An analysis of energy needs and seawater-extraction approaches for the integration of primary magnesium production with nuclear power

The cost of primary magnesium production is highly dominated by the energy required to produce the metal. This, along with the current geographical concentration of its production, makes the magnesium price vulnerable as energy-production paradigms begin to rapidly change. In this work, four full-integration pathways for the efficient supply of heat and electricity to magnesium production from a nuclear power plant are considered. A production route using electrified metallothermic reduction is compared to a nuclear-heat-integrated electrolytic pathway. It is shown that while the former can achieve a lower primary energy consumption, 293 MJ/kg Mg compared with 301 MJ/kg Mg, the electrolytic pathway can both reduce emissions compared to current production and allow access to magnesium from seawater rather than a mined ore. The emissions from the process are reduced to 2 kgCO2/kg Mg, down from around 32 kgCO2/kg Mg in the Pidgeon process. Beyond energy and emissions, the four pathways considered are also compared to their ability to reduce locational dependence of the production plant and reduce process complexity. This work also highlights future advances in magnesium production with a potential scheme for the efficient extraction of magnesium from seawater with coproduction of desalinated water and the potential of demand-side response from magnesium electrolysis. This is the first work to consider the full integration of primary-metal production using nuclear cogeneration, and it is hoped the study paves the way for the analysis of economic nuclear integration within metal extraction and manufacturing.