palladium???

[Master Nater]

I'm only processing silver thus far, as i'm a newbie and am still working through my processes, and reading Hoke's guide as requested. if i ever become a jeweler, i'll let you know. anyhow, i ran a batch of electrical contacts that i purchased on eBay. i have gotten some strange results that i am unsure of, and would like to know what someone a lot smarter at chemistry than i, thinks. my first point is, i have used nothing stronger than nitric acid, as i was not expecting anything more valuable than silver. the solution is brown. after filtering, the solution is a bright green. and the stannous test and resulting precipitate from using copper are BLACK. and i mean black like tar. i have read that at certain times, palladium will go into heated nitric without HCl, which is what leans my thinking in that direction. after 10 minutes or so, the performed stannous test, eventually changed to a black/?bluish? color. is it possible that i somehow got palladium contacts??? or am i dealing with something else entirely?

i'm not sure that i'm ready to deal with potential platinosis, but would like a heads-up if i am... thanks in adavance, gentlemen. hope you all had a great weekend. i had lots of fun expanding my horizons.

 

[Yggdrasil]

I'm only processing silver thus far, as i'm a newbie and am still working through my processes, and reading Hoke's guide as requested. if i ever become a jeweler, i'll let you know. anyhow, i ran a batch of electrical contacts that i purchased on eBay. i have gotten some strange results that i am unsure of, and would like to know what someone a lot smarter at chemistry than i, thinks. my first point is, i have used nothing stronger than nitric acid, as i was not expecting anything more valuable than silver. the solution is brown. after filtering, the solution is a bright green. and the stannous test and resulting precipitate from using copper are BLACK. and i mean black like tar. i have read that at certain times, palladium will go into heated nitric without HCl, which is what leans my thinking in that direction. after 10 minutes or so, the performed stannous test, eventually changed to a black/?bluish? color. is it possible that i somehow got palladium contacts??? or am i dealing with something else entirely?

i'm not sure that i'm ready to deal with potential platinosis, but would like a heads-up if i am... thanks in adavance, gentlemen. hope you all had a great weekend. i had lots of fun expanding my horizons. View attachment 62354View attachment 62355View attachment 62356View attachment 62357

Palladium will dissolve with Nitric alone.
Was this before or after our recommendations in your welcome?
Please do not process material before you have studied and understand what you do.
The cement from Pd will be black and fine, from Silver it will look like cement.
Here is what a Stannous test look like. From LazerSteve:

Sadly if there is Silver in Solution Stannous is not a good testing method.

 

[kurtak]

First off in looking at the pic of the contact points on the watch glass (second pic) there is likely no Pd in those point (though anything is possible)

Generally speaking points that big are rarely if even made with Pd &/or a Pd/Ag alloy

Pd &/or Pd/Ag points are almost always VERY small points & found in things like OLD telecom relay switching gear

If those points are not wanting to fully dissolve in nitric (even with heat) then they are more then likely the tungsten/silver points

Here is a thread where I posted some things about tungsten silver points ---------

https://goldrefiningforum.com/threads/electrical-contacts.34106/

and the stannous test

You do not use stannous to test for silver in solution - I have posted about why you don't do that several times so here is a link to search results of things I have posted about that ------

https://goldrefiningforum.com/search/90246/?q=photo+grey&c[users]=kurtak&o=relevance

To test for silver you take a few drops of you solution (silver nitrate) & add a drop of HCl to the nitrate solution

If the nitric dissolved silver - the HCl will cause the silver in the nitric to convert to silver chloride which is a white cottage cheese precipitate - that silver chloride will then photo gray when exposed to light

and resulting precipitate from using copper are BLACK. and i mean black like tar.

IF (the BIG IF) those are the tungsten/silver contacts then the nitric likely only dissolved a small amount of silver on the surface of the points - so there is likely not a lot of dissolved silver ions in the solution - so when you put the copper in the solution it cemented out very small silver particles which will be black instead the larger "cement grey" silver particles you normally see when the solution is "loaded" with dissolved silver ions

Kurt

 

[Master Nater]

kurtak -

those in the picture are only the larger of the contacts that i removed from the solution, to get some of the junk out of it. i believe you are correct and that they are tungsten. there are other contacts in the solution as well. this batch had a variety of contacts, and i did not sort as well as i hind-sightedly should have. the reason that i decided to hit it with a stannous test is that i dipped a piece of copper in solution after hitting it with some nitric, to see if i had any excess nitric left in it, and it immediately began giving me a black precipitate on the copper. i don't mean soft, silver precipitate. it looked like wet tar. that result, along with the fact that the nitric solution was a bright green and not blue is why i decided to run a stannous chloride test on it. surprisingly, it hit black. after reading your post on silver chloride, it does seem to be going from black to a purple-ish. i'll expose it to more light, and see what it does. like i said, i'm still learning, and appreciate your insight. i do not believe that any chlorine got into my solution, but anything is possible. i've had that solution sitting on the shelf for a while, and anything is possible. i would think it would have to be a lot of chlorine to render this much silver chlorate precipitate. getting back to the story at hand, i followed hoke's law of "when in doubt, precipitate it out." so, i stuck the copper bar in there to see what all would precipitate out. so far, it's been a lot, and the solution is still green, and still precipitating. my assumption is that the solution will begin turning blue when i have almost all of the metals replaced with copper in the solution. is this a correct assumption?

so, now that i'm where i am, how is the best way to go about testing to see if that precipitate is silver or gold? treat it as silver chloride, and then re-dissolve?

thanks again, for the help.

