What If We Get The Ability To Extract By Nanotech Rare Elements From The Bulk of The Earth?

A guest article by Joseph Friedlander

Given that energy supply is severely limited, and the Peak Everything people tend to take that as a given, sharp limits appear in vital mineral resources in many areas of supply; thus the Peak (fill in the blank) articles you read now and then.
But what if technology develops in an unexpected direction?  What if we get a limited form of nanotech which does not allow for self-reproduction (the actual nanites or components are grown in specialized vats in giant refinery like chemical complexes) but does allow for precision mass assembly and remote control by computer?
Not self reproducing in the field, just producible under controlled conditions in the vat and pumped to their site of work. But once there, they can morph into structures under computer command then repool, reminiscent of the polymetal alloy in the Terminator 2 movie.
Many uses would be possible for such a constrained nanotech, but among the most dramatic would be the ability to extract rare elements scattered in the Earth’s crust and concentrate them sufficiently to be of commercial use.
Let us imagine such a scenario: Where a small surface installation grows ‘fingers’ and ‘tree roots’ doing down into the Earth. (programmable nanites forcing their way in tendrils by atom by atom dis-assembly of even the hardest rock, forming circulatory pathways down to the limits of temperature tolerance.)
There are a number of ways this could happen and be utilized, but let’s just do an outline of one possible scenario.
Note that we are dealing only with very average crustal rock, even though there are practically unlimited amounts (tonnage wise) of rock with 2 to even 10 times average crustal abundance of many scarce elements. They are sub-ores, not usually profitable when richer ores are available but for this scenario we just concentrate on the crustal average– which will be concentrated!
Even if the nanites are quite expensive by the ton they should almost all be recoverable as long as tendrils remain contiguous and operating temperatures are not exceeded.
 And if you are dealing with one tendril path per cubic meter, and the chained nanite shaft of crawling locking and unlocking, recrawling and tunneling (by pushing atoms of rock apart) units  is only 100 nanometers wide, that means per cubic meter you only have 10,000 cubic microns  (.–a meter is a million microns long but the 100 nanometer shaft is only .1 x .1 or .01 million cubic microns per meter of length.)
 That means you could have a prepositioned string of nanites within a fraction of a meter of any given atom with a cubic of 10 billion cubic microns (10 cubic millimeters) per million meters (1000 kilometers) of nanite chain.
 So to mine a 10 kilometer deep cube (1000 cubic kilometers, typical rocks 2-4 trillion tons of mass, would only take 10 kilometers linear chain per square meter of surface or 10 million kilometers linear chain (1000 x 1000) per square kilometer, or a billion kilometers linear  for 100 square kilometers (surface of a 1000 cubic kilometer cube).
A billion linear kilometers of such nanite mining string would be 10 million billion cubic microns– or 10 million cubic millimeters–or 10 cubic decimeters (10 individual 4″ cubes). A man could carry them in a tool box.
This tendril net would give down to the individual meter, a programmable access and sensor network. Now we must imagine something like vibrational tomography that would use sound, ultrasound or other communicable pulses to listen for and ‘feel’ out the atoms within reach. The analysis of the data would be a new definition of Big Data, made possibly by the nanites data processing cousins in vats on the surface.
A statistical analysis of the data would give probabilities for each atom species, and over time perhaps a thousand times more nanites would join the stream– still only  enough to fit in a  delivery van.  Subtendrils could migrate and seek out the highest probability paths to harvest the atoms of interest.  This week, Bismuth, next week, Iodine, as the market demands. Over time the recovery would again be of a probabilistic nature, with reasonable assurance of having mined say 95% of the gold resource in the 1000 kilometer cube.
The elements of interest would be streamed up the nano-pipeline,  easily its own volume a second. Still, that is tons a second of fairly rare elements making its’ way to the wellhead, making for a busy stream of trucks removing the output– possibly assembled in bar form.
But the wealth this would make possible!
Here is a table of the average richness (or paucity) of crustal rock.
1967 US-GS report on abundances in Earth’s crust http://pubs.usgs.gov/pp/0440d/report.pdf
Wikipedia on abundances in Earth’s crust. https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust 
I have highlighted lithium boron  gallium and bismuth (in yellow) as sample elements that would have many new uses if millions of tons were available as cheaply as say aluminum is today. Obviously gold silver and platinum group metals  ( highlighted in silver) have their own charm. I am sure if  abundantly available they would be used without ostentation and responsibly by all, including governments.  Or not. 
Note that gold is only in parts per billion– yet in 1000 cubic kilometers of random crustal rock is 2-4000 tons of gold–more than the official gold reserves of any nation but the USA –even exceeding Germany and the IMF itself. https://en.wikipedia.org/wiki/Gold_reserve#IMF_Gold_Holdings

What other elements would be targets early on?  Obviously silver and the platinum group metals– but a lot would be the minor commercially valuable elements. Only 171300 tons gold holdings so given 3000 tons from 100 sq km surface area even medium sized countries could mine more holdings than the world has today.
Next Big Future readers will be familiar with the battery and nuclear uses of lithium. Unlimited lithium cheaper than aluminum today would make possible an all electric world.  Boron is useful for fiber, energetic reactions., nuclear uses and for making green flames.

Cheap boron would make possible very lightweight structures.
 The most game changing might be unexpected uses for heretofore unremarkable elements.  
Take Bismuth for example– non toxic, easy to work, capable of making beautiful crystals (a bismuth crystal lined room would bring awed sounds from children if properly lit) and usable in levitation technology (equally entertaining to kids)
Take Gallium for example– which can melt in your hand (or your mouth–not recommended)  like chocolate. I can see having a Gallium waterbed if it were cheap enough– the perfect form fitting mattress. (Not in winter though!)


But tech saboteurs might wish to make gallium-mercury bullets to induce structural failure.


 And of course 1% gallium helps make plutonium manageable for nuclear warhead use. So gallium isn’t always the HappyFunElement(TM)
 What is your nominee for the element most likely to surprise for good or evil when made possible to amass cheaply in huge quantity? 
List your nominees in the comments below.