Sciencemadness Discussion Board

Burning GOLD to oxid

pneumatician - 26-12-2021 at 18:37

Ep!

what amount of volts/Amp is enough, or best ratio to burn Gold wire in a green flame and convert it to Gold oxide???

depend on thickness??

possible too with a little 1 gram bar??

and if Gold is not pure... what the hell will happen? :-)


violet sin - 26-12-2021 at 19:51

https://www.911metallurgist.com/blog/gold-oxides

Does not talk about burning gold with electricity. Does talk about gold chemistry some and had a number of ways to get gold oxide.

pneumatician - 27-12-2021 at 07:07

Quote: Originally posted by violet sin  
https://www.911metallurgist.com/blog/gold-oxides

Does not talk about burning gold with electricity. Does talk about gold chemistry some and had a number of ways to get gold oxide.


batua!

no info around? so I need to "rediscover" this method reading old chem bulletins 8-)

maybe I try the "how is it done? doing it!" method and connect Gold to a power source and start to raise volts and amps... I'ved one of 48V, 3 Amp :-)
the problem is find the right tools if is necessary 1000's of volts.

maybe this idea/project is for guys playing with Tesla coils...


Vomaturge - 27-12-2021 at 20:59

That source mentions starting with gold chloride. Wikipedia mentions Au2O3 losing oxygen at 160C, and says gold doesn’t react permanently with diatomic oxygen at any temperature but can react to ozone above 100C. I don’t think just heating it by electricity will enable you to get an oxide.

draculic acid69 - 28-12-2021 at 20:21

Gold and platinum are the 2most unreactive metals and therefore are
found in there unoxidised elemental form in nature which is a rare thing indeed.
Look at what it takes to oxidise platinum, I imagine gold would be equally
difficult.

violet sin - 28-12-2021 at 22:02

And like stated all over the place... High temps often liberate the oxygen as a nuisance, leaving free metal. Honestly I'm not sure how much UV they could take w/o freeing it up. Hmmm.... It seems it may actually help some. This paper should have some answers, has some references to past methods, besides the main title objective. Maybe worth a shot.

Oxidation of gold by ultraviolet light and ozone at 25 °C
https://www.semanticscholar.org/paper/Oxidation-of-gold-by-u...

Attachment: king1995.pdf (390kB)
This file has been downloaded 70 times

Lion850 - 29-12-2021 at 01:05

The purpose of the electricity is to heat the gold. Thus, the amps are important, not the volts. The gold will need to be as thin as possible to have higher resistance and thus reduce the current required. If you can get the gold thin enough (like a thin wire) a car battery should provide more than enough current.

Usually if metal wires are heated to the point of oxidation in air some of the oxide will be carried off as 'smoke'. So you may want to do this in a contained space like an Erlenmeyer flask. Having a supply of oxygen going into the vessel will probably help to lower the temperature needed.

It may be an advantage if the current can be controlled to ensure the gold does not melt, else you end up with a break in your gold wire and the current stops.

All above just random thoughts.

woelen - 4-1-2022 at 00:45

Heating the gold will not work. You may get it so hot, that it melts, but certainly if you have a bullion (not a very thin wire), then you probably firsat melt your leads and/or power supply :D

Try to dissolve the gold in aqua regia or a mix of H2O2 and conc. HCl. This takes some time, but can be done. Boil off most of the acid (do this outside, you'll produce a lot of really nasty fumes). Then precipitate the gold with an alkaline solution. You will get hydrous gold oxide, which needs to be rinsed. Gentle heating will remove most of the adhering water. You'll end up with impure partially hydrated Au2O3, having possibly some chloride in it as well. Getting really pure Au2O3 seems to be quite difficult. The wiki page on Au2O3 tells that you need to heat the impure product (as I describe here) with a mix of perchloric acid and an alkali perchlorate at 250 C and a pressure of an insane 30 MPa (which is appr. 300 bar).