# Electrolytic refining of copper



## w0lvez (Apr 23, 2011)

I can't figure out why the AC DC adaptor is overheating. I'm using a sterling silver anode and pure copper cathode in copper sulfate and sulfuric acid bath. I tried using a 12v-3v adaptors but they all heats up too fast after few minutes. I already tried adjusting the distance of the electrode but didn't solve the problem. :?: :?:


----------



## Sucho (Apr 23, 2011)

sterling silver anode and copper cathode in sulphate electrolyte ????


----------



## qst42know (Apr 23, 2011)

Sounds like you are exceeding the Amp rating of your components.


----------



## goldsilverpro (Apr 23, 2011)

Sucho said:


> sterling silver anode and copper cathode in sulphate electrolyte ????



wOLvez,

I would ask the same question, as this makes zero sense to me. What are you trying to accomplish?


----------



## w0lvez (Apr 23, 2011)

goldsilverpro said:


> I would ask the same question, as this makes zero sense to me. What are you trying to accomplish?



I think this is the best and more efficient way to refine silver. Using a sterling silver anode in a copper cell will remove 99.9% of copper making it almost pure silver and dissolve it in nitric acid. :idea: :idea:


----------



## 4metals (Apr 23, 2011)

While that may be possible if the anode is thin enough and has a lot of surface area for the copper to dissolve out, I don't think it would hold true where 92.5% of the material is silver and the anode is a thick slab. I think the silver will prevent all but the surface layer of copper from leaching.


----------



## w0lvez (Apr 23, 2011)

4metals said:


> I think the silver will prevent all but the surface layer of copper from leaching.



It will not because the whole anode will dissolved. I can see the sludge dropping below the anode. The problem is I can't run it too long because it's overheating the power source. I'm currently using a thick cathode with large surface area because I can't find a pure thin copper with large surface. Is it possible it's overheating because of the cathode?


----------



## Barren Realms 007 (Apr 23, 2011)

w0lvez said:


> 4metals said:
> 
> 
> > I think the silver will prevent all but the surface layer of copper from leaching.
> ...



Sounds like your surface area is too large and putting too much of a load on your equipment. 

Have you tried getting you a piece of copper pipe and cutting it length ways down the center and flatening it out?


----------



## w0lvez (Apr 24, 2011)

Barren Realms 007 said:


> Have you tried getting you a piece of copper pipe and cutting it length ways down the center and flatening it out?



I tried using copper tube but I haven't tried cutting and flattening it. I'll try it and hope it works.


----------



## goldsilverpro (Apr 24, 2011)

4metals said:


> While that may be possible if the anode is thin enough and has a lot of surface area for the copper to dissolve out, I don't think it would hold true where 92.5% of the material is silver and the anode is a thick slab. I think the silver will prevent all but the surface layer of copper from leaching.



wOLvez,

At first glance, I would agree with everything 4metals said. 

Have you been able to completely dissolve a sterling anode? Are you getting a lot of gassing at the anode?


----------



## butcher (Apr 24, 2011)

I think you will end up with silver and copper powders as sludge, powders are easy to dissolve later, copper and silver are hard to separate without dissolving both in nitric acid and cementing out copper, silver can then be purified in thumb cell, the advantage here seems powders should react faster (careful) and use less nitric acid.

Heat is wattage, to lower wattage you can use a light bulb in series with cell to limit the current in the total circuit, + --------O-------anode cell ,+ power supply, ---- jumper wire, O tail lamp from car.


----------



## goldsilverpro (Apr 25, 2011)

I'm assuming he's using a typical weak sulfuric, copper sulfate bath. Like 4metals, I don't think it will break the bar down. I think there will just be a lot of gassing at the anode and the copper already in solution will be depleted by plating out at the cathode.


----------



## w0lvez (May 18, 2011)

goldsilverpro said:


> I'm assuming he's using a typical weak sulfuric, copper sulfate bath. Like 4metals, I don't think it will break the bar down. I think there will just be a lot of gassing at the anode and the copper already in solution will be depleted by plating out at the cathode.



I tried using a stronger sulfuric but it just lessen the heating but still overheating after running the cell for few minutes. I tried using a thin silver/copper dog tag anode but I think it has more copper than a sterling because it's very thin but not soft and replace the phone charger with car charger as power supply. It works successfully. I think the anode should be thin with large surface area to be easily break down and avoid overheating. Now, the problem is how will i make a thin sheet of anode? 

*I'm sure this will work because this method is used to recycle and refine in the big scale. *

