Answer & Solution
Answer: Option
B
Solution:
Boxhole Definition:
A boxhole in underground mining is a small, typically rectangular, opening or chamber excavated from a larger mine opening (like a level or drift). It's specifically designed for a particular purpose related to material handling or access.
Correct Answer: Option B: Raise driven upward for loading
Boxholes are commonly used as the bottom loading point for raises. A raise is an inclined or vertical shaft driven upwards from a lower level to a higher level in a mine. The boxhole provides a convenient and controlled location to load broken ore or rock from the raise into mine cars or other haulage equipment. Its relatively small size compared to the raise itself makes it easier to manage the loading process and minimize spillage.
Why other options are incorrect:
Option A: To store explosives
Storing explosives requires much stricter safety regulations and specialized, well-ventilated storage areas, not a simple boxhole. Boxholes are not designed for the safe handling and storage of explosives.
Option C: Air exhaust system
Airflow in underground mines is managed by larger, more carefully designed ventilation systems, not small boxholes. Boxholes are too small and their locations aren't typically optimal for efficient ventilation.
Option D: Drainage gallery
Drainage galleries are larger, dedicated passages constructed specifically for collecting and channeling water away from the mine workings. A boxhole's size and design are not suitable for this purpose.
