Bond Work Index
Infer Bond work index from measured net specific energy and feed/product P80; distinct from the laboratory ball-mill test correlation.
Description
A measured net specific grinding energy can be inverted through the Bond relation to infer a work index.
A measured net specific grinding energy can be inverted through the Bond relation to infer a work index. The same P80 and tonne conventions must apply to the measured energy and size term.1
The tool returns inferredWorkIndexKwhPerTonne. The computation uses supplied observations and parameters rather than acquiring measurements.
When to use Bond Work Index
Use this for the following task: Infer Bond work index from measured net specific energy and feed/product P80; distinct from the laboratory ball-mill test correlation. Prepare observations and calibration parameters on the same unit and reporting basis.
How to use Bond Work Index and understand its results
- Prepare the measured quantities and supplied model parameters. Match the units and align paired lists before calculating.
- Enter measuredSpecificEnergyKwhPerTonne, feedP80Micrometers, productP80Micrometers according to the field table, then run the tool.
- Read inferredWorkIndexKwhPerTonne. Use the calculation below to interpret the selected mean or the model’s signs, units and comparison flags.
- Review the supplied assumptions and calibration before comparing or reporting the result.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| measuredSpecificEnergyKwhPerTonne | Measured specific energy kwh per tonne | number | Required |
| feedP80Micrometers | Feed p80 micrometers | number | Required |
| productP80Micrometers | Product p80 micrometers | number | Required |
Use nonnegative measured energy and positive micrometre P80 sizes with product strictly smaller than feed. Zero energy returns a zero inferred index.
work index = measured kWh/t /(10/√productP80−10/√feedP80) The symbols and boundary conditions refer to the supplied fields and the implementation described above.
| Output field | Meaning | Value type |
|---|---|---|
| inferredWorkIndexKwhPerTonne | Inferred work index kwh per tonne | number |
{
"input": {
"measuredSpecificEnergyKwhPerTonne": 10,
"feedP80Micrometers": 10000,
"productP80Micrometers": 100
},
"output": {
"inferredWorkIndexKwhPerTonne": 11.11111111111111
}
}Limitations and assumptions
This is an inversion of a circuit-energy observation. It does not perform a standard laboratory ball-mill work-index test or remove unreported power losses.
Numerical inputs must be finite. Input-shape and calculation checks do not establish measurement quality or the validity of a supplied calibration.
Alternative or Complementary methods
Choose Comminution Energy when you need its operation: Predict corrected Bond net energy and power for supplied throughput; no-load mill power and hardware sizing are excluded. Choose Bond Ball Mill Work Index for the complementary operation: Apply a supplied Bond ball-mill laboratory correlation to closing screen and grams/revolution; constant must match test protocol and tonne convention.
Background reference: Determining the Bond Efficiency of Industrial Grinding Circuits.
References
-
Determining the Bond Efficiency of Industrial Grinding Circuits — Global Mining Guidelines Group
Similar or alternative tools
- Comminution Energy
Predict corrected Bond net energy and power for supplied throughput; no-load mill power and hardware sizing are excluded.
- Bond Ball Mill Work Index
Apply a supplied Bond ball-mill laboratory correlation to closing screen and grams/revolution; constant must match test protocol and tonne convention.