1. What is Cut Off Grade?

Cut Off Grade is the minimum grade required for a mineral deposit to be economically viable. It represents the break-even point where mining and processing costs equal the revenue from the recovered metal.

2. How Does the Calculator Work?

The calculator uses the cut off grade formula:

Where:

• Operating Cost — Total mining and processing costs (dollars/ton)
• Recovery — Percentage of metal recovered during processing (unitless, 0-1)
• Price — Market price of the metal (dollars/ton)

Explanation: The formula calculates the minimum metal concentration needed to cover all operational expenses and achieve zero profit.

3. Importance of Cut Off Grade Calculation

Details: Accurate cut off grade determination is crucial for mine planning, resource estimation, and economic evaluation of mining projects. It helps define ore reserves and optimize mining operations.

4. Using the Calculator

Tips: Enter operating cost in dollars per ton, recovery as a decimal (e.g., 0.85 for 85%), and price in dollars per ton. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What factors affect cut off grade?
A: Market metal prices, mining costs, processing recovery rates, and economic conditions all influence cut off grade calculations.

Q2: How does recovery rate impact cut off grade?
A: Higher recovery rates lower the cut off grade, making more material economically viable to process.

Q3: Can cut off grade change over time?
A: Yes, cut off grade is dynamic and changes with fluctuations in metal prices, operating costs, and technological improvements.

Q4: What's the difference between cut off grade and average grade?
A: Cut off grade is the minimum economic threshold, while average grade is the mean metal content of the entire deposit or ore body.

Q5: How is cut off grade used in mine planning?
A: It determines which material is classified as ore (above cut off) versus waste (below cut off), guiding mining sequence and production planning.