![]() So it buy you time to let it settle and filter the gold in usual fashion and only minor losses. When there are remains of "weak" AR, or better said some "oxidizing species", gold will be dissolved anyway, but VERY SLOWLY. Nitrosyl chloride isn´t that powerful oxidant, and undergo quick degradation to nitrogen dioxide in AR solutions.Īlso with strong solution of AR, dissolution of gold isn´t particulary quick reaction. And alongside with NOCl, giving the AR fumes the unmistakeable "yellow" hue. It also evaporates from reaction, mainly while still hot - removing "oxidizing force" of the juice. Chlorine is very quick, reacting immediately with anything around, but also undergo slow decomposition to oxygen and hydrochloric acid (but this is minor and slow reaction). Nitric acid undergo decomposition in acidic chloride enviroment, producing mainly nitrosyl chloride and chlorine. redox potential required to dissolve the gold back to the solution. Remains of nitric acid are still present, but it does have much with redox potential of liquid vs. There is practically always some minor loss, but it could be recovered from washes.Ĭlick to expand.It is a bit more complicated. You will always lost some values, mainly in washing steps of the gold powder with acid. Or you can cement the metal with more reactive metal (gold with copper etc.). Most efficient way how to precipitate metal in quantitative way is make inslouble compound, which could be filtered (like AgCl). Which will reduce not only gold, but also other junk from the solution. Very nasty, unforgiving, toxic and explosive stuff. I work my life hand in hand hydrazine, because I am in organic chemistry and use it a lot as building block. Which could in the end contaminate your gold.īe aware of hydrazine. Simply said, you produce (alongside the product) lots of unwanted sideproducts. This reaction has very low "atom economy", as it is named these days. So for one auric ion, you need 3 ferrous sulfate molecules. If we take it more analytically, iron (II) oxidation is one electron process. So when dropping gold, you inevitably introduce a lot of iron to the solution. Also easy to tell when you added enough.įerrous sulfate has an disadvantage - it contain iron. Practically non-toxic, cheap and very effective. The filtering trouble you mentioned makes me expect tin also, here inceneration of cemented values needed.SMB or any sulfite is a winner for me. No it is not ruined, will take more work to get it back. The gold connectors that were in there turned a dull copper color. This means gold was not dissolved, in a dirty copper and base metal solution this can make seperation of values harder as these flakes can stay in solution with base metals (and if they do not settle), will not be cemented with the values dissolved in solution, when using a metal higher in series like copper to cement values. In the solution that I pulled out there was quite a bit of gold flakes (small) floating in it. I should not go straight for the AR process and skip the Nitric.ĭo not skip any steps, thats one way people fall down. I was unable to filter it properly because the stuff was too thick. ![]() i still believe that silver is in there some where. I have save the solution that resulted from my attempt at nitric acid and silver. People get lost trying to take shortcuts.
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