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Beehole1234

Member
Joined
Jan 1, 2017
Messages
12
I've been using hcl and peroxide along with a air pump to disollve the copper from silver that I get from electrical equipment. After using this a few times a grey powder is covering everything .I need to know if I am dissolving my silver as well as the copper???
 
HCl acid does attack silver but it does so very slowly. The outside surface of the piece will develop a white layer of silver chloride that resist further oxidation of the silver metal. The layer of silver chloride slows the oxidation down but it doesn't stop it completely. The reaction can be sped up by adding oxygen or by heating the solution. There are other forces that can be applied such a pressure but the first two is the most common. By keeping the solution oxygenated through the process of dissolving base metals, it is dissolving silver too. Since silver can't stay as a liquid in HCl, it precipitates out as solid AgCl.
 
I did not want to go into detail on this thread because the method is not a good method. If the OP gets lucky he will convert all of the silver to silver chloride, but likely some will fall to the bottom of the vessel, some will cling to the scrap as chloride and some will fail to come off at all and remain as plating on the scrap. So as an effective recovery method, this technique is poor.

Due to the price of silver and the thickness of electroplated silver, recovery is difficult to do profitably. The brightest light in the tunnel for silver plating is the cell Jon is describing on this thread. http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=40&t=24899
 
4metals said:
Due to the price of silver and the thickness of electroplated silver, recovery is difficult to do profitably. The brightest light in the tunnel for silver plating is the cell Jon is describing on this thread. http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=40&t=24899
Click to expand...

I assume you are talking about running Jon's winning cell in conjunction with a cyanide leach operation - that would certainly be the away to go for silver plated items 8) :!:

Kurt
 
Thanks for the upvote chaps but do bear in mind that actual leach process used will depend upon the base material in the silver plate. Pewter is most heavily prevalent in the UK however if you come across it as a base material you will need to use an acid based leach. Same leach system, same cell though :D

We're working on an alkali based leach for this however it's a way off and it isn't a given that it will work.
 
Ok so I have all these chunks of silvery attached to the copper what is the best way to remove the copper? And how do I get my silver back out of the acid ?
 
This is not silver plate.these are pads of silver that come from contacts that run the industrial compressors for refrigeration units at my job.
 
To be honest I think you need some nitric and of you can source some try and pick pieces with the least copper and dissolve it all, once it's all dissolved use some more contacts to cement out the silver, this will also recover the silver from the contacts you are using to cement.
If it were me I would then build a silver cell, details are fully discussed and detailed here on the forum ( palladium built a great mini cell ) and use some of the recovered silver to make your electrolyte and use the rest to bring the contents up to at least 97 percent and melt it into cornflake for the cell anode, when the cell is running you can use any harvested silver to repeat the process, the electrolyte will foul, too much copper in it so use more contacts to recover the silver from it, again a free recovery of the silver content which can then be used either for a new electrolyte or for more anode material, this process will be the most economic way I can think of and also the process will allow some free recovery of the values.
 
Ok i have a bottle of nitric have not used it yet .this is my first time doing something like this.I watched a few you tube videos and thought I could do it . I have a good bit of silver but it all has copper on it.I have done a couple of small batches so far. But this was a large batch.I removedall the contacts from the acid. Now that it has dried they have turned green on the copper part.so if I disollve everything I can just precipitate out the silver .and what do I do with the gallon of hcl and peroxide that is full of copper and silver . I would like to get the copper back also.would like to make a bar of pure copper to go with the other ones.
 
Beehole1234 said:
This is not silver plate.these are pads of silver that come from contacts that run the industrial compressors for refrigeration units at my job.
Click to expand...

Ok - so you are talking about silver "contact points" that are attached the copper "bus bars"

Are the "points" soldered on the bus bars - or are they riveted to the bus bar ?

How big are they ? (pictures would be very helpful)

If they are soldered to the bus bar you will be best served to de-solder the points from the bus bar :!:

If they are riveted to the bus bar you should ether drill the rivet out (on the back side) or cut the point off the bus bar as close to the point as possible :!:

The reason for this is that you want to remove as much copper as possible before dissolving the silver in nitric :!:

The reason for that is that the same amount of nitric will dissolve 4 times more silver then copper - so - what that means is that the more copper you remove manually (before trying to dissolve them) the "less" acid (by a LOT) you will use to process/recover your silver

Example; - it takes about 1 gallon of 70 percent nitric plus 1 gallon of "distilled" water to dissolve "only" 2 pounds of copper - on the other hand - with that same gallon of nitric you will dissolve about 8 pounds of silver

Note; - when dissolving silver with nitric (& if your nitric is 67 - 70 percent nitric) you "need" to dilute the nitric by at least half AND you "need" to use distilled water - do NOT use tap water --- if your nitric is less then 67 percent you can dilute it less - how much you dilute the nitric depends on the (percent) concentration of your nitric

Again - pictures of what you have would be good as it helps us "see" what you are working with :!:

Put something like a quarter in the picture so we can see a size comparison

Kurt
 
The other times it did not turn green like this .but I guess my solution is saturated now .so I stuck a stainless steel spatula in the solution . It is getting coated with something is that copper or silver?1483486795399857488638.jpg
 
Why do people insist on using stainless steel for cementing copper out of solution? Where did that bit of misinformation come from? I have tried to comment on all the youtube videos that I see it pop up on but it had to start somewhere.
Stainless steel is a poor choice of metal to cement copper out of solution with. Plain mild steel works better and is cheaper. There are components in some stainless steel that is more toxic than the copper.
Roast what you have to a dull red heat and dissolve a sample in nitric acid. Take a small sample of this solution and put it in a small glass container. Add a few crystals of table salt. If a white cloud forms, it is silver.
 
All I have seen is you tube videos.this all new to me .but I would like to get it right because I have access to plenty more silver like this.I know silver is cheap but I do nothing to get it a couple of friends just bring it to me all the time
 
Topher_osAUrus said:
The wrong information of cementing on stainless came from the youtuber moosescrapper.
Click to expand...

That's where I first heard about it also, but it seemed to work for him. Takes longer and is more expensive.
 

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