Microwave Induced Carbothermic Reduction of Iron Oxides in Lunar Soil Simulant

Microwaves have been used for a number of years as a convenient source of controlled, penetrating radiation providing rapid and selective heating through differential coupling. This paper describes using microwave radiation to drive the carbothermic reduction of iron oxide present in a lunar soil simulant (JSC-1). The goal is to repeat a previous experiment which used a Martian soil analog (JSC Mars-1) and compare results of both experiments. Microwave energy is used to directly convert iron oxide into metallic iron using a minimum amount of energy and equipment without beneficiation. A two-gram sample of JSC-1 was used along with an amount of powdered graphite equal in mass to the percent of elemental Fe contained in the soil. The samples were placed in small alumina crucibles and heated in a domestic microwave oven. The reaction occurs after only a few minutes of exposure to high power. Mössbauer spectroscopy analysis indicates that about nine percent of the iron oxide was converted into elemental iron which corresponds surprising well to the previous experiments with the Martial soil similant.