General crushing equation exponent:\nBond’s crushing law is obtained from the general size-reduction equation by taking n = ________ with an infinite feed size.

Introduction / Context:
Generalised comminution expressions can be specialised to the three classical laws by selecting an exponent n. Correctly recalling which exponent yields Bond’s law is important for applying work index correlations and for exam problems connecting theory to practice.

Given Data / Assumptions:

• General form reduces to Bond by setting n to a specific value.
• Feed is considered infinitely large for the simplification.

Concept / Approach:
In the general size-reduction energy relation, Rittinger corresponds to n = 2, Kick to n = 1, and Bond to the intermediate exponent n = 1.5. With this selection and F → ∞, the Bond form E ∝ 1/√P emerges. Remembering the “middle” value 1.5 helps distinguish Bond’s theory from the surface-based (Rittinger) and size-ratio (Kick) forms.

Step-by-Step Solution:

Verification / Alternative check:
Handbook derivations list Bond’s “third theory” explicitly with the 1.5 exponent, consistent with work index equations used in design.

Why Other Options Are Wrong:

• n = 1: Kick’s law.
• n = 2: Rittinger’s law.
• n = 2.5 or 0.5: not used in the classical triad.

Common Pitfalls:
Memorising formulas without associating the corresponding exponent; use the mnemonic Kick(1), Bond(1.5), Rittinger(2).

Final Answer:
1.5