The IRR headline figure of 15% isn't the main problem, although...

The IRR headline figure of 15% isn't the main problem, although that figure is very, very borderline... Its that it is reliant on commodity price assumptions much higher than current prices, as well as a sulphate premium which may not be realised as further supply comes online, to generate the borderline IRR. The finance was never going to be organised by the end of 2018 deadline based on the current BFS, hence them looking to 'enhance' it.

You've listed a whole lot of copper projects for comparison of which also have a low IRR but ignore than they assume copper prices around current spot prices and these projects also don't use a ridiculously low 8% discount rate, they also use 9.5 - 10%. The 8% discount rate further enhances the numbers for AUZ.

Carpenteena is just a simple example off the top of my head that has an IRR of 20% assumed a copper price well below $3 pound with about $1bn capex. Plenty more examples I am sure.