Cut off grade is

Solution (By Examveda Team)

Option A: The grade of ore ultimately fed to the beneficiation plant

This option is incorrect. While the cut-off grade can influence the grade of ore fed to the beneficiation plant, it specifically refers to the economic threshold below which mining is not profitable.

Option B: Always the same average grade

This option is incorrect. The cut-off grade is not always the same as the average grade. It is determined by economic factors and can vary depending on market conditions, costs, and other variables.

Option C: The grade of ore through net the ore body

This option is incorrect. The grade of ore through the ore body refers to the overall distribution of mineral content, but the cut-off grade specifically refers to the minimum grade at which mining becomes economically viable.

Option D: The grade of ore below which mining is uneconomical

This option is correct. The cut-off grade is the grade of ore below which mining operations are not economically feasible. It is a critical factor in determining whether a deposit can be profitably mined.

Conclusion:

The cut-off grade is the grade of ore below which mining is uneconomical, making Option D: The grade of ore below which mining is uneconomical the correct answer.