Ann: Kharmagtai Resource Grows to 1.1 Billion Tonnes, page-23

It's a porphyry deposit so I don't think the grade is an issue as long as it is big enough and the metallurgy isn't problematic. There's still plenty of scope for growing the resource.

I don't see Rio's issues with OT as being a massive black mark against Mongolia. Sure, there are definitely some political issues, but a good sized chunk of the problem has been caused by Rio itself mismanaging the project IMO.