Physical Characterization and Kinetic Analysis of the Iron Ore Pellets Produced with Marble Waste

The technical viability of the marble waste as raw material in the iron ore pelletizing sector was investigated. The effects of binary basicity (0.15 to 0.45), fixed carbon (0.5 to 1.1 wt pct), and bentonite percentages (0.5 to 0.7 wt pct) on the pellet properties were also investigated. The physical properties of the pellets were determined for drop number, tumble strength, porosity, green pellet resistance, and fired pellet resistance. The reducibility test was determined by kinetic investigation under CO flow in the temperature range of 700 °C to 1100 °C applying the Forced Stepwise Isothermal Analysis method. The results demonstrated that the marble waste has potential to be used as raw material in the iron ore pelleting process. The maximum performance was obtained with a basicity of 0.45, fixed carbon of 0.5 wt pct, and bentonite content of 0.5 wt pct. This composition reached a mechanical strength of 284.38 kgf/pellet, drop number of 3.5 drops/pellet, tumble strength of 0.56 wt pct, and green pellet resistance of 1.53 kgf/pellet. The kinetic investigation reveals that the diffusion mechanism was the best-fitted mode that displayed an activation energy of 79.4 kJ/mol between 700 °C and 800 °C and 157.2 kJ/mol in the temperature range of 850 °C to 1050 °C.