| LUNAR MAGNESIUM PRODUCTION |
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| Solar energy is focused into retort containing Mg ore, flux and silicon reductant. |
| David A. Dietzler, 2007 Producing magnesium on the Moon might be as simple as heating mare regolith that has had ilmenite and iron bearing minerals extracted magnetically and electrostatically in a solar furnace at 1500 C. and higher to volatilize silica and magnesium oxide. In air at 1 ATM pressure MgO does not melt and volatilize until much higher temperatures; however, in the vacuum of the Moon magnesium bearing minerals will decompose and evaporate at much lower temperatures (1). This mixture of SiO2 and MgO would then be reacted with CH4 to reduce the SiO2 leaving a mix of Si and MgO that could be mixed with flux, perhaps calcium aluminate from thermal decomposition of anorthite, and heated in a solar furnace to 1200-1500 C. The magnesium metal will vaporize and be condensed. From: http://solar.web.psi.ch/data/publications/pdf_books/Solar_Thermochemical_Process_Technology.pdf we find that CH4 reduces SiO2 at 1520 K ( 1250 C) and MgO at 1770 K ( 1500 C). It might also be possible to separate SiO2 and MgO electrostatically and reduce the MgO with FeSi from magma electrolysis and some flux. MgO can be used as a iron and steel making flux when mixed with CaO and/or CaAl2O4 and it can be reduced with silicon to magnesium metal that evaporates and is condensed to obtain magnesium metal. Magnesium can be used to alloy aluminum and it might be used as an explosive when made into a slurry with LOX contained in magnesium tanks detonated by a high energy electric spark. Silicon for MgO reduction can be obtained from FeSi obtained by molten silicate electrolysis. Some CaO or CaO-Al2O3 flux is also required. Iron does not participate in the reduction. What if producing magnesium was even easier? Aluminum can reduce silicon from anorthite in a lithium fluoride and calcium flouride flux (2). What if magnesium bearing olivines and pyroxenes after electrostatic sepearation of ilmenite from mare soil that also separates anorthosite, agglutinates, etc. was done (3)? This would be followed by magnetic extraction of iron bearing olivines and pyroxene. What if the magnesian olivines and pyroxenes (forsterite-Mg2SiO4 and Enstatite-Mg2Si2O6 and Diopside-MgCaSi2O6 respectively) were simply mixed with a CaO-Al2O3 flux and FeSi and roasted with solar energy? More research must be done. |
| 1) Rudolf Keller and David B. Stofesky of EMEC Consultants " Selective Evaporation of Lunar Oxide Components" reported in SPACE MANUFACTURING 10 PATHWAYS TO THE HIGH FRONTIER Proceedings of the Twelfth SSI-Princeton Conference May 4-7, 1995; pg. 130. 2) Christian W. Knudsen and Michael A. Gibson Processing Lunar Soils for Oxygen and Other Materials <http://www.belmont.k12.ca.us/ralston/programs/itech/SpaceSettlement/spaceresvol3/plsoom1.htm> 3) William N. Agosto "Lunar Beneficiation" <http://www.belmont.k12.ca.us/ralston/programs/itech/SpaceSettlement/spaceresvol3/lunarben1.htm> |
| more info about silicothermic magnesium production: http://en.wikipedia.org/wiki/Pidgeon_process http://members.tripod.com/Mg/mggen.htm |
| http://www.webelements.com/magnesium/physics.html magnesium reflectivity 74% http://www.webelements.com/aluminium/physics.html aluminum reflectivity 71% Magnesium is a slightly better reflector than aluminum. Lightweight magnesium reflectors might be the key to solar thermal power satellites. Producing magnesium seems to be more straight forward than aluminum production. It does not require carbon, upported chlorine, H2SO4, or an upported LiF flux as does Aluminum. Mg production simply requires MgO, CaO, FeSi and heat; all available on the Moon |
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