Development and Design of the First Industrial Magnetohydrodynamic Slag-Cleaning Reactor From Execution and Analysis of Pilot Plant Tests Through Coupled CFD Simulations

Abstract

AbstractThe future challenge for copper smelters is to increase metal yield by reducing copper losses and valorizing the slag as a marketable by-product. This can be achieved through further slag cleaning in a conventional submerged arc furnace (SAF) where remaining metallic oxides are reduced, and metal droplets have more settling time. Nevertheless, a significant amount of copper matte and metallic copper is still present as slight inclusions that cannot settle through the slag layer under simple gravity after SAF treatment. This work presents the development of a new industrial type of slag-cleaning concept, based on the magnetohydrodynamic (MHD) principle, that can be coupled downstream of conventional slag-cleaning technology (e.g., electric reduction furnace). The cleaning efficiency and operating conditions were evaluated in several pilot test campaigns using a SAF supplemented by an externally applied magnetic field (electromagnet), which interacts with electrodes generating Lorentz forces, which are responsible for an MHD stirring effect. In order to simulate experimental conditions and thus understand reaction kinetics and settle mechanisms during pilot tests, this work includes computational fluid dynamics (CFD) models. In order to represent these electromagnetic conditions, the focus of this work is to develop a new coupled CFD model. Numerical simulations showed the interactions between MHD flow field, slag properties, and metal recovery in an industrial slag-cleaning reactor and demonstrated the MHD cleaning effect on non-ferrous slags.