Q212
Which method involves retreating while extracting support pillars?
A.
Block caving
B.
Longwall mining
C.
Retreat mining
AnswerD.
Sublevel caving
Answer: Option C
Solution
Answer: Option C
Solution:
Retreat mining removes pillars during withdrawal from a mined area.The correct answer is: Retreat miningCommonly used in coal mines.Requires high monitoring due to collapse risk.