Potential Methods of Ore Extraction on the Lunar Surface
By Alexander M. Lapides
Research Contributed by: Matt R. Straus
I. Introduction
A. State purpose of Artemis project
B. State purpose of this report
C. List types of extractive metallurgy being explored
D. Transition
II. Electrometallurgy
A. Definition Ð Electricity and electrolysis are used to create a reduction reaction in metals in order to purify them and extract them from their ores. The actual extraction process is called electrowinning and the actual purification process is called electrorefining.1
B. Use in Artemis
1. Branches from electrolysis
2. Can be used to reduce metals
(especially oxides) to extract both the metal and the oxide, thus providing two
useful materials2
3. Useful in refining and purifying; most elements on the moon (as on earth) are mixed with others and therefore not pure
C. Pros
1. Good purification technique with double benefit of oxide and metal
2. Common, proven method of extraction and purification
3. Applicable with a variety of metals
D. Cons
1.
Potentially unprofitable electrodes (platinum)3
2. Maintenance hassle and cost (replace cathodes, anodes, power supply; keep them all clean and functioning)
3. Unknown (to me) % yield
4.
E. Plausibility
1. Good potential
2. (Pending) benefits of killing two birds with one stone extraction techniques and usefulness in purifying will yield ready-to-use chemicals and metals, especially if cheap cathodes, anodes, and storage can be found
III. Chemical Processes4
A. Definition Ð The use of single and double replacement reactions, along with other chemical processes, to attain a needed elemental metal while recycling the elements used to get it
B. Use in Artemis
1. This has already been explored in the Artemis Data book (Section 2.2.3: Ore Processing).
2. Depending on the chemicals available, many metals can be obtained.
C. Pros
1. The chemistry behind most of these has already been determined and is in the data book. (2.2.3: Ore Processing).
2. Large amount of chemicals attainable from this process
3. Many are found on the moon and can therefore be easily supplied
4. Theoretically cost-effective and simple
D. Cons
1. Many processes involve chemicals not found on the moon (like NaOH) which would have to be continuously supplied/recycled
2. Messy process; often multiple steps are necessary (Schubert)
3. Used in tandem with electrolysis (for recycling), so multiple processes necessary
E. Plausibility
1. Scientifically sound and currently the best plan the Artemis Project has
2. Once recycling techniques are made more efficient, could be a very profitable way to extract metals from regolith
IV. All-isotope Separator5
A. Definition Ð Patent of Dr. Peter Schubert that uses concentrated sunlight to vaporize regolith into plasma and then separates the elements present using an electric field and their charge/mass ratios.
B. Use in Artemis
1. Would be used specifically to extract silicon (and other metals) used to make solar cells)
2. Can be applied to other elements to be mined for commercial use
C. Pros
1. Multiple elements can be extracted using simple mathematical adjustments (i.e. no extra/different chemicals are needed)
2. Thoroughly developed plan for extraction and use of materials (includes figures)
3. Moon Society (Peter Schubert) owns the patents; only group using technology
4. Leftover material is known to be very strong and heat durable
D. Cons
1. Technology has never been practically tested
2. ÒMessyÓ technology; containment a problem
3. No mention of how sunlight can be concentrated
4. Hypothetical numbers with no actual experimentation completed
5. Generally idealized idea (in a perfect world, this would happen)
E. Plausibility
1. Very promising technological advancement
2. Lack of numbers and experimentations creates ÒtrustÓ problem
3. With more experimentation and perhaps cheaper operating and shipping costs, this could be applicable in several years
V. Magnetic Separators6
A. Definition Ð This technology uses an electromagnet to obtain free ferrous metal particles (iron) from within the regolith on the moon.
B. Use in Artemis
1. Used to get iron for the railroad tracks for the solar panels
2. Construction (of habitats?)
3. Catapult
C. Pros
1. Proven technology
2. Can extract iron where it needs to be placed so transportation (of iron) is unnecessary
3. Can (I believe, at least theoretically) be operated without direct human interaction (unmanned)
D. Cons
1. Value of iron (and railroad tracks) depends on success of solar panels
2. Only collects ferrous metals
E. Plausibility
1. Seems very applicable, cheap, and technologically sound (with supporting mathematical data)
2. Use is limited; could be used in tandem with other methods of extraction
VI. Factors to Consider When Choosing a Method
A. Cost
B. State of technology now
C. Gaps in technology? Limiting factors?
D. Independence from other technologies
VII. Conclusions and Suggestions
A. If Artemis happened todayÉ
1. Chemical and electrometallurgy mixture
2. Why - Technology is tested; cost effective (at least on earth)
3. Improvements Ð better recycling of chemicals, easily replaceable anodes and cathodes, storage, and shipment
B. In the futureÉ
1. All-isotope separator with electrometallurgy for refinement (if necessary)
2. Why Ð Ability to obtain many elements without use of different chemicals; no replacement required
3. Assumes Ð all-isotope separator is applicable and profitable; free-iron sweeping device works; solar panels give acceptable yield values; concentrating sunlight
C. Other Areas of Consideration
1. Commercial development of metals for use on earth
2. Maintenance costs
References and Sources
1. Duby, Paul. ÒElectrometallurgy.Ó <www.accessscience.com/Encyclopedia/> (18 July 2006)
2. Brown, Theodore L, et al. ÒElectrometallurgy.Ó <http://cwx.prenhall.com/bookbind/pubbooks/blb/chapter23> (18 July 2006)
3. Schrunk, David, et al. The Moon: Resources, Future Development, and Colonization. Chichester: John Wiley & Sons, 1999.
4. ÒOre Processing.Ó <http://www.asi.org/adb/02/02/03/> (Artemis Website)
5. Schubert, Peter. ÒSynergistic Construction Mechanisms for Habitats in Space Environs.Ó
6. Schubert, Peter. ÒA Novel Method for Element Beneficiation Applied to Solar Panel Production.Ó
Other References:
Chamberlain, Peter G., et al. ÒA Review of Possible Mining Applications in Space.Ó eds. Lewis, J,. et al. Resources of Near-Earth Space. Tucson: University of Arizona Press, 1993.
ÒItÕs Not Made of Cheese!Ó 19 February 2004. <http://www.neiu.edu/~jmhemzac/mooncomp.htm> (24 July 2006)
Lewis, John S. Mining the Sky. Reading, MA: Helix Books, 1996.
Taylor, Lawrence A. and W. David Carrier III. ÒOxygen Production on the Moon: An Overview and Evaluation.Ó eds. Lewis, J,. et al. Resources of Near-Earth Space. Tucson: University of Arizona Press, 1993.