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________________?
A. 6.35 kWh/ton
B. 9.0 kWh/ton
C. 18 kWh/ton
D. 25.4 kWh/ton