Sodium Hydroxide Method for Extracting Oxygen from Lunar Minerals

Dr. Larry Friesen

The sodium hydroxide (NaOH) process can get all metals (in addition to oxygen) from lunar rocks/regolith. Most other processes only get some metals. An important problem is to separate the reduced metals.

In Binder's approach, all recoveries could be done in the same tank.

• Fractional distillation (boiling) can be used to get Na, K, P.

• Magnesium floats on NaOH. You can skim pure Mg from the top.

• Al is soluble in alkalies. Boil off the NaOH at the end (to clean up) to get a pure Al residual.

• If you add water, Ca, Ba, and Y form hydroxides. Refine these with NH3.

• If you pump CO2 into the residuals, you will form carbonyls. These can be separated easily. You end up with a steel having about 1% Mn and 2% Cr in it.

• A weak HCl solution will leach out Ti.

This is based on remarks by Alan Binder at a Lockheed/NASA Advanced Missions group meeting, August 23, 1988. Alan Binder is currently Principal Scientist for the NASA Lunar Prospector mission.