Modelling breakage and reagglomeration during fine dry grinding in ball milling devices

Modelling of grinding of fine powders in ball milling devices is addressed. The model quantitatively describes breakage and agglomeration phenomena by considering two populations, i.e. primary particles and porous aggregates. The population balance approach takes into account breakage and aggregation kernels which are considered functions of the size of the two populations. The proposed model is able to properly simulate the inversion from the breakage to the agglomerative regime typical of a fragile material powder system undergoing ball milling. A suitable fitting procedure is performed for separately determining the adjustable parameters of the model. Model reliability is tested against experimental data, while the proposed breakage/agglomeration kernels are related to the quantitative description of ball milling apparatus dynamics.