What is the purpose of a crown pillar in underground mining?
A. Provide ventilation
B. Support overlying rock mass
C. Drain water
D. Guide drilling
Answer: Option B
Solution (By Examveda Team)
Crown pillar is a layer of unmined rock left between an underground mine and the surface.The correct answer is: Support overlying rock massIt prevents collapse and surface subsidence.Critical in near-surface deposits.This Question Belongs to Mining Engineering >> Mine Development And Mining Methods
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