5:15 PM - 7:15 PM
[PPS08-P15] Extraction of Fe under Simulated Lunar Environmental Conditions
Keywords:In-situ Resource Utilization, Regolith, iron extraction experimen, space resource utilization
In recent years, research on In-situ Resource Utilization (ISRU) has become increasingly active for the development of manned lunar bases. The lunar polar regions are believed to contain traces of water (H2O), which can be used as fuel for spacecraft, while minerals rich in metallic elements have been found near the lunar equator. There is growing interest in the extraction of these resources.Focusing on iron, which is useful as a structural material, extraction methods utilizing reducing agents or electrolysis have been investigated [1]. However, these methods pose challenges such as the need for reducing agents during reduction and the high energy consumption of electrolysis. Therefore, this study aims to melt and reduce iron (Fe) from lunar regolith simulant using a CO2 laser in a high vacuum environment without using reducing agents, separate iron from slag through interfacial solidification partitioning, and extract high-purity iron with low energy consumption.
Experiments
Two main experiments were conducted in this study.
Experiment 1:A high-purity Fe3O4 sample was heated in a muffle furnace at 300 degrees Celsius for 2 hours to remove moisture attached to the sample. The preheated sample was then quickly placed on the sample stage of a vacuum heating apparatus to prevent moisture absorption from the air. The chamber was evacuated to the order of 10-5 Pa, and the sample was heated using a CO2 laser. The laser output was set to 50 W, and a single-point heating process was performed for 20 seconds. After heating, the laser-irradiated area was observed using a scanning electron microscope (SEM), and the atomic concentration distribution was analyzed using energy-dispersive X-ray spectroscopy (EDX).
Experiment 2:A stepping motor was used to move the sample linearly in a vacuum while performing laser irradiation. After laser irradiation, the sintered sample's molten state was observed using SEM, and the crushed sample was analyzed using powder X-ray diffraction (XRD).
Results
Result 1
At the center of the laser irradiation point, where the temperature was the highest, the oxygen concentration decreased compared to the surrounding area, confirming that reduction had occurred.
Result 2
The sample movement speed was 92 um/s. The XRD pattern of the laser-irradiated sample showed only magnetite peaks, and no significant reduction was observed (i.e., no Fe peaks were detected).
In Experiment 1, melting was observed, and slight reduction due to oxygen release occurred. However, in Experiment 2, no significant melting or reduction was observed. This is likely because the heating temperature at the laser irradiation point in Experiment 2 was lower than that in Experiment 1.To improve the process, modifications to the apparatus will be made to increase the heating temperature. Additionally, instead of using high-purity Fe3O4 samples, experiments will be conducted using actual mineral samples to study the reduction process and the separation of iron and slag. Future experiments will focus on achieving complete sample melting and exploring iron extraction methods that do not require reducing agents.
References
[1] Xu, Youpeng, et al. Overview of in-situ oxygen production technologies for lunar resources. International Journal of Minerals, Metallurgy and Materials 32.2 (2025): 233-255.
Experiments
Two main experiments were conducted in this study.
Experiment 1:A high-purity Fe3O4 sample was heated in a muffle furnace at 300 degrees Celsius for 2 hours to remove moisture attached to the sample. The preheated sample was then quickly placed on the sample stage of a vacuum heating apparatus to prevent moisture absorption from the air. The chamber was evacuated to the order of 10-5 Pa, and the sample was heated using a CO2 laser. The laser output was set to 50 W, and a single-point heating process was performed for 20 seconds. After heating, the laser-irradiated area was observed using a scanning electron microscope (SEM), and the atomic concentration distribution was analyzed using energy-dispersive X-ray spectroscopy (EDX).
Experiment 2:A stepping motor was used to move the sample linearly in a vacuum while performing laser irradiation. After laser irradiation, the sintered sample's molten state was observed using SEM, and the crushed sample was analyzed using powder X-ray diffraction (XRD).
Results
Result 1
At the center of the laser irradiation point, where the temperature was the highest, the oxygen concentration decreased compared to the surrounding area, confirming that reduction had occurred.
Result 2
The sample movement speed was 92 um/s. The XRD pattern of the laser-irradiated sample showed only magnetite peaks, and no significant reduction was observed (i.e., no Fe peaks were detected).
In Experiment 1, melting was observed, and slight reduction due to oxygen release occurred. However, in Experiment 2, no significant melting or reduction was observed. This is likely because the heating temperature at the laser irradiation point in Experiment 2 was lower than that in Experiment 1.To improve the process, modifications to the apparatus will be made to increase the heating temperature. Additionally, instead of using high-purity Fe3O4 samples, experiments will be conducted using actual mineral samples to study the reduction process and the separation of iron and slag. Future experiments will focus on achieving complete sample melting and exploring iron extraction methods that do not require reducing agents.
References
[1] Xu, Youpeng, et al. Overview of in-situ oxygen production technologies for lunar resources. International Journal of Minerals, Metallurgy and Materials 32.2 (2025): 233-255.