(389g) Direct Two Step Solar Metallothermic and Electrolytic Production of Rare Earth Elements from Oxides
Energy consumption and environmental concerns, coupled with the fact that the current electrolytic production method must occur at high temperatures, provides significant motivation for investigating solar driven metallothermic/ electrolytic processing routes as alternatives to conventional REE production for providing âcleanâ high temperature process heat and electricity. In this work, a new two-step REE production route consisting of direct metallothermic reduction of RE-oxides using Ca and subsequent electrolytic recovery of metallic Ca in a mixed chloride bath has been explored from the theoretical energy consumption perspective. The new process is critically evaluated using thermodynamic analysis and compared with the state-of-the-art. The two-step process shows promise in terms of significant improvement in the energy efficiency compared to the current electrolysis routes. The potential technological challenges in scale-up and impact of solar variability will be discussed as well.