Metal ore mining in Europe Mineral Processing. Kiruna (Fig. 4) is the largest, most famous and at the same time northernmost mine. The ore body in Kiruna is a massive block of highgrade magnetite ore, 4 km long, 80 m wide and extending over a depth of 2 km. Fig. 5 shows the proven existing reserves of iron ore at the 4 LKAB mines, as well as the iron grades of the ores in the reserves.