Sulfuric mess with silver plate

[disPaw]

Alright. . . bring on the flames. . . I'm feeling pretty stupid over here and know I deserve it. I've been lurking for a few months and researching a bit longer. . . still accept that I'm a newb.

I deplated a buncha silver flatware using saltwater & 12V PSU. This was my first go at it and I generated quite a few filter papers. The original plan was to just burn it all up as I melted everything down in the furnace and determine my next step from there. Instead, I found the proverbial wild hair and decided it'd be savvy to incinerate everything and dissolve that in H2SO4 (well, 95% via Liquid Fire). Now I have a grainy, bubbling, black witch's brew that doesn't present any silver chloride if I drip HCL (muriatic acid) into a test sample.

Since I don't seem to have an silver in solution, my thought is to filter it down and burn the solids in hopes to recover the silver (and all sorts of other junk, I'm sure) at the bottom of a crucible in my furnace.

Is that a better track?

 

[Lino1406]

Bunch = ?g amount of silver expected?

 

[disPaw]

Bunch = ?g amount of silver expected?

Ah. . . thanks for keeping me honest. Before & after deplating weights suggest a max of 157g.

I should add that, after posting this, I decided to test another sample with HCl. This time, the solution was quite a bit warmer. I'll have to try again. . . but, I could swear I saw the "plume" of AgCl form as I dropped the HCl in the beaker. It seems to go away after it cools down, however. It seems I'll be learning even more from this venture!

 

[Lino1406]

Seems not worth the effort

 

[disPaw]

Seems not worth the effort

Understandable. . . I'm learning. . . the worth is personal so I'll continue on that way. Thanks.

 

[galenrog]

Seems not worth the effort

I agree. If the goal is to recover silver, then the economics are against you. If I have silver plated copper, I use it to cement silver from solution. Silver on about anything else is not profitable on a small scale.

Time for more coffee.

 

[disPaw]

Seems not worth the effort

I agree. If the goal is to recover silver, then the economics are against you. If I have silver plated copper, I use it to cement silver from solution. Silver on about anything else is not profitable on a small scale.

Time for more coffee.

Got it. . . much appreciated. I didn't bring up cost because it wasn't part of my conversation. This is a small-scale learning event for me. I know what I should've done. . . and that I probably should've just left this alone, completely. I know I'd have a much better idea of my actual yield, by now, had I just stuck with my original plan and melted everything down after deplating. I know I messed that up.

Anyway, just because, I let everything settle and have started pouring the "solution" off into smaller containers. I'll eat the elephant by attempting to process everything in smaller batches to see what come of it. If nothing. . . sweet. . . I didn't lose much since it wasn't worth the effort.

Thanks again!

 

[Topher_osAUrus]

If no silver is in solution, then it is still in the paper/solids.
Decant, rinse, rinse, rinse, rinse, dry. That should get you pretty close to square 1.

I dont think much would or could be in solution.. itd be silver sulfate. And its solubility is almost 8.5g/L, which of course increases with heat. If i read correctly, you say the white forms while hot, but goes away upon cooling? I don't know about that..

I have never, ever, done the salt water electrolysis though, so. This could all be bunk

 

[disPaw]

If no silver is in solution, then it is still in the paper/solids.
Decant, rinse, rinse, rinse, rinse, dry. That should get you pretty close to square 1.

I dont think much would or could be in solution.. itd be silver sulfate. And its solubility is almost 8.5g/L, which of course increases with heat. If i read correctly, you say the white forms while hot, but goes away upon cooling? I don't know about that..

I have never, ever, done the salt water electrolysis though, so. This could all be bunk

Much appreciated! After thinking through it, I believe I was seeing the HCl clean the solution up for a moment. I have, since, been able to process a small bit of the solid material and get some (of what I believe to be) AgCl to drop out. . . a very small amount. I was trying to clean the solution up and used boiling water. . . after that, it seemed like some may have gone back into solution. So, what you're telling me about the temperature makes perfect sense.

I'll, definitely, get on this. Thanks for the help. . . I'll get back with updates!

 

[disPaw]

Alright...I've attached some pictures of what I saw as soon as I removed the bucket that was covering this muck. I did pour some into a beaker, boiled it, and hit it with HCl. From what I can tell, I see this grey material come back when I pour the HCl in the beaker. It's, definitely, heavier than everything else...these flakes are the the first to settle as I rinse everything out.

Since it's present while the solution is cool and seems to dissolve when I heat it, am I seeing (dirty) silver metal drop to the bottom? If that's the case, I'm thinking I should just melt all that down after all the rinsing Tophur suggests...and start over from there...except with a cleaner, more efficient method! :lol:

 

[disPaw]

Well crap. . . this happened after trying to dissolve a small sample of what I thought was silver sulfate into sulfuric acid, again. I was trying to see if I could drop actual silver chloride by sprinkling salt into it.

