Probably would still be an issue with contaminating the aluminum with carbon and possibly other impurities. You'd probably need some other process to purify the aluminum afterwards, which likely makes it too expensive.
But that process by itself is always going to be more energy efficient than winning the aluminum from bauxite ore.
Of course you need a purification step after dealing with scrap, but aluminum scrap, even when contaminated is quite valuable, basically the price is a function of how pure it already is.
Of course you need a purification step after dealing with scrap, but aluminum scrap, even when contaminated is quite valuable, basically the price is a function of how pure it already is.