Evaluating the Rheology of Lunar Regolith Simulant Melts and their Interaction with Crucible Refractory Materials

In-situ resource utilization (ISRU) for producing metals and oxygen on the lunar surface is essential for building infrastructure, generating chemical propulsion fuel, and supporting life on the Moon. Common terrestrial extraction techniques, such as carbothermal reduction and the Bayer-Hall-Héroult process, are impractical since they require materials unavailable on the Moon. Molten regolith electrolysis (MRE) is a promising alternative that produces metals and oxygen directly from lunar regolith, the upper 10 m of granular multicomponent oxides and glasses on the surface. MRE requires temperatures of 1600℃ to melt and dissociate the regolith, which can degrade containment materials through thermochemical interactions. Determining the processing ability of lunar regolith and its compatibility with crucible materials is therefore crucial for long-term MRE operation. This study evaluates the rheology (viscosity and liquidus temperature) of two molten lunar regolith simulants, i.e., lunar highlands (LHS-1) and maria (JSC-1A) simulant, and their chemical interaction with potential crucible refractory ceramics, including Al2O3, magnesia-stabilized zirconia, and yttria-stabilized zirconia, per the methodology described in the standard ASTM C621-84. The results will be discussed in the presentation.