I think we are missing a very important fact here guys about these NPV calculations as presented in the BFS. These numbers are based on the worst and most conservative case possible without factoring in 171M tons of open pit material in the high grade zones that are considered as waste (by the BFS study) and worth 0$. This cost money to remove and is a factor that greatly skews the profitability and NPV calculations. Just to give you an idea of how much is missing from processing this "waste rock" lets take a look at some numbers:

171M tons x $6.56/ton (mining costs) = $1.12B in cost to remove

Missing revenue from waste rock:

$30/ton ( 0.44% Cu eq ) x 171M tons = $5.13B in revenue

So instead of counting 5.13 B in extra revenue we are saddled with an extra $1.12B is extra costs. This imo, greatly skews the NPV and IRR numbers greatly. If the 171M tons were counted as ore in the BFS it would make a tremendous difference in the final NPV numbers. I am sure Teck as any other Major will take this into consideration and will not miss this important difference here.