[El_Phil]

Mining asteroids? *cough* b***ocks *cough*

Sorry about that but I am a minig engineer and the idea is ridiculous. The costs will be brutal, certainly epically in excess of any deposit on earth. Hell getting gold out of seawater would be cheaper.

Assuming dirt cheap space flight and all the other odds and ends to get enough gear to the asteroid, or move the asteroid to your mining site, you face two major problems.

1. Nickel-Iron compounds are very very tough. How on earth are you going to cheaply break them up?
2. So you have your small chunks of nickel-iron. How do you get the gold out. Any recovery process relies on communation (breaking down the ore) which as we've established is difficult/expensive and then there's actually getting to the gold.

Now of course the tech. for all this probably will be developed, but frankly my money would be on other planet mining happening. Mercury probably would be the best prospect, lots of solar energy and it's very dense which would suggest lots and lots of heavy metals in the crust.