Mechanical grinding kinetics and particle packing novel characterization of iron ore tailings as inert filler for cement mortar

Abstract

This study utilized image processing techniques to extract the morphological parameters of IOTs and established a grinding kinetic equation for particle morphology. The Divas-Aliavden equation and RRB model were applied to analyze the grinding kinetics of particle physical parameters. The Fuller and MAA particle packing models were employed to discuss the packing structure and density of particles in mortar. The relationship between particle physical parameters and compressive strength in the IOTs-cement system was explored through path analysis and grey correlation analysis. The results indicated that as the grinding process of IOTs progressed, the particle fineness decreased, the uniformity of particle size distribution and roundness increased, and using IOTs as inert fillers in mortar improved the particle packing structure and increased system density. Path analysis revealed the key influence of particle roundness on compressive strength, while the grey correlation analysis revealed that particles in the 2–60 μm range exerted a positive impact on the compressive strength of the composite binder system, with the most pronounced effect observed within the 8–16 μm range. Based on economic and technical considerations, the optimal mechanical grinding time for IOTs used as inert filler in cement mortar was determined to be 2.5 h.