I have some extremely high tech of mining machinery that needs no fuel and has no moving parts.
All you do is grab one end of this amazing implement (there are different models, Advancetechpick, Advancetechhammer, and
Advancetechhoe) and drop it on the rocks. As long as it drops on the rock, some reduction is taking place. Some models have sharp ends and some have flat.
When the rocks are suitably smashed you throw it all in nearby river using a simple, again, no fuel, one wheel dump with convenient handles.
When the dull broken rock is washed away, the shiny metal is sucked out with a wet shop vac, and chucked in a nearby fire with some limestone. You can dig the metal out of the ashes, knock the slag off and sell it to smiths.
This is mining.
Costs? Practically zero.
Patents pending.
Highest costs, least efficient part of milling is grinding. Only 1% efficient. Find a way to raise that to 10% efficiency (possibly by emphasizing tension breakage) and you would save billions and billions each year in NA alone.
Even explosives are more efficient than grinding. True story.
EC<:-}