A huge iron-ore rail and port project has been launched in Guinea, in West Africa, by a consortium including Rio Tinto and several investment companies, including five from China. The consortium is building a 650-km railway, the “Trans-Guinean Railway,” which will link the huge Simandou iron ore deposits to a port to be built at Matakog, an island near the Sierra Leone border. The cost of the infrastructure is expected to be in the region of $17 billion, an expense the consortium justifies by the size and purity of the Simandou reserves, which Rio Tinto says contain the world’s largest remaining untapped reserve of high-grade iron ore, estimated at over 2 billion tons.