Electrochemistry Electrolisis for recovering Cu from Cu-Cl solutions.

[philddreamer]

To all our experts on this great Forum!
I tried, a couple of months ago, electrolisis in order to recover some copper from my saturated AP & waste stock pot solutions. It seemed to work.
I did some searches, but didn't find a straight answer on a Cu-Cl cell. I found copper sulfate cell & copper nitric cell, but no copper chloride cell.

I'm running close to 3 dozen pounds of high grade pins, ( I say high grade because a pound of one type of pin's yield was 2.5g; one pound of the other type
yielded 4g.) After trying nitric, and the sulphuric cell & tried AP and that's the process I'll be using for the remaining pins. Cheaper chemicals, & less hassle...
So, I have a few pounds of copper left over in the solutions & I want to "clean" the solutions by extracting the copper, thus re-using a cleaner AP & hope I'll save on HCl.
Remember, I'm not a chemist... I'm just is the company of some of the best! 8)

I used a clean copper grounding strip for the cathode, & one of Lazersteve's 2" x 2" hard graphite for an anode. The anode didn't break down, (like it did when I tried in the nitric cell), after a couple of days use, (about 48 hrs.) A battery charger on the 6v setting, drawing 13 to 15 amps.

I'll be posting some of the comments & advise GSP shared with me thru PM's on this matter.

Please, any comments.

Thank you!

Phil

 

[nickvc]

Phil personally I like the whole idea, it's saves on acids and waste disposal, it's gives back a metal we can use in our processing for cementation and removes a potentially dangerous bio haste from the waste stream as a useable element. It's a win win process..Well done.

 

[Geo]

very nice experiment. i have heard and then read to find out for myself. when you dissolve base metal with hcl, it emits hydrogen. when you remove the copper with electrolysis it emits chlorine. did you notice the smell of chlorine when you were doing this. in other words, is it something that must be done outside or in a fume hood, or can you do it in a well ventilated enclosed space?

 

[goldsilverpro]

I wondered about what the black stuff was. Now that I see what your anode is, I think the black is a breakdown of the carbon.

 

[Smack]

Phil,
How warm did the solution get? Were any of your pins Kovar or all copper based?

 

[ericrm]

I wondered about what the black stuff was. Now that I see what your anode is, I think the black is a breakdown of the carbon.

no
as far i know if your let your cathode/anode deep enuf all the solution become light green.
you black stuff come from one of your anode/cathode and is made during electrolysis,i think it is actualy copper (CuCl) and not carbon(but i could be wrong).
for me i was never able to get it clear, i also stop using it because you endup with clorine in your solution.
but that would be a nice tread to read go for it

 

[goldsilverpro]

The anodes are graphite = carbon. In certain solutions, graphite as an anode will erode and produce a very fine black suspension not unlike the photos. I've seen it many times.

Phil, you need to bag the anode.

 

[ericrm]

i talk about what i have done and try, no guess here...

no need to bag the anode/cathode, the dark stuff is not a powder, put your anode and cathode the same lent and deep enuf to do all the dept of your beaker and you will not have this dark stuff.

also my anode/cathode were both graphite and are still as pretty as the day they were remove from batterie.


(((((Re: Electrolysis of aq CuCl2 with Ag electrode

Cu+2 could be reduced to Cu+1, depending on voltage and conditions of solution; not sure if this is reasonable for electrolysis. Probably is.)))))
((((Normalement, le cuivre en solution est un ion Cu2+, et il se décharge en recevant deux électrons de la cathode.
Mais s'il n'en reçoit qu'un, il forme l'ion Cu+, et cet ion réagit avec l'eau selon :
2 Cu+ + H2O --> Cu2O + 2 H+
Si on ajoute de l'acide, donc des ions H+, on empêche la réaction de se faire, car on produit une nouvelle réaction :
Cu2O + 2 H+ + 4 Cl- --> 2 CuCl2- + H2O ))))

 

[philddreamer]

Thank you all for your input!
Thanks Nick, that's the main reason of the experiment, maybe some members can use this procees to recover the copper & re-use the solution. I have a question, though, will the solution be able to be used as AP?

