A comparison of 2D and 3D shape characterisations of free gold particles in gravity and flash flotation concentrates

The focus of this study was to characterise and quantify the nature of free gold particles recovered in a plant setting featuring parallel gravity concentration and flash flotation processes, with an emphasis on the influence of size and shape as a review of the literature suggests the importance of such attributes on a particle's recovery behaviour. Automated mineralogical analysis (AMA) was employed to quantify the free gold particles' circularity and sphericity measurements using two and three dimensional (2D/3D) methods. As expected, the 2D results indicated that free gold particles (−212/+38 μm) reporting to the gravity concentrate in were, on average, more circular than those of the flash concentrate. However, 3D sphericity characterisations of the same samples offered opposing results. Such a conflict identifies the limitation for application of simple 2D and 3D shape characterisations for malleable and irregularly shaped free gold particles.