Ah yea, it sounds great until you get the feds into the act. Not to mention the EPA! Forget it Jake, it’s planet earth and it’s bureaucrats and despots that inhabit it that is the greatest obstacle.
I believe Fedgov is a signator to a treaty that makes all resources in space the "common property of all mankind", thus not exploitable by mere private entities.Don't know if that treaty ever made it through Senate ratification or not, though actual Constitutional procedure doesn't seem to matter any more.
Personally, if it were me, I'd mine whatever I want and when the UN asks for its cut, I'd say "sure" and drop several tons of iron from space stright down to the UN building in NY.
Space mining will eventually bring untold riches to us all. A single decent-sized asteroid could well contain more iron and other metals than have mined in the history of mankind, and it's all available with zero "environmental impact".