(Corrects the year when the smelter will start operations in third paragraph)SEOUL, Dec 15 : Korea Zinc said on Monday that it plans to build a smelter to produce key metals and minerals in the United States in a project that would cost $7.4 billion.     Korea Zinc said the U.S. government asked

SEOUL, Dec 15 : Korea Zinc said on Monday that it plans to build a smelter to produce key metals and minerals in the United States in a project that would cost $7.4 billion. Korea Zinc said the U.S. government asked the company to build the facilities, to respond to the expansion of global supply chain ri