The Swebrec© function: linking fragmentation by blasting and crushing

A new three-parameter fragment size distribution function has been found that links rock fragmentation by blasting and crushing. The new Swebrec function gives excellent fits to hundreds of sets of sieved fragmentation data with correlation coefficients of 0997 or better (r 2 >0995) over a range of fragment sizes of 2-3 orders of magnitude. A fiveparameter version reproduces sieved fragmentation curves all the way into the -100 m range and also handles ball mill grinding data. In addition, the Swebrec function: (i) can be used in the Kuz-Ram model and removes two of its drawbacks -the poor predictive capacity in the fines range and the upper limit cut-off to block sizes; (ii) reduces the JKMRC one-family description of crusher breakage functions based on the t 10 concept to a minimum; and (iii) establishes a new family of natural breakage characteristic (NBC) functions with a realistic shape that connects blast fragmentation and mechanical comminution and offers new insight into the working of the Steiner's OCS sub-circuits of mechanical comminution. It is suggested that the extended Kuz-Ram model, with the Swebrec function replacing the Rosin-Rammler function, be called the KCO model.