I think you are confusing up the difficulty of extracting aluminum from bauxite ore versus melting aluminum once it is a pure metal.
I’ve seen a few videos on youtube in which the people making casts of ant nests using a clearly home made setup in which they are using charcoal pellets as fuel and steel pot as a furnace with a leaf blower in a forced draft arrangement to get the temperature up to a level that it will melt aluminum. There’s even a video posted by YouTube user who did it using a hair drier, plastic pipe, charcoal chimney, charcoal and a small pot to melt aluminum cans
