### A Method of C alculating Autogenous/ Semi …

mills with the rod mill and ball mill laboratory work indices. Note, in Figure. 1, that the rod mill product slope is less than 0.5 due to an extra amount of nes present being ﬁ ﬁ ner than 650 μm. These ﬁ nes proceed to the ball mill improving the ball mill efﬁ ciency. Also, the plotted rod mill P80 value, as shown in Figure 1, is 2900 ...