Three-dimensional characterization of porosity in iron ore pellets: A comprehensive study

This paper presents a comprehensive study on the production and reduction of high-quality iron ore pellets characterized by a basicity index nearing 0.5 and diameters ranging from 1 to 2 cm. The reduction process was carried out in a hydrogen atmosphere at temperatures spanning 800–1000 °C and a pressure of 8 bar. Initial findings revealed substantial variations in pellet density and compressive strength, attributed to their mean dimensions. To delve into the microstructural transformations occurring during reduction, meticulous microtomographic analyses were conducted on each pellet before and after the reduction process. The research assessed reducibility factors such as porosity, pore size, and tortuosity adjustments across diverse reduction conditions. The study highlights the intimate connection between the reduction process rate, processing parameters, and pellet microstructure. Furthermore, the metallization tendencies were explored through extensive reduction experiments involving multiple pellets. These findings offer crucial insights into optimizing iron ore pellet performance during production and reduction processes, contributing to advancements in industrial applications.