COMPUTATIONAL MODELING AND SIMULATION OF ALUMINIUM SMELTING PROCESS USING OPENFOAM

The electrolytic smelting is the process in aluminum industries to produce liquid aluminium metal from refined alumina powder. Smelting occurs in an electrolytic cell filled with an electrolyte subjected to Direct Current (DC). Alumina powder fed into the cell dissolves into the electrolyte and is reduced to aluminium metal on cathode. To ensure optimum productivity and energy efficiency of the cells, a distinct understanding of flow physics inside the cell is required, involving multiphase momentum, heat and mass transfer, along with magneto hydrodynamics. A computational fluid dynamics (CFD) model based on a multi-fluid Eulerian-Eulerian approach is proposed to model the smelting physics. The CFD model accounts for several physics involving (1) Voltage drop and current densities (2) Turbulent multiphase phase flow (3) Alumina dissolution, transport and consumption, (4) thermal energy evolution due to alumina dissolution and (5) magnetohydrodynamics. The proposed CFD model is implemented in the multiphaseEulerFoam solver framework available in the OpenFOAM-v8 group of multiphase solvers. The CFD modeling of the smelting physics and implementation in OpenFOAM is discussed herein. An Unsteady Reynolds Averaged Navier-Stokes (URANS) simulation is performed on an industry-representative computer-aided design (CAD) model for a unit anode electrolytic cell. Limited validation and verification of the simulation are performed. The preliminary results obtained from the simulation indicate that the CFD model predicts the trends of the above listed multi-physics reasonably well. The future plan involves extending the model with additional physics and rigorous validation, along with high fidelity turbulence modeling approaches with realistic smelting cells.