Wet grinding vs. dry grinding in a revolving mill\nIn industrial comminution practice, which effect is typically observed when grinding is carried out wet (with a slurry) instead of dry in the same revolving mill and for the same target fineness?

Introduction / Context:
Plant engineers often must decide between wet and dry grinding modes for ball, rod, or tube mills. This choice affects power draw, liner life, product handling, and—crucially—throughput. Understanding the dominant trends allows better sizing and operating policies without exhaustive pilot testing.

Given Data / Assumptions:

• The same mill geometry and media are assumed in both cases.
• Target product fineness and material properties are comparable.
• Wet grinding means a slurry with appropriate solids percentage; dry grinding means negligible moisture.

Concept / Approach:
In wet grinding, the presence of water forms a slurry that reduces interparticle adhesion, improves transport of fines out of the breakage zone, and cushions impacts, which collectively reduces overgrinding. Slurry transport also enhances the effective classification inside the mill, permitting a higher solids throughput at the same fineness. Consequently, mills operated wet typically achieve higher capacity. Additional known effects are reduced liner and lifter wear (water lubricates and transports chips) and easier size classification. Conversely, wet product handling can be more complex (pumps, thickeners, dryers) though this is outside the specific capacity comparison.

Step-by-Step Solution:

Verification / Alternative check:
Standard mill performance curves and plant reports show greater tonnage in wet grinding at comparable product size (e.g., cement raw mills and ore grinding circuits). Pilot tests further confirm higher net production rates due to improved classification and reduced dust-related losses.

Why Other Options Are Wrong:

• Gives less wear: often true, but the question asks for what is typically observed; capacity increase is the most universal and decisive operational effect.
• Requires more energy: for the same fineness, specific energy is usually similar or lower in wet grinding, not higher.
• Complicates handling: may be true operationally, but it is not the primary mill performance effect.
• All equally true: not all statements hold equally across materials; capacity increase is the most consistent trend.

Common Pitfalls:
Comparing at different fineness targets or solids percentages; conclusions must be drawn at equal product size to be meaningful.

Final Answer:
Increases the mill's throughput (capacity) at a given fineness