Validation of CFD-DEM model for iron ore reduction at particle level and parametric study

Iron ore reduction is a primary unit operation in current metallurgy processes and dominates the energy consumption and greenhouse gas (GHG) emissions of the iron-making process. Therefore, even a slight improvement of the energy efficiency or GHG emissions of iron ore reduction would yield considerable benefits to the cost of pig iron and, more importantly, to mitigation of the associated carbon footprint. The current study presents a discrete model that describes the iron ore reduction process for a single pellet. The transient reaction progress can be predicted and is validated against experimental measurements under various operating conditions, including different reducing gases and temperatures. The effects of pressure, isothermality, gas composition, and flow rate on reduction are investigated. The reduction rate increases significantly with increasing pressure until 5 atm, and the entire reduction process occurs more slowly under non-isothermal conditions than under isothermal conditions. This work provides a solid foundation for the development of a comprehensive particulate system model that considers both heat and mass transfer. (C) 2019 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.