Prediction of fragmentation and yield curves with reference to armourstone production

Armourstone production involves aspects of blast design and yield prediction. How they differ from methods drawn from experience in mining and aggregates blasting operations is examined. A number of possible blast fragmentation models and associated prediction methods are described, several being outlined in full. Their applicability to armourstone production and yield curve prediction is discussed by comparing model results based on a hypothetical armourstone blast design in a rock mass with realistic properties for an armourstone quarry. It is suggested that appropriate models for armourstone yield prediction will require some form of an in-situ block size distribution assessment. Such approaches rule out the standard application of the Kuz–Ram model. The recently reported ‘Swebrec’ function and associated prediction model, developed by the Swedish Blasting Research Centre, provides a promising replacement for the Rosin–Rammler based models for representing armourstone blast yield curves.