US3006825A - Method of charging aluminium furnaces - Google Patents

Method of charging aluminium furnaces Download PDF

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Publication number
US3006825A
US3006825A US781405A US78140558A US3006825A US 3006825 A US3006825 A US 3006825A US 781405 A US781405 A US 781405A US 78140558 A US78140558 A US 78140558A US 3006825 A US3006825 A US 3006825A
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United States
Prior art keywords
furnace
alumina
charging
gases
gas
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Expired - Lifetime
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US781405A
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English (en)
Inventor
Sem Mathias Ovrom
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Elektrokemisk AS
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Elektrokemisk AS
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
    • C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
    • C25C3/14—Devices for feeding or crust breaking

Definitions

  • the present invention has for its object a method for charging furnaces for melt-electrolytic production of aluminium, especially such furnaces where the current is supplied to the anode by means of vertical contact rods which at the same time serve as suspension of the anode.
  • furnaces are usually provided with an arrangement for collection of the furnace gases in concentrated for-m. This arrangement usually consists of a ring surrounding the lower part of the anode near the bath surface.
  • the content of A1 0 in the bath will be reduced and when a certain limit has been reached, usually about 1.5%, the bath tension will rise. This is usually indicated by a bell which sounds or a lamp which lights up.
  • the phenomenon is called anodic effect or lighting of the furnace. Wh n the anodic effect takes place new A1 0 must be supplied to the furnace. This is usually done by breaking down the crust at one or more places at the long sides of the furnace and then introducing A1 0 through these openings. When the crust is broken down in this way, some of the furnace gas will of course escape through the openings and get lost. This gas is rich in both CO and fluorine compounds, and in a large furnace hall where many furnaces operate in series considerable values will get lost both as COgas and as valuable fluorine compounds. Furthermore the fluorine gases are detrimental to the neighbouring vegetation.
  • the furnace gas is combusted in a burner in connection with the furnace as shown for example in Jouannet Patent 2,526,875, and then led to a washing device where its content of fluorine can be recotered in the form of cryolite or the like.
  • the cryolite is then retur ed to the furnace.
  • the fluorine content is recovered, but the heat of combustion of the CO-gas is lost.
  • the inventor has found that this heat of combustion generated in the burner can be utilised by directly after combustion leading the gases in counter current to A1 0 which is supplied to the furnace through a hopper which is connected with a feeding device for continuous feeding.
  • A1 0 which is supplied to the furnace through a hopper which is connected with a feeding device for continuous feeding.
  • the oxide is dried and the above described drawback of sticking in the feeding apparatus is avoided and at the same time a certain preheating of the oxide is attained.
  • Warm oxide is also more easily soluble in cryolite than cold oxide.
  • the gas can if desired, be led through a dry cyclone located before the burner.
  • a dry cyclone located before the burner.
  • dust and condensed tar particles will be separated out.
  • Such a cyclone has a very favourable effect as the dust will agglomerate on account of the tar so that the dust particles will ball together and increase in size.
  • the content of F and HP in the gases will also become adsorbed to the surface of the aluminium oxide and at the same time fluorine-containing dust still present will settle.
  • the gas is led through the feeding device and/or the hopper in such a way that at the same time it will transport the oxide forwards towards the furnace. This is attained by leading the gas into the hopper through slots or holes in the inclined side walls of the hopper. If desired one can also use perforated or porous plates in these walls.
  • the gas will then blow through the charge and dry it.
  • the dried oxide will partly become fluidised in the gas current and on account of whirling motion created thereby an intimate contact between gas and charge is obtained which facilitates the adsorption of the fluorine compounds.
  • the gas current can also be used for transport of the oxide from the main storage bin to the hoppers of the individual furnaces.
  • the hoppers should then be so connected that each of them will have an overflow device. When one hopper is full, the excess of oxide will be transported to the next one, etc. in this way all hoppers can always be kept full.
  • Dry and preheated A1 0 is as stated above more easily soluble in the cryol-ite melt than moist unheated oxide and has less tendency to form crusts.
  • the danger of the furnace clogging up below the charging device is thereby reduced and a simple mechanical device which presses the charge into the bath will be suflicient.
  • the above described way of adsorption of fluorine makes the complicated arrangements for recovery of fluorine superiluous as the precipitated fluorine will automatically be returned to the furnace. The fluorine losses are very much reduced and the economy of the process improved.
  • the invention is schematically illustrated in the appended drawing which shows a section through a feeding hopper placed on the long side of a furnace close to the anode.
  • the gas current is indicated by arrows.
  • the drawing 1 is the hopper filled with aluminium oxide 2.
  • the combusted furnace gas is led from the burner (not shown on the drawing) through the pipe 3 which is provided with a control valve 4.
  • the hopper 1 has a double bottom and the inner bottom 5 is provided with slots or openings through which the furnace gas can pass. This bottom can also be made of perforated plate.
  • 6 is a feed pipe leading from the hopper to the smelting chamber.
  • the pipe can if desired be provided with a device for controlling the supply of charge.
  • This pipe should also be provided with a control valve 12.
  • the oxide is supplied to the hopper 1 from the hopper of the preceding furnace or from the main storage bin through the pipe 13.
  • furnace gas is used for the transport. it is, however, also possible to employ air pr ssure for such transport.
  • excess oxide is led through the pipe 14 to the hopper of the next furnace.
  • the selective adsorption is of course independent of the charging of the furnace being continuous or batchwise. If the furnace is charged in the usual batchwise way by breaking down the crust when anodic efiect occurs, the furnace gas may simply be led through a container located outside the furnace which contains the alumina to be charged.
  • the method of charging electrolytic aluminum furnaces with alumina which comprises moving such alumina with the aid of gravity over a fluidizing bed toward the furnace, collecting gases from such a furnace, burning the combustible elements of such gases, passing the 20 hot gases from such combustion through the alumina on such fluidizing bed whereby such alumina is rendered more fluid and its flow toward the furnace is assisted and at the same time fluorides of the hot gases are absorbed by the alumina, and introducing such alumina into the furnace whereby charging of the furnace is aided and fluorides are returned to the furnace.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Furnace Details (AREA)
US781405A 1957-12-19 1958-12-18 Method of charging aluminium furnaces Expired - Lifetime US3006825A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NO12653157 1957-12-19

