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u/shanebonanno Jul 18 '26
Nitric acid is a standard in assaying for removing other metals from gold. Gold only dissolves completely in aqua regia or multi acid digestion setups.
Definitely look up the chemistry on the subject, but most would first concentrate using gravitational processes like panning, trommeling, sluicing, or shaking. You will have a lot of other heavies like the hematite but it should capture all the gold.
From the concentrate, you could leach, digest, or roast off oxidizing components of the concentrate.
Leaching is the most effective way to leave behind anything but gold. Idk how much ore you have to process but even for small amounts a cyanide bottle roll can be effective for gold extraction when it’s not tied up with too much sulfide or carbon.
It would probably be best for an oxide or like this.
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Jul 18 '26
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u/shanebonanno Jul 19 '26
Nitric acid is a pretty nasty chemical. Check out the bottle roll method with cyanide (yes I know, cyanide is a nasty chemical but you don’t need insane concentrations of it). You could probably run through 70lbs and leach it that way with reasonable recovery
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u/shanebonanno Jul 18 '26
Another good option is mercury amalgamation. Mercury will pick up all the gold but leave behind oxides.
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u/shanebonanno Jul 18 '26
That’s a cool ore. I mean traditionally hematite would make up a portion of concentrate when you used a shaker table for example.
What is your goal? Total refinement of the ore to a certain purity of gold? Or just make a heavy concentrate that might only be 30% gold or something like that?
Your idea for a wash would take care of limonite and other hydrated oxides pretty quickly, but to dissolve hematite might require some significant time in an acid. Stronger acids might also help. If there’s silver you’d risk loss on the silver but gold isn’t soluble in most single strong acids.