How hot do they get the piles of dirt? They are making steam from it?

600'C at the high end seems to be the cited number. Steam or other heat extraction method such as air.

Wow that is insane. Steel is brown-red at that temp.

	▲	tgtweak 2 days ago \| parent [-]
		Oxidization also rapidly accelerates at these temperatures so durability of the greeting element is doing to be a significant challenge.