O I SKARIN N O TIKHONOV CALCULATION OF THE REQUIRED ball mill feed and EF5 for final milling size these factors are only introduced if exceed 1 For RWI and BWI in kWh/t the formulas below are valid ·BWI 7 F 80 EF4 CDBM = 1 1 2 F 80/P 80 4000√/RWI EF5 = P 80 / 80 3 It is worth noticing that calculation of EF4 CDBM requires RWI and BWI and F 80 in 2 is understood as the initial size of