Vibration-induced size segregation of lunar regolith and simulants for in situ resource utilisation (ISRU)

Effective beneficiation of lunar regolith for in situ resource utilisation (ISRU) requires size classification methods compatible with vacuum environments, where fluid-based systems are impractical. This study evaluates vibrational segregation as a dry alternative, using sealed-vial excitation under Earth gravity. We test Apollo sample 15601 alongside three lunar simulants (JSC-1, LMS-1, TUBS-M) across multiple vibrational conditions. Micro-CT imaging, Rosin–Rammler modelling, and Jensen–Shannon Divergence analysis quantify internal structure and simulant similarity. Mechanistic models of aerodynamic drag and bulk mobilisation clarify the roles of fines, cohesion, and confinement. A15601 develops a stable three-layer structure driven by fines immobilisation and coarse particle lofting. LMS-1 exhibits similar layering but weaker compaction. TUBS-M provides the closest statistical match, while JSC-1 segregates efficiently but less representatively. Particle size distribution breadth emerges as the primary driver of compaction and stratification. Though tested under terrestrial conditions, the findings offer a framework for evaluating simulants and designing passive ISRU separation systems.