[chimera]

Nothing particularly new here. I was doing trace element analysis of both unburned coal and fly ash back in the 1970s. Neutron activation analysis is particularly sensitive to many of the REEs in fly ash. The combustion process drives off the carbon (which is a problem for the environment, but that's a topic for another thread) and other volatiles, and leaves the heavier stuff. The problem, as always, is to pick the residue that has the highest concentrations of the good things, and see if the extraction process is economical.

[fella]

What is and has been done with this ash waste?

[Vaquero]

We buy most rare earths from China. Do they give underpaid minions next to nothing to separate the rare earths from ash?

[Paladin2]

Too bad Hg is volatile.

[zeugma]

The problem, as always, is to pick the residue that has the highest concentrations of the good things, and see if the extraction process is economical.

The trouble is, this will come down from the leviathan feral government as a mandate regardless of whether or not it is a economically viable idea.