Numerical Modeling of Direct Reduction of Iron-Ore in Fluidized Beds with CFD-DEM

Description

The thermochemical reduction of iron-ores has gained much attention in the past decades as it is a core process in the ironand steelmaking industries. Fluidized beds and moving bed reactors are some of the procedures used to reduce the iron-ore efficiently. Due to harsh conditions inside the reactors, accesibility is limited, therefore simulation tools are utilized in their research. One such tool uses the coupling of Computational Fluid Dynamics (CFD) and the Discrete Element Method (DEM) method, where the reacting gas is calculated in the Eulerian side and the iron-ore particles in the Lagrangian side. In this work, the common types of mathematical models that represent the reduction of iron-ores, the shrinking particle and the unreacted core models, are added into the CFDEM coupling library. The shrinking particle model is used to determine the communication framework between the CFD and DEM. The unreacted core model is then used to calculate the reduction of iron-ore. Firstly, it is validated with comparing the simulations of a single hematitic iron-ore for various gas compositions with available experiments. Particle parameters such as the particle porosity, pore diameters as well as the critical kinetic parameters such as the equilibrium constants, activation energies and frequency factors are calibrated according to the single ore reduction. With the modified parameters, the reduction of iron-ore inside a fluidized bed is calculated and validated with experiments that take the different reduction steps for the iron-ore reduction into account. The kinetic model proves to be in good relation with the experimental data for various operating conditions.

Period	22 May 2019
Event title	10th International Conference on Multiphase Flow (ICMF 2019)
Event type	Conference
Location	Rio de Janeiro, BrazilShow on map