The expensive part is extracting aluminum from the ore, which uses the Bayer process I think. But if you pick up any rock off the ground, likely it has some aluminum in it. It’s just purifying it which is the thing.
“The expensive part is extracting aluminum from the ore, which uses the Bayer process I think.”
indeed ... a smelting process that’s driven entirely by electricity ... in fact, aluminum is often called solidified electricity for that reason, and is the metal that is the biggest energy-conversation win to recycle ...