Yes it is not that simple calculation, the truth of SFR suceed was based on this:
"By November 2010, about 18 months from discovery, the company had established a resource of 644,000t of copper and 724,000oz of gold. A subsequent definitive feasibility study projected operating cashflow of $2.4bn on $4.2bn revenues over life of mine."
As what I said, all depends on the result from the ground.
