Reuse copper nitrate

[lazersteve]

Here is some data from the Dictionary of Chemical Solubilities which I highly recommend to anyone interested in chemistry.

Sat. solution contains
%Cu(NO3)2 @ temperature C= spgr
60.01@25C= 1.646 spgr (5.26M)
60.44@30C=1.693 spgr
61.51@40C=1.714 spgr
62.62 @50C
64.17@60C=1.766 spgr
65.79@70C=
67.51@80C=1.8312 spgr (6.59M)
77.59 @114.5 (mpt)

My own testing of recycling real world copper nitrate solutions are typically in the range of 1.7 g/ml spgr when saturated which is closely in line with the Dictionary referenced table at 25C.

My procedure for testing spgr involves a 0.01 accuracy gram scale, a clean and dry all plastic 0.1ml x 10ml medicine syringe, and a room temperature sample of the liquid to test. Tare the scale with the syringe empty on it and record syringe mass. Draw in exactly 5ml without any bubbles and record the mass of the liquid only. Divide the liquid mass by 5ml.

Steve

 

[Shark]

thanks Martjn
I’m going to work on my lawnmower and digest this and rework the solution on paper not head

Sometimes it helps to step back and rethink things. It can help a lot to look at the same issues with a clear and rested mind.

 

[BGDOCK]

Sometimes it helps to step back and rethink things. It can help a lot to look at the same issues with a clear and rested mind.

Guys really thanks I was just trying to reduce my waste stream and reuse the copper nitric solution I started gathering materials and still researching. Things discovered today
1.)Going to need to take better notes / write down data .
2.) recovering silver from silver chloride takes way too much water and time.

Thanks again

 

[Yggdrasil]

Bragbasil,

I as taught if your going to do a job do it right the first time so I was looking for a good starting point . I think I am on track.

Molar mass of Cu (NO3)2 = 187.5558 g/mol
6M = 1123.38 g/mol
One gram same as one mL right
So, move three place to left
1.123 SG

g/mol do not make sense, it is the same as gram/gram
Molar mass of Cu (NO3)2= 187.5558 g
6M = 6 moles per liter = 1123.38 g per liter
at 20 C and 1 Atm pressure 1gram is 1ml correct.
No, if you have 1123.38 g of water it works, but you have 6 moles (1123.38 g) of Copper Nitrate
which you will top up with water to get one liter.

 

[Yggdrasil]

g/mol do not make sense, it is the same as gram/gram
Molar mass of Cu (NO3)2= 187.5558 g
6M = 6 moles per liter = 1123.38 g per liter
at 20 C and 1 Atm pressure 1gram is 1ml correct.
No, if you have 1123.38 g of water it works, but you have 6 moles (1123.38 g) of Copper Nitrate
which you will top up with water to get one liter.

Oops there were replies I did not see, so my reply became almost moot.

 

[BGDOCK]

Here is some data from the Dictionary of Chemical Solubilities which I highly recommend to anyone interested in chemistry.

Sat. solution contains
%Cu(NO3)2 @ temperature C= spgr
60.01@25C= 1.646 spgr (5.26M)
60.44@30C=1.693 spgr
61.51@40C=1.714 spgr
62.62 @50C
64.17@60C=1.766 spgr
65.79@70C=
67.51@80C=1.8312 spgr (6.59M)
77.59 @114.5 (mpt)

My own testing of recycling real world copper nitrate solutions are typically in the range of 1.7 g/ml spgr when saturated which is closely in line with the Dictionary referenced table at 25C.

My procedure for testing spgr involves a 0.01 accuracy gram scale, a clean and dry all plastic 0.1ml x 10ml medicine syringe, and a room temperature sample of the liquid to test. Tare the scale with the syringe empty on it and record syringe mass. Draw in exactly 5ml without any bubbles and record the mass of the liquid only. Divide the liquid mass by 5ml.

Steve

Steve the solution is 2.542 g/ml .
Sorry it took so long I had to order another scale .

 

[BGDOCK]

Steve the solution is 2.542 g/ml .
Sorry it took so long I had to order another scale .

