Doesn't this seem like we are just going to use up iron supplies. Iron would then become a used up commodity and drive up prices. Just like when Corn was used for ethanol, the side effect was driving up corn prices, and raising food prices. This could use up Iron, and then impact a ton of stuff.

EDIT

Missed this: "This can later be reduced—that is, the oxygen can be stripped away—back into iron powder. “You can think of iron fuel as a clean, recyclable coal,” says Bergthorson."

So guess it's all good.