Sydney: Rio Tinto Group, the world’s second-largest exporter of iron ore, has committed $4.2 billion to expanding mines in Australia’s Pilbara and the Simandou operation in Guinea as Chinese demand grows.It will spend $3.7 billion expanding a mine, building new port berths and extending railways in Western Australia as part of a plan to boost output to 353 million metric tons a year by 2015, the London-based company said in a statement today.
