Difficulty: Easy
Correct Answer: 1.34
Explanation:
Introduction / Context:
Bond’s work index (Wi) is widely used to estimate energy requirements. Because transport and cushioning differ in wet vs dry circuits, empirical adjustments are made to compare conditions.
Given Data / Assumptions:
Concept / Approach:
Industry practice applies a multiplicative factor to the wet Wi to estimate dry circuit energy, commonly about 1.34, reflecting additional energy to overcome increased coating, dispersion issues, and classification inefficiencies in dry grinding.
Step-by-Step Solution:
Start with wet Wi.Multiply by 1.34 to obtain dry Wi.Use the adjusted value for dry energy sizing.
Verification / Alternative check:
Cement and mineral processing design texts cite the 1.34 factor as a rule-of-thumb adjustment.
Why Other Options Are Wrong:
1.0: ignores known differences.0.5/0.75: opposite trend.4.34: unrealistically high.
Common Pitfalls:
Treating Wi as universal without noting test conditions (wet/dry, closing screen).
Final Answer:
1.34
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