Centauri's Thoughts

Chemistry has always fascinated me, and while I had it in high school, and understand the basics, the finer points of chemical reactions, specifically, why certain reactions take place over others, is something I suppose I would know better with a college course or much more reading. Specifically, as it relates to Space Sciences, things like the removal of oxygen bound to ores for purification, and reversal of systems.


Today I read about the use of Sodium Alanate (NaAlH4) As a way to carry hydrogen safely, for liberation later as fuel. Also in these articles, is the discussion of Titanium doping to make this process more efficient. In addition to Zinc and Magnesium, these are making for many ways to use hydrogen that is chemically bonded with something rather than trying to move and store dangerous H2 gas.


As I kept reading, I hit WebElements.com for some more answers. In particular, it listed the process of reducing Bauxite (A type of common ore containing Aluminum)

Aluminium is mined in huge scales as bauxite (typically Al2O3.2H2O). Bauxite contains Fe2O3, SiO2, and other impurities. In order to isolate pure aluminium, these impurities must be removed from the bauxite. This is done by the Bayer process. This involves treatment with sodium hydroxide (NaOH) solution, which results in a solution of sodium aluminate and sodium silicate. The iron remains behind as a solid. When CO2 is blown through the resulting solution, the sodium silicate stays in solution while the aluminium is precipitated out as aluminium hydroxide. The hydroxide can be filtered off, washed, and heated to form pure alumina, Al2O3.


The next stage is formation of pure aluminium. This is obtained from the pure Al2O3 by an electrolytic method. Electrolysis is necessary as aluminium is so electropositive. It seems these days that electrolysis of the hot oxide in a carbon lined steel cell acting as the cathode with carbon anodes is most common.

I knew about the process of using an acid with metals, but I was not familiar with bases and those reactions. I suppose I will be studying more, as these refining processes would be quite useful to know for mineral refinement processes on lunar ores. With just a few of the basic elements, and some knowledge, there should be no problem in refining metals, and getting PLENTY of oxygen for breathing. (And retaining the rest of the chemicals for re-use, like the Hydrogen)