I drew in 10 mg it would be 1.271g/ ml spgr

 

[lazersteve]

Your solution is still too dilute. Concentrate it further.
Gently evaporate without boiling to 2/3 it's original volume, allow to cool to room temperature and settle, then decant off liquid from settled solids.
Retest spgr after performing these instructions.
Steve

 

[BGDOCK]

So I started the copper nitrate cell up last night .
I started w/ a stainless steel cathode at first notice a little bubbles plated copper out you could see the copper forming a fog / mist around the cathode ( copper ion layer ?) realized I might be making a weak nitric acid which would react with the stainless steel . Switch out the cathode using graphite . I have cemented out silver ( moss). I’m stoked the beaker is full now stopped the cell.
So decant or filter the cemented silver moss , treat w/ HCl ( dilute or full strength) retain the solution ( CuCl2 ) wash , create shot and run through cell.
Reuse the electrolyte solution for more processing .
Questions:
After I deplete the copper in solution I cement out the silver in solution . I add a little HCl to rejuvenate the electrolyte to make nitric acid and start the process over again. How do you know how much HCl to add?

 

[FrugalRefiner]

The best method is a Volhard titration, but I can't give details right now.

Second best is to take a measured sample and start adding HCl slowly till no more silver chloride forms. Multiply that amount by your total electrolyte volume and add a little less than the calculated amount.

Dave

 

[BGDOCK]

Thanks . I have to say I’m very thankful for the tips. This saved money and time .

 

[BGDOCK]

Dave you don’t have to give details on the Volhard method I looked it up I’m good for now using “Dave’s second best method ,”

 

[BGDOCK]

So the cement/ silvery moss is accumulating quickly this was from 8-10 hours of operation . I have broken the med up and rinsed three times.
Increased the cell size today

 

[BGDOCK]

Realized I made a mistake I didn’t get as much copper out of solution as needed it still cemented out the silver moss which skips the “traditional nitric/ sulfuric acid methods “ the second cell experiment I remove the copper out as ( follow instructions better )
The silver moss is much finer running it at 2 VDC /.5 A picture attached cell on left is the dirty solution with cemented silver the middle on running has the lowered copper content smallest beaker is cemented silver yet to be treated w/ HCL

 

[BGDOCK]

Wrong picture

 

[BGDOCK]

So I’m finishing up the copper nitrate cells today. Overall pretty successful I think . Definitely needs some tweaking on my part. The cemented silver has a little more copper in it. I feel like running it one more time after I make shot . I would like to say thanks this was an awesome trial run, I’m pretty sure more questions will follow. I would also like to apologize I get a little mixed up where to post when to quote and whatnot . But to everyone whom has help out or straightened me out thanks. Cemented out silver from cell 1 beaker cracked ( drag) in the Tupperware . Cell 2 cemented silver is on the left .

 

[BGDOCK]

Edit : hot HCl rinse for the cemented silver didn’t work so well. Also rinsed until it was clear but the shot melted horribly. Flame went from green~> blue-> purple . Very little shot was produced when a ran a sample shot pour.
Currently trying HCl plus H2O2 to attack copper ( and palladium ) in the cemented silver .

 

[Yggdrasil]

Edit : hot HCl rinse for the cemented silver didn’t work so well. Also rinsed until it was clear but the shot melted horribly. Flame went from green~> blue-> purple . Very little shot was produced when a ran a sample shot pour.
Currently trying HCl plus H2O2 to attack copper ( and palladium ) in the cemented silver .

Not a good idea, Peroxide alone might dissolve some Silver.
Why do you expect Pd?

 

[BGDOCK]

This last batch and previously processed antique flatware the solution was also green.
So after cementing out the solution with copper pipe the solution had changed to a coil alt blue that I associate with copper nitrate.
Using reactivity scale everything below copper cements out right?
So if it was Nickel it would have stay in solution and wouldn’t the have stayed green?
That cemented silver didn’t melt very well either .
I thought HCl and H2O2 didn’t react with silver and would dissolve Pd that why I chose to go that route.
My Intent was to remove copper and potentially Pd from the cemented silver and use the silver cement to make a new electrolyte for another go a silver cell.

 

[BGDOCK]

Edit : I thought silver is an inactive metal and that it reacts with hot concentrated H2SO4 , HNO3 and AR.