Rittinger’s number and grindability:\nRittinger’s number denotes new surface area created per unit mechanical energy during grinding. A larger Rittinger’s number implies:

Introduction / Context:
Grinding performance can be discussed in terms of how effectively energy is converted into new surface area. Rittinger’s law asserts that energy is proportional to new surface created; therefore, a material that generates more surface per unit energy is “easier” to grind to fine sizes, and this is captured by Rittinger’s number.

Given Data / Assumptions:

• Rittinger’s number increases with surface area generated per unit energy.
• We compare relative grindability across materials at similar conditions.

Concept / Approach:
If Rittinger’s number is high, each kilowatt-hour of input yields a larger increase in surface area. That means, for a given target fineness, less energy is needed—i.e., the material is more amenable to grinding. Conversely, a low Rittinger’s number suggests that more energy is required to create the same surface area, indicating poor grindability.

Step-by-Step Solution:

Verification / Alternative check:
Comparative milling studies frequently report materials with high friability achieving target fineness at lower specific energy, consistent with higher Rittinger’s numbers.

Why Other Options Are Wrong:

• Poor grindability/higher power: contradict the definition.
• No relation: incorrect because Rittinger’s number explicitly ties surface to energy.
• Particle sphericity: unrelated to this metric.

Common Pitfalls:
Confusing Rittinger’s number with Bond work index; the former relates to surface creation per energy, the latter to specific energy scaling with size reduction.

Final Answer:
Easier grindability (more surface created per energy input)