A New Process for Production of Oxygen from Lunar Minerals

The carbothermal reduction of ilmenite and iron- bearing silicates are important in the manufacture of steel and perhaps for manufacture of oxygen on the moon. Oxygen recovery from ilmenite and iron silicates is of interest because of the abundance of such minerals on the lunar surface and the relative ease of their reductions. A novel carbothermal reduction process is developed for the reduction of these minerals.

This presentation summarizes an experimental study of the carbothermal reduction of ilmenite and iron-bearing silicates at temperatures between 850°C and 1100°C. Extremely high reduction rates are observed and investigated for carbothermal reduction of ilmenite by using deposited carbon. These results are compared to previous kinetics studies with regards to the different activation energy values reported. Fayalite, the iron end member of the olivine series(Fe,Mg)₂SiO₄, is initially reduced into a intermediate Fe_2-xSiO_4-y and Fe; At low temperatures(below 1000°C), the major reduction products are α-Quartz and Fe, but at higher temperatures (above 1100°C), the major products are α-Cristoblite and Fe. The iron formed during the reduction is segregated from the SiO₂ phase. This is different from hydrogen reduction which results in iron distribution throughout the SiO₂ phase.