Metal and civilisation

There’s a throwaway line in Oryx and Crake, where Crake opines that if some disaster destroys civilisation and reduces mankind to sticks and stones, we are permanently screwed.

The reason for this is that we have used up all the useful metals near the Earth’s surface, so our post-apocalyptic successors would have no joy climbing the technological ladder.



Metals don’t generally evaporate at the temperatures we normally associate with life, with the possible exception of mercury, so I’m not sure why anyone would expect the metals we’ve already extracted to be unavailable, even if it were true that we’ve completely depleted all the mineable metals (we haven’t). If anything, I’d suspect we’ve given our successors a leg up in that regard.

That makes no sense. We may have mined out a good chunk of easily accessible ores, but where do you think the resulting minerals are now? We haven’t been sequestering them in the Marianas Trench (well, except for that once) or launching them all into orbit.

I hear that making aluminum cans by recycling old aluminum cans only requires 5% or 20%, (like I said it’s hearsay), of the the resources necessary to pruduce the same cans from ore.

I may be off in my figures, but since it takes less resources to melt down existing metals than to mine, smelt and refine from ores, wouldn’t the survivors of The End Of The World As We Know It have an easier time producing metal from the detritus of The World As We Know It than their ancestors had building TWAWKI?

We are, however, reducing the availablilty of hydrocarbon liquids and gases which have (literally) fueled the Industrial Revolution, which in turn dramatically reduced the amount of labor required to grow and distribute food, thus allowing a greater amount of leisure time in which to foster universal literacy, research and cure disease, build great civil works, construct globe-spanning computer networks, and demolish entire cities with a single blast. Okay, so there’s some good and bad in all of that, but the point is without natural petroleum and coal (which is just about perfect as a fuel, other than the residual pollution from combustion products) we’d have a hard time getting a civilization to the point of developing and deploying any other advanced technology.

Of metals we have plenty, and they’re more readily recoverable in their current refined state than they are from ore. A future civilization would be about as short on metal as it would be on silica for glass.


Lots easier! Assuming that civilization collapses for some reason, there will still be a huge amount of metal on the surface or near the surface that is in relatively pure metallic form. That would then simply require just re-forming the metal into whatever new shape is required (swords, plowshares, etc.). The original problem was getting the metals out of their ore forms, which takes quite a bit more effort. The amount of energy required to melt and re-form aluminum is only about 5% of the energy required to extract the aluminum from bauxite (an aluminum ore). See for a quick rundown on aluminum production.

If we’ve done anything, it’s make metals more accesible for future civilizations, by extracting it and puting it in easily recovered form.

Aluminum is a real anomoly here. If you want to save society now, one of the best things you can do is recycle aluminum. Aluminum is a VERY reactive metal. It is only by a fluke that aluminum reacts so quickly with the atmosphere that a protective oxide layer forms preventing further oxidation. Aluminum hates being metalic. That is why it takes so much energy to get aluminum out of bauxite.

Actually, while we’ve made things easier in terms of aluminum, we might have made things more difficult in terms of iron. A car would be an easily reworkable hunk of metal a dozen or so years after civilization implodes, 200 or 300 years later, however, and the car’s going to be literally a pile of rust. A primitive society isn’t going to recognize that pile as iron, much less have idea of how to rework it into something useful.

Why wouldn’t a “primative society” recognize rust as iron, particularly a post-apocalytic one? It’s not like ores resemble finished metal, either.

What you do to turn rust into iron I have no idead, though.

A society that had just been scavenging metal would probably not have an idea of what metal in any other form, than finished, looked like. The theory as to how our ancestors discovered metal is that some ore bearing rocks were heated by a fire, and the metal in them ran out.

Me either.

You’d smelt or directly reduce it. Iron ore is nothing but an oxide of iron, typically hematite (Fe[sup]2[/sup]O[sup]3[/sup]) or magnetite (Fe[sup]3[/sup]O[/sup]4). The former is the most typical form that comprises rust.

And society technically advanced enough to work metals is going to recognized rust as being an oxide of iron; indeed, rust is particularly easy to identify and extract due to its ferromagnetic properties.