Diluted Nitric Acid Recovery

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icejj said:
Is 60 degrees C ideal for evaporation of water without loss of nitric? How did you come up with this figure? I plan on evaporating quite a bit of solution soon, and I don't want to lose nitric, but I couldn't come up with an ideal temperature for evaporation... Thanks!
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I have watched some videos of nurdrage and others.
According to wiki the decomposition temperature of the trihydrate is114C and a video i saw says 80C so i kept it way under that in a glass oven tray in a sand bath on a hotplate for one week. Refilled it twice a day.
When it becomes syrup you can bottle it or go straight to distilling with H2SO4.
Use a copper cel to electrowin sheets of copper on a stainless steel cathode plates and use those in the stockpot.
Use the sufuric for other distillations of copper nitrate.
 
jimbo12 said:
Well, Based on my calculations the Gold that was left (which I have Not Done AR on as of yet) weighs pretty close to what it should be .However The Silver That I added and Recovered Was Spot On . so, I missed some Silver Recovery or there was No Silver at all in the gold that was processed which is Impossible... At this point I will Run My Gold 1 more time in 50/50 Nitric / Distilled Water just to be sure.
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The thing is, if there is silver trapped within the gold sponge, and your gold weighs a bit more then what you calculated, treating in a new bath of nitric will still not get it.
You will have to inquart again to get the last bit out. Or it just might be just to little silver so you can dissolve it in AR.
 
jimbo12 said:
Well, Based on my calculations the Gold that was left (which I have Not Done AR on as of yet) weighs pretty close to what it should be .However The Silver That I added and Recovered Was Spot On . so, I missed some Silver Recovery or there was No Silver at all in the gold that was processed which is Impossible... At this point I will Run My Gold 1 more time in 50/50 Nitric / Distilled Water just to be sure.
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How much does the gold sponge weigh you have left? If that is 8 oz, you should be able to digest more silver and base metals out if there are any. Just cover it with the 50/50 dilute nitric, no more.
Your total weight for inquarting should not have been more than 32 oz.
So you were way over that.
Which makes mee suspect your nitric from that first run is all consumed.
What about the 6 gallon solution? You can test if there is any free nitric with a testtube and a piece of copper. Heat it to see if any bubbles form.
 
Yggdrasil said:
You either deNOx or dispose, if you deNOx you can't recover.

How did you create your Silver Chloride?

Salt or HCl?
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If one were to use salt to create silver chloride instead of HCL or copper, would the distillation process to recover the nitric be the same as if you used HCL or copper to create silver chloride?
 
Martijn said:
How much does the gold sponge weigh you have left? If that is 8 oz, you should be able to digest more silver and base metals out if there are any. Just cover it with the 50/50 dilute nitric, no more.
Your total weight for inquarting should not have been more than 32 oz.
So you were way over that.
Which makes mee suspect your nitric from that first run is all consumed.
What about the 6 gallon solution? You can test if there is any free nitric with a testtube and a piece of copper. Heat it to see if any bubbles form.
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No ,total weight for inquarting was 54 ......21 AU. @ approx 15.1 Kt, 20 AG., 13 CU , recovery 15.2 AU sponge
 
icejj said:
If one were to use salt to create silver chloride instead of HCL or copper, would the distillation process to recover the nitric be the same as if you used HCL or copper to create silver chloride?
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Same, but HCl regenerates Silver Nitrate to Nitric. Salt creates Sodium Nitrate.
 
jimbo12 said:
No ,total weight for inquarting was 54 ......21 AU. @ approx 15.1 Kt, 20 AG., 13 CU , recovery 15.2 AU sponge
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Ok, so there is at least 2 oz silver or copper still in your gold. which means there is no free nitric in the 7/8 gallon solution and you can go ahead with digesting the last bit out with 50/50 HNO3/ distilled water. With the 25 % expected loss mentioned earlier you could recover up 0.75 gallon of nitric.

Which also means you have no risk of loosing nitric while evaporating unless you over heat and decompose the copper trihydrate into copper oxide and NO2 fumes.

I was thinking if it may be possible to convert the copper nitrate into an insoluble nitrate salt to filter from the solution, but the solubility chart shows all metal nitrates are soluble. If there are any non metal nitrates I have no idea, maybe a chemist can chime in here.
And it needs to let go of the copper and bind to some other element.
 
For solutions containing recoverable amounts of nitrate from dissolved Cu(NO3)2 a good (no distillation method) is too add a calculated amount of sulfuric acid and then freeze the solution to remove as much copper as possible as CuSO4*5H2O in crystalline form. Be sure to pour the cold solution off of the blue crystals before it warms.

To determine how much sulfuric acid to add test the Cu content of 100ml (+/- 0.1ml) of the nitrate solution. Divide the weight of clean, dry Cu produced by 63.55g to determine the moles of sulfuric acid required to liberate the dissolved Cu. You can alternately precipitate the carbonate or hydroxide of copper using known methods and divide the resulting mass by the molecular weight of the copper compound you form.

Your cold solution will lose copper in the form of beautiful copper sulfate crystals and they will be replaced by twice as many moles of nitric acid.

The blue crystals can then be recycled into copper and sulfuric acid via electrolysis.

Steve
 
lazersteve said:
For solutions containing recoverable amounts of nitrate from dissolved Cu(NO3)2 a good (no distillation method) is too add a calculated amount of sulfuric acid and then freeze the solution to remove as much copper as possible as CuSO4*5H2O in crystalline form. Be sure to pour the cold solution off of the blue crystals before it warms.

To determine how much sulfuric acid to add test the Cu content of 100ml (+/- 0.1ml) of the nitrate solution. Divide the weight of clean, dry Cu produced by 63.55g to determine the moles of sulfuric acid required to liberate the dissolved Cu. You can alternately precipitate the carbonate or hydroxide of copper using known methods and divide the resulting mass by the molecular weight of the copper compound you form.

Your cold solution will lose copper in the form of beautiful copper sulfate crystals and they will be replaced by twice as many moles of nitric acid.

The blue crystals can then be recycled into copper and sulfuric acid via electrolysis.

Steve
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I just slowly added H2SO4 to 100ml of the copper nitrate, took small drops in a small beaker at intervals and heated it. When the salts are white (anhydrous) when dry, all nitrates are converted. Calculate the total needed to convert it all.
 
lazersteve said:
For solutions containing recoverable amounts of nitrate from dissolved Cu(NO3)2 a good (no distillation method) is too add a calculated amount of sulfuric acid and then freeze the solution to remove as much copper as possible as CuSO4*5H2O in crystalline form. Be sure to pour the cold solution off of the blue crystals before it warms.
Click to expand...
I performed the steps of the cold method of recovering nitric from my copper nitrate solution/waste. The copper nitrate solution/waste was a result of performing the 50/50 method of nitric and distilled water on gold filled material. After adding sulfuric to the waste and pouring the cold solution off of the blue crystals, my solution was a light tinted green clear color. My question is...Is there any way to get the other metals out of the solution to make it clear? Is the reason why the solution is not clear is because there are other metals (other than copper or silver) still in solution that need to be precipitated out)? I tested the dilute nitric produced and it works, but I'm trying to see if maybe I missed a step that would've given me better results.
 

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