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Electrowinning, also called electroextraction, is the electrodeposition of metals from their ores that have been put in solution via a process commonly referred to as leaching. Electrorefining uses a similar process to remove impurities from a metal. Both processes use electroplating on a large scale and are important techniques for the economical and straightforward purification of non-ferrous metals. The resulting metals are said to be ''electrowon''. In electrowinning, a current is passed from an inert anode through a liquid ''leach'' solution containing the metal so that the metal is extracted as it is deposited in an electroplating process onto the cathode. In electrorefining, the anodes consist of unrefined impure metal, and as the current passes through the acidic electrolyte the anodes are corroded into the solution so that the electroplating process deposits refined pure metal onto the cathodes.〔 pp 142-143〕 == History == Electrowinning is the oldest industrial electrolytic process. The English chemist Humphry Davy obtained sodium metal in elemental form for the first time in 1807 by the electrolysis of molten sodium hydroxide. Electrorefining of copper was first demonstrated experimentally by Maximilian, Duke of Leuchtenberg in 1847.〔Alexander Watt, (''Electro-Deposition a Practical Treatise'' ), Read Books (2008), p. 395. ISBN 1-4437-6683-6〕 James Elkington patented the commercial process in 1865 and opened the first successful plant in Pembrey, Wales in 1870.〔John Baker Cannington Kershaw, (Electro-Metallurgy ), BiblioBazaar, LLC, 2008. ISBN 0-559-68189-5〕 The first commercial plant in the United States was the Balbach and Sons Refining and Smelting Company in Newark, New Jersey in 1883. 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「Electrowinning」の詳細全文を読む スポンサード リンク
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