EP4399352A1 - Corps d'électrode d'une électrode pour la production électrolytique d'un métal - Google Patents

Corps d'électrode d'une électrode pour la production électrolytique d'un métal

Info

Publication number
EP4399352A1
EP4399352A1 EP22865972.8A EP22865972A EP4399352A1 EP 4399352 A1 EP4399352 A1 EP 4399352A1 EP 22865972 A EP22865972 A EP 22865972A EP 4399352 A1 EP4399352 A1 EP 4399352A1
Authority
EP
European Patent Office
Prior art keywords
electrode body
electrode
anode
body according
adjacent
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP22865972.8A
Other languages
German (de)
English (en)
Other versions
EP4399352A4 (fr
Inventor
Charles SHANTA
David Prince
Larry MICKELSON
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Elysis LP
Original Assignee
Elysis LP
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Elysis LP filed Critical Elysis LP
Publication of EP4399352A1 publication Critical patent/EP4399352A1/fr
Publication of EP4399352A4 publication Critical patent/EP4399352A4/fr
Pending legal-status Critical Current

Links

Classifications

    • 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
    • C25C3/08—Cell construction, e.g. bottoms, walls, cathodes
    • C25C3/12—Anodes

Definitions

  • the present invention generally relates to an electrode body of an electrode, an electrode comprising the same, and an electrolytic cell comprising the electrode(s) for the production of a metal, such as for instance aluminum.
  • the electrode body is used for the making of an inert or oxygen-evolving anode.
  • Aluminum metal also called aluminium
  • alumina also known as aluminium oxide (IUPAC)
  • IUPAC aluminium oxide
  • the cells have a crucible comprising a steel shell, containing a carbonaceous cathode material, steel current conducting bars and refractory insulation materials capable of containing the electrolyte, at least one cathode and at least one anode.
  • the direct current that passes through the anodes, the electrolyte and cathodes causes alumina redox reactions, and is also capable of maintaining the electrolyte bath at the target operating temperature by the Joule effect.
  • the electrolysis cell is regularly supplied with alumina so as to compensate for consumption of alumina caused by electrolysis reactions.
  • the anodes are made of carbon and are consumed during the electrolytic reaction.
  • the anodes need to be replaced after 3 to 4 weeks. Consumption of the carbonaceous material releases large quantities of carbon dioxide in the atmosphere.
  • a recently developed electrolytic cell for the production of aluminum or other metals may comprise alternating rows of inert anodes and wettable inert cathodes, immersed in a molten salt bath with sufficient ionic conductivity to pass current.
  • a molten salt bath has the capacity to dissolve a compound of the metal to be reduced (e.g. a metal oxide, chloride, carbonate, etc.).
  • Gas, such as oxygen, chlorine or carbon dioxide, is produced on the anodes and exits the cell as an offgas.
  • Liquid metal is produced on the cathodes and runs down in a thin film by gravity into a pool or sump for collection.
  • anode-cathode distance ACD
  • the electrodes also define an overlapping dimension, known as anode-cathode overlap or ACO.
  • ACD anode-cathode overlap
  • the shape and size of inert anodes is related to the desired cell resistance, current density, cathode plate dimensions and cell dimensions.
  • Anodes may be complex to manufacture, in particular when the anode body is made from materials such as a cermet or ceramic for the making of an inert / oxygen evolving anodes.
  • the invention is directed to an electrode body of an electrode for the electrolytic production of a metal, the electrode body extending longitudinally along an axis Z and comprising: a first portion configured for operatively connecting the electrode body to an electrolytic cell; a second portion, opposite the first portion; and a middle portion extending between the first and second portions; wherein the electrode body has a continuous external surface forming a round transition between the second and middle portions, and wherein the continuous external surface of the middle portion defines two opposite outer flat surfaces for facing surfaces of adjacent electrodes when the electrode is plunged into an electrolytic bath of the electrolytic cell comprising said adjacent electrodes.
  • the electrode body as disclosed herein may further comprise a longitudinal inner hole extending from the first portion and configured for receiving, at least in part, an electrode pin for operatively connecting the electrode body to an electric power supply when the electrode pin is installed therein, the longitudinal inner hole and the electrode body then defining a body wall around the longitudinal inner hole.
  • the longitudinal inner hole may define a non-uniform cross-sectional area between the first and second portions of the electrode body. More preferably, the non-uniform cross-sectional area of the inner hole adjacent the first portion may be larger than the non-uniform cross-sectional area adjacent the middle and/or second portions.
