"Generally speaking, the deeper mining more expensive. Our mines getting pretty deep now. They approach 1500 meters and it presents challenges related to ground support, logistics in mines that is, how to transport both the masses and the people in the mine in the most efficient manner. And it also brings challenges in terms of security", says Jenny Greberg, assistant professor at Luleå University.
[http://sverigesradio.se/sida/artikel.aspx?programid=83&artikel=6515305]
