Use of Thermodynamic Modeling for Selection of Electrolyte for Electrorefining of Magnesium from Aluminum Alloy Melts

Abstract

experimental proof-of-concept was demonstrated for RE-12 TM electrorefining process of extraction of desired amount of Mg from recycled scrap secondary Al molten alloys. The key enabling technology for this process was the selection of the suitable electrolyte composition and operating temperature. The selection was made using the FactSage thermodynamic modeling software and the light metal, molten salt, and oxide thermodynamic databases. Modeling allowed prediction of the chemical equilibria, impurity contents in both anode and cathode products, and in the electrolyte. FactSage also provided data on the physical properties of the electrolyte and the molten metal phases including electrical conductivity and density of the molten phases. Further modeling permitted selection of electrode and cell construction materials chemically compatible with the combination of molten metals and the electrolyte.

Fluid Mechanics of Liquid Metal Batteries

“…While the two strongly coupled LMB types (Li||Te and Li||Se) have limited practical relevance due to the scarcity of their positive electrode materials, three-layer refinement cells are almost always strongly coupled. Gesing et al [45,46] formulate it as a characteristic of their Mg-electrorefinement method that the electrolyte has to have a density halfway between that of Al and Mg, i.e., they require a coupling param-…”

“…The application of three-layer processes was also proposed for electronic scrap reclamation [43], removal of Mg from scrap Al [44,45,46], and electrorefining of Si [47,48,49]. Research on the fluid mechanics of current bearing three-layer systems can therefore potentially be useful beyond LMBs.…”