← Back to NASA Technology Projects
Completed TRL 3 (started at 2, targeting 4)
Project Objective
The project aims to assess the technical feasibility and reliability of extracting and separating metals from lunar regolith, metallic slag, and recycled material feedstocks using Marangoni-effect-driven electrochemical molten reduction (MEMR) in conjunction with fractional decomposition. The core concept of the Marangoni effect on molten materials under vacuum and MEMR is detailed in the New Technology Report (NTR) 1693591210.
Project Description
The project evaluated critical metal extraction and separation aspects in the molten phase through the Marangoni effect on the melt, complemented by electrochemical methods (MEMR) and fractional decomposition. The two fundamental elements that needed to be studied are: 1) the conditions that lead to the upward migration of the melt in bulk and film patterns along the crucible wall, facilitating both a) the electrochemical reduction of the melt film in contact with the electrode film deposited on the crucible wall, and b) the fractional separation of the melt and metals as they continue to ascend the wall at different rates; and 2) the degradation and durability of the electrode film deposited on the crucible wall, which is in contact with the molten material.
Project Results and Conclusions
While the MRE process appears to be the most effective option for extracting oxygen and metals from lunar regolith and industrial ores (such as iron ore for stainless steel production)—requiring no consumables beyond regolith and the ore—its technology readiness assessment lags behind other methods that rely on consumables. Significant challenges still unaddressed in the MRE include the limited service life of anode materials and the degradation of the wall in contact with the melt caused by operation at high temperatures approaching 1,600 °C. The Marangoni-driven MRE addresses this significant challenge by operating at a lower temperature (1,000-1,100 °C) while demonstrating melt affinity with both the crucible wall and electrode film, thus preserving the integrity of the crucible wall and the electrode film.
The MEMR process represents a fundamentally different approach to conducting electrochemical molten reduction, featuring several clear advantages:
1) Operation at lower temperatures without needing a flux agent, as it functions under vacuum conditions.
2) Significantly larger electrode surfaces as the electrode film covers nearly the crucible's inner wall.
3) Reduced degradation of both the crucible wall and the electrode film due to the lower operational temperatures and the experimentally observed affinity of the melt for the crucible wall and electrode film, resulting in minimal degradation of the wall and potentially extending the service life of the electrode material.
4) A likely ability to achieve fractional production of metals and alloys as they form and are transported upward through the Marangoni effect.
5) Enhanced electrochemical decomposition of regolith oxides for oxygen and metal generation, driven by vacuum-induced spontaneous decomposition of certain regolith oxides.
6) No necessity for inert gas or post-processing of O2 separation from inert gas.
7) Facilitates further optimal design that includes O2 generation.
Research results would lead to further research on well-established but highly polluted industrial production of alloys (stainless steel) and metals (aluminum, gold, titanium, niobium, tantalum, etc.). The current aluminum process generates more CO2 by weight than aluminum; it is very energy-demanding and requires a flux agent (97% cryolite and 3% alumina) to reduce the melting point, leading to large industrial-scale plants. Electrochemical generation of aluminum from alumina via MEMR would eliminate or radically reduce the cryolite and CO2 generation.
An alternative setup for the MEMR standard was designed to generate O2 detached from the melt, easing the immediate O2 availability as it flows freely separated from the melt. A YSZ tube with the anode film deposited throughout its inner wall surface is vertically set in the center of the tubular alumina crucible with the cathode film deposited on the inner wall surface. The sample is housed between the crucible's inner side and the YSZ tube's outer side. Oxygen ions (O2-) within the melt are transported through the YSZ tube wall (YSZ is a good O2- conductor at elevated temperature) to release the two electrons on the outer wall surface of the YSZ tube and generate gaseous O2 separated from the melt, easing the immediate O2 availability as it flows freely through the YSZ tube.
While the MRE process appears to be the best alternative for extracting oxygen and metals from lunar regolith, requiring no consumables beyond regolith, its technology readiness assessment lags other options that rely on consumables. The main challenges the MRE faces, which have yet to be addressed, include the short service life of anode materials and the degradation of the wall in contact with the melt due to operating at high temperatures, nearing 1,600 °C. The Marangoni-driven MRE addresses this significant challenge by not only functioning at a lower temperature (1,000-1,100 °C), but also demonstrating melt affinity with the crucible wall and electrode film, thereby preserving the wall's and electrode film integrity.
Research results would lead to further research on well-established but highly polluted industrial production of alloys (stainless steel) and metals (aluminum, gold, titanium, niobium, tantalum, etc.). The current aluminum process generates more CO2 by weight than aluminum; it is a very energy-demanding and requires a lot of flux agents (97% cryolite and 3% alumina) to reduce the melting point, leading to large industrial-scale plants. Electrochemical generation of aluminum from alumina via MEMR would eliminate or radically reduce the cryolite and CO2 generation.
Listed on TechPort itself — the most direct way to ask about this specific project.
This is early/mid-stage (TRL 3) — the most realistic path in is NASA SBIR/STTR, which funds small businesses and research institutions to develop technology aligned with NASA's needs (equity-free, phased funding). Check whether a current SBIR/STTR solicitation topic overlaps with this project's technology area, or contact the project directly (above) to ask.
None of these are guaranteed paths for this specific project — TechPort itself doesn't have an "apply" button. Reaching out to the contact(s) above with a specific question is usually the fastest way to find out what's actually open.