  • the non-uniform cross-sectional area of the inner hole adjacent the first portion has a first geometry that is different than a second geometry of the non-uniform cross-sectional area adjacent the second portion. More preferably, the first geometry defines a circular cross-sectional area whereas the second geometry defines a rectangular cross-sectional area.
  • the second portion of the electrode body is closed, the body wall defined by the second and middle portions may thus have a uniform or nearly uniform thickness.
  • the second portion of the electrode body is closed, the body wall defined by the second portion may therefore have a first thickness superior to a second thickness of the body wall defined by the middle portion.
  • the second portion of the electrode body may have an oval -like shape or a rectangle-like shape with round comers.
  • the first portion of the body wall may have a circular or oval shape.
  • the outer flat surfaces may be configured to extend from the second portion to the first portion according to an angle a with the longitudinal axis Z of about 0° such as to be parallel to a plane formed by the adjacent electrodes’ surfaces and provide a constant distance between the middle portion of the electrode body and adjacent electrodes.
  • the outer flat surfaces may be configured to inwardly extend from the second portion to the first portion according to an angle a with the longitudinal axis Z of between 0,5° and 5°.
  • the middle portion of the body wall may also comprise two opposite outer lateral surfaces connecting the two opposite outer flat surfaces, the outer lateral surfaces forming a round shaped transition between the two opposite outer flat surfaces of the electrode body.
  • the outer lateral surfaces extends inwardly from the second portion to the first portion. More preferably, each of the two inwardly extending opposite outer lateral surfaces defines a shouldershaped transition along the longitudinal axis Z between the middle portion and the first portion.
  • the electrode body as disclosed herein may further comprise a failsafe system adjacent the first portion to mechanically connect the electrode body to the refractory package.
  • the failsafe system may comprise an external groove in the electrode body around and adjacent the first portion.
  • the electrode is an anode
  • the electrode body is an anode body made from a metal or alloy thereof, a ceramic or a cermet material to form an inert or oxygen-evolving anode.
  • the invention is also directed to an electrode comprising the electrode body as defined herein and an electrode pin inserted into the electrode body.
  • the electrode is for use for the making of a metal, such as aluminum.
  • an electrode body with round fillets (no sharp comers) for the transition between the second and middle portions allows reducing stress concentrators and avoiding crack initiation, compared to a electrode plate.
  • the electrode body as disclosed herein also comprises opposites flat surfaces for facing adjacent electrodes in the cell, providing as such a more constant ACD compared to a cylindrical anode.
  • Figure 1 is a three-dimensional illustration of an electrode body in accordance of a first preferred embodiment
  • Figure 2 is a side view of the electrode body illustrated on Figure 1;
  • Figure 3 is a cut view of the electrode body of Figure 2 along line A-A;
  • Figure 4a is a top view of the electrode body illustrated on Figure 1;
  • Figure 4b is the detailed view of the section B of the electrode body illustrated on Figure 4a;
  • Figure 5 is a cut view of the electrode body of Figure 4a along line G-G;
  • Figure 6 is the detailed view of the section C of the electrode body illustrated on Figure 3;
  • Figure 7 is a three-dimensional illustration of an electrode body in accordance of a second preferred embodiment
  • Figure 8 is a side view of the electrode body illustrated on Figure 7;
  • Figure 9 is a cut view of the electrode body of Figure 10a along line A-A;
  • Figure 10a is atop view of the electrode body illustrated on Figure 7;
  • Figure 10b is the detailed view of the section D of the electrode body illustrated on Figure 10a;
  • Figure 11 is a cut view of the electrode body of Figure 10a along line B-B;
  • Figure 12 is the detailed view of the section E of the electrode body illustrated on Figure 11.
  • weight % wt.%
  • time, resistance, volume or temperature can vary within a certain range depending on the margin of error of the method or device used to evaluate such weight %, time, resistance, volume or temperature.
  • a margin of error of 10% is generally accepted.
  • the invention is first directed to an electrode body extending longitudinally along an axis Z and comprising a first portion configured for operatively connecting the electrode body to an electrolytic cell; a second portion, opposite the first portion; and a middle portion extending between the first and second portions.
  • the electrode body has a continuous external surface forming a round transition between the second and middle portions.
