APPENDIX
SUGGESTED EXTRACTION PROCESSES

From the several possible methods for extracting metals and oxygen from the lunar and asteroidal resources, the following are considered best suited for nonterrestrial conditions:

  1. Carbochlorination of lunar plagioclase concentrate in conjunction with Alcoa electrolysis for Al
  2. Carbo chlorination of lunar ilmenite concentrate followed by Ca reduction of TiO2 and subsequent reduction of Fe2 O2 by H2 for Ti and Fe, respectively
  3. Silicothermic reduction of asteroidal olivine concentrate for Mg
  4. Methanation of CO and electrolysis of H2 O and/or solidstate electrolysis of gas mixture containing CO, CO2 and H2O for oxygen.
The principal reactions of interest in the metal and oxygen extraction process along with the thermodynamic data, mass, and heat balances of the processes considered are detailed in

TABLE 3 .-REACTIONS OF INTEREST IN METAL AND OXYGEN EXTRACTION PROCESSES
1. Al2O3(s) + 3C(s) + 3CL2 (g) 2AlCl3 (g) + 3CO(g)
2. CaO2 (s) + C(s) + Cl2 (g) CaCl2(s) + CO(g)
3. SiO2(s) + 2C(s) + 2Cl2(g) SiCl4(g) + 2CO(g)
4. CaO Al2O3 2SiO2(s) + 8C(s) + 8Cl2(g) 2AlCl3(g) + CaCl2(g) + 2SiCl4(g) + 8CO(g)
5. FeTiO3(s) + 3C(s) + 3/2Cl2(g) FeCl3 + TiO2(s) + 3CO(s)
6. FeCl3(s) FeCl3(g)
7. FeCl3(s) + 3/2O2(g) 2Fe2O3(s) + 3Cl2(g)
8. Fe2O3(s) + 3H2(g) 2Fe(s) + 3H2O(g)
9. Fe2O3(s) + 3CO(s) 2Fe(s) + 3CO2(g)
10. TiO2(s) + 2Ca(s) Ti(s) + 2CaO(s)
11. Mg2SiO4(s) + 4CaO(s) + Si(s) 2Ca2SiO4(s) + 2Mg(g)
12. 2CO(g) CO2(g) + C(s)
13. Co(g) +2H2(g) CH4(g) + H2O(g)
14. H2(g) + 1/2 O2(g) H2O(g)

TABLE 4 .-THERMODYNAMIC DATA FOR SOME PERTINENT REACTIONS IN METAL AND OXYGEN EXTRACTION PROCESS
Reaction
no.
Temperature
K
Go
Kcal
Ho
Kcal
KPartial pressure of species (Pi = 1 atm)
Gaseous
species
Pi Gaseous
species
PiGaseous
species
Pi
1 900-62.237.71.26X1015AlCl3~0.4CO~0.6Cl23.0X10-6
1000-73.337.71.07X1015AlCL3~0.4CO~0.6Cl21.4X10-6
2 900-73.3-63.46.5X1017--CO~1.0Cl21.6X10-18
1000-74.4-63.41.8X1016--CO~1.0Cl25.5X10-17
3900-41.56.21.2X1010SiCl4~0.333CO~0.667Cl23.5X10-6
1000-48.86.21.7X1010SiCl4~0.333CO~0.667Cl23.0X10-6
4900-190.611.91.9X1046SiCl4or
AlCl3
~0.166CO~0.667Cl22.3X10 -6
1000-213.111.93.7X1046AlCl3-CO~0.667Cl22.0X10-6
51000-69.2-762.7X1033FeCl30.25CO0.75Cl25.3X10-21
1100-74.1-762.7X1030FeCl30.25CO0.75Cl21.21X10-21
650011.233.21.3X10-5FeCl31.3X10-5----
6006.733.23.8X10-3FeCl33.8X10-3----
7500-25.6-8.61.5X1011O23.6X10-8--Cl2~1
600-29.0-8.63.5X1010O29.3X10-8--Cl2~1
81000-3.615.36.62H20.348--H2O0.625
1200-7.615.324.0H20.257--H2O0.743
91000-5.9-9.019.9--CO0.27CO20.73
1200-5.4-9.094.7--CO0.325CO20.675
101200-70.3-81.36.3X1012------
1300-69.4-81.34.6X1010------
111300+7.764.75.2X10-2Mg0.23----
1500-1.164.71.46Mg1.21----
12800-7.3-41.0101.0------
12009.4-41.01.92X10-2------
1310006.4-54.63.9X10-2------
12008.6-54.62.8X10-2-------
141000-46.0-59.31.16X1010------
1200-43.4-54.37.9X107------

