US3857774A - Cathodes for electrolytic cell - Google Patents

Cathodes for electrolytic cell Download PDF

Info

Publication number
US3857774A
US3857774A US00373313A US37331373A US3857774A US 3857774 A US3857774 A US 3857774A US 00373313 A US00373313 A US 00373313A US 37331373 A US37331373 A US 37331373A US 3857774 A US3857774 A US 3857774A
Authority
US
United States
Prior art keywords
cell
hanger bar
valve metal
copper
cathode
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.)
Expired - Lifetime
Application number
US00373313A
Other languages
English (en)
Inventor
P Morton
J Wortley
A Woolcock
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.)
Imperial Metal Industries Kynoch Ltd
IMI PLC
Original Assignee
Imperial Metal Industries Kynoch Ltd
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 Imperial Metal Industries Kynoch Ltd filed Critical Imperial Metal Industries Kynoch Ltd
Application granted granted Critical
Publication of US3857774A publication Critical patent/US3857774A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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

  • each mother plate or cathode is connected to the current carrying bus-bar by means of a hanger'bar which stretches across the electrolytic cell and contacts the bus-bar located on one side (or both sides) of the cell.
  • hanger bars have been formed of copper and the connection between the copper and the titanium mother plate or cathode has been by means of bolts or rivets.
  • the electrical contact between the mother plate or cathode (hereinafter referred to simply as the cathode) and the hanger bar has been found to be inconsistent.
  • the cathode and hanger bar are tightly held in the vicinity of the bolts or rivets but elsewhere the surfaces can become slightly separated. This separation can occur as a result of mechanical deformation, or differential thermal expansion.
  • splashes of electrolyte can be forced into the gaps, and on drying out leave crystals of, for example, copper sulphate in the gap.
  • the gap is closed by other deformations, the crystals prevent full closure. Further movement allows more material to build up in the gap, and as a result the gap is widened out by a ratcheting type of action.
  • the reduction of surface contact area results in an increase in resistance of the joint.
  • cathodes are used in parallel, and the current supplied is constant, if the resistance of one of them increases it receives less current. Not only does this result in a lower rate of deposition on that cathode, it also increases the current passing through the remainder of the cathodes. This can cause the next highest resistance cathode to become overloaded and to overheat, distort and increase in resistance. This results in a further increase in current through the remainder of the cathodes, and a cascade of failures can then occur.
  • the heating of a cathode can, in addition to increasing the load on the remainder of the cathodes. distort the cathode. Any small amount of distortion is compounded by extra local growth where the cathode approaches the anode. This can then result in nodular growth of deposit on the cathode, with a rapid build up of deposit on the cathode, and a short between the cathode and anode.
  • valve metal as used herein is meant an oxide film forming metal chosen from the group titanium, niobium, zirconium, tantalum, hafnium or an alloy of these metals.
  • an object of the present invention to provide an electrolytic cell wherein the previous disadvantages mentioned above are overcome. It is also an object of the invention to provide an electrolytic cell including an anode and a cathode, the cathode comprising a hanger bar of aluminium or copper at least partly sheathed with a valve metal, and a continuous sheet of valve metal welded along one edge only to at least part of the length of the hanger bar.
  • the hanger bar may be completely sheathed with a valve metal.
  • the edge may be in the form of cranked legs, said legs being welded to said hanger bar. Said legs may be staggered and may be spaced apart. Said edge may be spot welded to said hanger bar.
  • the cell may be an electro-winning cell and the anode may be a nonconsumable anode.
  • the cell may alternatively be an electrorefining cell, and the anode may be a consumable anode.
  • the cell may have said hanger bar located with at least one end on an electrical bus-bar, the hanger bar having the valve metal sheath relieved at the point of contact with the busbar. There may be a plurality of cathodes.
  • the continuous sheet of valve metal may be free from precious metal.
  • the hanger bar may be produced by co-extruding at an elevated temperature, the copper or aluminium core and a valve metal sheath or part sheath.
  • the valve metal is preferably ti tanium.
  • the valve metal may be surrounded by a lubricant metal such as copper, the lubricant metal being subsequently removed. for instance, by pickling or machining.
  • the hanger bar may include strengthening means.
  • FIG. 1 is a scrap sectional view of a rivetted joint
  • FIG. 2 is a scrap sectional view of a bolted joint
  • FIG. 3 is a scrap sectional view of a copper/titanium interface end
  • FIG. 4 is a perspective view of a hanger bar and a portion of a cathode.
  • FIG. 5 is a view along the arrow V of FIG. 4;
  • FIG. 6 is an enlarged view along the arrow VI of FIG.
  • FIG. 7 is a scrap perspective view of an electrolytic cell and cathode assembly
  • FIG. 8 is a graph of milivolts v time
  • FIG. 9 is a cross-section of an extrusion assembly
  • FIG. 10 is a crosssection of an alternative hanger bar.
  • FIG. 1 shows two plates of copper 1, connected to a plate of titanium 2, by means of a rivet 3.
  • the rivet 3 is placed in a hole passing through the plates 1 and 2 and is compressed to hold it in position.
  • the compression tends to fatten the centre of the rivet so that the centre of the rivet is forced into intimate contact with the bore of the hole through the plate 2.
  • the heads of the rivet are also forced into intimate contact with the faces 5 on the plates 1.
  • the current path for current passing from the titanium plate 2 to the copper plates 1 tends to pass along the direction of the arrow 6, through the interface between the bore in the plate 2 and the surface of the rivet 3, along the rivet, and through the surfaces 5 into the copper plates 2. Thermal cycling of the rivet tends to cause it to relax and the contact resistance consequently increases.
  • the bolted joint shown in FIG. 2 has a different configuration.
  • the plates 1 and 2 are shown bolted together by means of bolt 7 and nut 8.
  • the act of tightening the bolts tends to stretch it, tending to thin the bolt, resulting in a gap 9 along its length between the bolt and the bore.
  • the current path between the titanium 2 and the copper l is largely along the lines of the arrows 6a. It can be seen that the current largely passes between the copper and the titanium in the compressed regions beneath the head of the bolt 7 and the nut 8. Thermal cycling of the joint results in the tension in the bolt gradually becoming less because of creep in the bolt and in the copper. There is consequently a decrystals, for example, copper sulphate.
  • the differential expansion of copper and titanium may cause the copper to move away from the titanium and the deposit builds up as shown as 10 in FIG. 3.
  • the copper cannot contract fully onto the titanium as it is held by the wedge of salt 10.
  • the next cycle forces the copper further away from the titanium and is prevented again from returning by a further deposit of electrolyte salt which builds up the wedge 10.
  • a ratcheting action occurring which tends to separate the copper from the titanium and hence to increase the contact resistance of the joints.
  • the thermal cycling affects the oxide layer on the titanium tending to increase it and again increasing the surface contact resistance of the joints.
  • the copper layers 1 have been shown on both sides of the titanium core 2, it will be appreciated that there could be only a single layer of copper 2 utilising a rivetted or bolted joint and the same principles would apply.
  • a hanger bar 11 has welded to it a titanium sheet l2.
  • the titanium sheet has at its upper end, cranked, staggered legs l3, l4 and 15, two of which 13 and 15 are on one side of the hanger bar 11 and the other 14 is on the other side of the hanger bar 11.
  • the staggered legs 13,14 and 15 are spaced apart to leave gaps 16 and 17, which ease handling of the cathode assembly in use.
  • the legs 13,14 and 15 are spot welded as at 18 to the hanger bar.
  • the hanger bar 11 has a central copper core 19 as is seen most clearly in FIG. 5. Surrounding the copper core 19 is a titanium sheath 10. Thus the legs 13,14 and 15 of titanium are welded themselves to a titanium surface to provide a good electrical contact. The end 21 or 22 of the hanger bar 11 is machined to remove the titanium sheath to reveal a face 23 of copper.
  • FIG. 7 illustrates an electrolytic cell 25 containing a series of anodes and cathodes spaced alternately.
  • the anodes have hanger bars which connect to bus-bar 24a on the left-hand side of the cell as seen in the drawing and the cathodes have hanger bars which connect to the bus-bar 24b on the right-hand side of the cell as seen in the drawing.
  • the anodes are consumable, whereas in the case of electrowinning, the anodes are non-consumable and may be of lead, graphite, platinised titanium or any other suitable material.
  • the cathode working surface is a continuous surface and it is important to notice that there are no apertures, or bits of large size in the surface which would otherwise act as a key the material deposited onto the cathode and preventing its subsequent easy removal.
  • the cathode deposited material in a single operation and it would not normally be practical to machine off or dissolve the deposited material. It may be desirable to use some form of releasing coating on the cathode surface to enhance removal. However, it is unnecessary to coat the surface with a precious metal which is, of course, extremely expensive.
  • the cathodes would not act as anodes if the polarity of the cell were reversed since the plain valve metal surface would rapidly oxidise under the anodic conditions to form a non-conducting oxide film which would stop further electro-conduction.
  • the hanger bar 11 is prepared by co-extruding a copper core and titanium sheath at an elevated temperature in the range of 400800C to provide a good metallurgical bond between the copper and the titanium.
  • the electrical current path is between the copper bus-bars 24 and the copper core 19 via the face 23, through the interface between the core 19 and the sheath 20 and through the welds 18 into the cathode l2.
  • FIG. 8 which shows expected millivolt drops across a hanger bar/cathode interface v time in use
  • the lines 26, 27, 28 and 29 represent millivolt drops in the bolted constructions
  • the line 30 represents millivolt drops in a welded arrangement.
  • FIGS. 9 and 10 Although the hanger bar illustrated and described above has a continuous sheath of titanium completely surrounding it, it will be appreciated that it is within the scope of the invention tohave only a partial sheath as, for example, has been illustrated in FIGS. 9 and 10.
  • a copper billet 31 is inserted into two titanium curved sheets 32 and the billet is then extruded at a high temperature to effect a metallurgical bond between the copper and the titanium. The excess copper is then machined away from the extruded section to re veal the titanium plates 32 so that welds can be made to them.
  • a copper billet 33 is almost completely surrounded by a titanium sheet 34 and the assembly extruded to form a metallurical bond between the titanium and the copper.
  • the hanger bar is then used in the same way as has been described above.
  • the hanger bar may be strengthed by using a strong steel insert to support the weight of the coated cathode when used and also the weight of workmen walking over the surface of the cells using the hanger bars as a floor.
  • An electrolytic cell including an anode and a cathode, the cathode comprising a hanger bar of aluminium or copper at least partly sheathed with a valve metal, and a continuous sheet of valve metal welded along one edge only to at least part of the length of the valve metal sheath of the hanger bar.
  • hanger bar is located at at least one end on an electrical bus-bar, the hanger bar having the valve metal sheath relieved at the point of contact with the bus-bar.

