From terrestrial basalt to customizable lunar regolith simulant: Preparation via thermal phase-tailoring

The advancement of In-Situ Resource Utilization (ISRU) technologies necessitates the development of lunar regolith simulants (LRS) that accurately reflect the chemical composition of natural lunar materials, while allowing for research on mineral composition disparities. Current methods for producing LRS mostly involve mechanically mixing different terrestrial counterparts. However, the mineral phase compositions in these LRS remain as a result rather than as refined objects. It restricts the clarity of the minimal composition variation's effect on ISRU processes involving multiple physical chemistry reactions. This study introduces a new method for preparing and programming LRS by thermal phase-tailoring a single type of terrestrial basalt simulant. The approach involves controlled melting, amorphization, and recrystallization cycles. It focuses on programming the primary mineral phase abundances in LRS materials, including plagioclase, pyroxene, olivine, and glass. A proposed nonlinear programming model identified the best blending ratios of these thermally treated products. The mineralogy's fitness matched the specific lunar regolith data from Apollo 67,701 and CE5C0600. The customized simulants replicated the mineral intergrowth textures observed in natural basalt. The spectral reflection features highly correlate with the corresponding nature of lunar regolith data. Additionally, the integrated solar absorptivity of the customized LRS was within 4 % of natural regolith samples. The melting temperatures of these simulants are also much closer to those of natural lunar samples compared to the original basalt material. This work highlights the effectiveness of controlling mineral phases through thermal processing. It provides a reliable approach for developing composition designability and high-thermal-physical fidelity LRS. These advancements are crucial for ground-researching ISRU technologies that depend on accurate optical and thermal properties, including sintering and solar manufacturing applications.