Lunar Mining Machine

[Success_Machine]

Lunar Mining Machine #1 operations:

-excavate 40 tonnes of lunar soil in under 30 days
-powderize soil in an ultrasonic rock crusher
-extract pure aluminum in a chemical reactor
-stockpile pellets of pure aluminum

Initial calculations indicate that 40 tonnes of lunar soil would yield 1 tonne of pure aluminum.

The intent of this project is to create a working machine. The Lunar Mining Machine will be created using modern 3D CAD software, built and space qualified by the Canadian Space Agency's anecoic thermal vacuum chamber facility. Endurance & efficiency testing will then take place using vacuum settled regolith simulant. Thermal cycle vulnerability testing will be used to test the temperature stabilization mechanism.

The Lunar Mining Machine will comply with the standards set out in the Outer Space Treaty (1967) and the Moon Agreement (1974) to be internationally regulated, to prevent undue contamination/disruption of the lunar environment, to promote world peace & cooperation, and to facilitate human exploration of space.

[Success_Machine]

The challenge: to design a Lunar Mining Machine capable of excavating up to 40 tonnes of lunar soil in less than 30 days, to
work steadily to extract and stockpile 1 tonne of pure aluminum pellets. This stockpile would be the supply for future
manufacturing missions to the moon.

Previous design obstacles include finding an appropriate power source. The most inspirational concept was proposed by
Corky Corcoran such that two missions would be sent to either side of the moon to manufacture fields of solar panels.

Reference: http://www.spacedaily.com/news/robot-00l.html

This power could then be transmitted anywhere on the moon by microwave relay stations or satellites and converted to DC
electrical power by a rectenna with an efficiency of between 40 - 84 percent. This would provide power to the Lunar Mining
Machine location even during the lunar night.

Reference: http://rasc5.kurasc.kyoto-u.ac.jp/plasma-group/sps/history2-e.html

Another interesting design obstacle is the micron-sized electrostatically charged lunar dust. This dust would cause extra wear &
tear on moving parts and cause premature failure of bearings, mechanisms, etc. The solution proposed by myself was properly
designed housings to protect moving parts, grounding any conductive components, and magnetic collars to draw charged
particles away from access ports.

Vacuum settled regolith increases static friction. Depth-core sample drills used during the Apollo missions siezed up and had to
be abandoned for this reason. Vacuum-settled regolith simulant demonstrated the same problem with increases in static friction
from 50-600 percent. Vibration was proposed as an effective means to loosen soil prior to sampling. Ultrasound core sampling
is now seem as a feasible means of obtaining core samples in cryogenic vacuum environments.

But the moon presents a harsh environment. The temperature on the moon varies between -230 deg. C and +150 deg. C and
both extremes are maintained for the duration of the two-week lunar day and two-week lunar night. This poses the most
significant obstacle to the success of the Lunar Mining Machine.

I suspect that equipment will have to be stored inside a nuclear-electic heated shelter for the length of the lunar night to prevent
damage. Therefore, the amount of soil processed by the original Lunar Mining Machine would be halved to only 20 tonnes.
And only 500 kg of pure aluminum may be yielded. This must be accomplished in less than 13.5 days before seeking shelter
from the cold. The minimum temperature on Mars is a less severe but still daunting -160 deg. C. However missions to mars are
far more expensive and risky, and not likely to be considered with the current NASA policy.

Still, I am not giving up on the Lunar Mining Machine.
S_M out...

[Success_Machine]

There are two reasonable case scenarios for lunar mining operations depending on the location selected.

Case 1:
If the soil is composed of 90 percent anorthite, a plagioclase feldspar, the chemical composition means that processing 1 tonne of lunar soil could yield

449 kg silicon dioxide (Si-O2)
340 kg aluminum oxide (Al2-O3)
190 kg calcium oxide (Ca-O)
14 kg magnesium oxide (Mg-O)
11 kg iron oxide (Fe-O)

Case 2:
If the soil is composed of 90 percent ilmenite, also a feldspar, the chemical composition means that processing 1 tonne of lunar soil could yield

480 kg titanium dioxide (Ti-O2)
430 kg iron oxide (Fe-O)
38 kg silicon dioxide (Si-O2)
13 kg magnesium oxide (Mg-O)
11 kg calcium oxide (Ca-O)
11 kg aluminum oxide (Al2-O3)

As on earth dry electrostatic separation into these components should be possible due to the difference electrostatic affinities of each mineral. Fine particles are charged and passed through an electric field at high speed. Particles with different charges are deflected by different amounts. Once the minerals are deposited into multiple bins arranged by type and in their respective quantities heat is added to drive off oxygen leaving the pure metal.

A great deal of oxygen is produced in each case.
For case one the yield is:

210 kg silicon
180 kg aluminum
136 kg calcium
8 kg magnesium
9 kg iron
457 kg oxygen (10733 cubic meters at sea level temperature & pressure)

For case two the yield is:

288 kg titanium
334 kg iron
18 kg silicon
8 kg magnesium
8 kg calcium
6 kg aluminum
338 kg oxygen (7938 cubic meters at sea level temperature & pressure)

Storing this oxygen in its non-oxidized form may not be possible at first. The amount of energy required to evolve the oxygen from the metals has yet to be calculated. It is quite possible that the amount of heat required to process these minerals will keep the Lunar Mining Machine toastie even during the lunar night when the temperature dips to -233 deg.C for a period of two weeks. There may even be the extra requirement for heat dissipation fins and radiant heat pipes for operation during the lunar day when the temperature reaches +123 deg.C.

