) to try to get the syrup-like consistency. After that I will add HCl and proceed as Hoke describes.
What makes me uncomfortable is that there is a lot of NaCl in the solution and it continues precipitating even after evaporating the solution to a third of what it was (I had 60 liters, now I have 20). Will it affect the recovery of Pd at some point of the process? Has anyone here experienced the same problem?

Thank you in advance for your comments.


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## Topher_osAUrus (Jan 6, 2017)

Well, if the silvers already out. Why not just cement the pd onto copper?


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## Platdigger (Jan 7, 2017)

I second that notion. All though you may want to bring the ph up a bit so you don't dissolve so much copper.


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## Trypanosoma (Jan 7, 2017)

It sounds like a good idea, I'll give it a try.
Thanks for the fast answer by the way.



Platdigger said:


> I second that notion. All though you may want to bring the ph up a bit so you don't dissolve so much copper.



Should I use NaOH for that?
I read somwhere that a pH=1 would be good for dropping the Pd but that may be wrong, if it is, what would be a proper pH? Also, I was thinking that having less volume would help in not using a lot of copper, am I right? Maybe 10 liters would be a good volume.
I know that there are about 100 g of Pd in solution if that helps, although I don't how much NaCl there is.


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## jeneje (Jan 7, 2017)

Trypanosoma said:


> It sounds like a good idea, I'll give it a try.
> Thanks for the fast answer by the way.
> 
> 
> ...


If you have a 100grams of Palladium in solution, and have never dropped PGM's, I would advise you to contact Lou and see if you can send it to him for recovery. Although you can cement the Palladium out as stated above, the purity is going to be low and you will have to send the black powder to a refinery anyway to get it refined. I don't know if Lou does that, but I would really consider it. 

A word of CAUTION here, PGM are Extremely Dangerous to recovery and refine without the proper equipment and/or knowledge. Not to dredge up old memories but, a very valued member of the forum passed away a few years back from a disease caused by PGM's, he was a Chemist. 

Edited to add: Stay away from the vapors and DO NOT GET any on you skin. Wear PPE when around the solution. Good luck.

I would consider all my options, just saying.
Ken


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## goldandsilver123 (Jan 7, 2017)

If you are precipitating NaCl you added Much more than it's needed.

Silver precipitates "quantitavely" with chloride ions

AgNO3 + NaCl -> NaNO3 + AgCl

If you have excess NaCl you could lose some of the silver, not much, because:

AgCl + NaCl -> Na[AgCl2] this is soluble, just like AgCN isn't soluble but Na[Ag(CN)2] is.

It can be NaNO3 precipitating, how concentrated in silver was your solution, and how did you do the AgCl precipitation?

I would reduce with copper or with zinc dust, if you didn't exceeded in nitric, then work with the solid.


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## jeneje (Jan 7, 2017)

Trypanosoma said:


> Hello there friends
> 
> I got nitric acid in which there is Pd dissolved that I'm trying to drop.
> Turns out some refiners I know, recovered silver from jewelry scrap containing Ag and Pd. They were going to throw away the water since they didn't know how to recover the Pd. The used NaCl to cement the silver.
> I did my homework and researched about the process, I read Hooke's book and studied before I came up with a plan.


Since you have studied Hoke's book and done your research, you have tested the solution with Stannous Chloride to make sure that there is Palladium in the solution, RIGHT! Or, used DMG to test it and got a yellow salt that precipitated out. I ask because you have not said how you know, other than, some refiners got the Ag out. I question this because, if they were refiners, they would not leave 100 grams of Palladium in a solution. Sorry, but that is the way I see it. That is like leaving money on the table, so to speak and walk out. 100 grams of Pd at current market value is $2424.43 breaking that down would be $24,24 per gram at current market of 754.00 a troy ounce so, i have to ask, why would you leave that for someone else? Makes NO SENSE!

Ken


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## Trypanosoma (Jan 9, 2017)

jeneje said:


> Since you have studied Hoke's book and done your research, you have tested the solution with Stannous Chloride to make sure that there is Palladium in the solution, RIGHT! Or, used DMG to test it and got a yellow salt that precipitated out. I ask because you have not said how you know, other than, some refiners got the Ag out. I question this because, if they were refiners, they would not leave 100 grams of Palladium in a solution. Sorry, but that is the way I see it. That is like leaving money on the table, so to speak and walk out. 100 grams of Pd at current market value is $2424.43 breaking that down would be $24,24 per gram at current market of 754.00 a troy ounce so, i have to ask, why would you leave that for someone else? Makes NO SENSE!
> 
> Ken



Yes, I tested it first with SnCl2. I haven't tried to get DMG yet.
We are gonna split the money 2:1, which seems like good bussiness to me.
It also didn't make sense for me when they told me they THROW PALLADIUM AWAY. I was astonished. All they care about is gold and silver.
Seems like there isn't any Pd refiner in my state. Actually, to sell the recovered Pd we will have to travel to a different area.
If you guys were to see how they work.. god... when I first worked with them, I had them buy gas masks that actually worked, encouraged them to use eye protection at all times and I'm trying my best to make them work with longs sleeves. I use a lab coat to work, but these guys just use a regular T-shirt.
I'm a chemist, but metals are not my area of expertise, I'm well aware of the dangers thought; so, I appreciate all the safety advices that I have seen all over the forum.
Currently I'm still evaporating the excess nitric to work with a smaller volume, but it's taking forever.
As soon as something new comes up, I'll let you guys know


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## Topher_osAUrus (Jan 9, 2017)

I was thinking the same thing as Ken, but I figured there are a few circumstances that could end up with this situation you have. Not being educated well enough is one of them.. Recovering silver and gold is easy, dealing with pgm's isn't so much.

And, as far as the t-shirt thing goes, I know of a few people on here that opt for them. Only because its easy to know when you get a splish splash on your arm, and it may not be as evident on a long sleeve... Which would then slowly permeate through and get on your skin, and if you were working with platinum in solution, that is not something you want happening.

As far as the gas mask thing, I would also say, maybe a fume hood is a better option than respirators.

Can't wait to see your recovered Pd!

-toph


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