EP1428910A1 - Procédé de conversion d'un appareil à raffinage électrolytique et dispositif correspondant - Google Patents

Procédé de conversion d'un appareil à raffinage électrolytique et dispositif correspondant Download PDF

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Publication number
EP1428910A1
EP1428910A1 EP02102750A EP02102750A EP1428910A1 EP 1428910 A1 EP1428910 A1 EP 1428910A1 EP 02102750 A EP02102750 A EP 02102750A EP 02102750 A EP02102750 A EP 02102750A EP 1428910 A1 EP1428910 A1 EP 1428910A1
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EP
European Patent Office
Prior art keywords
section
bar
head
cell
cells
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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.)
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Application number
EP02102750A
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German (de)
English (en)
Inventor
Pascal Briol
Patrick Guillaume
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.)
Paul Wurth SA
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Paul Wurth SA
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Filing date
Publication date
Application filed by Paul Wurth SA filed Critical Paul Wurth SA
Priority to EP02102750A priority Critical patent/EP1428910A1/fr
Publication of EP1428910A1 publication Critical patent/EP1428910A1/fr
Withdrawn legal-status Critical Current

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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
    • C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
    • C25C7/06—Operating or servicing
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B9/00—Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
    • C25B9/60—Constructional parts of cells
    • C25B9/65—Means for supplying current; Electrode connections; Electric inter-cell connections
    • C25B9/66—Electric inter-cell connections including jumper switches
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
    • C25C7/02—Electrodes; Connections thereof

