In comminution theory, which empirical law states that the crushing energy is proportional to the new surface area created during size reduction?

Difficulty: Easy

Correct Answer: Rittinger’s law

Explanation:


Introduction / Context:
Energy–size reduction relationships help estimate power requirements and select suitable grinders. Three classic laws—Rittinger, Kick, and Bond—apply in different size ranges and fragmentation regimes.


Given Data / Assumptions:

  • The question asks specifically for energy proportional to new surface area.
  • Applies best to fine grinding where surface area increase is large.


Concept / Approach:
Rittinger’s law: E ∝ ΔA (increase in surface area). Kick’s law: E ∝ ln(d1/d2). Bond’s law: E ∝ (1/√d2 − 1/√d1). Thus, only Rittinger directly ties energy to new surface created, matching systems where fracturing creates many fines.


Step-by-Step Solution:
Identify law with energy–surface proportionality.Match to Rittinger’s statement.Select Rittinger’s law.


Verification / Alternative check:
Fine grinding design commonly references Rittinger for micronization contexts, validating the selection.


Why Other Options Are Wrong:
Taggart’s rule: screening/misc. correlations, not energy law.Fick’s law: diffusion, unrelated to grinding energy.Kick/Bond: different functional forms, not directly to surface area.


Common Pitfalls:
Confusing Bond’s widely used work index with Rittinger’s fine-grinding emphasis.


Final Answer:
Rittinger’s law

More Questions from Mechanical Operations

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion