Not my area of expertise however from investing in pure Au...

Not my area of expertise however from investing in pure Au companies and companies that produce both Au and Cu the best being Earnest Henry Gold copper mine - the mine plan is built around extracting both copper and gold or if no Cu just Au- Deflector initially had problems separating the 2 and the middling's produced were sold as a combination of Au and Cu overseas - I understand that if this was a pure Au mine the AISC would be much much more however it is a Copper and Gold mine and producing as built and the AISC is very very good because of this - They don't need to separate the two because the mine plan was built around what is in the ground. Bit like BHP's Olympic dam it has even more than just Au and Cu and is a world class mine -I'm more interested in the potential increase in production to maybe 100k Au from Da Vinci that will potentially bring the AISC down even further and also bringing AW back on line because there is still a lot of gold in the ground up there as long as it is profitable however I think these guys will find a way....let's see.