Definitions

  • the present invention generally relates to a method for converting an electrorefinery and to a device for use therein.
  • Electrorefining is a process that allows producing metals such as e.g. copper, lead, tin and other non-ferrous metals with a very high purity level.
  • Electrorefining of copper for example, consists of electrolytically dissolving copper from relatively impure anodes of about 99.7% copper, and selectively plating the dissolved copper in pure form (99.997% and higher) onto a cathode. This reaction takes place in an electrorefining cell containing an electrolyte which is basically copper sulfate and sulphuric acid.
  • anodes and cathodes are arranged alternately at specified spacing in an open-top electrorefining cell containing the necessary electrolyte therein.
  • the anodes and cathodes have a general sheet-form and are provided in their upper part with conductive lugs, which serve for their support in the cell and for their electrical connection. Therefore, each cell has about a top edge a number of adequately spaced anodic contacts, on which the anode lugs rest when installed in the cell.
  • the electrorefining cell includes a number of adequately spaced cathodic contacts on which the cathode lugs rest.
  • Electrorefining cells are grouped by sections 14 1 ...14 10 , each section 14 i containing a plurality of electrorefining cells 12 1 ...12 40 .
  • the sections 14 1 ...14 10 are connected in series in an electrical circuit 16 including a power supply 18, which provides the current necessary for the electrolytic process.
  • the cathodic and anodic contacts are provided by means of a so-called equipotential bus-bar, in which anodic and cathodic contacts are connected with each other, so that the electrorefining cells 12 1 ...12 40 are connected in series.
  • first cell 12 1 of each section 14 i is connected to the electrical circuit 16 by means of an upstream head-bar 20 and the last cell 12 40 of each section 14 i is connected to the electrical circuit by means of a downstream head-bar 22, these head-bars 20 and 22 being configured for operating at a cathode spacing corresponding to that of the electrodes in the cells.
  • An electrorefinery typically comprises a plurality of such electrorefining units.
  • each section of an electrorefining unit is generally isolated once a week either for loading/unloading electrodes or for maintenance.
  • the section to be isolated is disconnected from the electrical circuit by use of short-circuiting means (indicated 24 in Fig.1) situated between the head-bars of this section.
  • short-circuiting means indicated 24 in Fig.1
  • the cathodes consist of so-called “starter sheets” of high purity copper. These starter sheets are produced by a special electrolytic treatment involving electrodeposition of copper onto either hard rolled copper or titanium blanks.
  • the object of the present invention is to provide an improved method for converting a conventional electrorefinery to the permanent cathode technology with a different cathode spacing, which allows minimising production loss. This object is achieved by a method as claimed in claim 1.
  • a method for converting an electrorefinery comprises the steps of:
  • the problem due to the incompatibility between the initial head-bars that are configured for operating at a cathode spacing d1 and the new electrodes that should operate at cathode spacing d2 is overcome by bypassing the first and last cells of a section.
  • This allows to bring a partially converted section (end of step (a)) back into production, while another section is isolated for conversion.
  • the power supply is interrupted and the head-bars are changed, which will allow finishing the conversion by charging the first and last cells of each section with electrode sets at the spacing d2.
  • step (d) the whole unit has been converted, with the exception of the first and last cells of each section.
  • the method will thus advantageously include a further step (e), which consists in finishing the conversion of a given section by removing the cell bypassing devices from the first and last cells of the section and installing in these cells electrode sets at spacing d2.
  • step (e) is preferably carried out for a given section at a time chosen in function of the section's anodic cycle. Indeed, it is preferable to charge the first and last cells of a section with new electrode sets at spacing d2 at the time anodes need to be replaced in the other cells of the section.
  • the cell bypassing device should thus preferably be capable of bypassing the first and last cells independently of the head-bar contacts spacing. Since after step (d) the circuit is equipped with head-bars configured for operating at spacing d2, the conversion can be finished at any time, since a section can be disconnected from the electrical circuit by means of the short-circuiting means without affecting production in the other sections.
  • step (d) it would also be possible to carry out step (d) at the time a given section in the unit comes to the end of its anodic cycle.
  • step (e) can be carried out for the given section directly after step (d), before current is turned back on in the electrical circuit, so that for this particular section, all cells will be charged with electrodes sets at spacing d2.
  • step (a) preferably includes replacing the bus-bars configured for operating at cathode spacing d1 with bus-bars configured for operating at a cathode spacing d2.
  • the first cell of each section will generally have on one side an upstream head-bar defining anodic contacts configured for operating at cathode spacing d1 and about its opposite side a bus-bar defining cathodic contacts configured for operation at cathode spacing d2.
  • the last cell of each section will generally have on one side a downstream head-bar defining cathodic contacts configured for operating at cathode spacing d1 and about its opposite side a bus-bar defining anodic contacts configured for operating at cathode spacing d2.
  • the first, respectively the last cell of the section is advantageously bypassed by means of a cell bypassing device including a rigid central part and a first contacting structure on a first side of the central part for coming into electrical contact with at least part of the head-bar.
  • the device further includes a second contacting structure on an opposite second side of the central part for selectively coming into contact with at least part of the contacts on the bus-bar, the second contacting structure being electrically connected with the first contacting structure.
