US3919058A - Aluminum furnace charging methods - Google Patents

Aluminum furnace charging methods Download PDF

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Publication number
US3919058A
US3919058A US469701A US46970174A US3919058A US 3919058 A US3919058 A US 3919058A US 469701 A US469701 A US 469701A US 46970174 A US46970174 A US 46970174A US 3919058 A US3919058 A US 3919058A
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United States
Prior art keywords
crust
anode
aluminum oxide
electrolyte
bath
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Expired - Lifetime
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US469701A
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English (en)
Inventor
Torsten Goran Emil Waenerlund
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Granges Essem AB
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Granges Essem AB
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Publication date
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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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Definitions

  • the present invention relates to a method of charging electrolysis smelting furnaces intended for the manufacture of aluminium and being of the type which comprise a vessel which forms the furnace cathode and which contains a molten bath comprising aluminium, formed by the electrolysis of aluminium oxide, and a molten electrolyte, such as cryolite, which has aluminium oxide dissolved therein, and a crust of solidified electrolyte and aluminium oxide located on top of said bath, and which furnaces further comprise at least one anode construction which is movable at least vertically and which has an electrode immersed in said electrolyte.
  • the invention is primarily intended for application with furnaces operating with anodes of the Soderberg type and having vertical electrical contact bolts, although it can also be applied in conjunction with electrolysis furnaces which use other types of anodes, such as pre-baked anode blocks.
  • An object of the invention is to provide a novel and useful method of automatically charging aluminium oxide to the furnace, without the use of expensive or complicated auxiliary equipment.
  • FIG. 1 is a schematic vertical sectional view through an electrolysis smelting furnace suitable for carrying out the method of the invention
  • FIG. 2 is a side view of a part of the furnace shown in FIG. 1.
  • a trough-shaped vessel which contains a molten bath comprising a lower layer 11 consisting of aluminium, obtained by the electrolysis of aluminium oxide, and an upper layer 12 consisting of an aluminium oxide containing electrolyte.
  • the electrolyte may comprise substantially molten cryolite.
  • electrical contact devices not shown
  • a current source not shown
  • Electrode body 14 Immersed in the molten aluminium oxide containing electrolyte is an electrode body 14 enclosed in a casing 13.
  • the electrode body which is consumed during the electrolysis, is of the Soderberg type and is replenished in a conventional manner during the course of the electrolysis, by supplying fresh electrode mass thereto from above.
  • the electrode body 14 is supported by a plurality of contact bolts 15 which are arranged in said body and which are suspended from an anode beam 16 connected to the positive pole of a current source (not shown).
  • the casing 13 is also suspended from the anode beam, by means of jacks or adjustable holder de vices l7.
  • Extending around the casing 13 is a gas collecting hood 18 for collecting the gases formed during the process of electrolysis.
  • the hood 18 is connected by means of a line (not shown) to a suitable device for recovering or combusting the gases collected in said hood.
  • the anode l3, 14, the contact bolts 15, the anode beam 16, the holders l7 and the hood 18 together form a coherent anode construction which is vertically adjustably supported at the ends of the beam 16 by means of the schematically illustrated jacks 19 which in turn are supported by a frame 20, which is only partially illustrated.
  • the anode construction 13-18 carries two magazines 2] which are capable of storing sufficient aluminium oxide to satisfy the requirements of the electrolysis furnace for a considerable period of time, for example 24 hours.
  • the magazines 21 are carried by the casing 13, although said magazines could also be carried by some other suitable part of the anode construction or by the frame 20 or by some other appropriate stationary supporting device.
  • the pipes 22 are arranged to discharge at such a distance above the crust and the horizontal extension of the discharge orifices of the pipes 22 along the adjacent side of the anode construction is of such magnitude and/or the pipes 22 are arranged in such close relationship relative to each other that overlapping fall cones are formed at the exit orifices of said pipes so that the crust 23 along said anode construction side is constantly kept covered with a supply 24 of aluminium oxide.
  • overlapping fall cones are seen in FIG. 2.
  • the anode construction 13-18 is raised and low ered by means of the jacks 19 whilst maintaining the contact between the electrolyte l2 and the enclosed electrode body 14.
  • the crust 23 is broken adjacent the hood 18, so that part of the crust together with part of the aluminium oxide resting on the crust passes down into the electrolyte l2 and is dissolved therein, thereby to raise the aluminium oxide content of the electrolyte.
  • charging of the furnace is effected suitably at such close time intervals and the quantities of aluminium oxide charged are of such insignificant magnitude that the content of dissolved aluminium oxide of the electrolyte 12 is maintained at a relatively constant level favourable to the electrolysis process, whereby the maximum current yield can be obtained.
  • the anode construction is provided with an additional array of jacks in order to hold the anode casing still when making regulations to the funace, these additional jacks must be disengaged or the like when charging the furnace in accordance with the invention.
  • the total extent of vertical movement executed by the anode construction during a furnace charging sequence is dependent on the depth to which the anode is immersed in the molten electrolyte and normally reaches to between and mm.
  • the magazines 21 or pipes 22 should be provided with means which enable communication between the magazines 21 and the stores 24 to be temporarily broken when so desired.
  • the charging movement of the anode construction l3-l8 can be obtained either by manually controlling the drive means of the jacks 19 or automatically by means of a programmed mechanism or data machine, for example arranged to initiate said charging movement at specific intervals in time.
  • the method of the present invention requires but the minimum of manual superintendance. since it is only necessary to fill the magazines 21 a few times each day and since the correct amount of aluminium oxide is constantly and automatically maintained on the crust 23. This affords a considerable saving in manpower, and owing to the free flow of aluminum oxide from the magazines 2] environmental problems in the form of leaking gas are avoided.
  • the magazines constitute at 4 the same time a protection against heat radiation from the anode l3, 14, thereby making any work which must be carried out in the vicinity of the furnace more comfortable.
  • a method of charging electrolysis smelting furnaces for the manufacture of aluminum and being of the type which comprise a vessel which forms the furnace cathode and which contains a molten bath comprising aluminum, formed by the electrolysis of aluminum oxide and a molten electrolyte, which has aluminum oxide dissolved therein, and a crust of solidified electrolyte and aluminum oxide located on top of said bath, and which furnaces further comprise at least one anode construction which is movable vertically and having an electrode immersed in said electrolyte, and an aluminum oxide magazine having at least one supply line depending therefrom and discharging a substantially predetermined distance above the crust for supplying aluminum oxide to the crust along the length of at least one side of the anode construction, aluminum oxide being fed to the molten bath by partially breaking the crust by raising and lowering the anode construction whilst maintaining contact between said electrode and the molten electrolyte, the improvement comprising maintaining a constant free communication between said magazine and said crust during normal operation of the furnace thereby to provide an automatic flow of aluminum
  • anode construction comprises a gas collecting hood extending along said anode construction side, characterized in that aluminium oxide is charged to the furnace externally of the gas collecting hood.

