[bsder]

Why? The asteroids aren't really composed of anything that useful.

In addition, the total mass of the asteroid belt is something like 4% of the moon's (and half of that mass is in the 4 largest asteroids). You would be better off just mining the moon.

[trukterious]

Apparently there's stuff like gold, iridium, silver, osmium, palladium, platinum, rhenium, rhodium, ruthenium and tungsten.

These might be transported back to earth. Plus there's iron, cobalt, manganese, molybdenum, nickel, aluminium, and titanium for construction of moon settlements and factories.

https://en.wikipedia.org/wiki/Asteroid_mining