Production of Highly Metalized Direct Reduced Iron (DRI) in Fluidized Bed by CO and H2: Determination of the Kinetic Triplet

Abstract In this study, calcined iron ore samples from Menteş, Türkiye were isothermally reduced in a laboratory-scale fluidized bed reactor using several blends of CO, H 2 , and N 2 gases. The experiments were carried out at 3 temperatures (800 °C, 850 °C, and 900 °C), with 4 reductant concentrations (1:1:2, 0:1:3, 1:1:6, and 1:0:3 molar ratios for “CO:H 2 :N 2 ,” respectively). Almost full metallization was achieved with the first gas composition at 800 °C and 850 °C. However, 900 °C tests exhibited the lowest reduction degrees for almost all reductant compositions due to the sintering of the particle surfaces. The results showed that the conversion of the ore was more sensitive to reductant concentration (especially to the H 2 ratio in the mixture) than the temperature. The kinetic analysis revealed that the gaseous reduction of calcined Menteş iron ore in the fluidized bed can be represented by the “Two-Dimensional Diffusion, D2(α)” model and the process requires 19.73 kJ/mol activation energy (E a ). Thanks to the low E a requirement and relatively high Fe 2 O 3 content, calcined Menteş iron ore was evaluated as a proper raw material for DR applications.