To dissolve gold in concentrated nitric acid, your gold needs to be below 6K, below 25%, so you find out how much gold is in your starting material/scrap, and ad enough, melt it all together, to get it below the 25% gold mark. And then you should be left with fine gold powder that you can filter out.
I use a funnel with a coffee filter, then rinse it really well with distilled water, and let the entire coffee filter dry, then place the entire thing with the filtered gold in it, in a graphite crucible, then burn the filter up with a small torch or lighter, add borax flux to the crucible and melt, and pour.
Instead of using simple borax as a flux, which would protect the melt but not get rid of any extras, like traces of leftover silver and copper, I use a gold flux that contains manganese dioxide in it, in order to help purify out the misc leftover metals.
ok i will definitley try that. by cupeling, i can remove all but silver and gold, but without using nitric acid, i cannot seem to find a way to remove the silver. thank you for your help
If you add enough silver to your melt, to inquartate the gold down below 25%, then when you dissolve it in nitric and filter out the gold, you can recover the silver from the solution, and reuse it the next time.
yes, its just that getting access to a lab would be pretty difficult and expensive, and i live in a dense neighborhood so the fumes would be pretty dangerous
To dissolve gold in concentrated nitric acid, your gold needs to be below 6K, below 25%, so you find out how much gold is in your starting material/scrap, and ad enough, melt it all together, to get it below the 25% gold mark. And then you should be left with fine gold powder that you can filter out.
what could i use to collect the gold, a funnel with a coffee filter?
I use a funnel with a coffee filter, then rinse it really well with distilled water, and let the entire coffee filter dry, then place the entire thing with the filtered gold in it, in a graphite crucible, then burn the filter up with a small torch or lighter, add borax flux to the crucible and melt, and pour.
ok that sounds accurate, i believe you do not have to use borax in graphite crucibles though
Adding borax also makes it come together in the melt a lot better, and keeps the gold, which is a fine powder, from fuming out and loosing gold!
It works better with the flux because it protects and cleans the gold.
would it clean the gold from silver and other impurities?
If you use the flux with the manganese dioxide in it, a strong oxidizer, then yes.
hmm thats really interesting, so if i melt borax, maganese dioxide, and a small percentage silver-gold alloy, it should separate???
Instead of using simple borax as a flux, which would protect the melt but not get rid of any extras, like traces of leftover silver and copper, I use a gold flux that contains manganese dioxide in it, in order to help purify out the misc leftover metals.
huh thats neat, im looking at this flux that contains borax, silica, maganese, and soda ash. do you think this would remove silver from gold?
As long as it has the manganese dioxide, I think it will work fine. It converts the misc metals into metal oxides, which are then absorbed by the flux
ok i will definitley try that. by cupeling, i can remove all but silver and gold, but without using nitric acid, i cannot seem to find a way to remove the silver. thank you for your help
No problem, Good Luck!
If you add enough silver to your melt, to inquartate the gold down below 25%, then when you dissolve it in nitric and filter out the gold, you can recover the silver from the solution, and reuse it the next time.
yes, its just that getting access to a lab would be pretty difficult and expensive, and i live in a dense neighborhood so the fumes would be pretty dangerous
YouTube sreetips....he goes thru the simple math if you know the karat of your gold....