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)
US00373313A 1973-01-26 1973-06-25 Cathodes for electrolytic cell Expired - Lifetime US3857774A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB413273A GB1415793A (en) 1973-01-26 1973-01-26 Cathodes

Publications (1)

Publication Number Publication Date
US3857774A true US3857774A (en) 1974-12-31

Family

ID=9771358

Family Applications (1)

Application Number Title Priority Date Filing Date
US00373313A Expired - Lifetime US3857774A (en) 1973-01-26 1973-06-25 Cathodes for electrolytic cell

Country Status (5)

Country Link
US (1) US3857774A (fr)
AU (1) AU473223B2 (fr)
BE (1) BE810190A (fr)
GB (1) GB1415793A (fr)
ZM (1) ZM1474A1 (fr)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4014763A (en) * 1974-11-08 1977-03-29 Imperial Metal Industries (Kynoch) Limited Cathode and hanger bar assembly and electrolysis therewith
FR2361481A1 (fr) * 1976-04-28 1978-03-10 Diamond Shamrock Techn Cathode pour depot electrolytique de metal
US4125448A (en) * 1974-02-22 1978-11-14 Roller Paul S Cell and electrodes for electrolytic production of insoluble metal hydroxide
US4186074A (en) * 1979-02-09 1980-01-29 Copper Refineries Pty. Limited Cathode for use in the electrolytic refining of copper
US4217199A (en) * 1979-07-10 1980-08-12 Ppg Industries, Inc. Electrolytic cell
US4251337A (en) * 1979-06-08 1981-02-17 Titanium Industries Novel titanium-containing electrode and electrolytic processes employing same
US4264426A (en) * 1978-06-06 1981-04-28 Finnish Chemicals Oy Electrolytic cell and a method for manufacturing the same
US4269687A (en) * 1979-01-23 1981-05-26 Imi Kynoch Limited Electrode suspension bars
US4370215A (en) * 1981-01-29 1983-01-25 The Dow Chemical Company Renewable electrode assembly
US4610773A (en) * 1983-02-05 1986-09-09 Showa Entetsu Co., Ltd. Immersion type electrode structure
US5584975A (en) * 1995-06-15 1996-12-17 Eltech Systems Corporation Tubular electrode with removable conductive core
US5944965A (en) * 1992-07-01 1999-08-31 Gould Electronics Inc. Method and apparatus for sequentially metalizing polymeric films and products made thereby
WO2000017419A1 (fr) * 1998-09-24 2000-03-30 Outokumpu Oyj Procede de fabrication d'une barre de suspension pour cathode
US20100276281A1 (en) * 2009-04-29 2010-11-04 Phelps Dodge Corporation Anode structure for copper electrowinning
EP2630275A4 (fr) * 2010-10-18 2014-05-28 Epcm Services Ltd Ensembles cathodes électrolytiques à barre de suspension creuse
WO2017176118A1 (fr) * 2016-04-06 2017-10-12 Beheermaatschappij Clement Weert B.V. Support de cathode destiné à être utilisé dans un dispositif d'électrolyse et dispositif d'électrolyse correspondant

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4490223A (en) * 1983-09-21 1984-12-25 Asarco Incorporated Electrode for electrometallurgical processes

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1515348A (en) * 1921-09-24 1924-11-11 Isaac H Levin Electrode
US2848411A (en) * 1955-04-12 1958-08-19 Forest H Hartzell Electrode
DE2019806A1 (de) * 1969-04-28 1970-11-26 Marston Excelsior Ltd Elektroden fuer elektrochemische Verfahren
US3761385A (en) * 1971-06-30 1973-09-25 Hooker Chemical Corp Electrode structure

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1515348A (en) * 1921-09-24 1924-11-11 Isaac H Levin Electrode
US2848411A (en) * 1955-04-12 1958-08-19 Forest H Hartzell Electrode
DE2019806A1 (de) * 1969-04-28 1970-11-26 Marston Excelsior Ltd Elektroden fuer elektrochemische Verfahren
US3761385A (en) * 1971-06-30 1973-09-25 Hooker Chemical Corp Electrode structure

