Kinetic analysis for agglomeration-Flotation of finely ground chalcopyrite: Comparison of first order kinetic model and experimental results

Abstract

Particle size-flotation rate relationships can be discussed by a first-order kinetic model for flotation, which considers the probability of particle-bubble collision, attachment and detachment; and it was confirmed that recovery rate of finely ground hydrophobic particles in the froths are very low because of the limited particle-bubble collision probabilities. One method to improve the flotation of fine minerals is to agglomerate them before flotation using oil as a bridging liquid, an approached that has been shown to improve the flotation rates dramatically. A mathematical kinetic model for the flotation of agglomerated particles would be useful to design and optimize the agglomeration-flotation process, but no generally applicable model has been established yet. In this paper, flotation experiments of finely ground chalcopyrite were carried out with and without oil-agglomeration as pretreatment and the kinetic data (time-recovery curves) were compared with the conventional first-order kinetic model for flotation. Without agglomeration, time-recovery curves determined by the experiments fitted well with the model calculations, but there were significant deviations between experimental results and model calculations for the agglomerated particles; that is, experimental flotation recoveries were much higher than those calculated by the model. The conventional first-order kinetic model does not consider particle size changes during flotation while the experimental results suggested that the size of agglomerates increased in the flotation cell. This may be one of the reasons why significant deviations between the experimental and modelling results were observed, suggesting that the kinetic model for agglomeration-flotation need to consider the growth of agglomerates during flotation.