[Titus]

I have a quick question. I know a little about chemistry(been a long time since college) and would like to know if there is an easier way to remove silver oxide from aluminum oxide both being in a mixxed powder form? The ratio is roughly 17% silver oxide, the rest is aluminum oxide. I have tried smelting in a furnace with poor results due to the amount of aluminum oxide. I am attempting to remove the silver oxide from aluminum oxide to smelt, but not with using acids. Would electrolysis be an option???

[Hunter2]

Probably caustic soda will go. NaOH can built aluminate with aluminium salts. Silveroxide will be still insoluble. But alumijnium oxide is also not easy to dissolve, especially if it was baked before.

[AWK]

NH₃ will dissolve Ag₂O

[Titus]

Thanks for responding
I will try both methods mentioned and let you guys know how it worked.

[AWK]

Al₂O₃ dissolves in solution NaOH poorly even in concentrated hot solution if you sample was sintered.
see: Bayer process in Wikipedia

[Titus]

So adding NH3 will give me [Ag(NH3)2] and will the NH3 have a reaction with Al2O3?  The Ag2O + Al2O3 powered is very fine. The aluminum oxide was made like a ceramic then crushed to be used as a blasting agent to clean silver oxide off of mechanical parts and collected in a dust system. The dry dust has a composition similar to diamatasious earth. Does that affect the solution? And if I have Only [Ag(NH3)2] is just a matter of filtering of the alumina and the smelting?

[AWK]

Al₂O₃ does not react with NH₃. Ammonia-silver oxide complex is very good soluble in water

[Enthalpy]

Heat the mix?

Silver oxide decomposes easily (and also melts) leaving silver which melts at 962°C while alumina is refractory, so have a good melting pot (alumina?) and some burner. Propane+air may suffice, and if not, acetylene+oxygen will.

Vibrating the mix would separate the very different densities but it's never perfect.

[Titus]

Melting it is the process we do now. Vibration is something I wanted to try also before the melt and then separate the two compounds at least to get a higher concentrate of silver oxide. Do you think it would work if I used a certain kind of flux in the melt to create a liquid type bath where the two different densities could separate better....cause that is the main problem with melting too much dang alumina 😩

[Enthalpy]

I hadn't put "flotation" because liquids denser than alumina are a bit nasty, typically perhalomethane.
https://en.wikipedia.org/wiki/Tetrabromomethane liquid above +95°C
https://en.wikipedia.org/wiki/Dibromochloromethane

But you could try a fluidized bed.
- With air but no flames, if the powders are fine enough
- With water flowing gently upwards.
Adjust the speed, better in a divergent, so the lighter or smaller grains rise and the others sink.

If the powder is fine enough, try to throw it horizontally through the air, maybe from a spinning horizontal disk, and check if the denser or coarser powder flies farther away.