OFFICIAL This initial work indicated that flyrock projectile fragments seem to be more compact in shape (Figure 5), where most literature references tend to be more bladed. Figure 5 – Measured flyrock projectiles Sneed & Folk classification These empirically derived values replaced assumptions in the model’s calculations, and together with the inclusion of the effects of altitude (as a number of the mine sites in Anglo American is situated at 3000-4000m above sea level) is leading to more site-specific predictions of flyrock travel distances (Fmax). Apart from changes in the prediction model, another critical step in the modelling component was to introduce the prediction of flyrock at multiple stages in the drill and blast cycle (Figure 6). Figure 6 – Multi-Stage flyrock modelling Flyrock modelling is not a one-time task. The framework applies modelling at three stages of the drill and blast process: • Design/Concept Stage: An initial prediction made during blast planning using the design parameters.
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