|
||||||||||
|
Once cesium oxide has been isolated, metallic cesium can be produced. This can be done at moderately high temperatures with strong reducing metals such as sodium, potassium, magnesium, barium, iron, zirconium, aluminum, or silicon. Iron will likely be the best choice:
3 CeO + 2 Fe = 3 Ce + Fe2O3
The iron oxide can then be recycled by hydrogen reduction in a solar furnace:
Fe2O3 + 3 H2 = 2 Fe + 3 H2O
As the hydroxides, carbonates, halides, sulphates, chromates, and nitrates of cesium, as well as similar compounds or oxides of several other metals such as rubidium, are all reduced by the first process, the impurities will tend to collect in the second, hydrogen reduction step. Cesium halides, for instance, will not be reduced by hydrogen, and will constitute the small quantities of functionally inert slag which will require occasional purging for eventual further processing.
The hydrogen required for the second step can be reclaimed by water electrolysis, a well-understood and highly refined process requiring roughly 27.5 KWh per kilogram of hydrogen released:
2 H2O = 2 H2 + O2
In addition to solar heat, about 0.21 KWh of electrical energy is required per kilogram of cesium refined, if an iron reduction process is used. Other processes are likely to be similar.
Read more about cesium's role as a raw material in the 2.13.2. Raw Materials: Metals chapter of the Artemis Data Book, and an article about the occurrence of lunar cesium in the M.8.4. Incompatable Trace Elements chapter of the Data Book.
|
|
|