 New resources were exploited, especially copper mining in Katanga province.The Belgian-owned Union minière du Haut-Katanga, which would come to dominate copper mining, used a direct rail line to the sea at Beira.World War I increased demand for copper, and production soared from 997 tons in 1911 to 27,462 tons in 1917, then fell off to 19,000 tons in 1920.