BHP Billiton and Rio Tinto have raised their bets on global copper demand, approving plans for a $4.5 billion expansion of the massive Escondida mine in Chile, while BHP plans to reopen a U.S. copper mine idled three years ago.
See http://www.mineweb.com/mineweb/view/mineweb/en/page36?oid=145332&sn=Detail&pid=92730.