Micro-CT imaging of a frozen bubble cluster: Sample holder development and image processing techniques

Abstract

The significance of clusters in the flotation of coarse particles is well-known. This paper presents a novel technique for micro-computerized tomography (micro-CT) imaging of bubble clusters. A bubble cluster was collected using a customised arrangement and subsequently frozen to keep the cluster in a fixed position. A sample holder with a cooling chamber was designed and constructed to maintain the frozen state of the cluster during the micro-CT imaging process. The cooling chamber maintained a continuous flow of coolant at −10 °C across the sample, effectively preserving the frozen state of the bubble cluster during imaging. By utilizing this custom sample holder, high-quality imaging of the frozen bubble cluster sample was achieved. Image processing techniques enabled 3D visualization and quantitative analysis of the bubble cluster. The analysis includes measurements of cluster dimensions, particle and bubble sizes, volume distribution, and the percentage of particles in each size range within the cluster. These insights provide valuable information for understanding the underlying structure and characteristics of the bubble cluster, which cannot be obtained through the traditional photographic method.