# Need help



## Beehole1234 (Jan 1, 2017)

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???


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## 4metals (Jan 1, 2017)

Yes you are and it is dropping out as silver chloride.


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## jeneje (Jan 1, 2017)

4metals said:


> Yes you are and it is dropping out as silver chloride.


I always thought AP would not dissolve silver, Learned something new with this post. Thanks
Ken


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## Geo (Jan 1, 2017)

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.


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## 4metals (Jan 1, 2017)

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


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## kurtak (Jan 2, 2017)

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



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


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## anachronism (Jan 2, 2017)

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 

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.


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## Beehole1234 (Jan 2, 2017)

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 ?


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## Beehole1234 (Jan 3, 2017)

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.


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## nickvc (Jan 3, 2017)

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.


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## Beehole1234 (Jan 3, 2017)

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.


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## anachronism (Jan 3, 2017)

How much have you got please? Also can we have some pictures?


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## kurtak (Jan 3, 2017)

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.



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


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## Beehole1234 (Jan 3, 2017)

View attachment 1


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## Beehole1234 (Jan 3, 2017)

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?


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## Beehole1234 (Jan 3, 2017)




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## Geo (Jan 3, 2017)

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.


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## Beehole1234 (Jan 3, 2017)

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


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## Topher_osAUrus (Jan 3, 2017)

The wrong information of cementing on stainless came from the youtuber moosescrapper.


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## Grelko (Jan 3, 2017)

Topher_osAUrus said:


> The wrong information of cementing on stainless came from the youtuber moosescrapper.



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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## Topher_osAUrus (Jan 3, 2017)

Oh yah, itll work. The HCl just has to eat away the chromium layer first, and some some stainless that doesnt take long at all.


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## Grelko (Jan 3, 2017)

Topher_osAUrus said:


> Oh yah, itll work. The HCl just has to eat away the chromium layer first, and some some stainless that doesnt take long at all.



Make sure not to use galvanized or you'll contaminate the copper with zinc. (If you're trying to reclaim the copper)


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## 4metals (Jan 4, 2017)

Try an experiment on a small sample of the pieces shown in the photo's. In a beaker cover the pieces with household ammonia solution (unscented) This will dissolve any silver chloride you have generated. Then filter the solution and add Hydrochloric acid to the filtered liquid. 

The silver will drop out as silver chloride and you can collect it by filtering. This process will likely clean up what you have already started processing. The parts should be free of chlorides and should be processed in nitric as if they were not processed yet at all. 

You can search for methods to convert the silver chloride you generate on the filter paper back to silver metals here on the forum. If the parts had solder on them when you started it is possible you have introduced lead into the mix and the lead will also be traveling with the silver. By boiling the silver chloride you have collected and filtered out in hot water, the lead chloride will dissolve while the silver chloride will remain. (mostly) 

If you have satisfactory results on your small sample, try stronger ammonia (ammonium hydroxide) and distilled water to process larger lots. 

Hopefully this will get you back to where you started with no losses.


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## g_axelsson (Jan 4, 2017)

Are all the contact points as yellow as the picture suggests? It looks almost like molybdenum.

Usually we use copper for cementing silver from solution, that way we don't get so much copper into our silver.

Forget anything you have seen on youtube unless it is made from one of the members on the forum.
Here is a collection with some pointers to good youtube videos.
http://goldrefiningwiki.com/mediawiki/index.php/YouTube

Göran


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## nickvc (Jan 4, 2017)

Goran ilooked at the photo after your comment and even the coin looks yellow so it could just be the lighting.


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## g_axelsson (Jan 4, 2017)

nickvc said:


> Goran ilooked at the photo after your comment and even the coin looks yellow so it could just be the lighting.


