Seems to be alot of misinformed posts around about how the Mitsubishi deal works.
MMX owns 100% of the mine.
So its 25mtpa NOT 12.5mtpa.
Once the resource is proved up then Mitsubishi will be able to buy out the 50% at a market price (fair for both MMX and Mitsubishi).
So basically, the bigger the resource, the more Mitsubishi will have to pay.