  • the continuous external surface of the middle portion defines two opposite outer flat surfaces for facing surfaces of adjacent electrodes when the electrode is plunged into an electrolytic bath of an electrolytic cell comprising the adjacent electrodes.
  • the invention is described as an anode body. Of course, similar embodiments can apply to a cathode body.
  • Cathodes of an electrolytic cell for the making of a metal are electrically conductive, chemically resistant to metal and bath, and have good wettability for the produced metal.
  • Cathodes may be for instance vertical plates of a given thickness presenting therefore two opposite flat surfaces for facing the adjacent anodes.
  • Figures 1 to 6 show a first embodiment and figures 7 to 12 show a second embodiment of an anode body of an anode for the electrolytic production of a metal.
  • Reference numerals of the drawings in the 100 series identify the first embodiment whereas the reference numerals in the 200 series identify the second embodiment.
  • An anode as described herein preferably comprise an anode body in which is inserted an anode pin for conducting the electricity. Examples are provided in U.S. patent US 9,945,041 B2 (Reed et al.), the content of which is incorporated herein by reference.
  • the anode body 100, 200 comprises a longitudinal inner hole 110, 210 configured for receiving, at least in part, an anode pin (not illustrated) for operatively connecting the anode body to an electric power supply (not illustrated) when the anode pin is installed therein.
  • anode pin not illustrated
  • an electric power supply not illustrated
  • Other possible configurations for electrically connecting the anode body to the power supply can be considered without departing from the scope of the present invention.
  • the anode body 100, 200 also comprises a body wall 120, 220 around the longitudinal inner hole 110, 210.
  • the body wall comprises or defines the following portions: a first or open portion 130, 230 adjacent an opening 111, 211 of the longitudinal inner hole; a second or closed portion 140, 240, opposite the open portion 130, 230; and a middle portion 150, 250 extending between the first / open portion 130, 230 to the second / closed portion 140, 240.
  • the anode body 100, 200 has a bore shape with a continuous external surface 121, 221 of the body wall forming a round transition 141, 241 between the second / closed portion 140, 240 and the middle portion 150, 250.
  • Such round fillets no sharp comers, for the closed portion, but also preferably for the middle and first / open portions, allows reducing stress concentrators and avoiding crack initiation.
  • the second portion 240 and the middle portion 250 of the body wall 220 of the anode body 200 have a uniform, or nearly uniform, thickness 222.
  • Uniform, or nearly uniform lateral wall and bottom thickness allow for uniform, or nearly uniform electric current distribution across said (nearly) uniform thickness, leading to (nearly) uniform heat transfer and temperature gradients. This is particularly advantageous for preserving temperature sensitive materials, such as ceramics or cermets, from cracking.
  • the body wall 120 of the second / closed portion 140 has a first thickness 122 superior to a second thickness 123 of the body wall 120 of the middle portion 150.
  • the closed portion 140 of the anode body 100 may have an circular-like shape.
  • the closed portion 240 of the anode body 200 may have a rectangle-like shape with rounded comers. This specific shapes allows reducing cell resistance and achieving more uniform current distribution across the portions of the anode body.
  • circular it is meant in the instant disclosure any geometry from ovoid to circle.
  • rectangular it is meant in the instant disclosure any geometry from a rectangle to a square.
  • the first / open portion 130, 230 of the body wall 120, 220 and the opening 111, 211 of the longitudinal inner hole 110, 210 may have a circular shape. This circular shape provides more space than a rectangular shape, and as such allow easing the insertion and reception of the electrical pin in the longitudinal hole of the anode body.
  • the middle portion 150, 250 of the anode body 100, 200 comprises or defines two opposite outer flat surfaces 151, 251 for facing adjacent outer surfaces of cathode bodies (not illustrated) when the anode is plunged into an electrolytic bath of an electrolytic cell comprising said cathode bodies.
  • cathode bodies may be plates with two opposite flat surfaces for facing adjacent anodes.
  • Other cathode shapes can be considered without departing from the scope of the present invention.
  • the outer flat surfaces 151 of the anode body are configured to outwardly extend between the second / closed portion and the first / open portion according to an angle a with the longitudinal axis of the inner hole of between 0.5° and 5°.
  • the angle a can be chosen for an accommodation of the bubble plume (or oxygen bubbles) formed during electrolysis using oxygen-evolving electrodes. If during the electrolytic process, the ACD is completely filled or impinged by O2 bubbles - the resistance is higher through gas than liquid. Also, oxygen bubbles should not hit the cathode plates (or the liquid aluminum will back-react to alumina), which may lower the efficiency of the cell.
