Which of the following mining methods is most suitable for low-grade, large-scale ore bodies?

Solution (By Examveda Team)

Low-grade ore body: An ore body with a relatively low concentration of valuable minerals. This means that a large volume of rock must be mined to extract a worthwhile amount of valuable material.

Large-scale ore body: A very extensive ore deposit, implying significant size and volume.

Now, let's analyze why Block Caving is the most suitable method:

Block Caving is a bulk mining method designed for large, low-grade ore bodies. It involves creating an undercut at the bottom of the ore body to initiate a controlled collapse of the ore. The broken ore then flows downwards through draw points, where it is collected and transported to the surface. This method is highly efficient for low-grade ores because it allows for the extraction of large volumes of material at a relatively low cost per ton. The scale of operation is ideally suited to the vast size of large ore bodies.

Why other options are less suitable:

Shrinkage Stoping: This method is suitable for steeply dipping, high-grade ore bodies. It involves mining in a series of levels and filling the stopes (excavations) with broken ore. This makes it unsuitable for low-grade deposits, where the dilution of ore with waste rock would reduce profitability.

Room and Pillar: This method involves creating rooms separated by pillars of ore. It’s more suitable for relatively flat-lying, tabular ore bodies. While it can handle some scale, it's not as efficient for the extreme volumes found in large, low-grade deposits. The percentage of ore left in pillars as support reduces overall extraction.

Cut and Fill: This method involves mining in horizontal slices, with waste rock used to create fill. While it can be used for steeply dipping ore bodies, it's generally not economically viable for extremely large, low-grade deposits due to higher costs associated with the filling process.

In summary, Block Caving is the most efficient and economical method for extracting valuable minerals from large, low-grade ore bodies due to its bulk mining nature and high extraction rate.