Simandou, a 110-kilometer range of hills deep in the hinterland of Guinea in Western Africa, boasts the world's largest untapped iron ore reserves. They could reshape the global supply chain of the critical ingredient of steel, the world's second-most traded commodity behind crude oil.
The rich assets have lured global investors, especially from ore-thirsty China, but pulling the mineral out of the ground has turned out to be a thorny challenge with entangled interests and risks stemming from technical, capital and political uncertainties.
