"It will never be a public city."
Crazytrade, never say never. While not a city there will likely be a town built right in or on the perifary of the Ring.
I would like to see "Richard's Town" or city as it's name (am ok with Nemis but Richard's sounds better to my ear).

As you say it is a huge area. The present proposed mine sites are just the tip of the potential ice berg that will exist.
People that work at the mines and those servicing the workers will have to live within easy distance. So homes, motels, McDonalds, schools and stores will be built in the area. There is no escaping that. Just look at Edmonton or Yellowknife.
While it will not be thousands of square kilometers 'destroyed' (actually converted from forest and muskeg to cement and pavement) but it will be a few to perehaps a few tens.
I suspect, more nature will be destroyed by the all year road, rail and power lines. But that is progress. We make trade offs and live with them. Just look at how much forests were converted by the invasion of Europeans onto the N. American continent. Some how I do not see much complaining about that, at least not by the Europeans.
Same will be with the Ring.