The variation of ball size in a planetary ball mill (PBM) was studied in terms of its effect on the specific impact energy of balls as a result of ball to ball and ball to vial collision calculated through a computer simulation. The mean crystallite size of calcium
carbonate in the course of milling as well as the required time for obtaining a thoroughly formed calcium
carbonate was also analyzed with variation in ball size and ball to powder mass ratio (BPR). The crystallite size and formation time of calcium
carbonate changed as ball size and BPR varied. Based on XRD results it was found that a ball to powder mass ratio of 20:1 required a shorter time for the formation of nano‐crystalline calcium
carbonate. Moreover, it has been seen that the presence of randomness in choosing ball sizes leads to finer crystallite sizes.