Mine Development And Mining Methods - Study Mode
[#136] Which of the following is an example of selective mining?
Correct Answer
(C) Cut and fill
Explanation
Solution: Selective mining extracts high-grade portions while minimizing waste.The correct answer is: Cut and fillSuited for narrow, irregular, or high-grade ore bodies.High cost but precise extraction.
[#137] What is an advantage of using rubber-tired vehicles in underground mines?
Correct Answer
(C) Higher maneuverability in small headings
Explanation
Solution: Rubber-tired vehicles like LHDs are flexible and fast.The correct answer is: Higher maneuverability in small headingsIdeal for narrow drifts and variable layouts.Require good ventilation due to diesel emissions.
[#138] What kind of shaft is typically used to transport miners and materials?
Correct Answer
(D) Service shaft
Explanation
Solution: Service shaft is designed for personnel, materials, and utilities.The correct answer is: Service shaftIt often includes elevators, ladders, and pipe installations.Ore shafts are primarily for hoisting rock.
[#139] What is the role of a grizzly in an underground ore pass system?
Correct Answer
(C) Separation of oversize rock
Explanation
Solution: Grizzly is a grid or grate placed over ore passes or bins.The correct answer is: Separation of oversize rockIt prevents large boulders from blocking chutes.Oversize is then broken manually or by hydraulic hammers.
[#140] Which of the following is used to prevent spontaneous combustion in coal mines?
Correct Answer
(A) Nitrogen injection
Explanation
Solution: Spontaneous combustion occurs when coal oxidizes and self-heats.The correct answer is: Nitrogen injectionNitrogen displaces oxygen, stopping oxidation.Other methods include sealing and temperature monitoring.