Capy,
Just to let you know, when valuating the equity value of a property, it isn't that simple.
Saying that 400 million tons x $58/ton = $23.2 billion which translates into a $400+ shareprice is ridiculous.
More commonly, a company will receive 5-10% of the in situ value, the "in the ground value" applied to their market cap. In this case it would come out to:
(23 billion x 0.1) / 30mil shares out = $77.33
(23 billion x 0.05) / 30mil shares out = $38.67
The reason for this is that you have to account for someone paying for the infrastructure (P,P and E) to get the stuff out of the ground, the milling, logistics all over the place, labor, etc. Not to mention that iron ore is sold in large contracts so that $58 can be variable.
IMO, always take an extra lowball valuation so you don't get shafted when it all goes down.