No, once a technological civilization has used the minerals, they’re too scattered and worn to be efficiently gathered. When the minerals are still in the planet, you can use geological knowledge to predict where they are and find them in concentrated form. Once Sentients start using them for various purposes, they lose the order and usefulness they once had.
In short, the entropy of the minerals massively increases, because the information about its distribution is destroyed. Therefore, it requires greater energy to convert back into useful form, almost certainly needing a higher energy expenditure per unit useful mineral obtained (otherwise, humans would be currently mining modern middens (aka landfills) for metals).
OTOH, when large concentrations of metal (buildings, vehicles) are disposed of, they’re almost always recycled. Many such large concentrations would survive a collapse. I’m not sure how long it would take for iron/steel buildings to mostly rust away, or how much steel would be buried safe from rust.
I do. So do a lot of other people. Because it is, in fact, a good idea. IIRC, it’s more efficient than mining, what with all the easily-accessible minerals already mined out.
No, once a technological civilization has used the minerals, they’re too scattered and worn to be efficiently gathered. When the minerals are still in the planet, you can use geological knowledge to predict where they are and find them in concentrated form. Once Sentients start using them for various purposes, they lose the order and usefulness they once had.
In short, the entropy of the minerals massively increases, because the information about its distribution is destroyed. Therefore, it requires greater energy to convert back into useful form, almost certainly needing a higher energy expenditure per unit useful mineral obtained (otherwise, humans would be currently mining modern middens (aka landfills) for metals).
OTOH, when large concentrations of metal (buildings, vehicles) are disposed of, they’re almost always recycled. Many such large concentrations would survive a collapse. I’m not sure how long it would take for iron/steel buildings to mostly rust away, or how much steel would be buried safe from rust.
We do. It’s called “recycling”.
You should recycle.
I do. So do a lot of other people. Because it is, in fact, a good idea. IIRC, it’s more efficient than mining, what with all the easily-accessible minerals already mined out.