Cooper, B.L. (1994) Reservoir estimates for the Sulpicius Gallus region. Space 94: Engineering, Construction and Operations in Space, pp. 889-896. American Society of Civil Engineers, New York.
"Abstract: The Sulpicius Gallus area... of Mare Serenitatis, covering an area of approximately 6000 km2. It appears to contain an orange glass component that would be an excellent feedstock for hydrogen reduction. Because the glass occurs as a relatively pure material, and because it does not clump up very much, it would be easy to excavate. The deposits may be up to 50 meters thick in some places. Certain sub-areas may have thicker deposits than others (up to 50 meters), and spectroscopic evidence suggests that two areas in particular, which have the highest Mg/Al ratios, contain up to 66% pyroclastic glass on the surface. Estimates presented here show that 1.1x109 metric tons of oxygen could be produced from one of the enriched areas that have been detected by spectrographic studies. Furthermore, the orange glass is known to have volatile-rich coatings, which could be extracted by gentle pre-heating of the material before the hydrogen reduction process begins. Thus, in addition to the oxygen, we could extract 8.8x106 tons sulfur, 5.8x106 tons zinc, 1.9x106 tons chlorine, 1.9x106 tons iron, 1.5x106 tons nickel, 5.1x105 tons copper, and 3.1x105 tons gallium, along with smaller amounts of many other elements. The upper 50 cm of the soil would also contain some solar-wind implanted volatiles, such as hydrogen, nitrogen, carbon, helium, and helium-3..."
Cooper also says in the article quoted above that the glass is located in two 300 km^2 areas, the best one being 40 km SSE of the crater Sulpicious Gallus because it is less mountainous. This area might contain 9.77 cubic km. of glass or 19.5 billion tons.
Say we just excavate one 1/1000th of that or 19.5 million tons, that's in the range of regolith mining shemes proposed for mining volatiles, iron fines, etc. We'd get 1.1 million tons of oxygen; 8,800 tons of sulfur; 5,800 tons of zinc; 1,900 tons of chlorine; 1,900 tons of iron; 1,500 tons of nickel, 510 tons of copper, 310 tons of gallium. That's not bad, and the glass beads just have to be heated to vaporize or melt these elements off their surfaces, though iron would be obtained by hydrogen reduction and nickel by carbonyl processing. Extracting copper and zinc, used to alloy Al and Mg respectively, from regolith will be difficult. Chlorine extraction from regolith is difficult too and would either be done by high temp pryolysis of apaptite in KREEP or H2SO4 leaching. Simply heating volcanic glass is more appealing.
510 tons of copper would make plenty of electrical wires. 8,800 tons of sulfur would make plenty of sulfuric acid, about 27,000 tons of it. 1,900 tons of chlorine would make plenty of CaCl2 for FFC cell electrolyte. 310 tons of gallium would make plenty of GaAs thin film solar panels if we had the arsenic.
See: http://astrogeology.usgs.gov/Projects/LunarPyroclasticVolcanism/lunpyroWebDb.html |
