Energy-based modelling of single-particle breakage by slow compression

Artikel i vetenskaplig tidskrift, 2024

Compression of particles to a fixed final gap is the mode of application of stresses in many crushing devices. Understanding and modelling this particle fracture process is indispensable for comminution operations. The present work is based on detailed compression tests conducted with a polymetallic ore to different applied deformation ratios to characterize the size-dependent fracture energy distribution and progeny size distribution. An energy-based model is then proposed that accounts explicitly for particle thickness and maximum deformation to define if the particle is classified for breakage (classification function), the likelihood that the classified particle is sufficiently nipped to break (breakage probability) and the extent of breakage the particle will undergo (breakage distribution). Expressions that allow calculation of the energy absorbed by the particle in both primary and secondary breakage regimes are proposed. The validity of the model is demonstrated by accurately predicting, without any fitting, the progeny and energy consumption of compression using fixed gaps and breakage in a double roll crusher. The advantage of the approach not only lies in its ability to accurately predict the product size distribution, but also the energy demanded in the operation.