Aluminum

Introduction

Here is my first nieve attempt to briefly examine the possibilities for refining a basic element on Mars from in situ resources, First I have tried to understand a little about the chemistry and then the process on Earth and then how to prospect for the raw materials followed by a brief look into usage and the further process required to then use the pure Aluminum such as for electrical cabling, building materials or for mirror making, I have made a basic short conclusion at the end.

Aluminum production on Mars

Aluminum can be found in igneous rocks on Mars as it is found in the most abundant rocks that also contain iron, magnesium, calcium, and potassium. Also Mars soil contains about 10% aluminium oxide(Al₂O₃).

Refining Aluminum

Like most heavy industry processes is a power hungry process and complex as it needs other chemicals to refine, On Earth it needs Sodium Aluminum Fluoride salt(Na₃AI F₆) called cryolite as a flux this has to be Synthesized by fusion of sodium fluoride and aluminum fluoride. Sodium is available on Mars as sodium perchlorate(Na Cl O₄) also Fluoride(F) has been found.

Videos informative for refining aluminium oxide on Earth

Aluminium smelting Hall-Héroult Electrolysis Cell

How It's Made Aluminum

Prospecting for Aluminium

Now we have a little idea of how to refine Aluminum we can consider how to start producing it on Mars.

The most likely First way will be to use the Martian soil until a more rich vein of the raw materials has been prospected.

We know that Mars' crust is thought to be one piece. Unlike Earth, the red planet has no tectonic plates that ride on the mantle to reshape the terrain. Since there is little to no movement in the crust, molten rock flowed to the surface at the same point for successive eruptions, building up into the huge volcanoes that dot the Martian surface, so these areas on Mars may be more suitable for mining for raw materials but this will be done later in the colonies evolution.

The Ore form the soil should easily be available using relative simple mining equipment and vehicles that can be autonomous similar to that required to mine the ice for water production, but the power requirement would suggest a nuclear reactor as well as the plant required for all the various different processing systems, needed to be brought from Earth to start with.

Refining steps

The Soil will be mostly Iron Oxide that will need to be seperated, Iron Oxide will have its own refining process.

The other major constituents are also useful and will need separating and especially any off the important nutrients such as sodium, potassium, chloride and magnesium.

Aluminum it is extracted by electrolysis using the Hall-Héroult process, useful byproduct is Oxygen.

One major issue will be Carbon anode manufacturing, may have to be imported from Earth for some time.

Energy

The best aluminium smelters on Earth use about 13 kilowatt hours (46.8 megajoules) of electrical energy to produce one kilogram of aluminium.

The Hall-Héroult process uses a huge amount of electricity; hundreds of thousands of amperes are used in each cell.

Energy production on Mars will be a limiting factor for producing large enough quantities of aluminium for more than specialised needs at first.

The demand for constructions purposes will push the development of higher energy production on Mars as soon as feasible.

Initial Uses of Aluminum on Mars

Pure Aluminum can be used with glass to make mirrors. Mirrors have many important applications such as focusing light on to solar panels and into underground food production facilities.

But for construction purposes it will need to go through other process to mix it with other chemicals to make it strong.

Wiring is another potential use for Aluminum again additional process involved.

In the future it is a important element for making semiconductors useful for power switching and solar panel storage equipment on Mars but the initial quantity required will be low and possible to refine these amount with smaller equipment.

Conclusion

The in situ process for producing important refined materials is going to be a major undertaking requiring considerable amounts of Energy and other Manufacturing resources used in the different process to extract the pure elements.

The hardware required to achieve any usable quantities will need to be substantial and the equipment to achieve it will need to be designed and produced on Earth and transported to Mars as there appears no easy way to bootstrap everything required on Mars. Aluminum is an important element for building and expanding the Mars Colony.

Most likely a highly miniaturised system will need to be developed and shipped to Mars on a BFR to kick start any refining on Mars.

Any systems shipped to Mars will need to be very low maintenance until a martian skill base of servicing mechanics, industrial electricians and engineers are available in sufficient numbers to oversee any such production systems.

PLEASE feel free to Email me with any suggestions on of any information and ideas, particularly on items I have missed or any errors I have made.