Publications (1)

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US3006825A true US3006825A (en) 1961-10-31

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US781405A Expired - Lifetime US3006825A (en) 1957-12-19 1958-12-18 Method of charging aluminium furnaces

Country Status (6)

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US (1) US3006825A (en:Method)
CH (1) CH366976A (en:Method)
DE (1) DE1089553B (en:Method)
FR (1) FR1211874A (en:Method)
GB (1) GB875794A (en:Method)
SE (1) SE216123C1 (en:Method)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3135672A (en) * 1959-01-16 1964-06-02 Nippon Light Metal Co Method for feeding alumina to electrolytic cell
US3192140A (en) * 1960-06-27 1965-06-29 Montedison Spa Removal, by suction, of anodic gases formed in electrolytic cells employed for aluminum production
US3207681A (en) * 1960-03-19 1965-09-21 Elektrokemisk As Process of exhausting gases from furnaces for production of aluminum by melt-electrolysis
US3216918A (en) * 1959-09-03 1965-11-09 Pechiney Prod Chimiques Sa Machine for picking and distributing aluminum oxide into electrolytic cells
US3322659A (en) * 1964-06-17 1967-05-30 Paquet Jean Louis Treating of electrolytic aluminum reduction cell gases to recover fluorine values
US3664935A (en) * 1971-01-21 1972-05-23 Arthur F Johnson Effluent filtering process and apparatus for aluminum reduction cell
US4016053A (en) * 1975-10-01 1977-04-05 Kaiser Aluminum & Chemical Corporation Feeding particulate matter
US4050999A (en) * 1974-06-26 1977-09-27 R.C.M. Corporation Process for the production and use of activated alumina to produce aluminum
US4111764A (en) * 1977-05-17 1978-09-05 Aluminum Company Of America Method for feeding a subliming material into a liquid
US4321115A (en) * 1979-03-02 1982-03-23 Swiss Aluminium Ltd. Method and device for providing a continuous measured supply of alumina to an electrolytic cell
US4332660A (en) * 1979-09-10 1982-06-01 Swiss Aluminium Ltd. Storage bunker device for feeding electrolytic cell
US4450053A (en) * 1979-08-28 1984-05-22 Swiss Aluminium Ltd. Device for feeding electrolytic cells and method of operating the said device
WO1992006229A1 (en) * 1990-10-05 1992-04-16 Portland Smelter Services Pty. Ltd. Method and apparatus for continuous supply of alumina
EP0693578A1 (en) * 1994-06-22 1996-01-24 Norsk Hydro A/S Pulse-operated point feeder
WO2004033761A3 (en) * 2002-07-01 2004-06-24 Storvik As Point feeder and use of point feeder
US20090308721A1 (en) * 2008-06-17 2009-12-17 Mac Valves, Inc. Pneumatic System Electrical Contact Device
US20110008995A1 (en) * 2008-06-17 2011-01-13 Mac Valves, Inc. Pneumatic System Electrical Contact Device
US20180030605A1 (en) * 2014-07-15 2018-02-01 United Company RUSAL Engineering and Technology Ce ntre, LLC Device for controlled feeding an electrolytic cell for producing aluminum (variants)
US10633752B2 (en) * 2016-03-30 2020-04-28 Elysis Limited Partnership Feeding systems and methods of using feeding systems

