Several empirical Laws Governing Size Reduction describe the energy required for size reduction:
Laws Governing Size Reduction
1. Rittinger’s Law:
Suggests that the energy required for size reduction is directly proportional to the new surface area generated.
where
E = energy required
Kr = Rittinger's constant
D1 = initial particle size
D2 = final particle size
Applicable for fine grinding where the creation of new surface area is significant.
2. Kick’s Law:
Proposes that the energy required for size reduction is proportional to the size reduction ratio.
Where
E = energy required
Kk = Kick's constant
D1 = initial particle size
D2 = final particle size
Best for coarse crushing where the size reduction ratio is small
3. Bond’s Law:
Combines the aspects of Rittinger’s and Kick’s laws and states that the energy required is proportional to the reduction in particle size based on the work index of the material.
where
E = energy required
Kb = Bond's constant
D1 = initial particle size
D2 = final particle size
Suitable for intermediate grinding processes