It is quite simple to extract aluminum from nearly all rock and soil. Aluminum silicates are one of the most common minerals found in the Earth's crust.
Using a nickel or iron pot add sodium hydroxide pellets (as dry as possible) and heat until the alkali becomes a liquid. Add stones such as flint or dry soil, granite, basalt in small pieces. These will dissolve. Allow the mixture to cool then add pure water. The solution is an alkaline solution of the components. Add acid until neutral. A white precipitate of Aluminum Hydroxide occurs. Filter and wash. Heat to dryness. The result is aluminum oxide (bauxite).
Use the usual process of electrolysis of bauxite to recover Aluminum Metal.