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4125448A (en) * 1974-02-22 1978-11-14 Roller Paul S Cell and electrodes for electrolytic production of insoluble metal hydroxide
US4014763A (en) * 1974-11-08 1977-03-29 Imperial Metal Industries (Kynoch) Limited Cathode and hanger bar assembly and electrolysis therewith
FR2361481A1 (fr) * 1976-04-28 1978-03-10 Diamond Shamrock Techn Cathode pour depot electrolytique de metal
US4264426A (en) * 1978-06-06 1981-04-28 Finnish Chemicals Oy Electrolytic cell and a method for manufacturing the same
US4269687A (en) * 1979-01-23 1981-05-26 Imi Kynoch Limited Electrode suspension bars
US4186074A (en) * 1979-02-09 1980-01-29 Copper Refineries Pty. Limited Cathode for use in the electrolytic refining of copper
US4251337A (en) * 1979-06-08 1981-02-17 Titanium Industries Novel titanium-containing electrode and electrolytic processes employing same
US4217199A (en) * 1979-07-10 1980-08-12 Ppg Industries, Inc. Electrolytic cell
US4370215A (en) * 1981-01-29 1983-01-25 The Dow Chemical Company Renewable electrode assembly
US4610773A (en) * 1983-02-05 1986-09-09 Showa Entetsu Co., Ltd. Immersion type electrode structure
US6224722B1 (en) 1992-07-01 2001-05-01 Gould Electronics Inc. Method and apparatus for sequentially metalizing polymeric films and products made thereby
US5944965A (en) * 1992-07-01 1999-08-31 Gould Electronics Inc. Method and apparatus for sequentially metalizing polymeric films and products made thereby
US5584975A (en) * 1995-06-15 1996-12-17 Eltech Systems Corporation Tubular electrode with removable conductive core
WO2000017419A1 (fr) * 1998-09-24 2000-03-30 Outokumpu Oyj Procede de fabrication d'une barre de suspension pour cathode
EA003342B1 (ru) * 1998-09-24 2003-04-24 Оутокумпу Ойй Способ изготовления штанги для подвески постоянного катода
AU762884B2 (en) * 1998-09-24 2003-07-10 Outokumpu Oyj Method for manufacturing of a cathode suspension bar
US20100276281A1 (en) * 2009-04-29 2010-11-04 Phelps Dodge Corporation Anode structure for copper electrowinning
US8038855B2 (en) 2009-04-29 2011-10-18 Freeport-Mcmoran Corporation Anode structure for copper electrowinning
US8372254B2 (en) 2009-04-29 2013-02-12 Freeport-Mcmoran Corporation Anode structure for copper electrowinning
EP2630275A4 (fr) * 2010-10-18 2014-05-28 Epcm Services Ltd Ensembles cathodes électrolytiques à barre de suspension creuse
AU2011318202B2 (en) * 2010-10-18 2015-09-03 Epcm Services Ltd. Electrolytic cathode assemblies with hollow hanger bar
US9388501B2 (en) 2010-10-18 2016-07-12 Epcm Services Ltd. Electrolytic cathode assemblies with hollow hanger bar
WO2017176118A1 (fr) * 2016-04-06 2017-10-12 Beheermaatschappij Clement Weert B.V. Support de cathode destiné à être utilisé dans un dispositif d'électrolyse et dispositif d'électrolyse correspondant

Also Published As

Publication number Publication date
AU473223B2 (en) 1976-06-17
GB1415793A (en) 1975-11-26
BE810190A (fr) 1974-07-25
AU6452074A (en) 1975-07-17
ZM1474A1 (en) 1975-08-21

Similar Documents

Publication Publication Date Title
US3857774A (en) Cathodes for electrolytic cell
US4014763A (en) Cathode and hanger bar assembly and electrolysis therewith
US5492609A (en) Cathode for electrolytic refining of copper
EP2080820B1 (fr) Dispositif et procédé pour court-circuiter une ou plusieurs cellules dans un agencement de cellules d'électrolyse prévues pour la production d'aluminium
US6569300B1 (en) Steel-clad cathode for electrolytic refining of copper
AU2003201532B2 (en) Hanger bar
US6113756A (en) Cathode construction
AU2003201532A1 (en) Hanger bar
US3650941A (en) Electrolytic reduction cell
AU2005201814B2 (en) Join zone, join method resistant to corrosion between copper materials and stainless steel or titanium, constituent of the permanent cathodes for electrolysis processes and cathode obtained thereof
US4486647A (en) Method of welding aluminum to titanium and a welded joint so produced
US4264426A (en) Electrolytic cell and a method for manufacturing the same
JPS5943996B2 (ja) 銅の電解精錬用陰極
WO2017163162A1 (fr) Connecteur électrique souple destiné à une cellule électrolytique
CA1259950A (fr) Anode enrobee de metal de transition pour l'extraction electrolytique des metaux ou de leurs oxydes
US6531038B2 (en) Cathode arrangement
WO2018058204A1 (fr) Anode carbonée pour l'électrolyse de l'aluminium avec pièce rapportée en aluminium et son procédé de construction
RU2175689C2 (ru) Соединение в катодной секции электролизера и способ его изготовления
RU2850407C2 (ru) Электролизер для производства алюминия и катодный токоотводящий узел
JPS5832236B2 (ja) 陰極および懸吊棒組立体
CA1071142A (fr) Cathode
US20240240342A1 (en) Cathode current collector bar of an aluminium production cell
JPH0156871B2 (fr)

Legal Events

Date Code Title Description
PS Patent suit(s) filed