Ore Processing
Section 2.2.3.
Home Tour Join! Contents Team News Catalog Search Comm

Integrated Aluminum, Iron, and Silicon Extraction using SiC Alumina Reduction

On Earth, a complex and expensive electrolytic reduction process is used to extract aluminum, which would be a poor choice on the moon for two reasons. The first is that it involves large amounts of fluorine electrolytes and consumes a carbon cathode in the chemical process, and the second is that its power source is electrical and not thermal. As unlimited solar heating is available with the use of inexpensive solar reflectors on the moon, the energy intensity of a process contributes little to the overall cost. On Earth, most of the usual price of US$1,500 per tonne is made up of electrical energy costs.

One promising process simultaneously extracts aluminum, silicon, and iron, without involving the costs inherent in halide electrolysis. The first step of the process involves reducing silica with carbon to produce silicon carbide:

SiO2 + 3 C = SiC + 2 CO

Silicon carbide is also a handy abrasive, although titanium carbide is stronger for the imported carbon mass, and alumina is another good abrasive, but it can be found on the moon.

The silicon carbide is then used to reduce alumina, yielding metallic silicon and aluminum:

Al2O3 + 3 SiC = 2 Al + 3 Si + 3 CO

The carbon monoxide can then be used to reduce iron oxides:

Fe2O3 + 3 CO = 2 Fe + 3 CO2

Carbon dioxide can be recycled for further use by producing methane via the sabatier process, pyrolizing the methane, and electrolyzing the water:

CO2 + 4 H2 = CH4 + 2 H2O
CH4 = C + 2 H2
2 H2O = 2 H2 + O2

Ore Processing

Home Tour Join! Contents Team News Catalog Search Comm
ASI W9800490r1.0. Copyright © 2007 Artemis Society International, for the contributors. All rights reserved.
This web site contains many trade names and copyrighted articles and images. Refer to the copyright page for terms of use.
Author: Simon Rowland. <> Maintained by ASI Web Team <>.
Submit update to this page. Maintained with WebSite Director. Updated Thu, May 28, 1998.