Work

Editors’ Choice—Molten Salt Electrolysis in Chloride Melts for Energy-Efficient Iron Metal Production

Year: 2025

Type: article

Abstract: This study explores chloride molten salt electrolysis (CMSE) as a promising route for energy-efficient iron metal (Fe) production. Moderate temperature (500 °C) LiCl-KCl molten salts offer excellent thermodynamic stability, high ionic conductivity and diffusivity, and high solubility for FeCl3, thereby enabling efficient Fe metal extraction at high electrowinning rates. Here, we demonstrate the two essential steps for converting taconite ore into Fe metal. First, Fe2O3 from taconite pellets was selectively leached in HCl yielding a high-purity FeCl3 aqueous solution, while the gangue components settled at the bottom. Then, anhydrous FeCl3 was electrolyzed in a LiCl-KCl eutectic molten salt at 500 °C at high current density (1 A cm−2) and at high Coulombic efficiency (>85%). Analysis of the electrowon Fe deposits revealed dendritic structures with purity of >99 wt%, which could be further improved to nearly 100 wt% through arc re-melting. CMSE offers low specific energy consumption (3.7 kWhr kg−1), competitive with H2-DRI and other electrolytic approaches being pursued globally. Our findings underscore the potential of CMSE as an energy-efficient route for electrosynthesis of Fe metal.

Source: Journal of The Electrochemical Society

DOI: 10.1149/1945-7111/adbd7d

Authors: Anar Badalbayli, Nicholas Sinclair, Eunjeong Kim, Alexander A. Baker, Rohan Akolkar

Language: English

Topic: Molten salt chemistry and electrochemical processes

Subfield: Fluid Flow and Transfer Processes

Field: Chemical Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Responsible consumption and production

Open Access status: hybrid

Estimated APC paid: $1,950

Funder: Lawrence Livermore National Laboratory