ddzx to simplify what you've said - and I'm erring on the side of high production costs intentionally -
the deposit has an IGV of $18 billion
deduct 50% for OPEX = $9 billion
deduct $2b CAPEX = $7 billion
So the project still has a 'net worth' of $7 billion.
It's obviously not a project for a $10 million mc minnow but for a company that can finance the project with ease it has value.