the annual opex for the entire mine is around US$123M per annum...

the annual opex for the entire mine is around US$123M per annum

are you saying MNS can only process 25Ktpa of jumbo flake when 'screening' appears to be the final stage of processing?

below is an example from another company (since I could not find an MNS flowsheet):

The process plant is designed with a throughput capacity of 720ktpa for an average TGC grade of 96% and average annual production of 60ktpa. The process plant is based on a crush and grind comminution circuit (two stage crushing circuit with single stage rod mill) followed by rougher flotation. The tailings are reground in a ball mill before they enter the scavenger flotation. The rougher and scavenger concentrates are combined and fed into the primary cleaner section, consisting out of polishing mills and cleaner flotation banks. The concentrate is than screened into two size fractions, with subsequent polishing and four stage cleaning applied with no further milling required in the cleaning circuit. Product is then dewatered, dried and screened into saleable size fractions.