Arafura Rare Earths Ltd, page-317

I may be mistaken, but I reckon on the Sky Business Weekend interview with the ARU CEO he referred to it as "multi generational" (check my thread on it, I think I noted it). I think it may have also been compared to Olympic Dam.

I'm going 100 years.

edit: actually I'm going with less than 100 years as I reckon they will ramp it up to meet the huge predicted shortfall. They may well indeed end up providing 10% of the world's NdPr. Huge barriers to entry for new entrants. Much easier to ramp up existing large super long life mines.
> More ARU supply = more revenue (and larger NPV)