  • the first contacting structure is also capable of coming into contact with at least part of a head-bar configured for operating at spacing d2 (i.e. after the change of head-bars).
  • a cell bypassing device for an electrorefining cell having about a first longitudinal side a head-bar defining a number of anodic, respectively cathodic, contacts at a spacing d1, and about an opposite longitudinal side a corresponding number of cathodic, respectively anodic, contacts at a spacing d2.
  • the present cell bypassing device is adapted to rest on the cell and includes:
  • This device allows to bypass a cell that has anodic and cathodic contacts configured for operating at different cathode spacings, but its first contacting structure is not limited to a particular cathode spacing on the head-bar. Indeed, contrary to the second contacting structure which is designed to selectively engage the contacts on the bus-bar, the first contacting structure is capable of coming into electrical contact with at least part of the head-bar, that is with any part of the head-bar that allows establishing the electrical contact. When the device is installed in the cell, current flows from the head-bar into the first contacting structure to the second contacting structure and then into the contacts of the bus-bar.
  • the present device is particularly well suited to be used in a method for converting an electrorefining plant to a technology employing a cathode spacing different from the initial cathode spacing.
  • it proves particularly advantageous when converting a conventional electrorefinery operating with starter sheet cathodes to the permanent cathode technology with a reduced cathode spacing.
  • the present device by laying across the cell, also allows covering the open-top electrorefining cell, which is interesting with regard to safety.
  • the head-bar is an upstream head-bar defining anodic contacts at spacing d1 and the bus-bar defines cathodic contacts at spacing d2.
  • the head-bar is a downstream head-bar defining cathodic contacts at spacing d1 and the bus bar defines anodic contacts at spacing d2.
  • the cell bypassing device includes an electrically conductive central structure.
  • the first contacting structure is an electrically conductive bar with a flat side that can be laid on the head-bar contacts when they are arranged in a plane.
  • the second contacting structure includes a number of fingers extending away from the central part and spaced from each other by a distance corresponding to cathode spacing d2. These fingers thus engage the contacts on the bus-bar. Current thus flows from the first to the second contacting structure through the central part.
  • the typical layout of an electrorefining unit 10 is shown in Fig.1.
  • the shown unit 10 includes ten sections 14 1 ...14 10 consisting each of two rows of twenty electrorefining cells 12 1 ...12 20 and 12 21 to 12 40 .
  • the sections 14 1 ...14 10 are connected in series in an electrical circuit 16 including a power supply 18, which provides the current necessary for the electrolytic process (the direction of current in the electrical circuit 16 is indicated by arrows 19).
  • the cells 12 1 ...12 40 are connected in series, so that the current flows through the section 14 i according to the path indicated by arrow 23.
  • an electrorefining cell 12 2 or 12 3 conventionally consists of an open-top tank charged with electrode sets that are arranged to obtain an alternance of anodes 30 and cathodes 32 at a specified cathode spacing.
  • the anodes 30 and cathodes 32 have a general sheet-form and are provided in their upper part with conductive lugs, which serve for their support in the cell and for their electrical connection.
  • the cell 12 i is filled with the necessary electrolyte and electrodes 30, respectively 32, of similar polarity are connected in parallel.
  • each cell 12 i has about a top edge a number of adequately spaced anodic contacts (not shown), on which the anode lugs rest when the electrodes are in place in the cell.
  • the electrorefining cell 12 i includes a number of adequately spaced cathodic contacts (not shown) on which the cathode lugs rest.
  • the cathodic and anodic contacts are provided by means of a so-called bus-bar (not shown), in which anodic and cathodic contacts are connected with each other.
  • a bus-bar installed e.g. between cells 12 2 and 12 3 thus has a number of cathodic contacts next to e.g. cell 12 2 and a number of anodic contacts next to cell 12 3 , so that the electrorefining cells 12 1 ...12 40 are connected in series.
  • first cell 12 1 of each section 14 i is connected to the electrical circuit 16 by means of an upstream head-bar 20 and the last cell 12 40 of each section 14 i is connected to the electrical circuit 16 by means of a downstream head-bar 22, these head-bars 20 and 22 being configured for operating at the cathode spacing of the electrodes in the cells.
  • this head-bar 20 is configured to define anodic contacts, which are spaced from each other by a given distance adapted to the cathode spacing.
  • downstream head-bar 22 ends a section 14 i , it is configured to define cathodic contacts at the adapted cathode spacing.
  • an upstream head-bar 20 may be a copper bar that is partially covered with an insulator on areas defining cathode support zones and the non-insulated areas provide the anodic contacts.
  • the configuration is inverted, i.e. the insulated areas define anodic support zones.
  • each section 14 i is provided with short-circuiting means 24 that allow to selectively direct the current from the section's upstream head-bar 20 directly to the downstream head-bar 22.
  • the third section 14 3 is short-circuited (indicated by arrows 26), and thus allows maintenance or loading/unloading of electrodes in the section 14 3 .
  • the cathode spacing is generally reduced with regard to the starter sheet technology. This thus leads to an incompatibility between the installed head-bars that are configured for operating with a cathode spacing d1 and new electrode sets that are to be arranged at a reduced cathode spacing d2.
  • FIG.2 This incompatibility is schematically illustrated in Fig.2, wherein an upstream head-bar 20' is partially shown from above.
