Fragmentation drives crusher throughput, dig rates, and secondary blasting costs. The Kuz-Ram model predicts the mean fragment size (X50) from blast geometry and explosive energy — if you calibrate it properly.
The model in one line
X50 = A × (V₀/Q)^0.8 × Q^0.167 × (115/E)^0.633 — where A is the rock factor, V₀ the rock volume per hole, Q the charge per hole, and E the explosive’s relative weight strength.
Where it goes wrong
- Using a generic rock factor instead of calibrating A from sieve or image-analysis data
- Ignoring geology — jointing and bedding change A more than any other input
- Treating X50 as the only output; X80 matters just as much for crusher feed
Calibration in practice
Run 5–10 blasts, measure fragmentation (sieve or photogrammetry), and back-calculate A for your site. Once calibrated, the model becomes a reliable design tool — and the foundation of an AI blast optimizer.
Our BlastManager Pro software includes Kuz-Ram prediction and lets you log measured results to refine the model blast after blast.