Example SAGBall Mill Circuit WI Efficiency Calculation • SAGball circuit F80 = 165,000 um P80 = 125 um W = kWh/t Wlo = / [( 10 / SQRT 125) – (10 / SQRT 165,000)] = kWh/t • Bond Test WI's (kWh/t): Crushing: Rod Mill: Ball Mill: • Bond Standard Circuit Work Index: