3D printing of conical centrifuge system for mineral particle separation

Abstract

Establishing a lunar base and refueling station for future deep space missions depends on available resources, such as oxygen and raw metals, that will need to be extracted from extraterrestrial sources. Beneficiation represents the first step in the extraction process and therefore plays a critical role in the success of deep space missions. Current beneficiation processes require heavy prefabricated devices that cannot be manufactured in space, such as on the surface of the Moon, making them expensive to transport. In this work, a polymer conical centrifuge system was explicitly designed to be fabricated on the lunar surface through fused deposition modeling (FDM) three-dimensional (3D) printing, in which molten polymer filaments are deposited layer-by-layer to construct complex 3D structures. A mechanics model was developed to unveil the separation mechanism of this system. Polylactic acid cones were fabricated and tested to analyze the effects of cone geometries and surface roughness on separation efficiency. Additionally, cone geometries do not significantly affect surface roughness, but layer height can be used to control the surface roughness of the printed cones directly. Peak values of fine particle concentration, experimental recovery, and theoretical recovery were measured as 74.2%, 53.5%, and 45.6%, respectively, when using the conical centrifuge system during fine particle separation, validating the effectiveness of the proposed system and separation method.