TABLE 5 .-THEORETICAL AMOUNTS OF RACTANTS AND PRODUCTS IN VARIOUS METAL EXTRACTION PROCESSES
Extraction
process
for:
Basis,
1 kg
ReactionReactants required, kgProducts formed, kg
Aluminum Anorthite 4 CaOAl2O32SiO 2 C Cl2 AlCl3 CaCl2SiCl4a CO
(1)(0.345)(2.036)0.956) (0.399)(1.221)(0.805)
Electrolyte -- AlCl3 Alkalai and
alkaline earth
chlorides
Alkalai and
alkaline earth
chlorides
ALCL2--
(0.05)(0.95)(0.95)0.0101)(0.00399)--
Titanium and ironIlmenite 5FeTiO3 CCl2FeCl3TiO2-CO
(1)(0.040)(0.463)(0.708)(0.463)-(0.093)
10TiO2Ca-CaOTi--
(0.463)(0.463)-(0.650)(0.277)--
7FeCL3O2-Fe2O3 Cl2--
(0.708)(0.053)-(0.347)(0.463)--
8Fe2O3H2-FeH2O--
(0.347)(0.013)-(0.243)(0.117)--
MagnesiumOlivine11 Mg2SiO4CaOSiCa2SiO4Mg--
(1)(1.594)(0.200)2.448)(0.346)--

aIf SiCl4 is suppressed, 0.775 kg of SiO2 can be recovered.

TABLE 6 .-THEORETICAL HEAT REQUIREMENTS AND SENSIBLE HEATS FOR SOME REACTIONS IN METAL EXTRACTION PROCESSES
Extraction
process
for:
ReactionTemperature,
K
HT-H298
reactants,
Kcal
Enthalpy of
reaction H,oT,
Kcal
Sensible heat in
products
HT-H298, Kcal
Al41000119.811.9141.2
Ti5110037.4-76.0158.3
10120029.9-51.531.4
Fe760017.8-8.618.4
8100038.915.3161.8
Mg111500115.664.7178.7

TABLE 7 .-ILMENITE PROCESSING DETAILSa
Year (SMF frame)23456
Ilmenite concentrate
(X10-3tons/year)
1640618181
Tubes in use4651160177023502350
Rutile requirement, tons7.418.428.137.337.3
Carbon requirement, tons/day1.84.46.78.98.9
Chlorine requirement, tons/day20.350.877.5103103
Ferric chloride produced,
(X10-3tons/year)
11.328.343.157.357.3
Rutile produced,
(X10-3tons/year)
7.418.528.237.537.5
Carbon monoxide produced
tons/day
4.110.215.620.720.7
Tubes producing hematite23058088511751175
Oxygen requirement,btons/day
4.611.417.423.123.1
Hematite produced,
(X10-3tons/year)
5.613.921.228.128.1
Hydrogen requirement,
tons/day
0.581.442.202.922.92
Iron produced,
(X10-3tons/year)
3.99.714.819.719.7
Calcium requirement,tons/day20.350.877.5103103
Titanium produced,
(X10-3tons/year)
4.411.116.922.422.4

aBased on expirements in references 11 and 12.
bRequirements should at least be doubled; 1 day in use, the next day being recycles.

Return to V-5

References

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