 

[Yggdrasil]

those are only the larger of the contacts that i removed from the solution, to get some of the junk out of it. i believe they are tungsten. there are other contacts in there as well. this batch had a variety of contacts, and i did not sort as well as i hind-sightedly should have. the reason that i decided to hit it with a stannous test is that i dipped a piece of copper in solution to see if i had any excess nitric left in it, and it immediately began giving me a black precipitate on the copper. i don't mean soft, silver precipitate. it looked like wet tar. that, and the fact that the nitric solution was a bright green and not blue is why i decided to run a stannous chloride test on it. surprisingly, it hit black. after reading your post on silver chloride, it does seem to be going from black to a purple-ish. i'll expose it to more light, and see what it does. like i said, i'm still learning. i do not believe that any chlorine got into my solution, but anything is possible. i would think it would have to be a lot of chlorine to get this much precipitate. so i stuck the copper bar in there to see what all would precipitate out. so far, it's been a lot, and the solution is still green, and precipitating. my assumption is that the solution will begin turning blue when i have almost all of the metals replaced with copper in the solution. is this a correct assumption?

thanks again, for the help.

To do a proper Stannous test on this.
Remove the Silver by converting to Silver Chloride.
Take a few ml and drop in a bit of Salt, let it clear up and dip a piece of paper or a cotton bud in it and then test this.
If it is too dark dilute it and try again.

 

[Yggdrasil]

those are only the larger of the contacts that i removed from the solution, to get some of the junk out of it. i believe they are tungsten. there are other contacts in there as well. this batch had a variety of contacts, and i did not sort as well as i hind-sightedly should have. the reason that i decided to hit it with a stannous test is that i dipped a piece of copper in solution to see if i had any excess nitric left in it, and it immediately began giving me a black precipitate on the copper. i don't mean soft, silver precipitate. it looked like wet tar. that, and the fact that the nitric solution was a bright green and not blue is why i decided to run a stannous chloride test on it. surprisingly, it hit black. after reading your post on silver chloride, it does seem to be going from black to a purple-ish. i'll expose it to more light, and see what it does. like i said, i'm still learning. i do not believe that any chlorine got into my solution, but anything is possible. i would think it would have to be a lot of chlorine to get this much precipitate. so i stuck the copper bar in there to see what all would precipitate out. so far, it's been a lot, and the solution is still green, and precipitating. my assumption is that the solution will begin turning blue when i have almost all of the metals replaced with copper in the solution. is this a correct assumption?

thanks again, for the help.

By the way, a Palladium solution is colored from a orange pinkish color dilute to a dark brown in a maroon shade concentrated, not green.
When we have Pd alone.

 

[Master Nater]

yggdrasil - the precipitate is black and quite fine. the only reason i ran stannous on it, was the green color of the solution, and the black precipitate, when i checked for excess nitric with a piece of copper. too many youTube videos, maybe?

to answer your question on timing, i had put this solution together and began running it before i had come to this forum. i'm right now, i'm in "clean up the lab and get a good process moving forward" mode. i have a feeling, this will take a while. but that's the fun and excitement of learning a new hobby. i'm just hoping to be able to do it safely, with a bit of expert advice from people who know better than i do. thank you again, for your help.

 

[anachronism]

If your precipitate is black and fine, and you can get some of it without the copper mixed in then dissolve some of that up into the Nitric alone and see what colour it is in solution. That way you "should" have Palladium Nitrate with very few contaminants in it, which could give you a far better colour indicator. Don't take it all, take a decent sample of it.

If it doesn't dissolve then naturally there are further questions to ask but I've got a hunch that it will.

You're thinking logically which is a great start, as if it was precipitated using copper it has to be a PM or a PGM so let's narrow the field a bit and see where it takes us.

Edit for typo.

 

[Marcel]

Let me add that melting Palladium is rather difficult compared to Gold from my perspective. Be smarter than me and check how it goes before you start. Otherwise you may lose a lot of value in doing so. You need the right crucible, the right torch and some more. There are some experts in this forum who can teach you how to do it. I find it far more difficut than melting Gold or Silver. So before you start trying to melt this Pd, get the info first...