Electrochemistry yellow scum from reverse plating of silver

[solarsmith]

after reverse plating one medium sized silver plate I got a lot of yellow scum floating on the top of my salt water electrolyte solution I am using non iodized salt and tap water. The silver is turning dark and flaking of the copper base like normal. any one have any ideas of what this might be?

 

[Lino1406]

Try mixing wet scum with caustc soda, see if blackens, then it is AgCl

 

[shruli]

I found a tip from Moose scrapper on YouTube that works really well... Add a small amount of HCl, any base metal particles in there are so fine they will dissolve in to solution almost instantly.

 

[kurtak]

after reverse plating one medium sized silver plate I got a lot of yellow scum floating on the top of my salt water electrolyte solution I am using non iodized salt and tap water. The silver is turning dark and flaking of the copper base like normal. any one have any ideas of what this might be?

Per the bold print - when de-plating silver in a H2O cell you do not need to add salt (& for that matter do not want to)

Adding salt to the water can/will cause the silver to turn to silver chloride

As well - an excess of chloride (sodium chloride) by adding salt - can/may/will cause a reaction with other (base) metals - including the SS bowl you are using for you cell

All you need is plain old tap water - you do not want to use distilled water - & you don't want/need to add salt to the tap water

There is a complete discussion about it here (12 pages long) read the whole thread

https://goldrefiningforum.com/threads/processing-silverplate-with-h2o-cell.16591/
Pay close attention to what solar_plasma posted in this tread - he took a deep dive into running an H2O cell using plain tap water --- on page 8 he talks about stripping 130 grams silver from a large plater --- on page 9 he makes this comment -------

It has become my favorite for silver plated material. I would not use any other process anymore.

Kurt

 

[Geo]

Post from mocodos in 2015. I think.
https://goldrefiningforum.com/threads/deplating-silver-from-silverplated-items.12530/

 

[kurtak]

Post from mocodos in 2015. I think.
https://goldrefiningforum.com/threads/deplating-silver-from-silverplated-items.12530/

Interesting thread - thanks for posting it Geo - as the saying goes - "there is more then one way to skin a cat"

What I find most interesting though is the comment made by solar_plasma at the end of the thread (last post in the thread)

Tap water cell is the best option in my eyes. CuSO4 has the problem of fouled electrolyte=a lot of actual waste solution.

solar_plasma played extensively with both cells - & it appears that in his (extensive) work with both cells - he found the "tap water cell" to be the best option for de-plating silver - at least by way of a cell


Kurt

 

[Yesterday]

I’m running a very similar but larger platter in the deplate cell atm I also have yellow slightly blue scum on mine. I’ve seen it before. Let me know what sort of base metals is on yours, mine seems to be brass with a copper strike, but there seems to be quite an amount of zinc in the brass also

 

[Barthel732]

Howdy. I have silver plated items in water removing the silver but in the process I have this this yellow stuff in the water. Yes I did add a little salt. Any ideas what this is

 

[Yggdrasil]

Howdy. I have silver plated items in water removing the silver but in the process I have this this yellow stuff in the water. Yes I did add a little salt. Any ideas what this is

As I said to you plated Silver is hard to recover profitably.
Anyway you need to give a lot more info before we can help you.
Have you even checked that it is proper Silver plated, not some of these Nickel alloys?
In a Water Cell there should not be any Salt if I remember correct.

 

[Barthel732]

Yeah it’s silver plated. I really didn’t do anything but put a teaspoon maybe less of salt in it and used a copper wire for the ground and hooked the other wire to the plated item and turned it on to 12 volts for half hour and this yellow stuff formed

 

[Yggdrasil]

Yeah it’s silver plated. I really didn’t do anything but put a teaspoon maybe less of salt in it and used a copper wire for the ground and hooked the other wire to the plated item and turned it on to 12 volts for half hour and this yellow stuff formed

Search and read about the water cell here in the forum.

 

[Barthel732]

Well you were right and I was wrong. There was stickers on these pieces saying silver plated. And the seller said they were plated but I just tested and not silver plated. Guess I should stop being so trusting with people.

 

[Shark]

As Yggdrasil said, search and study the post about water (H20) cells. Read it several times if needed and you will learn a lot about handling silver plated items. That said, you still won’t recover much silver, but you will be more successful at it.

 

[Barthel732]

Ok got it. Thank you both for your time and information.

 

[Martijn]

Post from mocodos in 2015. I think.
https://goldrefiningforum.com/threads/deplating-silver-from-silverplated-items.12530/

Awesome post. I'll be trying this one tomorrow!! Great way i never heard of. I love electrolysis. And this is one more use for my powersupplies silver plated ware and buckets full of copper sulfate.
Diving deep into it!
Curious if it will work on sterling or anodes from cement as well.

 

[Shark]

Awesome post. I'll be trying this one tomorrow!! Great way i never heard of. I love electrolysis. And this is one more use for my powersupplies silver plated ware and buckets full of copper sulfate.
Diving deep into it!
Curious if it will work on sterling or anodes from cement as well.

Do a work up on the forum of it. I would be curious as to how well it works out myself.

 

[silvergoblin]

Pretty sure it's copper hydroxide. My Ph with salt water goes to 10 pretty quickly.

Add some(not much) hcl and it will switch, over time, to copper oxide as the solution goes to around 2/3 ph

It's very spongy so try and keep it separate. I use a filter membrane Between anode and electrode to keep the plating and copper sponge apart.

When doing cleanup, there is agcl mixed with the sponge. I use ammonium to dissolve agcl from sponge, filter, then precipitate to agcl and save it.

Hope that helps some