Effect of particle shape on abrasive wear of screw flights during scaffold growth in a COREX shaft furnace

The scaffolding presence in the operation of the COREX shaft furnace is a serious problem, which exacerbates asymmetric loading on certain screw flights, causing uneven wear distribution and also exerts substantial influences on normal industrial production. To study the effects on the abrasive wear of screw flights by scaffolding growth process and particle shapes of burden, this paper employs the discrete element method (DEM) to establish a three-dimensional COREX shaft furnace model, simulating discharge process under eight working conditions and calculating the abrasive wear using Archard wear equation. The results show that different particle shapes affect the pressure evolutions experienced by the screw flights so as the distribution and magnitude of the abrasive wear. Under non-spherical particle conditions, the pressure will produce fluctuations with higher amplitude during the second stage of the discharge process, make the average pressure higher than that of spherical particles. With the continuous growing of the scaffold, the burden distribution changes as well as the pressure on the flights, leading to the impact on the abrasive wear. The abrasive wear on the screw flights near the scaffolding is lower, while that further from the scaffolding is higher. There is also a certain deviation on the macroscopic distribution of screw flights wear.