  • the outer flat surfaces 251 of the anode body are configured to be parallel to a plane formed by the adjacent cathode bodies.
  • the angle a between the outer flat surfaces 251 and the longitudinal axis of the inner hole is about 0°.
  • This characteristic provides a constant anode-cathode distance (ACD) between the middle portion of the anode and adjacent cathodes bodies.
  • the outer flat surfaces 251 extend according to an angle a of about 0° with the longitudinal axis of the inner hole,
  • the middle portion 150, 250 of the body wall 110, 210 also comprises two opposite outer lateral surfaces 152, 252 connecting the two opposite outer flat surfaces 151, 251, the outer lateral surfaces forming a round shaped transition 153, 253 between the two opposite outer flat surfaces of the anode body (see e.g. Figures 4a and 10a respectively).
  • the first / open portion 130, 230 typically located at the top of the anode when the anode is vertical, has atop flat surface 131, 231 perpendicular to the longitudinal inner hole or the axis Z.
  • This top flat shape of the electrode body allows for mechanical atachment of the electrode to a refractory package (the refractory package “sits” or distributes its load on this surface).
  • the body wall 120, 220 may have a failsafe system adjacent the first / open portion to mechanically connect the electrode to the refractory package. More preferably, the failsafe system comprises an external groove 132, 232 around and adjacent the top open portion, as the one illustrated on Figures 5-6 or 11-12.
  • the outer lateral surfaces 152 of the anode body 100 extend inwardly from the second/closed portion 140 of the body to the first/open portion 130 thereof.
  • the outer lateral surfaces 252 of the anode body 200 also extend inwardly from the second / closed portion 240 of the body.
  • the inwardly extending outer surface 252 defines a round transition forming a shoulder 254 between the middle portion 250 and the open portion 230.
  • the present invention preferably concerns anode bodies made from metals or alloys thereof, ceramics, or cermet materials typically used for that manufacturing of inert or oxy gen-evolving anode.
  • the present invention also concerns any electrode comprising at least the electrode body as defined herein, and an electrode pin inserted into the electrode body.
  • the present invention also concerns an electrode assembly comprising a plurality of the electrodes as disclosed herein operatively connected to a refractory package and means of current distribution.
  • the electrode body or electrode comprising the same as disclosed herein is particularly useful for the making of a metal, preferably aluminum.
  • an electrode body according to the present invention is preferably formed of
  • • may have a closed end/bore shape which allows receiving electrical member (pin) for reducing cell resistance and achieving more uniform current distribution across the part.
  • • may have similar or close wall and botom thicknesses for the anode body wall which allows for uniform heat transfer/temperature gradients for temperature sensitive materials (e.g. ceramics, cermets, etc).
  • temperature sensitive materials e.g. ceramics, cermets, etc.
  • • may comprise only fillets with no sharp comers for reducing stress concentrators, avoiding as such crack initiation.
  • the wall thickness between anodes being preferably thicker than the wall thickness between anode and cathode.
  • • may provide combination shape of oval-esque for electrolysis and a round bore for pin
  • the electrode body according to the present disclosure is an anode body with a hollow shape, allowing the hollow body to be fdled with a metallic material to conduct electricity to as close as possible to the active anode surface.
  • the hollow shape also allows minimizing the resistive losses and also facilitating a uniform current density over the active anode surface.
  • Electrode body as disclosed herein represent additional significant improvements over electrodes with cylindrical or flat bodies, in particular due to the body transitions from a rectangular shaped cavity in the bottom to a circular shaped cavity at the top of the anode. This provides several benefits:
  • the pin life is limited by the smallest cross-sectional dimension. For a given cross sectional area, a circular geometry will be best since a rectangular geometry will always have a smaller dimension.
  • circular cross section of the anode at the top facilitates a more robust (mechanically) refractory package required at the very top of the anodes.
  • an axisymmetric shape allows a more efficient manufacturing method for the pin.
  • a circular opening of the anode top avoids sagging and deformation of the anode opening that can occur during manufacturing of the anode if the opening is rectangular and the gravity force is normal to the long axis of the opening.
  • a circular opening has the natural mechanical strength of an arch when forces are applied normal to the anode surface.

