bremen68 wrote in news: snipped-for-privacy@h2g2000hsg.googlegroups.com:
But, but, but as a mineral, alumin(i)um is usually found as an oxide. It wasn't until after an expensive, energy-intensive way was found to free aluminum from its oxide that the metal became really useful. It is true that aluminum forms a protective oxide layer when exposed to air (in contrast to iron, which gets an autocatalytic layer of rust that eats further and further into the metal).
Freeing up hydrogen by letting water react with aluminum seems an uneconomical way to generate fuel.