Title

Evaluating The Use Of Tribocharging In Electrostatic Beneficiation Of Lunar Simulant

Keywords

Beneficiation; Lunar regolith; Triboelectrification; X-ray photoelectron spectroscopy

Abstract

Electrostatic beneficiation of lunar regolith is a method allowing refinement of specific minerals in the material for processing on the moon. The use of tribocharging the regolith prior to separation was investigated on the lunar simulant MLS-1 by passing the dust through static mixers constructed from different materials; aluminum, copper, stainless steel, and polytetrafluoroethylene (PTFE). The amount of charge acquired by the simulant was dependant upon the difference in the work function of the dust and the charging material. X-ray Photoelectron Spectroscopy (XPS) was used to characterize the simulant after it was sieved into five size fractions (> 100 uμm, 75-100 uμm, 50-75 uμm, 50-25 uμm, and < 25 uμm), where very little difference in surface composition was observed between the sizes. Samples of the smallest (< 25 uμm) and largest (> 100 uμm) size fractions were beneficiated through a charge separator using the aluminum (charged the simulant negatively) and PTFE (charged positively) mixers. The mass fractions of the separated simulant revealed that for the larger particle size, significant unipolar charging was observed for both mixers, whereas for the smaller particle sizes, more bipolar charging was observed, probably due to the finer simulant adhering to the inside of the mixers shielding the dust from the charging material. Subsequent XPS analysis of the beneficiated fractions showed the larger particle size fraction having some species differentiation, but very little difference for the smaller size. Although MLS-1 was made to have similar chemistry to actual lunar dust, its mineralogy is quite different. On-going experiments are using NASA JSC-1 lunar simulant. A vacuum chamber has been constructed, and future experiments are planned in a simulated lunar environment.

Publication Date

12-1-2006

Publication Title

AIChE Annual Meeting, Conference Proceedings

Number of Pages

-

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

Socpus ID

80053853606 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/80053853606

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