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The Climax mine, located in Climax, Colorado, United States, is a major molybdenum mine in Lake and Summit counties, Colorado. Shipments from the mine began in 1915. At its highest output, the Climax mine was the largest molybdenum mine in the world, and for many years it supplied three-fourths of the world's supply of molybdenum. After a long shutdown, the Climax mine has reopened and resumed shipment of molybdenum on May 10, 2012. The mine is owned by Climax Molybdenum Company, a subsidiary of Freeport-McMoRan. ==History== The prospector Charles Senter discovered and claimed the outcropping of molybdenite (molybdenum sulfide) veins in 1879, during the Leadville, Colorado Silver Boom, but he had no idea what the mineral he found was. Senter quickly determined that the rock contained no gold or silver, but he kept the claims anyway. The following year he settled down to live with his Ute Indian wife in a cabin a few miles north, and he made a living working a nearby gold placer. Each year he faithfully did the assessment work required to keep his lode claims, convinced that his mystery mineral must be worth something and in 1918 Senter finally received $40,000 for his mining claims and "settled into a comfortable retirement in Denver." 〔Steve Voynick (1996) "Climax", Mountain Press Publishing Company, September 1997.〕 Although Senter finally found a chemist who identified the gray mineral as containing molybdenum in 1895, at the time there was virtually no market for the metal. When steelmakers found the usefulness of molybdenum as an alloy in producing very hard steel, the first ore shipments from the deposit began in 1915, and the Climax mine began full production in 1914. The main ore bearing area was Bartlett Mountain, which was mined out during the early mining. But the demand for molybdenum fell drastically at the end of World War I, and the Climax mine shut down in 1919.〔Stewart R. Wallace and others (1968) ''Multiple Intrusion and Mineralization at Climax, Colorado'', in ''Ore Deposits in the United States 1933/1967'', v.1, New York: American Institute of Mining Engineers, p.605-664.〕 Molybdenum later found use in the metal alloys for the turbines of jet engines. Molybdenum is an important metal used in industrial work to increase the resistance of steel because of its much higher melting point compared to that of iron.〔Freeport-McMoRan Copper & Gold Inc. 2004-2001. “What is molybdenum”. Web.〕 Molybdenum was also used to fight weather erosion, friction, and chemical exposure of industrial equipment.〔Paul B. Coffman (1937) The Rise of a New Metal: The Growth and Success of the Climax Molybdenum Company. The Journal of Business of the University of Chicago. Vol. 10, No 1. Jan. 1937 pp. 35-40〕 The extraction of molybdenite hit its highest rate during World War I, it is believed, when the army realized that the Germans were using molybdenum as an alloy to strengthen and increase the durability of their weapons and tanks.〔Gillian Klucas(2004) ''Leadville: the struggle to revive an American town''. Washington, DC : Island Press. Print. 〕 The Climax Molybdenum Company re-opened the mine in 1924, and it operated the mine nearly continuously until the 1980s. The mine was shut down between 1995 and 2012, awaiting higher molybdenum prices. The mine's current owner, Freeport-McMoRan Copper & Gold, continues to work on environmental cleanup of past operations while holding the mine ready in the event of market changes. In December 2007 Freeport-McMoRan reported that it planned to reopen the Climax mine and that production should start in 2010. An initial $500-million project involves the restart of open-pit mining and construction of state-of-the-art milling facilities.〔Marcia Martinek, ''It's a go; Climax Mine will reopen'', Leadville Herald Democrat, 6 Dec. 2007, p.1, c.1.〕 The company stated that the Climax mine has "... the largest, highest-grade and lowest-cost molybdenum ore body in the world.".〔Steve Raabe, ''Leadville's hopes raised for Climax mine opening'', Denver Post, 25 Oct. 2007, p.C1, c.1.〕 The remaining ore reserves are estimated to contain about 500 million pounds of molybdenum, contained in ore at an average molybdenum percentage of 0.165%. Production was expected to be about 30 million pounds per year, starting in 2010.〔"Freeport to proceed with Climax moly mine restart," ''Engineering & Mining Journal'', Dec. 2007, p.8-10.〕 Due to lower molybdenum prices, Freeport-McMoRan announced in November 2008 that it was deferring the plan to reopen the Climax mine.〔Andy Vuong, "Climax redux cut short," ''Denver Post'', 11 Nov. 2008, p.5B c.1.〕〔("Restart of Climax Mine Near Leadville Postponed" ), November 10th, 2008〕 At the time, the company had spent about preparing for a restart of the mine, with an estimated more needed to complete the capital improvements and reopen.〔 In May 2012, following a 17-year shutdown, the Climax mine reopened and resumed shipment of molybdenum.〔(), Summit Daily News (Frisco, CO), May 10, 2012〕 〔(), Climax Molybdenum Press Release〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Climax mine」の詳細全文を読む スポンサード リンク
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