Copper Heads for Longest Winning Streak since July on Shrinking Supplies

SYDNEY, Dec.&nbsp;6 -- Rio Tinto and Chinalco will form a joint venture to explore mineral deposits in China with Rio holding 49 percent and Chinalco the rest.
The joint venture would come into operation in the first half of next year and will start with between 3 and 5 large exploration projects, Rio said in a statement.
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