The primary energy source should be solar power stations located on opposite sides of the moon, each with enough capacity to run the Lunar Mining Machine. This energy is beamed to the mining location via microwave relay transmitters located either in orbit or on the ground. Finally a rectenna at the mining location converts the microwave energy to DC electrical power to run the Lunar Mining Machine.

[Success_Machine]

Please note the following corrections:

Case #1: Processing 1 tonne of anorthite yields 457 kg oxygen gas (320 cubic meters at STP)

Case #2: Processing 1 tonne of ilmenite yields 338 kg oxygen gas (237 cubic meters at STP)

[Success_Machine]

Here are the preliminary power requirements:

These calculations assume that the metal oxides have already been separated by electrostatic beneficiation and deposited into separate bins (furnaces).

Processing 1 tonne of anorthite-rich regolith into its constituent metals would require the following amounts of energy:

449 kg silicon dioxide (Si-O2)6.81 GigaJoules
340 kg aluminum oxide (Al2-O3)5.59 GigaJoules
190 kg calcium oxide (Ca-O) 2.15 GigaJoules
14 kg magnesium oxide (Mg-O) 0.21 GigaJoules
11 kg iron oxide (Fe2-O3) 0.13 GigaJoules

Therefore assuming 100 percent efficiency, a power source supplying a total of 14.89 gigajoules of energy to the vacuum-insulated bins of metal oxides would liberate

210 kg silicon
180 kg aluminum
136 kg calcium
8 kg magnesium
9 kg iron
457 kg oxygen (320 cubic meters volume at sea-level standard atmosphere)

Again, assuming no heat loss it would require a 172.34 kilowatt generator 24 hours to heat up the furnace.

Processing 1 tonne of ilmenite-rich regolith into its constituent metals would require the following amounts of energy:

480 kg titanium dioxide (Ti-O2) 5.68 GigaJoules
430 kg iron oxide (Fe2-O3) 4.93 GigaJoules
38 kg silicon dioxide (Si-O2) 0.58 GigaJoules
13 kg magnesium oxide (Mg-O) 0.20 GigaJoules
11 kg calcium oxide (Ca-O) 0.13 GigaJoules
11 kg aluminum oxide (Al2-O3) 0.18 GigaJoules

Therefore assuming 100 percent efficiency, a power source supplying a total of 11.7 gigajoules of energy to the vacuum-insulated bins of metal oxides would liberate

288 kg titanium
344 kg iron
18 kg silicon
8 kg magnesium
8 kg calcium
6 kg aluminum
338 kg oxygen (237 cubic meters at sea-level standard atmosphere)

In this case it would require a 135.4 kilowatt generator 24 hours to heat up the furnace.

This is being very optimistic since I have used pure calculation and not taken into account efficiencies of the process.

Still, it looks quite feasible at this point.

[Success_Machine]

Mission Name: Lunar Mining Machine (faster, better, cheaper)
Mission Duration: 14 days

Mission Description:
The mission will take place during the two-week lunar day to take advantage of sunlit-temperatures as high as 123 deg.C. Surface-scraping equipment will remove one tonne of regolith (fine moon dust) from the surface and separate oxides by electrostatic beneficiation the same way it is done on earth. Separated oxides will then be placed in a furnace that will add heat to break molecular bonds. The result will be pure metal and liberated oxygen gas.

One tonne of moon dust that is anorthite-rich (greater than 90%) will yield the following amounts of oxides:

449 kg silicon dioxide (quartz, Si-O2)
340 kg aluminum oxide (Al2-O3)
190 kg calcium oxide (Ca-O)
14 kg magnesium oxide (Mg-O)
11 kg iron oxide (Fe-O)

These oxides would be separately placed in a furnace where heat of formation is added, effectively dissociating the oxides at the molecular level. A 20 kilowatt power source would provide each batch of oxides with an appropriate amount of heat energy and require the following amounts of time & energy to process:

210 kg silicon_____6.81 gigajoules__3.94 days
180 kg aluminum____5.59 gigajoules__3.24 days
136 kg calcium_____2.15 gigajoules__1.25 days
8 kg magnesium_____0.21 gigajoules__2.92 hours
9 kg iron__________0.13 gigajoules__1.81 hours

A total of 14.89 gigajoules and 8.63 days of time & energy would be consumed. As well 457 kg oxygen gas (320 cubic meters volume at sea-level standard atmosphere) would be liberated by the process.

Electrostatic beneficiation of one tonne of ilmenite-rich regolith would yield the following amounts of oxides:

480 kg titanium dioxide (rutile, Ti-O2)
430 kg iron oxide (Fe-O)
38 kg silicon dioxide (Si-O2)
13 kg magnesium oxide (Mg-O)
11 kg calcium oxide (Ca-O)
11 kg aluminum oxide (Al2-O3)

The oxides would be placed individually into a furnace and heat added to break apart the oxides at the molecular level. A 20 kilowatt power source would require the following amount of time and energy to process each batch:

288 kg titanium____5.68 gigajoules__3.29 days
344 kg iron________4.93 gigajoules__2.85 days
18 kg silicon______0.58 gigajoules__8.06 hours
8 kg magnesium_____0.20 gigajoules__2.78 hours
8 kg calcium_______0.13 gigajoules__1.81 hours
6 kg aluminum______0.18 gigajoules__2.50 hours

A total amount of 11.7 gigajoules and 6.77 days of time & energy would be consumed. In addition 338 kg oxygen gas (237 cubic meters at sea-level standard atmosphere) would be liberated by the process.

This is being very optimistic since I have used pure calculation and not taken into account efficiencies of the process. For example I have assumed that the furnace is perfectly insulated and no heat escapes.