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Calcimator

Ore Grade Calculator

Calculate recoverable metal tonnage from total ore tonnage, grade percentage, recovery rate, and cutoff grade.

Inputs

Results

Contained Metal

150 t

Recoverable Metal

135 t

Above Cutoff Grade?

Yes

Grade (g/t)15,000 g/t
Grade Margin over Cutoff1.2%
Metal per Tonne Ore13.5 kg/t
Waste Tonnage0
How to Use This Calculator
  1. Enter the Total Ore Tonnage in metric tons and the Ore Grade as a percentage of metal content.
  2. Enter the Recovery Rate percentage to account for metallurgical losses during processing.
  3. Enter the Cutoff Grade below which mining is uneconomic.
  4. Review Contained Metal and Recoverable Metal tonnage as the key reserve calculation outputs.
  5. Check Above Cutoff Grade and Grade Margin to confirm economic viability of the deposit.

How the result changes with Total Ore Tonnage (t)

Total Ore Tonnage (t)Contained MetalRecoverable MetalAbove Cutoff Grade?
100,000,0001,500,000 t1,350,000 tYes
350,000,0005,250,000 t4,725,000 tYes
650,000,0009,750,000 t8,775,000 tYes
900,000,00013,500,000 t12,150,000 tYes

What each input means

Total Ore Tonnage (t)
Total tonnes of ore to be processed.
Ore Grade (%)
Metal content as a percentage of ore weight. Copper: 0.5–2%, Gold: often expressed in g/t instead.
Recovery Rate (%)
Percentage of contained metal recovered during processing. Typical flotation: 85–95%.
Cutoff Grade (%)
Minimum grade that is economically viable to mine. Ore below this grade is waste.

How this is calculated

Formula

Recoverable Metal = Tonnage × Grade% × Recovery%

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Total Ore Tonnage (t) = 10000, Ore Grade (%) = 1.5, Recovery Rate (%) = 90, Cutoff Grade (%) = 0.3 = 4 input(s) provided
  2. Calculate Contained Metal
    Contained Metal
    150 = 150
  3. Calculate Recoverable Metal
    Recoverable Metal
    135 = 135
  4. Calculate Above Cutoff Grade?
    Yes = Yes
  5. Calculate Grade
    Grade
    15000 = 15000
  6. Calculate Grade Margin over Cutoff
    Grade Margin over Cutoff
    1.2 = 1.2

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