Landscapes

  • 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)

Abstract

Est divulgué un corps d'électrode pour la production électrolytique d'un métal comprenant une première partie permettant de connecter fonctionnellement le corps d'électrode à une cellule électrolytique ; une deuxième partie, opposée à la première partie ; et une partie intermédiaire s'étendant entre les première et deuxième parties. Le corps possède une surface externe continue formant une transition circulaire entre la deuxième partie et la partie intermédiaire. La surface externe de la partie intermédiaire comprend deux surfaces plates externes opposées servant à faire face à des surfaces d'électrodes adjacentes lorsque l'électrode est plongée dans un bain électrolytique de la cellule électrolytique comprenant lesdites électrodes adjacentes. De préférence, l'électrode est une anode et le corps d'anode possède une forme d'alésage avec une surface externe continue de la paroi de corps. De préférence, le corps d'électrode est constitué d'un alliage métallique, d'un matériau céramique ou d'un matériau cermet en vue de former une anode inerte ou à dégagement d'oxygène utilisée pour une production d'aluminium respectueuse de l'environnement.
EP22865972.8A 2021-09-07 2022-09-06 Corps d'électrode d'une électrode pour la production électrolytique d'un métal Pending EP4399352A4 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US202163241258P 2021-09-07 2021-09-07
PCT/CA2022/051333 WO2023035063A1 (fr) 2021-09-07 2022-09-06 Corps d'électrode d'une électrode pour la production électrolytique d'un métal

Publications (2)

Publication Number Publication Date
EP4399352A1 true EP4399352A1 (fr) 2024-07-17
EP4399352A4 EP4399352A4 (fr) 2025-10-08

Family

ID=85506048

Family Applications (1)

Application Number Title Priority Date Filing Date
EP22865972.8A Pending EP4399352A4 (fr) 2021-09-07 2022-09-06 Corps d'électrode d'une électrode pour la production électrolytique d'un métal

Country Status (9)

Country Link
US (1) US20240352611A1 (fr)
EP (1) EP4399352A4 (fr)
CN (1) CN117337343A (fr)
AU (1) AU2022343028A1 (fr)
CA (1) CA3216073A1 (fr)
DK (1) DK182132B1 (fr)
PY (1) PY2272939A (fr)
WO (1) WO2023035063A1 (fr)
ZA (1) ZA202401329B (fr)

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5713186A (en) * 1980-06-26 1982-01-23 Permelec Electrode Ltd Method for modification of metallic electrode for electrolysis
IT1152776B (it) * 1982-05-27 1987-01-14 Snam Progetti Anodi insolubili per l'estrazione del piombo dall'elettrolita nei processi elettrochimici per il ricupero dei metalli contenuti negli accumulatori esausti
CA2157827C (fr) * 1995-09-08 2000-04-25 Charles P. Tomba Electrodes ameliorees combinant une plaque interieure reguliere et une gaine exterieure enduite
WO2016039978A1 (fr) * 2014-09-08 2016-03-17 Alcoa Inc. Appareil d'anode
CN108779565B (zh) * 2016-03-25 2021-06-01 美铝美国公司 电解池的电极结构及其相关方法
EA201990554A1 (ru) * 2016-09-19 2019-07-31 Элизис Лимитед Партнершип Анодное устройство и относящиеся к нему способы
AU2021388087A1 (en) * 2020-11-27 2023-06-22 Elysis Limited Partnership Controlling electrode current density of an electrolytic cell

Also Published As

Publication number Publication date
AU2022343028A1 (en) 2024-02-29
CN117337343A (zh) 2024-01-02
ZA202401329B (en) 2025-01-29
CA3216073A1 (fr) 2023-03-16
WO2023035063A1 (fr) 2023-03-16
DK202470085A1 (en) 2025-06-30
DK182132B1 (en) 2025-09-02
EP4399352A4 (fr) 2025-10-08
PY2272939A (es) 2023-04-27
US20240352611A1 (en) 2024-10-24

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