U.S. Congress approves land swap for Rio-BHP copper mine in Arizona
December 12, 2014 at 17:16 PM EST
WASHINGTON/TORONTO, Dec 12 (Reuters) - The U.S. Congress has cleared the way for global miners Rio Tinto and BHP Billiton to swap land with the government, which will allow them to build a long-delayed $6 billion copper mine in Arizona.