The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond’s law) of the energy to grind the particles from a very large size to 50 μm is________________?

Question

Accepted Answer

18 kWh/ton. Bond's law suggests energy is proportional to the square root of the ratio of particle sizes. Since 50 μm is smaller than 100 μm by a factor of 2, the energy should be $\sqrt{2} \approx 1.41$ times the initial energy, which is closer to 18 kWh/ton.