Yes, that is why I asked if they really were as yellow as in the picture.
There are contactor points made up of molybdenum and silver which leaves a yellowish residue.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=24807

Göran


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## Beehole1234 (Jan 4, 2017)

ï


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## Beehole1234 (Jan 4, 2017)

So if I throw it all back in solution the copper should disollve and push out the silver .if I am understanding you correctly.once all the copper is gone I'll pull the silver out and put strait copper in to cement out any silver left in solution


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## Geo (Jan 4, 2017)

It depends on which solution you are referring to. If it's the HCl and peroxide solution, there will not be any silver in the solution. Any silver that is dissolved in this solution will precipitate out of solution as silver chloride on it's own. 
If you roast/incinerate the points that come from the HCl and peroxide and dissolve them in nitric acid, then you can use solid copper to cement the silver out of solution. 

Silver chloride, from a chloride solution, is a solid.

Silver nitrate, silver dissolved in nitric acid, is a liquid.

AP or copper(II) chloride (HCl and peroxide) is a good way of removing the majority of copper from the silver as the silver will dissolve very little. In the overall scheme of things, not enough to even worry about. Once you have collected the points from the AP solution, it has to be heated to drive off any residual HCl. The points can then be dissolved in the minimum amount of nitric acid needed and then the silver can be cemented out of solution on copper. The cemented silver will be relatively pure (upper 90%) depending on how well you rinsed and handled the material. 
Now all you need to know is how to do all of this. Start slow and do small batches. Never work inside without a fume hood. Never work with acids inside your house. Never breath any of the fumes. wear eye protection. Be safe.


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## Beehole1234 (Jan 4, 2017)

Ok thank you so much. I won'tbe watching any more you tube videos. That was very helpful. So the other stuff that cemented out of the solution is probably copper?


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## Geo (Jan 4, 2017)

If it cemented out of a solution of HCl and peroxide onto steel, even stainless steel, yes it was copper.


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## Beehole1234 (Jan 5, 2017)

Ok so i poured off a little solution and diluted it down sl i could see in it. There is a grey powder that fell to the bottom could this be silver that all the copper has pushed out?


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## g_axelsson (Jan 5, 2017)

Diluted copper chloride solution... grey powder... how about CuCl?

Pour off the clear solution, that is all CuCl2 and can only be used for another copper cloride leach. Wash the powder in HCl, I would hazard a guess that it will dissolve most of it, resulting in a very dark solution.

Put the grey-green connector in a beaker and wash with HCl, does it dissolve the surface and bring back the red copper surface?

If it does, then you only ran too long and ran out of HCl to dissolve the CuCl and that created a layer of gray surface on the copper. In air the copper and CuCl starts to react slowly and turns green over time.

If this doesn't help then I don't know what happened.

If you still have some powder left, catch it in a filter paper and let it dry out, then put it in sunlight, if it contains silver chloride it will turn purple after a while. If you have a lot of it, only take a sample and keep the rest wet for easier processing.

Silver chloride also turns black if you treat it with NaOH, this will turn it into silver oxide and can be dissolved in nitric acid.

Göran


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## DylanDownright84 (Apr 23, 2017)

Say you don't have access to any CP nitric and you're trying to remove a small amount of pewter that accidentally got melted into a 5oz bar of silver, would it be best to just let it be? Try burning it out by re-melting a few times? Soak the bar in an AP solution with a bubbler and heat? Or have a go at making poor man's ar? Sorry for all the questions fellas. Stumbled upon this thread and it helped me answer some curiosity, but I'm still not entirely clear on what I've read here just yet (still learning.) Ammonia helps in dissolving silver CHLORIDE? That's the first I've read about that so I'll be doing more research on that.


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## DylanDownright84 (Apr 23, 2017)

So ammonia can dissolve silver chlorde, but that's really nasty stuff. Gonna leave that to the pros for now. Kinda makes me feel a bit of sympathy for the people who first figured out some of these chemical processes and methods wondering if they knew what to expect or if they just tried and got hit in the face with noxious gases. Jeez.

Edited to put in correct info: Thanks Dave!


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## FrugalRefiner (Apr 23, 2017)

DylanDownright84 said:


> So ammonia can dissolve silver nitrate


Nope, not quite. Read through again. ammonia dissolves silver ___________.

Dave


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## DylanDownright84 (Apr 23, 2017)

Chloride. Thanks again Dave! I edited my post to reflect the correct info. Back to my relentless quest for knowledge.


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