Numerical Analysis of Ionic Mass Transfer in the Electrolytic Bath of an Aluminium Reduction Cell

On the analysis of ionic mass transfer in the electrolytic bath of an aluminum reduction cell

“…Since negative anions are attracted to the anode, the direction of diffusion flux of the ions is in the opposite direction compared to the flux of Na þ . As it was shown in a previous(one-dimensional) work by the authors [18] the diffusion magnitude flux starts from zero and becomes equal to the migration flux for larger times, so there is equilibrium between migration and diffusion fluxes for these electroinactive ions, as seen in Figure 14. For the present two-dimensional study, the same phenomenon is observed; however, the diffusion flux from left part of the cell to interelectrode surface near the cathode is also added to this surface.…”

“…[15] This finite volume model took into account the flow of aluminum, bath, and bubble layers under the anode and their interaction with each other, considering the MHD forces as the main momentum source term. [18] In the present study, after having calculated the electric current density and electric potential field for a two-dimensional model of whole cell, see Figure 1, the concentration and flux of the main ions of the NaF-AlF 3 -Al 2 O 3 system are calculated. In order to reduce the complexity of the multiphase model to a single-phase model, Kuzmin et al assumed the different regions of the bath as the mixture of electrolyte and aluminum with different concentration compositions, and then proposed a numerical model for the mass and momentum transfer due to these concentration patterns.…”

“…Addressing the momentum transport, Li et al established an inhomogeneous three-phase model for the calculation of the current efficiency of the cell. [18] Considering the bath as a concentrated solution alongside with the electrode reactions, this study was done for two categories of electroactive and electroinactive ions in the bath to obtain the transient movement of these ions in the cell. In this study, the concentration of dissolved Na þ is calculated assuming that it has a large effect on the current loss.…”

“…Finally, Ariana et al modelled one-dimensional mass transfer in the anode and the cathode mass transfer boundary layer for a onedimensional interelectrode distance. [18] Considering the bath as a concentrated solution alongside with the electrode reactions, this study was done for two categories of electroactive and electroinactive ions in the bath to obtain the transient movement of these ions in the cell. [18] In the present study, after having calculated the electric current density and electric potential field for a two-dimensional model of whole cell, see Figure 1, the concentration and flux of the main ions of the NaF-AlF 3 -Al 2 O 3 system are calculated.…”