Guessing this part is, definitely, falling into the lost cause category. . .

 

[Topher_osAUrus]

I feel like theres a step that I am missing/have overlooked.? Maybe a dozen steps..

...i disagree with you though, to a certain extent anyways

'Not worth it' ... ...now, if that is to say its not worth the time, effort, and money.. I kind-of get it. ..kind of..

......however ....
finding out a solution to your solution problem will give you valuable experience in one way or another, and that experience may be used, and may prove to be invaluable in the future.
Who knows, maybe that future usage, may end up making it 'worth it' ten fold over.

Wish i could help more... but, I'm not sure I know whats really going on. If it were me, I would probably try to rinse out all the acid and roast the solids, hoping I get a little lucky and reduce any complexes of silver into silver metal. Depending on what that looked like. I would either melt and shot it, or just directly leach with 50/50 nitric/h2o.

I think thats what I would try anyways. Difficult to say without it right in front of me.

Good luck! Please post more as you progress.

Regards
Topher

 

[disPaw]

Thanks Topher. . . seriously. . . I decided to put the mystery crystals aside for now. I might crush it up and see if it dissolves in some boiling distilled water.

Anyway, I've rinsed that 5L beaker out with ~4 gallons of boiling tap water and the attached picture is what I have left. One thing I've noticed is that dark material settles almost as fast as the grey material. I really have no idea what it is. . . but, I'm at a point where I'm just gonna try melting it all down in my propane furnace with a mix of borax & soda ash covering it.

 

[disPaw]

Progress with some impure silver! This is from a test batch out of that beaker.

 

[disPaw]

Melted the rest down. I still have the buttons/beads and there's a little bit of "pour-over" needing to be cleaned...none of this is included in the amount seen here.

Deciding on whether I should keep it as my first real silver pour or run it through a refining process I can trust.

Regardless, I learned a lot and am learning more...pretty excited about how it all turned out!

 

[Topher_osAUrus]

Nice.
Looks like you are well on your way now.

Was there copious amounts of white smoke while melting? Or was it a fairly clean and easy melt?

What does your slags look like?
Did it take a massive amount of flux?
-gsp once mentioned doing a final rinse of the silver using an aqueous solution of borax and soda ash before drying and then proceeding on to melting. I used the method once, and it worked very well.

AgCl is a nuisance, and makes pretty much everything more difficult...especially melting, if it has not been fully converted before hand.

 

[Topher_osAUrus]

.
.... I've noticed is that dark material settles almost as fast as the grey material. I really have no idea what it is. . . but...

Forgot to give my 2 cents on this.

Im not for certain, but, it could be as simple as silver metal, and silver oxide.

Not a big deal if so, silver oxide will break down to silver metal upon heating up to temp. (There is, somewhere on the forum, a post by.... Goran? Maybe. Where the exact temps and times are listed, so as to reduce losses to a theoretical bare minimum when directly reducing and melting silver oxide) ...might have been Lou..

...i cant recall.

 

[FrugalRefiner]

-gsp once mentioned doing a final rinse of the silver using an aqueous solution of borax and soda ash before drying and then proceeding on to melting. I used the method once, and it worked very well.

I believe that's Lou's tip.

Dave

 

[Topher_osAUrus]

-gsp once mentioned doing a final rinse of the silver using an aqueous solution of borax and soda ash before drying and then proceeding on to melting. I used the method once, and it worked very well.

I believe that's Lou's tip.

Dave

Doh! ...my memory, in my old age, fails me..
Boy, do i have egg on my face.


Thanks Dave
Sorry, Lou

 

[disPaw]

Nice.
Looks like you are well on your way now.

Was there copious amounts of white smoke while melting? Or was it a fairly clean and easy melt?

What does your slags look like?
Did it take a massive amount of flux?
-gsp once mentioned doing a final rinse of the silver using an aqueous solution of borax and soda ash before drying and then proceeding on to melting. I used the method once, and it worked very well.

AgCl is a nuisance, and makes pretty much everything more difficult...especially melting, if it has not been fully converted before hand.

No crazy smoke...but, there was a slight eggy smell as it first burned off. I had to load it up with flux to keep all the material from burning too "dry." There was probably way too much...just seemed to need it every time I added more material.

I do believe you're right about the silver oxide and silver metal state I had. I'm pretty sure silver didn't stay in solution very long at all.

The nice thing is that I have a fair amount recovered. I will, no doubt, have an order of nitric in my near future and see why it makes so much more sense to combine silver recovery efforts with gold refining. I need to work up a better rig for pouring, as well...it's crazy how HOT you have to keep everything until you're ready for it to settle!