Theory 067/Mining & Minerals
Grinding Follows the Work Index
The claim
Grinding energy is set by the work index relative to the size reduction ratio, so a harder ore ground coarsely can use less energy than a softer ore ground finely.
01The mechanism
Energy per tonne scales with the work index and with the reduction ratio; the two trade against each other.
02Predictions
- P1Energy should collapse onto the product.
- P2Hard coarse grinding should beat soft fine grinding.
03Refutation
Energy tracking work index alone would remove the ratio.