Make Nitric Acid by Thermal Decomposition of Copper Nitrate

Calcium sulfate shouldn't participate in electrolysis. But it might interfere with fine details if that's your objective. I recommend running a few tests to see what happens. If you really want pure copper nitrate then you don't actually use copper sulfate at all. First you mix your copper sulfate with sodium carbonate or bicarbonate and precipitate copper carbonate. You thoroughly wash, filter, wash again, and filter the copper carbonate so you have very little sodium in it. Then you mix the *copper carbonate* with the calcium nitrate. This will precipitate calcium carbonate which is far less soluble than calcium nitrate or sulfate. You filter off the copper nitrate and leave behind the calcium carbonate and excess copper carbonate. The solution is then recrystallized to remove traces of sodium and calcium. It's a very involved process and i didn't bother showing it because when making nitric acid, a bit of calcium sulfate was inconsequential. But if you want truly pure copper nitrate, then make nitric acid and react that with bare copper wire. Copper wire is highly pure and the distilled nitric acid is also pure. You'll produce very high purity copper nitrate that way.

NurdRage

There has been some excitement about this video on an electro etchers Facebook group I belong to (Electro-Etchers Anonomous). People in the group etch copper and silver (and other metals in other solutions), to make designs in jewelry and other art. Many in the group use copper nitrate as an etching solution. Copper nitrate seems to be an enigma. It is a waste product, but is also hard to get or quite expensive depending where you live. The person posting (not me) is basically suggesting people use the beginning of the procedure in this video to make copper nitrate for etching. Questions: · Will the calcium sulfate contamination left in solution participate in the electrolysis? · Do you think it would negatively impact the etching? · What if a person (me for instance) wanted reasonably pure copper nitrate crystals using this method. How does one get rid of the calcium sulfate contamination, and get from solution to crystals without decomposing the copper nitrate?

Michael Aichlmayr

i'll see what i can do then, any idea what elements are in the "Circuit Board Liquor"? just copper? or other elements like lead? Copper is pretty easy to reclaim, but the other elements require extra work. If you have your own Birkeland Eyed reactor would you be willing to take some pictures and show me? i'm trying to design/build my own.

NurdRage

I'd like to see the end of this process expanded a lot. My nitric comes very slowly (from a BE reactor), and I've been using it to try and return electronics to their individual metals (for the challenge and education, as I don't plan to go into the recycling business). If I could take the "circuit board liquor", as I call it, and reclaim that precious HNO3, and then turn the residue into a bar for electrowinning, this would likely be less of a PITA than advertised.

Excellent work. This is a great quality video filled with interesting reactions. I am glad to see that you are back up and running again!