EP0501547A1 - Procédé de dépôt électrolytique sur une bande d'acier d'une couche métallique composé au moins partiellement de zinc - Google Patents
Procédé de dépôt électrolytique sur une bande d'acier d'une couche métallique composé au moins partiellement de zinc Download PDFInfo
- Publication number
- EP0501547A1 EP0501547A1 EP92200362A EP92200362A EP0501547A1 EP 0501547 A1 EP0501547 A1 EP 0501547A1 EP 92200362 A EP92200362 A EP 92200362A EP 92200362 A EP92200362 A EP 92200362A EP 0501547 A1 EP0501547 A1 EP 0501547A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- anode
- reaction
- zinc
- hydrogen
- electrolyte
- 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.)
- Granted
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D7/00—Electroplating characterised by the article coated
- C25D7/06—Wires; Strips; Foils
- C25D7/0614—Strips or foils
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/22—Electroplating: Baths therefor from solutions of zinc
Definitions
- the invention relates to a method of electrolytically coating a steel strip with a layer at least partly consisting of zinc in an electrochemical cell provided with a non-soluble anode, wherein the layer containing zinc is deposited onto the steel strip which is connected as the cathode.
- the strip is usually moving continuously.
- a strip-coating method as described above is in use.
- an electrolyte with a sulphate environment is universally used.
- a conventional dimension stable anode (DSA) is used as non-soluble anode, for example consisting of titanium with a catalytic coating.
- Zinc is dissolved in a regenerator, to replenish the electrolyte.
- reactions occurring in the known method are: .at the cathode: Zn2+ + 2e ⁇ ⁇ Zn (I) .at the anode: 2H2O ⁇ 4H+ + 4e ⁇ + O2 ⁇ (II) .in the regenerator: Zn + 2H+ ⁇ Zn2+ + H2 ⁇ (III)
- an electrolyte containing chloride is used for electrolytically coating a steel strip with a zinc layer in a cell with a non-soluble anode
- reaction (II) instead of reaction (I) the following reaction occurs: .at the anode: 2Cl ⁇ ⁇ Cl2 ⁇ + 2e ⁇ (IV)
- the chlorine gas formed in reaction (IV) creates such great complications in the apparatus and for efficient processing, that the use of an electrolyte containing chloride ions has to be avoided. Suitable chloride-containing electrolytes are nevertheless available.
- the invention aims to solve the problem discussed above and to provide an improved method for electrolytically coating a steep strip with a layer containing zinc with the aid of a non-soluble anode while using an electrolyte containing chloride.
- a method of electrolytically coating a steel strip with a metal layer at least partly of zinc in an electrochemical cell having an insoluble anode wherein the strip acts as cathode and the electrolyte in the cell contains chloride ions and hydrogen in the form of a hydrogen gas or gas containing hydrogen is supplied to the anode, the anode being such that the anode reaction: H2 ⁇ 2H+ + 2e ⁇ (V) takes place, said reaction (V) predominating at the anode over the reaction: 2Cl ⁇ ⁇ Cl2 ⁇ + 2e ⁇ (IV).
- reaction (V) resulting from the supply of hydrogen to the anode
- reaction (IV) does not occur or is minor. Consequently chlorine gas no longer forms or forms only slightly so that it is possible to make use of an electrolyte containing chloride ions.
- the hydrogen ions formed become incorporated into the electrolyte by reaction (V) and may be used in a regenerator for supplementing the zinc in the electrolyte, for example according to reaction (III).
- hydrogen gas formed during reaction (III) in a regenerator is collected and then supplied to the anode for the reaction (V).
- the rate of reaction(V) at the anode is at least three times the rate of reaction (IV). Most preferably, the reaction (IV) at the anode is wholly suppressed.
- anode suitable for causing reaction (V) it is preferable to use an anode of the hydrogen gas diffusion anode type, in which the anode is a porous anode carrying a catalyst and has means for feeding the hydrogen gas or gas containing hydrogen to a face of the anode directed away from the cathode, so that the gas contacts the electrolyte in pores of the anode and at the boundary of the gas, the electrolyte and the anode the reaction (V) takes place under the influence of the catalyst.
- the voltage drop between the anode and the cathode is equal to or less than 10 V.
- the advantage obtained with the invention consists primarily in that the electrolyte containing chloride ions can typically have conductivity approximately three times higher than the electrolyte with sulphate ions. For this reason when a chloride electrolyte is used, at one and the same current density, a voltage drop occurs which is approximately 15 V less than when a sulphate electrolyte is used. In a zinc-coating line with a 300,000 ton per annum production this means a saving in electricity of approximately 75 GWh per annum, representing a saving of approximately FL 7,500,000.-- (Netherlands currency) each year at the present electricity price. This takes into account the costs of the hydrogen gas required.
