Mine Development And Mining Methods - Study Mode
[#151] What is the term for a horizontal underground opening made at the lowest level to drain water?
Correct Answer
(D) Drainage adit
Explanation
Solution: Drainage adit is a horizontal tunnel designed to remove water via gravity.The correct answer is: Drainage aditEspecially common in older mines to reduce pumping needs.Positioned below the lowest active level.
[#152] Which of these stoping methods involves leaving horizontal pillars to support the roof?
Correct Answer
(B) Room and pillar
Explanation
Solution: Room and pillar leaves ore pillars behind to support the roof.The correct answer is: Room and pillarUsed for flat-lying deposits like coal and potash.Room extraction can be partial or full.
[#153] What is the key benefit of sublevel stoping?
Correct Answer
(C) Fast production rates
Explanation
Solution: Sublevel stoping uses multiple drilling levels and longhole blasting.The correct answer is: Fast production ratesSuitable for steep, competent ore bodies.Efficient but less selective and has moderate dilution.
[#154] What is a typical application of raise boring?
Correct Answer
(C) Creating smooth vertical holes
Explanation
Solution: Raise boring drills a small pilot hole, then enlarges it to full diameter.The correct answer is: Creating smooth vertical holesUsed for ventilation shafts, ore passes, and service holes.Safer and faster than conventional raises.
[#155] Which method involves ore fragmentation mainly by gravity?
Correct Answer
(C) Block caving
Explanation
Solution: Block caving undermines a large ore block, causing it to collapse under its own weight.The correct answer is: Block cavingMinimal drilling and blasting once caving begins.Low cost per ton but high dilution.