  • This upstream head-bar 20' is a copper bar selectively covered by insulating material generally indicated 34 to define anodic contacts 36 and cathodic support zones 38, an anodic contact 36 being an uncovered copper area in between two cathodic support zones 38 (i.e. areas of the copper bar covered by insulating material).
  • the shown head-bar 20' is configured for operating at cathode spacing d1.
  • Reference signs 30' and 32' illustrate the connecting lugs of anodes, respectively cathodes, that are arranged at a cathode spacing d2.
  • head-bar 20' does not allow a proper connection of anodes 30' nor a proper insulating support of cathodes 32' at the required spacing d2.
  • the short-circuiting means allows to convert a section without shutting-down the power supply.
  • the first 12 1 and last 12 40 cells of each section 14 i cannot be charged with electrodes at the new, reduced cathode spacing until the head-bars 20, 22 have been changed.
  • the common practice for converting an existing electrorefining unit is to start by converting one section after the other.
  • the conversion thus conventionally ends by replacing the head-bars and charging the new electrodes into the first and last cells of each sections.
  • the present method for converting an electrorefinery allows minimising production loss during conversion of an electrorefining unit, in particular during conversion to the permanent cathode technology with a reduced cathode spacing.
  • a first section 14 i of the unit 10 is short-circuited by closing the short-circuit 24, and meanwhile the section 14 i is converted, except for the first 12 1 and last 12 40 cells of the section 14 i .
  • This conversion of the section mainly involves:
  • a cell bypassing device is installed at step (a) in the first 12 1 and last 12 40 cells in order to bypass each of these cells 12 1 , resp. 12 40 .
  • Such a device basically includes a rigid structure apt to be laid on the cell and a first contacting structure on a first side of the central part for coming into contact with at least part of the head-bar, which defines a number of the anodic, respectively cathodic, contacts at spacing d1; and a second contacting structure on an opposite second side of the central part for selectively coming into contact with at least part of the cathodic, respectively anodic, contacts of the bus-bar (at spacing d2) arranged on the opposite side of the cell.
  • the first electrical contacts are linked with the second electrical contacts, so that the current can flow between head-bar and bus-bar.
  • the short-circuiting means 24 is opened to bring the section 14 i back into production.
  • the cell bypassing devices allow the passage of current from the upstream head-bar 20 to the second cell 12 2 , respectively from the penultimate cell 12 39 to the downstream head-bar 22.
  • the present method allows to bring a section 14 i back into production before changing the head-bars 20, 22, thereby minimising production loss due to conversion.
  • steps (a) and (b) are repeated for all the sections in the unit 10.
  • a next step (d) the power supply is interrupted and meanwhile the existing upstream 20 and downstream 22 head-bars configured for operating at cathode spacing d1 are replaced by upstream and downstream head-bars configured for operating at cathode spacing d2.
  • step (d) the whole unit has been converted, with the exception of the first 12 1 and last 12 40 cells of each section 14 i .
  • the method advantageously includes a further step (e), which consists in finishing the conversion of a given section 14 i by removing the cell bypassing devices from the first 12 1 and last 12 40 cells of the section and installing in these cells electrode sets at spacing d2.
  • step (e) is preferably carried out for a given section when it reaches the end of its anodic cycle.
  • the cell bypassing device is thus advantageously designed to be capable of bypassing the first and last cells independently of the head-bar spacing.
  • Fig.3 shows such a cell bypassing device 40 installed in the first cell 12 1 of a section.
  • the device 40 includes an electrically conductive rigid central part 42.
  • a first contacting structure for contacting the upstream head-bar 20 is provided by an electrically conductive bar 44 that is laid on the head-bar 20 so that it comes into contact with at least part of the head-bar 20.
  • the second contacting structure includes a number of electrically conductive fingers 46 extending away from the central part 42 and spaced from each other by a distance d2, so that they selectively come into contact with the cathodic contacts on the bus-bar (not shown) in-between cells 12 1 and 12 2 .
  • the individual fingers are in electrical connection with the bar 44 through the electrically conductive central part 42.
  • the current instead of flowing trough the first cell 12 1 , flows from the upstream head-bar 20 trough the device 40 to the opposite bus-bar.
  • the bar 40 allows connection to the head-bar independently of its configuration with regard to cathode spacing. Indeed, when the cell is empty, any part of the head-bar could be contacted.
  • the bar 44 of the device 40 is thus laid on the head-bar in such a way that there is an electrical contact with at least part of the head-bar.
  • the upper surface of a head-bar is typically selectively covered by an insulator, to define support areas for the electrode lugs that should not be in electrical connection with the head-bar. If desired, when the cell is empty, it is possible to remove the insulator to facilitate the contact between bar 44 and head-bar. Similarly, when installing the new head-bars, the installation of the insulator may be delayed to the moment when the devices 40 are not anymore required (i.e. when charging with new electrode sets).
  • the head-bar has an embossed upper surface, which defines the zones where the insulator is to be installed.
  • anodic contacts may e.g. be defined by raised zones of the head-bar surface and the cathodic support areas are recesses filled with insulator. It follows that all the anodic contact surfaces will substantially be in a same plane, and that when the bar 44 is laid with its flat side on the head-bar, it will contact all the anodic contact surfaces.
  • the device is preferably made of metal having good electrical conductivity, such as e.g. copper.
  • the device 40 is shown as a single element laying over the whole length of the cell 12 1 .
  • the device 40 may be designed to bypass only one region of the cell 12 1 , so that e.g. two or three devices 40 will be laid next to each other to cover the whole length of the cell 12 1 .