I found a video on youtube using that method Link<----


----------



## Tinker Terry (May 20, 2013)

I have been working on a similar project. Burned up a furnace transformer right off the bat. That was using AC electrolysis to dismantle computer parts. That was just experimenting for fun. My last experiment I used a saturated solution of copper sulfate and a 6/12 volt DC power supply. Had no problem with the power supply which has a 10 amp breaker. Only problem I had was the copper not bonding to the negative electrode. I hesitate to use the terms anode/cathode because there is so much confusing information available. Metal ions travel from the (cathode) electrode which is connected to the positive terminal of the DC power supply (which is the anode of a battery cell). 
An ampere meter and a variable resistance installed in the circuit should solve your problem. A household light dimmer switch might work for you, installed on the AC input side of the transformer. 
In my research I have learned that selectively removing metals is highly dependent on the voltage you use. I expect the electrolyte you use is just as important because the anode (which is connected to the - terminal of battery ) doesn't gather ions from the Cathode (+). Is gathers ions from the electrolyte, which are replaced by ions from the cathode. So using copper sulfate will result in copper plating whatever you connect to the - terminal be it a silver spoon or an iron nail. To purify silver you should first of all be using silver as your electrolyte. 
I would try dissolving a bit of pue silver in aqua regia and then add it to distilled water. Set up your cell with only distilled water for electrolyte, turn on the power and nothing will happen. Add your silver ions(the aqua regia/silver solution) a drop or so at a time. The more you add, the more amps you'll get. 
If you should happen accross a good chart that gives the voltages required to harvest the various element I would appreciate it muchly if you pointed me to it.


----------



## solar_plasma (May 20, 2013)

*Edit:  did not see this is an old thread, I answered to the prob above, sorry*

Ofcourse it works, in fact that's the kind of cell I am working with since over a week. BUT this is after my experience more recovering, than refining. You will cement all gold and pgm's together with the silver. With a fresh cell you can get almost white silver powder, absolutely true, but the most time you get darker grey or even brown silver powder from a extensively used electrolyte. I would say, "refining" starts in the case of silver at the point, you can cast anodes for the Ag/AGNO3-cell, which means 990+.



> I can't figure out why the AC DC adaptor is overheating.



I would guess, your adapters are not build for hard long term work. Can you post a picture? 

Have you checked this thread: http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=50&t=12530&start=40 ?

butcher


> I think you will end up with silver and copper powders as sludge, powders are easy to dissolve later, copper and silver are hard to separate without dissolving both in nitric acid and cementing out copper, silver can then be purified in thumb cell, the advantage here seems powders should react faster (careful) and use less nitric acid.
> 
> Heat is wattage, to lower wattage you can use a light bulb in series with cell to limit the current in the total circuit, + --------O-------anode cell ,+ power supply, ---- jumper wire, O tail lamp from car.



Agree!


@butcher et al.
wouldn't diluted sulfuric work to remove the copper?


----------



## Platdigger (May 20, 2013)

Tinker Terry, "dissolving a bit of pue silver in aqua regia"

Are you sure?

I know you meant to type "pure", this is not what I am questioning.


----------



## solar_plasma (May 20, 2013)

> Metal ions travel from the (cathode) electrode



No...and no, the *electrons *in the metallic conductor are kicking on another over to the battery's plus. Only in the electrolyte of the cell there are ions that are carriers of charge.




> which *is connected to the positive terminal* of the DC power supply



well, now your "cathode" has become an anode



> (which is the anode of a battery cell).



which doesn't matter for the copper cell


----------



## Harold_V (May 21, 2013)

w0lvez said:


> goldsilverpro said:
> 
> 
> > I would ask the same question, as this makes zero sense to me. What are you trying to accomplish?
> ...


I totally disagree with you in this operation. Sulfuric cells encourage the deposition of copper, and that's assuming that you're dissolving the silver at the anode. Why you think you can achieve 99% purity by this method escapes me. I'd be interested in anything you can provide in the way of information that shows I'm wrong. 

You are experiencing overheating because you're using a power source that is too small. The only thing you can do to change that is to run more of them in parallel, use one with greater capability, or to decrease the surface area of both your anode and cathode. Altering spacing won't yield a change big enough to warrant the trouble it takes to make the change. 

Harold


----------



## butcher (May 21, 2013)

AgCl silver chloride is insoluble, aqua regia will not dissolve but a tiny portion of silver, silver passivates in aqua regia forming an insoluble crust.

In a cell with chlorides in solution, silver at the anode would form a passivated crust protecting the anode from dissolving, some gases can be formed (dangerous chlorine gases), and these bubbles may flake off a little of this crust, just to passivate the next layer, basically you may have some flake off but it would basically be passivated.

Above I said very little silver will dissolve in aqua regia, this is a very minute amount, we sometimes see with our gold when we process it, this silver is not the normal AgCl silver chloride, but silver chloride with a higher oxidation state AgCl2, the AgCl2 you will only have in a concentrated aqua regia solution with high chloride content, when the solution is diluted we get the back that little bit of the silver as the insoluble white powder precipitant of AgCl which is insoluble in the dilute aqua regia.

Basically we can say silver does not dissolve in aqua regia (or at least to enough of an extent we could say that it will).

Silver sulfate is not very soluble, so a sulfate solution will not hold much silver sulfate in the solution, most of the silver would settle to the bottom of the vessel if formed, then we also have the problem of converting the silver sulfate back to a silver metal, making silver sulfate formation undesirable when we do not have to, well that's my opinion.

I would think this type of cell, the silver in solution would also try to plate out with the copper on the cathode (the silver ions that were in solution in the vicinity of the cathode), my guess is that the copper solution would not be clean enough to make a solid plate of copper on the cathode and fluff off to the bottom of the cell, and the silver would form a sulfate, mixing with the silver, yes copper sulfate is more soluble in sulfuric acid but then we still are left with silver sulfate to deal with, if we tried to dissolve the copper leaving silver sulfate (this just doesnt sound like my idea of a good time).


----------

