Calculator
Dilution
What mining waste rock alongside ore does to the grade that actually reaches the plant.
The formula
Diluted grade = (in-situ grade + dilution x waste grade) / (1 + dilution), with dilution as a decimal fraction.
What it assumes
- Dilution is expressed as a proportion of the ore tonnage.
- Waste is assumed to carry the grade you enter, zero by default.
Where it stops being reliable
- Real dilution varies hole by hole and stope by stope. A single figure is an average at best.
- Narrow, irregular or steeply dipping orebodies dilute much more than a simple percentage suggests.
- This shows the grade effect only. Dilution also raises the tonnage that has to be hauled and processed, which costs money.