They could probably be separated by distillation, but the temperature would be quite high. Alternately, maybe some element could be found that would preferenti

They could probably be separated by distillation, but the temperature would be quite high. Alternately, maybe some element could be found that would preferentially dissolve aluminum (magnesium?) and that then could be separated, again perhaps by distillation. Al/Mg mixtures can melt as much as ~200 C cooler than pure Al.