TechnologiesTechnology to decouple metalMetal production from CO2 emissionsEmissions while maintaining high productivity and adapting to increasingly complex ore and waste feedstocks are urgently needed. MoltenMolten sulfideSulfide electrolysisElectrolysis (MSE) uses sulfideSulfide chemistry to substitute for oxides for reduction, eliminating the need for carbonCarbon and consequent greenhouse gas (GHG) emissionsEmissions. A supporting electrolyteElectrolyte with sufficient ionic conductivity dissolves sulfideSulfide feedstocks at high concentrations, depositing metalMetal at the cathodeCathode while sulfurSulfur gas is generated at the graphite anodeAnode. Previous demonstration of this process in a 100A reactor showed the sequential deposition of liquid ironIron and copperCopper from chalcopyriteChalcopyrite (CuFeS2). More recent work shows the applicability of MSE to electrolytically decompose pyritePyrite (FeS) to produce cast ironIron with faradaic efficiencyEfficiency of >90% at currentCurrent densities of >1.5 A/cm2, demonstrating a viable route for ironmaking. The electrochemical properties of the novel electrolyteElectrolyte at the heart of the process are in the early stages of investigation. Initial measurements for total and electronic conductivity will be presented to begin shedding light on the mechanisms underlying the process and the implications of mixed conductivity.