@agox said:

Aluminum used to be a precious metal. Like, Napoleon had an aluminum silverware set and the Washington Monument is capped with aluminum. You're absolutely right about refining bauxite into aluminum being a post-electricity thing. I'm not too keen on the process, but I think it involves melting ore with giant electrical arcs in an oxygen poor atmosphere

hmm you do have to melt it but it is electrochemistry, if you just heated it all you'd get is molten aluminum oxide i guess, an electric potential is driving transfer of electrons from oxygen to aluminum atoms

You can heat it enough to melt it into aluminum, but it's like a thousand degrees more. More even than when you don't have the catalyst. Doable, but not in antiquity when they couldn't even melt iron.

By "melt it into aluminum" do you mean... I don't know, this is a chemical reaction, it's not melting.

I guess, at some temperature, it goes from liquid alumina to liquid aluminum with evolution of oxygen? This should happen at some temperature for entropic reasons, but I can't find any information about such a process (such as what temperature is required, or that there's a catalyst).

Best I can find is here, if you use carbon to take away the oxygen in the bauxite, but at around 2000C

https://chemistry.stackexchange.com/questions/166979/how-do-i-derive-metallic-aluminum-without-electricity

Also important to point out that it was not Napoleon who had the aluminum cutlery, but his nephew, Napoleon III. Aluminum wasn’t isolated until 1834.

yeah, that's hot. I think the electrolytic process is at like a thousand degrees celsius, so this is like a thousand hotter, as you originally recalled.