For me, there are two interesting points here.
The first is the volume of iron Korea uses annually. The article tells us that another mine in Gangwondo produces 455,000 tons and that is 1 percent of Korea's total demand. I have nothing to compare that to, but it seems a huge number.
The second point is described in the Chosun Ilbo. their article seems to be describing the same mine - how many closed iron mines that will soon re-open can there be in Yangyang- but also goes into detail about rare earth deposits located there.
Due to a hike in the price of iron ore in recent months, the Korea Resources Corporation decided to redevelop the mine that had been shut down in 1995 and found deposits of lanthanum and cerium. Because the mine is in the mountains more than 10 km from residential areas, mining can go ahead.
Dr. Sung Yoo-hyun of the corporation's research institute said the deposits found in the early stage seem to be of low quality, but there seems to be a large deposit of high-quality metals to be found when full-scale exploration of the huge mine gets underway." Iron ore and rare earth metals exist in areas where magma erupts to the surface, making it likely that the two coexist.