So I am moving from my house and wanted to reduce the number of jugs of copper nitrate waste that I’ve been collecting from silver refining so I have been using the method that I’ve seen on this board and also in NurdRage’s video where you convert the copper nitrate to copper sulfate and distill off the dilute nitric.
It’s been going well, as I have recovered a ton of distillate, but I decided to try to cycle some of the aqueous layer that’s on top of my copper sulfate beaker because I noticed that it had a decent amount of NOx collecting at the surface.
After THREE hours I stopped it because the volume of the boiling flask had only reduced by about 50% and I had no precipitation of copper sulfate that I usually get which causes me to stop early due to bumping despite having boiling chips in the flask.
What doesn’t make sense to me is that the solution in the boiling flask is a deep emerald green, and not the rich blue color that is easily recognizable as copper sulfate.
Another strange observation that I had is that after about 10 minutes of boiling, the vapor temp was at 119°c which made me think that I was distilling off azeotropoic nitric acid from the very beginning. However, about 90 mins later, I was only at about 108°c and when I turned off the heating mantle, it was about 103°c.
Once the column had cooled off enough (but still too hot to remove) I dropped a thermocouple down to the solution in the flask and it was still about 255°c making me think that I had a ton of excess sulfuric acid in there, which would make sense as most of the copper had been converted to copper sulfate prior to the previous distillation.
The question I have is, what could this green solution be? My nitric has only been used to refine sterling silver and after cementing out the silver, I would always leave it in the stockpot with excess copper for weeks to ensure all less reactive metals dropped out of solution.
The only green sulfates that I know of are nickel, iron and chromium, which all could be present in Raw silver, just not as common in sterling. As far as nitrates are concerned, I am only used to seeing my silver nitrate looking this deep emerald color when there is some palladium present, which it shouldn’t be because it’s been in the stockpot with copper for so long.
Any ideas?
It’s been going well, as I have recovered a ton of distillate, but I decided to try to cycle some of the aqueous layer that’s on top of my copper sulfate beaker because I noticed that it had a decent amount of NOx collecting at the surface.
After THREE hours I stopped it because the volume of the boiling flask had only reduced by about 50% and I had no precipitation of copper sulfate that I usually get which causes me to stop early due to bumping despite having boiling chips in the flask.
What doesn’t make sense to me is that the solution in the boiling flask is a deep emerald green, and not the rich blue color that is easily recognizable as copper sulfate.
Another strange observation that I had is that after about 10 minutes of boiling, the vapor temp was at 119°c which made me think that I was distilling off azeotropoic nitric acid from the very beginning. However, about 90 mins later, I was only at about 108°c and when I turned off the heating mantle, it was about 103°c.
Once the column had cooled off enough (but still too hot to remove) I dropped a thermocouple down to the solution in the flask and it was still about 255°c making me think that I had a ton of excess sulfuric acid in there, which would make sense as most of the copper had been converted to copper sulfate prior to the previous distillation.
The question I have is, what could this green solution be? My nitric has only been used to refine sterling silver and after cementing out the silver, I would always leave it in the stockpot with excess copper for weeks to ensure all less reactive metals dropped out of solution.
The only green sulfates that I know of are nickel, iron and chromium, which all could be present in Raw silver, just not as common in sterling. As far as nitrates are concerned, I am only used to seeing my silver nitrate looking this deep emerald color when there is some palladium present, which it shouldn’t be because it’s been in the stockpot with copper for so long.
Any ideas?
