Sciencemadness Discussion Board

Making pure aluminum powder from aluminum alloys

symboom - 29-4-2020 at 21:10

I came across a video of nitric acid attacking copper but not aluminum so I figured if an aluminum zinc alloy was made.
zinc can be dissolved using acetic acid. aluminum does not react with acetic acid leaving behind a brittle aluminum sponge that can be powderized.

DraconicAcid - 29-4-2020 at 22:39

Nitric acid doesn't attack aluminum only because it forms a passivating layer of aluminum oxide over it. I strongly suspect that an alloy containing aluminum will either get passivated (and not react at all) or react completely.

Refinery - 30-4-2020 at 01:14

Making aluminium powder chemically appears to be difficult. I'm not aware of chemical process that crashes out metallic aluminium.

Mechanically, ball mill, blender and al foil is the way to go.

If you wanna go hardcore, build a SS apparatus, melt Al in it, pressurize it with argon and inject pressurized argon gas stream to the nozzle, which will atomize the Al and you can easily process it from there down to micron size with ball milling.

symboom - 30-4-2020 at 10:12

Thank you for the replys I'm thinking of a process similar to Raney nickel, also called spongy nickel, is a fine-grained solid composed mostly of nickel derived from a nickel–aluminium alloy. The aluminum is resolved out of the nickel. Quote strongly suspect that an alloy containing aluminum will either get passivated (and not react at all) I agree with you there would have to be a low amount of aluminum so that the other metal in the alloy resolved around it. Acetic acid is the only acid im guessing due to aluminum's resistant to weak acetic acid the acid would have to be heated and acetic anydride in excess to resolve aluminum

[Edited on 30-4-2020 by symboom]

DraconicAcid - 30-4-2020 at 10:16

The Raney nickel works because the nickel is less reactive than aluminum. If you were to do something similar with aluminum, you'd have to alloy the aluminum with something more reactive, and then use a reagent that only reacts with the other metal due to inherent reactivity differences, not passivation). An alloy of sodium and aluminum in liquid ammonia, maybe?

symboom - 30-4-2020 at 10:27

I see what you mean guess no short cuts for aluminum powder
By the time a sodium aluminum alloy is made aluminum could have been powderized. The FFC Cambridge process seems to be the only method that can make aluminum powder from aluminum oxide directly using calcium chloride molten salt.