Relay Points

[jjhall68]

I ran across some small relays (Panasonic DSP1-DC24) that had what appeared to be gold points. I collected 2 grams of these to test and using Schwerter's Solution (thanks Phil) it appears these are gold plated silver. Has anyone run across these or processed them?
All the Best,
John

 

[macfixer01]

I ran across some small relays (Panasonic DSP1-DC24) that had what appeared to be gold points. I collected 2 grams of these to test and using Schwerter's Solution (thanks Phil) it appears these are gold plated silver. Has anyone run across these or processed them?
All the Best,
John

According to their data sheet the contacts are: Au-flashed AgSnO2 type

Datasheet here:

http://datasheet.octopart.com/DSP1-DC24V-Panasonic-datasheet-135794.pdf

macfixer01

 

[jjhall68]

Thanks for the reply and the info macfixer01.
Have you or anyone here ever processed this alloy? (AgSnO2) I did a quick search and the only mention I find of it on the forum is your reply to me.
I am curious if I could digest them in HCL to remove the SnO2 and then incinerate the Ag and process with Nitric?
If not perhaps warm 35% H2So4?
I read in Hokes book that nitric will make a mess of the tin so I will skip that.
I would appreciate any input. I am not in any hurry and at this point I only have about an ounce of these but I would like to know the best way to handle them?

All the Best.
John

 

[Harold_V]

I expect that you'll have no luck with either of those processes, but you should be able to dissolve the contacts with nitric, then recover the silver with copper. So long as you avoid filtration, you won't have any particular problems, and the traces of tin that will follow the silver will be eliminated when the silver is melted and fluxed.

My suggested approach would be to dissolve them in dilute nitric, using distilled water, to avoid creating any silver chloride---then simply recover the silver directly by adding pieces of copper. Once the silver is down, allow the cemented silver to settle well, then siphon the solution. Rinse (tap water is fine), and if you have any issues with tin, add some HCl to the rinse. Repeat the rinse until the water is clear, then it should filter perfectly well, so you can dry the recovered silver. By certain to flux with borax after melting, so it will absorb the oxides that are created. The silver should be of relatively good quality, certainly good enough to be sent to the silver cell.

Harold

 

[Geo]

what color should the silver powder be? i did exactly as you described and as the disolution proceeded alot of white pasty stuff formed.after the reaction stopped i filtered the liquid and cemented with copper but heres the issue.the filter dried with a purple color and the powder is a light tan.all the points were gold clad and i havent processed the white paste to try and reclaim any gold yet,could the gold have somehow gotten dissolve with the silver?i know this is unlikely as the glassware has never had any chloride in it and there was no other oxidizer present.

 

[jjhall68]

Harold,

Thank you for the reply I will try that just as you outlined. I will post my results in the next few days. I have read tons of your posts and would like to say thanks again for all the exchange of information here on the forum. This is an amazing opportunity for hobbyist like me to gain insight from folks with not only vast experience but from many different walks. I appreciate the time and energy put into this by many and although I know I am not the first to say how great I think it is I do want to let you know. I read you are in Washington so if you’re in the Seattle area I hope your lights are on today.

Geo,

I am new to the forum and to metal refining and I have read lots of your posts on here so I know that you have far more experience than I do. However in case it’s helpful I read about the white paste I think you have in Hokes book around page 70 through 72 she describes it as "Meta Stannic Acid, Tin Paste, and a Gelatinous Tin Paste". She describes how to deal with it however she may be referring to a higher concentration than what is in the AgSnO2 contacts, as the section is mainly about soft solders and weighted rolled and filled scrap. All that being said Harold’s process sounds simpler so that is the route I will take for my test batch. I would appreciate hearing how yours works out in case I ever find myself in the same spot.

All the Best,
John

 

[Harold_V]

what color should the silver powder be? i did exactly as you described and as the disolution proceeded alot of white pasty stuff formed.after the reaction stopped i filtered the liquid and cemented with copper but heres the issue.the filter dried with a purple color and the powder is a light tan.all the points were gold clad and i havent processed the white paste to try and reclaim any gold yet,could the gold have somehow gotten dissolve with the silver?i know this is unlikely as the glassware has never had any chloride in it and there was no other oxidizer present.

I expect that the gold is there, simply mixed with the tin. I do not see any reason for it to have gone in to solution, but if it received a hard boil, it certainly could have been broken down to fine particles. In regards to the purple color, that's pretty common when dissolving values and tin. I don't have an explanation, I simply am familiar with the phenomenon.

If you've been successful in separating the silver nitrate from the solids, I'd suggest you incinerate the solids, then pulverize and screen. I would then give them a wash in hot HCl (boiling, in fact), then rinse well. I would then dissolve the values (AR). The HCl wash allows the recovered values to be filtered without issue.

Assuming you had simply dissolved, then collected everything after cementation, I considered that the contacts may have a gold plating. That's why I suggested cementation without filtration (along with avoiding filtering a solution that is difficult). I'd simply allow everything to go to the furnace, where it most likely will be sorted by fluxing. The tin, no longer being in the elemental form, should make that a reality, and the gold, regardless of form, would end up alloyed with the recovered silver. It would be recovered from the silver cell as slimes.

Harold

 

[Geo]

thanks jjhall68 for pointing that out.it really is a bad habit on my part that i need to work on.i should have used the technical name or even the chemical formula for metastannic acid but in my defense members call it many things and none of it pleasant, as i was speaking to Harold, i knew he would know what i was talking about and that is one of my short comings assuming everyone is on the same level of understanding.

thank you Harold, i will do as you suggest and incinerate the lot.crush, screen and wash in boiling hcl follow with rinses with water and disolution with AR. it was just over two ounces of very small gold clad points so im not expecting more than a couple of grams of gold returned but im not too keen on losing it either.

 

[jjhall68]

Geo,

I figured as much (I was honestly reluctant to post my comment) but since I just referenced how Hoke said to treat the material when macfixer01 clued me in to what the alloy was I thought I would throw it out there in case it was useful. I have 50 or 60 of those little relays to pull apart. They are kind of like rock shrimp, you could starve to death while eating them but I have them and I would rather spend my spare time doing things like that than watching TV so I'll post how they turn out.

All the Very Best,
John

 

[johnny309]

From several relays producers(like Finder...as an example)...the gold plating on the relay contacts is 5 um. Hope that will help to figure the gold amount to be expected.