I'm finally seeing more proper mainstream coverage of the accelerating trend of mining "waste" for minerals. This N. Y. Times article is a pretty decent introduction. Thermal depolymerization, for one, always was presumed to base their long-term profit margins on this kind of thing. "Urban mines". I like the sound of that.
Not least of the implications of this is the inevitable event of people paying to buy mining rights to collections of what has previously been thrown away.
Now it seems to me that the kind of conventional mining industry approach the Japanese are using now is far from what may eventually become the norms. Far less brute force options may lie ahead. I've been saying for years that we will eventually see wormlike robots that will spend their days lying in the sun, charging, and their nights burrowing, eating their way through landfills and either simply leaving behind a more readily processed "soil" or themselves storing up valuable minerals, which are then left in little piles to be collected somehow. Another possibility is plants optimized to concentrate selected rare materials, just as some flowers do now, changing color as the contents of the soil they sit on varies, waiting to be picked and used as feedstock for further concentrating techniques.
There are many possibilities. And what they all have in common is that we should get used to thinking of what we now call "waste" as simply "matter out of place" as Burning Man people already do.
It's not waste once you start using it again.