- the invention is described above for coating a steel strip with a layer of zinc.
- the invention may equally be used for coating a steel strip with a layer having zinc as the main constituent, in which a part of the zinc is replaced by another metal in order to improve the properties of the layer.
- Examples of such alloys are zinc-nickel with 10-15% nickel and zinc-iron with 10-20% iron.
- the invention offers the additional advantage that there is no risk of Fe(OH)3 precipitation, in view of the fact that, if a chloride ion electrolyte with a chloride environment is used, no Fe3+ ions form, whereas they do form in a sulphate ion electrolyte.
- Fig. 1 shows a steel strip 1 coated with a layer containing zinc being produced in an electrochemical cell 2, comprising a rotating cathode roller 3 and an anode 4.
- the anode 4 shown in Fig. 1 is a radial type anode but it may alternatively be flat.
- the roller 3 and the anode 4 are connected to the negative and positive poles respectively of voltage supply 5. This permits steel strip 1 passing around the roller to function as the cathode in the electrochemical cell.
- Electrolyte is supplied at 6 at the gap between the cathode roller 3 and anode 4 and flows along this gap. The whole assembly is placed in a tank 7.
- reaction (I) causes a layer containing zinc to precipitate from the electrolyte, which contains chloride anions on to the steel strip.
- the used and zinc-ion impoverished electrolyte is collected at the bottom of the tank and taken by means of a pipe 8 to a circulation tank 9. From there the electrolyte is conveyed by a pump 10 through pipes 11 and 12 to a regenerator 13 where zinc 14 dissolves and enriches the electrolyte with zinc ions according to the reaction (III).
- the electrolyte thus enriched is taken to the electrochemical cell by means of a pipe 15, the circulation tank 9 and the pipes 11 and 16.
- the hydrogen gas formed and collected as a result of reaction (III) in the regenerator 13, optionally following scrubbing, is conveyed by means of a pipe 17 to the anode 4 and specifically to that side of anode 4 facing away from the cathode 3 for use in the reaction (V).
- the anode 4 used in the apparatus is a hydrogen gas diffusion anode which is described below.
- Fig. 2 shows the principle of a hydrogen gas diffusion anode.
- the anode 4 has a hydrophobic part 18 where the gas containing hydrogen is taken to the anode on the side of the anode facing away from the cathode. This part has coarse pores.
- the hydrophobic part consists of active carbon 19 held in a Teflon matrix 20 and the hydrophobic part is provided with a layer of Carbon Felt 21 (Torag paper) to help support the electrode and to help conductivity.
- the anode 4 has a hydrophilic part 22 with fine pores and a catalyst on the electrolyte side.
- the hydrophilic part consists of active carbon 23 charged with platinum 24 as catalyst, in a Teflon matrix and is 70 to 120 ⁇ m thick.
- the reaction (V) takes place in the fine pores at the three-way boundary surface of hydrogen gas, electrolyte and the active carbon 23. Under the influence of the catalyst 24 H+ ions form at this boundary surface.
- the gas containing hydrogen may be hydrogen or a mixture of hydrogen with one or more other gases or a compound of hydrogen such as natural gas, for example. However, preference is given to a gas that consists essentially of hydrogen.
- a steel strip is coated electrolytically with a layer containing zinc using the apparatus as shown in Figs. 1 and 2.
- the strip width is 1200 mm and the strip velocity of 100 m/min.
- a zinc coating weight of 70 g/m2 is applied.
- Use is made of an electrolyte containing zinc and chloride ions at a pH of about 2.
- the H2 consumption at the anode is about 32 kg per hour.
- the anode consists of porous graphite and the catalyst on it is Pt.
- Zn is supplied into the electrolyte in the regenerator.
- the hydrogen gas released in the regenerator is supplied (after a scrubbing process) to the anode.
- the concentrations in the electrolyte are: ZnCl2 135 g/l NaCl 230 g/l AlCl3.6H2O 22.5 g/l providing the ionic concentrations Zn2+ 60 g/l Cl ⁇ 250 g/l
- the current density is 200 a/dm2
- the anode/cathode spacing is 2 mm and the voltage drop across the cell is 6V.
- reaction (IV) at the anode is wholly suppressed.
- the anode/cathode spacing may be as much as 8 to 12 mm.
- Typical conditions for such a process are a strip width of 1,000 to 1,600 mm, a strip velocity of 70 to 200 m/min and a coating thickness of 30 to 100 g/m2 of zinc.
