Two major copper smelters in Japan have been shut down due to power cuts, following the recent earthquake.
Pan Pacific Copper, which is partially owned by JX Nippon Mining & Metals, has halted operations at its Hitachi refinery works.
Mitsubishi Materials has also ceased its smelter operations at the Onahama copper smelter that produces 30,0000t of copper annually, due to a lack of electricity.
The earthquake and subsequent tsunami hit north-eastern Japan on Friday 11 March.
Japan's refined copper output stood at about 1.52 million tons in 2010, which was about 7% of the global output.