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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)
EP02102750A 2002-12-13 2002-12-13 Procédé de conversion d'un appareil à raffinage électrolytique et dispositif correspondant Withdrawn EP1428910A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP02102750A EP1428910A1 (fr) 2002-12-13 2002-12-13 Procédé de conversion d'un appareil à raffinage électrolytique et dispositif correspondant

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Application Number Priority Date Filing Date Title
EP02102750A EP1428910A1 (fr) 2002-12-13 2002-12-13 Procédé de conversion d'un appareil à raffinage électrolytique et dispositif correspondant

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EP1428910A1 true EP1428910A1 (fr) 2004-06-16

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017174869A1 (fr) * 2016-04-04 2017-10-12 Outotec (Finland) Oy Procédé et agencement de commande du circuit électrique dans un processus électrolytique

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2040311A (en) * 1979-02-05 1980-08-28 Copper Refineries Pty Ltd Cathode for use in the electrolytic refining of copper
US4589966A (en) * 1985-10-03 1986-05-20 Olin Corporation Membrane cell jumper switch
EP0301115A1 (fr) * 1986-02-06 1989-02-01 Falconbridge Limited Suspensions de cathodes
EP0638666A1 (fr) * 1993-07-20 1995-02-15 De Nora Permelec S.P.A. Court-circuiteur pour électrolyseurs reliés électriquement en série

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2040311A (en) * 1979-02-05 1980-08-28 Copper Refineries Pty Ltd Cathode for use in the electrolytic refining of copper
US4589966A (en) * 1985-10-03 1986-05-20 Olin Corporation Membrane cell jumper switch
EP0301115A1 (fr) * 1986-02-06 1989-02-01 Falconbridge Limited Suspensions de cathodes
EP0638666A1 (fr) * 1993-07-20 1995-02-15 De Nora Permelec S.P.A. Court-circuiteur pour électrolyseurs reliés électriquement en série

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017174869A1 (fr) * 2016-04-04 2017-10-12 Outotec (Finland) Oy Procédé et agencement de commande du circuit électrique dans un processus électrolytique
AU2017245752B2 (en) * 2016-04-04 2019-11-28 Outotec (Finland) Oy Method and arrangement for controlling the electrical circuit in an electrolytic process

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