Electrowinning (sometimes abbreviated to EW, also known as Electrorefining) the electrodeposition of metals from their ores that have been put in solution or liquefied. Electrowinning is electroplating writ large and is an important technique that allows purification of non-ferrous metals in an economical and straightforward step. Electroplating is the the coating of an electrically conductive item with a layer of metal using electrical current. ... Hot metal work from a blacksmith In chemistry, a metal (Greek: Metallon) is an element that readily forms ions (cations) and has metallic bonds, and metals are sometimes described as a lattice of positive ions (cations) in a cloud of electrons. ... An ore is a mineral deposit containing a metal or other valuable resource in economically viable concentrations. ... Jump to: navigation, search Electroplating is the coating of an electrically conductive item with a layer of metal using electrical current. ... Non-ferrous metals are metals that do not contain iron. ...

History

It is the oldest industrial electrolytic process. Electrorefining was first demonstrated experimentally by von Leuchtenberg in 1847. Later, the English chemist Humphrey Davy, obtained sodium metal in elemental form for the first time in 1807 by the electrolysis of molten sodium hydroxide. It was James Elkington, however who patented the commercial process in 1865 and opened the first successful plant in Pembrey, Wales in 1869. An electrolyte is a substance which dissociates free ions when dissolved (or molten), to produce an electrically conductive medium. ... 1847 was a common year starting on Friday (see link for calendar). ... Humphry Davy Sir Humphry Davy (December 17, 1778 - May 29, 1829), often incorrectly spelled Humphrey, was an Cornish chemist. ... Jump to: navigation, search General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Atomic mass 22. ... Jump to: navigation, search Look up element on Wiktionary, the free dictionary. ... 1807 was a common year starting on Thursday (see link for calendar). ... I LOVE CHAMI In chemistry and manufacturing, electrolysis is a method of separating bonded elements and compounds by passing an electric current through them. ... Jump to: navigation, search Flash point non flammable Supplementary data page Structure and properties n, εr, etc. ... Jump to: navigation, search 1865 is a common year starting on Sunday. ... Jump to: navigation, search 1869 is a common year starting on Friday (link will take you to calendar). ...

Applications

The most common electrowon metals are lead, copper, gold, silver, zinc, aluminum, chromium, cobalt, manganese, and the rare-earth, alkali, and alkaline metals. For aluminum, this is the only practically used production process. Several industrially important active metals (which react strongly with water) are produced commercially by electrolysis of their pyrochemical molten salts. Experiments with using electrorefining to process spent nuclear fuel have been carried out. Electrorefining could separate heavy metals such as plutonium, cesium, and strontium from the less-toxic bulk of uranium. Many electroextraction systems are also avalable to remove toxic (and sometimes valuable) metals from industral wastestreams. General Name, Symbol, Number lead, Pb, 82 Chemical series poor metals Group, Period, Block 14, 6, p Appearance bluish white Atomic mass 207. ... General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance copper, metallic Atomic mass 63. ... General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ... General Name, Symbol, Number silver, Ag, 47 Chemical series Transition metals Group, Period, Block 11, 5, d Density, Hardness 10490 kg/m3, 2. ... Jump to: navigation, search General Name, Symbol, Number zinc, Zn, 30 Chemical series transition metals Group, Period, Block 12, 4, d Appearance bluish pale gray Atomic mass 65. ... Aluminum is a soft and lightweight metal with a dull silvery appearance, due to a thin layer of oxidation that forms quickly when it is exposed to air. ... General Name, Symbol, Number chromium, Cr, 24 Chemical series transition metals Group, Period, Block 6, 4, d Appearance silvery metallic Atomic mass 51. ... This article is on the chemical element. ... Jump to: navigation, search General Name, Symbol, Number manganese, Mn, 25 Chemical series transition metals Group, Period, Block 7, 4, d Appearance silvery metallic Atomic mass 54. ... A rare earth is an oxide of a rare earth element. ... For the battery, see alkaline battery The word alkali can mean:- In chemistry, an alkali is a specific type of base, formed as a carbonate, hydroxide or other ionic salt of an alkali metal or alkali earth metal element. ... The alkali metals are a chemical series. ... Aluminum is a soft and lightweight metal with a dull silvery appearance, due to a thin layer of oxidation that forms quickly when it is exposed to air. ... General Name, Symbol, Number plutonium, Pu, 94 Chemical series actinides Group, Period, Block ?, 7, f Appearance silvery white Atomic mass (244) g/mol Electron configuration [Rn] 5f6 7s2 Electrons per shell 2, 8, 18, 32, 24, 8, 2 Physical properties Phase solid Density (near r. ... General Name, Symbol, Number Caesium, Cs, 55 Series Alkali metals Group, Period, Block 1(IA), 6, s Density, Hardness 1879 kg/m3, 0. ... General Name, Symbol, Number strontium, Sr, 38 Chemical series alkaline earth metals Group, Period, Block 2, 5, s Appearance silvery white metallic Atomic mass 87. ... Jump to: navigation, search General Name, Symbol, Number uranium, U, 92 Chemical series actinides Group, Period, Block ?, 7, f Appearance silvery gray metallic Atomic mass 238. ...

