Welcome, Fiorafa! And no worries with your English.https://en.wikipedia.org/wiki/Bayer_process
isn't brilliant. Earth's crust contains as a mean 8% Al by mass, equivalent to 15% Al2
, while bauxite contains 30-60% Al2
. But you have a bauxite equivalent without mining it. Then, electricity cost matters. Aluminium producers operate where electricity is cheap, say in Québec, and prefer to transport aluminium ore over the oceans.
To my understanding, most minerals are silicates of aluminium and iron. That is, the oxides of Si, Al and Fe are not separated in them. The analysis result is just a conventional form of expressing element abundances in the form of oxides. So the separation, say by the Bayer process, is a chemical transformation.
The Hall-Héroult process must be seriously difficult to try in hobby style. Interesting challenge. On a small scale, a computer power supply can provide some intensity for little money, at 3.3V, 5V and (cells in series, most power) 12V.