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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)
  • Electrolytic Production Of Metals (AREA)
US469701A 1973-05-14 1974-05-13 Aluminum furnace charging methods Expired - Lifetime US3919058A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE7306755A SE373163B (it) 1973-05-14 1973-05-14

Publications (1)

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US3919058A true US3919058A (en) 1975-11-11

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US (1) US3919058A (it)
FR (1) FR2229778B3 (it)
NO (1) NO132437C (it)
SE (1) SE373163B (it)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5579889A (en) * 1978-12-11 1980-06-16 Mitsubishi Keikinzoku Kogyo Kk Alumina supply apparatus
US4302302A (en) * 1980-05-09 1981-11-24 Mitsubishi Light Metal Ind., Ltd. Method of feeding alumina to an aluminium electrolytic cell and apparatus therefor
US4342637A (en) * 1979-07-30 1982-08-03 Metallurgical, Inc. Composite anode for the electrolytic deposition of aluminum
CN100523307C (zh) * 2006-07-06 2009-08-05 中国铝业股份有限公司 一种铝电解槽装炉方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3632488A (en) * 1969-01-23 1972-01-04 Reynolds Metals Co Reduction cell control system
US3664935A (en) * 1971-01-21 1972-05-23 Arthur F Johnson Effluent filtering process and apparatus for aluminum reduction cell
US3681229A (en) * 1970-07-17 1972-08-01 Aluminum Co Of America Alumina feeder

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3632488A (en) * 1969-01-23 1972-01-04 Reynolds Metals Co Reduction cell control system
US3681229A (en) * 1970-07-17 1972-08-01 Aluminum Co Of America Alumina feeder
US3664935A (en) * 1971-01-21 1972-05-23 Arthur F Johnson Effluent filtering process and apparatus for aluminum reduction cell

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5579889A (en) * 1978-12-11 1980-06-16 Mitsubishi Keikinzoku Kogyo Kk Alumina supply apparatus
JPS5744756B2 (it) * 1978-12-11 1982-09-22
US4342637A (en) * 1979-07-30 1982-08-03 Metallurgical, Inc. Composite anode for the electrolytic deposition of aluminum
US4302302A (en) * 1980-05-09 1981-11-24 Mitsubishi Light Metal Ind., Ltd. Method of feeding alumina to an aluminium electrolytic cell and apparatus therefor
CN100523307C (zh) * 2006-07-06 2009-08-05 中国铝业股份有限公司 一种铝电解槽装炉方法

Also Published As

Publication number Publication date
NO132437B (it) 1975-08-04
NO741714L (no) 1974-11-15
SE373163B (it) 1975-01-27
FR2229778B3 (it) 1978-05-12
FR2229778A1 (it) 1974-12-13
NO132437C (no) 1979-11-15

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