>>13
The nickel-iron asteroids are basically components of the interior of a planet. That means they are extraordinarily metal-rich. Literally, a nickel-iron meteorite is a
chunk of nickel-iron, as
nickel and
iron, among other trace metals. Hence, a metallic asteroid is literally a miles-wide chunk of metal, with inclusions of rock.
As for purification/smelting, just use the sun. Build a huge mirror (tens of miles wide should be OK) and focus it upon the smelting zone. Free energy. We don't call it a star for nothing!
As for investment, I think you're underestimating the ROI difference between the two. Let me state it again: the Asteroid Belt contains about as much wealth as is represented by 1000 Human civilizations ... at least! With regard to current usage of materials, mining the Asteroid Belt would be like finding an
infinite mine of metals, semi-metals and carbonaceous materials. That means no matter where you go in the Belt, you can just reach out your mining business and start processing terawealth.
Of course, Flatlanders (i.e. Earthbound folk) are literally too stupid to realize all that. THAT's why they prioritize selling fraudulent financial products to fellow Flatlanders. They live at the bottom of a modest gravity well and think nothing for what's at the top of it.