In which mining method is ore extracted in horizontal slices starting from the bottom and advancing upwards?

Solution (By Examveda Team)

Definition of Cut and Fill Mining:
Cut and Fill is an underground mining method used primarily in steeply dipping, irregular ore bodies. In this method, the ore is extracted in horizontal slices, usually starting from the bottom of the ore body. After each slice is removed, the void is filled with waste rock, tailings, or other backfill material to provide ground support and a working platform for the next slice.

Correct Answer: Option B: Cut and Fill
The correct answer is Option B: Cut and Fill because this method involves the extraction of ore in horizontal slices from the bottom upward. Once a horizontal layer or "cut" of ore is removed, the resulting space is immediately backfilled to maintain stability. Then the next slice is mined on top of the backfilled material. This sequence is repeated until the entire ore body is mined.

This method is particularly suitable for ore bodies that are irregular in shape or structure and where selective mining is required. It provides excellent control over ore recovery and dilution and ensures worker safety by maintaining continuous ground support.

Explanation of Other Options:
Option A: Room and Pillar
Room and Pillar involves mining out "rooms" of ore while leaving "pillars" to support the roof. It is typically done in flat or gently dipping deposits and does not proceed in horizontal slices from the bottom upward.

Option C: Block Caving
Block Caving is a mass mining method where a large section of ore is undercut and allowed to collapse under its own weight. It is not performed in horizontal slices, nor does it progress upward in a controlled slicing manner.

Option D: Shrinkage Stoping
Shrinkage Stoping involves mining upwards in vertical stopes and temporarily storing broken ore in the stope to provide a working platform. Although it moves upward, it does not use horizontal slicing and backfilling like cut and fill.

Conclusion:
Therefore, the correct answer is Option B: Cut and Fill, as it is the mining method that involves extracting ore in horizontal slices starting from the bottom and advancing upwards, with each slice being backfilled to support the subsequent operations.