Relationships between particle breakage characteristics and comminution response of fine iron ore concentrates. (1st April 2021) - Campos, Túlio M.
Highlights: Relationships appeared between iron ore concentrates composition and breakage characteristics in 150–45 μm sizes. Single-particle compression tests discriminated well iron ore concentrate characteristics. Energy utilization appeared as a good measure to discriminate between materials amenability for breakage at such fine sizes. Higher efficiency for rigidly-mounted roll mill and piston-and-die, followed by lab-HPGR and ball mill. Abstract: Production of iron ore pellets typically requires regrinding of the iron ore concentrates. Although these concentrates are produced following close control of chemical composition, substantial differences may exist in their response to the size reduction operations that are used prior to pellet formation in the pelletizing disc or drum. Establishing relationships between some intrinsic characteristics of these concentrates and their response to size reduction is, therefore, worthwhile. Single-particle breakage testing has long been used to characterize the material intrinsic response to comminution. However, application of traditional breakage tests to iron ore concentrates is not possible, given their fine sizes. The present work analyzes the application of recent single-particle testing methods that are suitable for particles in the –150 µm size range to characterize breakage of four iron ore concentrates from Brazil. The response of particles when assembled in beds is then analyzed in great detail through piston-and-die testing, as well as by comminution tests in a bench-scale ball mill and high-pressure grinding rolls. Relationships between the results in the various devices, which represent the different levels of particle interaction, have been analyzed in light of their energy utilization. Furthermore, implications of differences in particle characteristics on the differences observed in breakage response are also analysed.