Remove copper from solution to use for a silver cell

[BGDOCK]

I have a silver nitrate and copper nitrate solution left over from inquarting gold. Instead of cementing out or using sugar + lye to recover the silver, can I remove some of copper through electrolysis then use this solution to run a silver cell ?
I was thinking of using a titanium cathode and anode to remove some the copper.

Jeff

Edited for correct spelling

 

[kurtak]

So - you are wanting to run the cell as a winning cell instead of as a parting

There is not a lot of difference between a winning cell & a parting cell - they both work on the same principle

They both work by causing metal ions that are dissolved in the electrolyte to deposit (as actual metal) at the cathode - as DC current (amps) flow through the electrolyte from the positive anode to the negative cathode

As the "metal" deposits at the cathode it is removing the dissolved metal ions from the electrolyte & in doing so it "frees up" some of the acid that dissolved the metal in the first place --- meaning you now have some free acid that can dissolve more metal

So - using a silver "parting" cell as the example - we start by dissolving silver with nitric acid to make an electrolyte that is "loaded" with silver ions - we then place our impure silver anodes in the anode basket

When we then turn the power supply on - the current flowing through the "silver" electrolyte causes those silver ions to start depositing at the cathode as actual silver metal --- in other words - the current is causing the metal ions in the electrolyte to be "displaced" out of the electrolyte & depositing silver at the cathode

As that happens it is also freeing up "some" of the nitric acid

This free nitric then goes to work at dissolving any nitric soluble metals at the anode thereby "replacing" metal ions in the electrolyte (from the anode) as metal (silver) ions are displace from the electrolyte & deposited at the cathode as metal (silver in this case)

In other words - in a parting cell - as metal ions are being displaced from the electrolyte & deposited at the cathode - they (metal ions) are also being replaced into the electrolyte due to the free nitric that is being produced which dissolves more metal at the anode

This is the "basic" principle of a parting cell - corruption of the electrolyte & co-depositing of "other" metals is another post/subject

In a winning cell - the same principle happens wherein the current flowing through the electrolyte causes the metal ions to displace from the electrolyte & deposit at the cathode

The difference is that in a winning cell we use an inert anode

In other words - an anode that won't be effected (or dissolved) by the acid that is being freed up - so no metal ions are being replaced into the electrolyte

Therefore - the current running through the electrolyte will cause any & all metal ions in the electrolyte to deposit at the cathode

In other words - no - you can not "selectively" win just the copper from the silver/copper nitrate in order to remove the copper & leave you with just a silver nitrate that can then be used as a silver electrolyte to run your silver cell --- & that is because in the winning cell the current passing through the electrolyte causes both the copper & the silver (& any other nitric soluble metal) to deposit at the cathode

However - because you are "winning" (displacing) metal ions from the electrolyte - but - also not replacing metal ions back into the electrolyte - you will be "freeing up" nitric acid - which can then be used to dissolve more metal

So (at least in theory) you could use the silver/copper "won" from the silver/coper nitrate for your next inquart
& as well use that freed up nitric to dissolve more metal

I say in theory because in the end the feed up nitric is going to be quite dilute - first from washing the acid out of the gold sponge - then washing the acid out of the "won" metal --- & as well the copper content of the "won" metal is going to go up (increase) each time you reuse the won metal for the next inquart & as you (likely) know it takes more nitric to dissolve copper then to dissolve silver

So though it can/will work - there are "trade offs" in its working

For what it is worth

Kurt

 

[BGDOCK]

I was thinking if I removed copper I could use it for the electrolyte for my silver cell.
The problem would be removing the copper freed up the nitric acid to dissolve more metal, I was thinking if I leavin the negative side powered up the copper clings to the cathode there place in a container with water turn power off drop the copper in the container. Now add pure silver to lower the copper concentration and increase the silver concentration I’m going to have re read your post and break out the note book . Thanks for taking the time to answer .

Jeff . .

 

[BGDOCK]

I decided to cement out the silver , it seemed like a waste of effort and energy. I will save copper nitrate then use the winning cell to remove the copper and reuse the nitric. Seemed like a good idea at the time