Liberation of oxygen from the mineral ilmenite (FeTiO3), which may be found on the Moon, Mars, or asteroids, is inefficient due to the abundance of other minerals in the excavated regolith that are present but not needed during the chemical processing. Energy for the reduction reaction is in short supply on the lunar, Martian, and asteroid surfaces. The ilmenite should be separated from other minerals to simplify and improve the process efficiency. Lunar and planetary basaltic lavas contain ilmenite, but they consist only of 12 to 20 percent by weight.
A process was developed whereby granular ilmenite is separated from excavated regolith for further processing in a chemical reactor. The separation process is known as beneficiation, and makes oxygen production more efficient by reducing the mass and volume of material that must be processed, and reducing the energy required.
The process consists of enhanced tri-bocharging of the undesirable minerals in planetary regolith using a high-speed gas stream to transport the regolith in a rapid spiral around the inside of an aluminum cyclonic particle separator. Aluminum and ilmenite are similar in terms of their tribo-electric charging characteristics, and do not charge each other. The non-ilmenite minerals develop either a positive or negative charge relative to aluminum. Rubbing these particles against the aluminum of the cyclonic separator takes place at high speed, and the undesirable minerals become highly charged. When the mixture of charged and uncharged minerals from the cyclone separator is subjected to a strong electric field, the undesirable particles are attracted toward the charged plates and away from the stream of ilmenite. The beneficiated ilmenite can then be collected for further processing.
This work was done by Ivan Townsend, James Mantovani, and Kyle Weis of Kennedy Space Center. For more information, contact the Kennedy Space Center Technology Transfer Office at 321-867-5033. KSC-13630