Q137
Which mining method involves retreating the face and allowing the roof to collapse behind?
A.
Block caving
B.
Longwall mining
AnswerC.
Cut and fill
D.
Room and pillar
Answer: Option B
Solution
Answer: Option B
Solution:
Longwall mining is common in coal mining with high productivity.The correct answer is: Longwall miningPowered supports advance with the face while the roof collapses in the gob area.This method is highly mechanized.