Thanks Geo! I learned from GSP that the anode releases oxigen & the cathode hydrogen. I don't know about the chlorine gas. I wear a respirator approved for chlorine & I can't smell it, plus the shed is open & well ventilated. And yes, it should be done under a fume hood or outside.

Chris, thanks for your help while I was preparing to run the test!
The pins are slightly magnetic, so, some iron, nickle or kovar are likely to be present.
The black soot deposits at the begining of the process, after that, copper starts to deposit. As the solution starts to heat up, copper deposits much faster and the electrodes start to to fizz, especially the anode. At this point the solution starts to become clear at the top, working its way down. I stir the solution, which helps to deposit the copper and clear the solution faster.

Hi Smack!
The solution gets hot, but I didn't see any "steam" so I kept running. If I was to notice any steam, I would stop & let the solution cool some. How hot should I allow the solution to get, I din't know.

Chris, I'll run the next test bagging the anode.

Eric, thanks for your comments.

I'll continue testing and encourage others to try it, too, and share your observations.

Thank you all!

Phil

 

[Smack]

From what I was told 120 to 130 degrees is best. I had good results from my experiment.

 

[philddreamer]

From what I was told 120 to 130 degrees is best. I had good results from my experiment.

The heat makes a big difference on the deposition, but I have no idea if it indeed needs to be some what hot. On my next test, I'll check the heat & see if it reaches a peak and stablelizes there, or if it will continue to get hotter.
I'm glad to hear you had good results. I just re-used the clear liquid on another pound of pins & the solution started to get dark. I added some peroxide & it cleared up some. We'll see what it looks like in the morning.

Let us know what reaction you get when you re-use yours.
Thanks!

Phil

 

[Smack]

Sorry Phil, forgot to mention that it was spent Nitric solution in a 5 gal. bucket. But I'm sure the solution no matter what it is need to be warm not hot for good electrolysis. The deposition will increase the warmer it gets to a point and like I had already stated I think it's between the 120 130 mark. Going to have to ask my dad again to be sure and what his source for knowledge was. I'll try to find out for ya by the weekend if you want.

 

[philddreamer]

I'll try to find out for ya by the weekend if you want.

That would be great! All the information I can get. 8)

I'll heading back down to CA. this coming week for 10 days, so I've been busy geting things ready for the trip. I'll be checking on and off the posts.

Thanks!

Phil

 

[lazersteve]

Phil,

Check out item 4b in this thread:

AP and Electricity

and another early discussion:

Electrolytically Regenerate AP

There are several other posts on the same topic if you dig for them.

Steve

 

[philddreamer]

Perfect!

Thank you Steve!

Phil

 

[philddreamer]

Back from our trip to CA. Nice & safe exprience. Getting ready for a follow up, since we couldn't climb down to a suspected deposit.

I've been buying e-scrap from a recycling outfit, so I'm running a test; & decided to try using some of the left over AP; I melted a 5.3 Toz anode. (Every pound of these pins yield 4g of gold, the rest is mainly copper.) I used again a strip of copper grounding foil for the cathode.
I started running 6 volts - 3 amps, the copper was spongy; after the solution reached 130F, it was drawing 7 amps and the copper is crystalizing. The gold is a black sludge. I continue to add spent AP as needed. It's been running for about 6 hours.

Phil

 

[Geo]

very nice. i tried an experiment to see if i could selectively draw the copper from a gold plated pin using copper chloride as the electrolyte. it dissolved the gold. not sure of the process. but it was a failure.

 

[philddreamer]

Thanks Geo!
So far the anode bag is holding the gold sludge. I'm also getting some nice crystals.

 

[Smack]

Hi Phil,
looking at the crystals on your cathode, I'm thinking maybe making the cathode a bit smaller to see if you get a more even coating of copper, if that don't help try a little bigger. Also the surface of the cathode may promote the irregular growth of crystals if it is rough, I polished my stainless cathode then after I cleaned the CU from it, used fine Schotch Brite to remove any residue left on it before I re-inserted the cathode for another run. Just some ideas for you to ponder.

 

[nivrnb]

Phil,

What is your anode made of?

" I melted a 5.3 Toz anode."

nivrnb