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58501951A (ja) * 1981-11-04 1983-11-17 エイチビ−−コンサルタント　ラドギバンデ　インゲニヨレル　アクテイエボラ−グ アルミニウム溶融工場における熱回収

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2593741A (en) * 1943-07-17 1952-04-22 Ferrand Louis Process for the electrolytic production of aluminum
US2713024A (en) * 1959-04-24 1955-07-12 Montedison Spa Process for the continuous feeding of electrolytic aluminum cells
US2859160A (en) * 1954-11-05 1958-11-04 Ver Aluminium Werke Ag Fa Electrolytic cell for producing aluminum

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2593741A (en) * 1943-07-17 1952-04-22 Ferrand Louis Process for the electrolytic production of aluminum
US2859160A (en) * 1954-11-05 1958-11-04 Ver Aluminium Werke Ag Fa Electrolytic cell for producing aluminum
US2713024A (en) * 1959-04-24 1955-07-12 Montedison Spa Process for the continuous feeding of electrolytic aluminum cells

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3135672A (en) * 1959-01-16 1964-06-02 Nippon Light Metal Co Method for feeding alumina to electrolytic cell
US3216918A (en) * 1959-09-03 1965-11-09 Pechiney Prod Chimiques Sa Machine for picking and distributing aluminum oxide into electrolytic cells
US3207681A (en) * 1960-03-19 1965-09-21 Elektrokemisk As Process of exhausting gases from furnaces for production of aluminum by melt-electrolysis
US3192140A (en) * 1960-06-27 1965-06-29 Montedison Spa Removal, by suction, of anodic gases formed in electrolytic cells employed for aluminum production
US3322659A (en) * 1964-06-17 1967-05-30 Paquet Jean Louis Treating of electrolytic aluminum reduction cell gases to recover fluorine values
US3664935A (en) * 1971-01-21 1972-05-23 Arthur F Johnson Effluent filtering process and apparatus for aluminum reduction cell
US4050999A (en) * 1974-06-26 1977-09-27 R.C.M. Corporation Process for the production and use of activated alumina to produce aluminum
US4016053A (en) * 1975-10-01 1977-04-05 Kaiser Aluminum & Chemical Corporation Feeding particulate matter
US4111764A (en) * 1977-05-17 1978-09-05 Aluminum Company Of America Method for feeding a subliming material into a liquid
US4321115A (en) * 1979-03-02 1982-03-23 Swiss Aluminium Ltd. Method and device for providing a continuous measured supply of alumina to an electrolytic cell
US4450053A (en) * 1979-08-28 1984-05-22 Swiss Aluminium Ltd. Device for feeding electrolytic cells and method of operating the said device
US4332660A (en) * 1979-09-10 1982-06-01 Swiss Aluminium Ltd. Storage bunker device for feeding electrolytic cell
WO1992006229A1 (en) * 1990-10-05 1992-04-16 Portland Smelter Services Pty. Ltd. Method and apparatus for continuous supply of alumina
EP0693578A1 (en) * 1994-06-22 1996-01-24 Norsk Hydro A/S Pulse-operated point feeder
WO2004033761A3 (en) * 2002-07-01 2004-06-24 Storvik As Point feeder and use of point feeder
US20090308721A1 (en) * 2008-06-17 2009-12-17 Mac Valves, Inc. Pneumatic System Electrical Contact Device
US20110008995A1 (en) * 2008-06-17 2011-01-13 Mac Valves, Inc. Pneumatic System Electrical Contact Device
US7915550B2 (en) 2008-06-17 2011-03-29 Mac Valves, Inc. Pneumatic system electrical contact device
US8367953B2 (en) 2008-06-17 2013-02-05 Mac Valves, Inc. Pneumatic system electrical contact device
US20180030605A1 (en) * 2014-07-15 2018-02-01 United Company RUSAL Engineering and Technology Ce ntre, LLC Device for controlled feeding an electrolytic cell for producing aluminum (variants)
US11028494B2 (en) * 2014-07-15 2021-06-08 United Company RUSAL Engineering and Technology Centre LLC Device for controlled feeding an electrolytic cell for producing aluminum (variants)
US10633752B2 (en) * 2016-03-30 2020-04-28 Elysis Limited Partnership Feeding systems and methods of using feeding systems

Also Published As

Publication number Publication date
DE1089553B (de) 1960-09-22
CH366976A (de) 1963-01-31
FR1211874A (fr) 1960-03-18
SE216123C1 (en:Method) 1967-10-17
GB875794A (en) 1961-08-23

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