I made some basic copper carbonate not long ago, and when I was done, I found some black clumps in the product... I didn't see anything about it in any of the videos on YT (from Dougs Lab, NileRed, etc). Eventually I found out that I was heating it too much when I was trying to dry it... forming CuO. You'd think that some detail like that would be included in the synthesis videos, lol.
@Bellithe How easily does Mn burn? I think my next experiment will be a large quantity of MnO2 thermite in an attempt to recover Mn metal. If it burns easily, this may not work as well as I thought. A good flare mix I've found is NaHCO3 and Mg. It burns very slowly with the intense orange flame which is characteristic of sodium. Maybe I'll post a video of it this weekend.
@Bellithe I just happen to have a couple of kilos of shavings from a machine shop that makes magnesium parts. I'll probably start using aluminum when I run out of Mg.
@Bellithe I have not tried SrCO3. My manganese dioxide is from a whole bunch of lantern batteries so it contains quite a bit of carbon mixed with it. This makes the thermite burn considerably slower than when I tried it with just plain MnO2. I will try the MnO2/Mg thermite in an underground ceramic chamber. I'm hoping that the excess carbon will create a reducing atmosphere to keep most of the Mn from re-oxidizing. Hopefully I get some Mn agglomeration with minimal loss as Mn vapor.
@Bellithe Yeah, I guess I'm just gonna have to see what happens. I usually leave my thermites unpacked. They're naturally very "fluffy" since my Mg comes as large shavings as opposed to a powder. I have also found that because the Mg shavings are coated in machine oil, powdered substances stick to the shavings very easily. I once made a flash pot by shaking Mg shavings with KNO3 to coat them. I ignited it in a "fluffed up" state and the result was a rather impressive fountain of burning Mg.
If I'm not mistaken, the blackness to your 5.55 grams of copper at the end was Copper (II) Oxide. Melting copper is a sure fire way to make CuO, you can see examples in any "home pour" copper video here on youtube. You will see a mostly black copper bar at the end. That's because, as soon as copper liquefies it starts sucking in oxygen like crazy. Or would the hydrochloric have eaten it off? I'm not thinking so, since it's still copper, just rusted. Right?
I'm 99% sure that insoluble copper salts (CuOH, CuCO3, and CuO) readily react with all strong acids to give the corresponding soluble copper salt. If that's not the case I'm positive that the HCl with enough friction will enable the CuO to rub off, therefore CuO dissolves in HCl.
You would be better off doppingnit with trace amounts, and adding a flux lime borax to slow rhe reaction down. But to answer your question, yes. Copper sulphate will also work.