Particulate Analysis – Particle Size

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

“…In the past, researchers have used circularity, as well as other 2D shape factors, to describe the shape of mineral particles in metallurgical samples while the 3D factors, such as sphericity, were more commonly used in drag calculations for the settling of particles in other fields such as pharmaceuticals, powders and lunar samples (Brown, 1991;Zeng, 2011). In this research 2D circularity shape factors for free gold particles will be calculated from SEM images generated during Quantitative Evaluation of Minerals by Scanning electron microscopy (QEMSCAN Ò ) and 3D sphericity factors will be determined by Micro Computed Tomography (Micro CT) analysis.…”

“…cumulative 50% mark has been inferred and is given in Table 1 to demonstrate the median sphericity factor for each sample along with values for ideal shapes (Brown, 1991;Zeng, 2011). The shape factors presented in Table 1 indicate a measurable difference in free gold shape can be noted.…”

“…Sphericity, which is essentially circularity in 3D terms, was characterised by the United States Pharmacopeial Convention (USP) General Chapter method given by Zeng (2011). This method states that the simplest three dimensional shape is the sphere and other particles of irregular shape can be described by sphericity (W) or deviation from the ideal sphere, as given in Eq.…”

A new approach of recognition of ellipsoidal micro- and nanoparticles on AFM images and determination of their sizes

“…Image analysis captures a 2-dimensional image of the 3D particle and calculates various size and shape parameters from this 2D image. One of the principle diameters calculated is equivalent circle diameter (EC diameter) [12,13] which is the diameter of a circle with the same area as the 2D image of the particle. Of course, different shaped particles will have an influence on this EC diameter but, importantly, it is a single number that gets larger or smaller as the particle does and it is objective and repeatable.…”