Numerical analysis of the effects of magnetite properties and injection types on flash reduction behaviour

Abstract

ABSTRACT In this work, a three-dimensional Eulerian–Lagrangian CFD model is developed to describe the flash reduction behaviour of magnetite in the drop tube reactor and investigate the effects of magnetite properties and injection types on particle dispersion and reduction. The results confirm that increasing final reduction degree can be achieved for concentrate particles with smaller particle size, lower particle shape factor and less particle moisture. The particles in cone injection may obtain higher final reduction degree than in surface injection. The particle trajectories show that the spreading extent of particles in the reactor enhances with the decrease of particle size and shape factor and the increase of cone angle. In addition, the evolution of particle characteristics along the reactor length are also analysed, in terms of particle temperature, particle velocity and reduction degree, aiming to understand the underlying influence mechanisms of these parameters on reduction process.