#### Investigating of the effect of ore work index and particle size on the ...

Batch grinding tests were carried out using a cm × cm (length × diameter) ball mill equipped with 4 lifters. The L/D ratio in both laboratory ball mill and the plant ball mill was similar. The maximum ball size for plant ball mill calculated from Bond formula (Eq. (4)) [24]: (4) d B (mm) = F 80 k s. g.