Jantimot,
So 6m tonnes of NCu ore at the 2 rates of 8-10% and 12-15% ore, averaging about 10% equals 600,000 tonnes NCu, or in dollar terms $3.8b.
For an easy to separate product, not bad. Having 100,000 tonnes already stockpiled, not bad.
My opinion is that you are clutching at straws to downramp this at this price.