I haven't checked your numbers but the Cu price would have to...

I haven't checked your numbers but the Cu price would have to stay higher the $3.18/lb ($7,000/T). I can't see the project start-up till at least $3.75 maybe $4.00. Note there's going to be a copper deficit in 2 yrs and growing because of insufficient exploration now.
No-ones going to fund, build and start a mine unless they expect pay back. This is a next generation mine.
I would expect Cu prices up to $5/lb and payback in 3-4 years which isn't unrealistic for a 15-20 year mine. In fact is' par for the course.
This isn't some 2-3% grade mine that mines 300-400,000 t of ore then stops. It's got to compete with Escondida and the likes. That's what it take to mine 0.5% Cu. Which is the next gen. be it open cut or block cave.

Anyway that analysis gives several scenarios where the feed is sweetened by the satellites. They're saying 21 c/s is the low case.

Sorry if my comments seem a bit aggressive. I'm just trying to curb expectations (general in the industry) that are going to run us into that copper deficit. There's a major Cu conference next month
(April) which should shed some light on the Cu supply/demand situation.