Process

Most metals occur in nature in oxidized form in their ores and thus must be reduced to their metalic forms. The ore is dissolved following some preprocessing in an aqueous electrolyte or in a molten salt and the resulting solution is electrolyzed. The metal is deposited on the cathode (either in solid or in liquid form), while the anodic reaction is usually oxygen evolution. Several metals are naturally present as metal sulfides; these include copper, lead, molybdenum, cadmium, nickel, silver, cobalt and zinc. In addition, gold and platinum group metals are associated with sulfidic base metal ores. Most metal sulfides or their salts, are electrically conductive and this allows electrochemical redox reactions to efficiently occur in the molten state or in aqueous solutions. Drinking water This article focuses on water as we experience it every day. ... An electrolyte is a substance which dissociates free ions when dissolved (or molten), to produce an electrically conductive medium. ... Jump to: navigation, search In chemistry, salt is a term used for ionic compounds composed of positively charged cations and negatively charged anions, so that the product is neutral and without a net charge. ... Diagram of a copper cathode in a Daniells cell. ... Diagram of a zinc anode An anode (from the Greek άνοδος = going up) is the positive electrode in an electrolytic system or circuit. ... Jump to: navigation, search General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... In chemistry, a sulfide (sulphide in British and Canadian English) is a chemical compound or combination of sulfur with an oxidation number of -2, with another chemical element or a radical thereof. ... General Name, Symbol, Number molybdenum, Mo, 42 Chemical series transition metals Group, Period, Block 6, 5, d Appearance gray metallic Atomic mass 95. ... General Name, Symbol, Number cadmium, Cd, 48 Chemical series transition metals Group, Period, Block 12, 5, d Appearance silvery gray metallic Atomic mass 112. ... General Name, Symbol, Number nickel, Ni, 28 Chemical series transition metals Group, Period, Block 10, 4, d Appearance lustrous, metallic Atomic mass 58. ... Jump to: navigation, search General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ... Jump to: navigation, search General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Atomic mass 196. ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Atomic mass 195. ... The most fundamental reactions in chemistry are the redox processes. ...

Some metals, including arsenic and nickel do not electrolyze out but remain in the electrolyte solution, these are then reduced by chemical reactons to refine the metal. Also after the process for the original target metal is complete, other metals which are reduced but not deposited at the cathode sink to the bottom of the electrolytic cell, where they form a substance refered to as anode sludge or anode slime. The metals in this sludge can be removed by standard pryrorefining methods. Jump to: navigation, search General Name, Symbol, Number arsenic, As, 33 Chemical series metalloids Group, Period, Block 15, 4, p Appearance metallic gray Atomic mass 74. ...

Because metal deposition rates are related to available surface area, maintaining properly working cathodes is important. Two cathode types exist, flat-plate and reticulated cathodes, each with its own advantages. Flat-plate cathodes can be cleaned and reused, and plated metals recovered. Reticulated cathodes have a much higher deposition rate, compared to flat-plate cathodes. However, they are not reusable and must be sent off for recycling.

References

• Electrometallurgy
• Recent Development and Trends in Electrorefining
• The Argonne process could recover useful uranium from spent fuel
• High Throughput Electrorefining of Uranium in Pyro-reprocessing
• Aluminum Electrowinning and Electrorefining