Dynamic image analysis of calcite particles created by different mills

Abstract

In this study, particle shapes of calcite mineral ground by different mills namely ball, rod and autogenous mills were measured using a new 3D analysis with random orientation technique (by Micromeritics® Particle Insight Dynamic Image Analyzer). The results were expressed by the shape parameters such as circularity, ellipse aspect ratio (EAR), bounding rectangle aspect ratio (BRAR) and feret aspect ratio (FAR). More than 6400 particles were measured for each mill product with a 99% statistical accuracy. The results showed that, the highest aspect ratio (EAR, BRAR and FAR) and the lowest circularity were obtained by autogenous mill. However, the highest circularity and the lowest aspect ratio were obtained by rod milling. These differences in shape were attributed to the different grinding mechanisms acted in the mills employed. The results of the 3D dynamic image analysis were also compared with previous study for the same mineral based on 2D SEM technique. Although different techniques were used for shape analysis, the results were in good agreement with each other. This approach will find various applications for calcite characterization, preparation and utilization processes as well as for other minerals.