- a zinc coating production line may have a capacity of approximately 300,000 tons of zinc-coated steel strip per annum, which is determined by the current rectifier capacity of 1,000 kA.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electroplating Methods And Accessories (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL9100353 | 1991-02-27 | ||
NL9100353A NL9100353A (nl) | 1991-02-27 | 1991-02-27 | Werkwijze voor het elektrolytisch bekleden van staalband met een zinkhoudende laag met behulp van een onoplosbare anode. |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0501547A1 true EP0501547A1 (fr) | 1992-09-02 |
EP0501547B1 EP0501547B1 (fr) | 1995-08-02 |
Family
ID=19858944
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP92200362A Expired - Lifetime EP0501547B1 (fr) | 1991-02-27 | 1992-02-10 | Procédé de dépôt électrolytique sur une bande d'acier d'une couche métallique composé au moins partiellement de zinc |
Country Status (8)
Country | Link |
---|---|
EP (1) | EP0501547B1 (fr) |
KR (1) | KR940007178B1 (fr) |
AT (1) | ATE125887T1 (fr) |
CZ (1) | CZ281552B6 (fr) |
DE (1) | DE69203752T2 (fr) |
ES (1) | ES2075587T3 (fr) |
NL (1) | NL9100353A (fr) |
PL (1) | PL167731B1 (fr) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014079911A3 (fr) * | 2012-11-21 | 2015-04-02 | Tata Steel Ijmuiden B.V. | Procédé pour le dépôt électrolytique de revêtements contenant du chrome à partir d'électrolytes à base de chrome trivalent |
US20220307151A1 (en) * | 2021-03-29 | 2022-09-29 | Suat Sen | Control of texture and morphology of zinc films through pulsed methods from additive-free electrolytes |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR102065228B1 (ko) * | 2017-12-26 | 2020-01-10 | 주식회사 포스코 | 전주 도금 장치 |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0346981A1 (fr) * | 1988-06-14 | 1989-12-20 | Hoogovens Groep B.V. | Procédé pour métalliser par voie électrolytique un substrat métallique en forme de bande et dispositif pour réaliser ledit procédé |
-
1991
- 1991-02-27 NL NL9100353A patent/NL9100353A/nl not_active Application Discontinuation
-
1992
- 1992-02-10 ES ES92200362T patent/ES2075587T3/es not_active Expired - Lifetime
- 1992-02-10 DE DE69203752T patent/DE69203752T2/de not_active Expired - Fee Related
- 1992-02-10 AT AT92200362T patent/ATE125887T1/de active
- 1992-02-10 EP EP92200362A patent/EP0501547B1/fr not_active Expired - Lifetime
- 1992-02-26 PL PL92293621A patent/PL167731B1/pl unknown
- 1992-02-27 CZ CS92586A patent/CZ281552B6/cs unknown
- 1992-02-27 KR KR1019920003139A patent/KR940007178B1/ko not_active IP Right Cessation
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0346981A1 (fr) * | 1988-06-14 | 1989-12-20 | Hoogovens Groep B.V. | Procédé pour métalliser par voie électrolytique un substrat métallique en forme de bande et dispositif pour réaliser ledit procédé |
Non-Patent Citations (1)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 13, no. 21 (C-560)(3369) 18 January 1989 & JP-A-63 223 192 ( TANAKA KIKINZOKU KOGYO KK ) 16 September 1988 * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014079911A3 (fr) * | 2012-11-21 | 2015-04-02 | Tata Steel Ijmuiden B.V. | Procédé pour le dépôt électrolytique de revêtements contenant du chrome à partir d'électrolytes à base de chrome trivalent |
US20220307151A1 (en) * | 2021-03-29 | 2022-09-29 | Suat Sen | Control of texture and morphology of zinc films through pulsed methods from additive-free electrolytes |
Also Published As
Publication number | Publication date |
---|---|
KR940007178B1 (ko) | 1994-08-08 |
KR920016616A (ko) | 1992-09-25 |
NL9100353A (nl) | 1992-09-16 |
PL167731B1 (en) | 1995-10-31 |
ATE125887T1 (de) | 1995-08-15 |
CS58692A3 (en) | 1992-12-16 |
PL293621A1 (en) | 1992-11-02 |
DE69203752T2 (de) | 1995-12-21 |
EP0501547B1 (fr) | 1995-08-02 |
CZ281552B6 (cs) | 1996-11-13 |
ES2075587T3 (es) | 1995-10-01 |
DE69203752D1 (de) | 1995-09-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5162079A (en) | Process and apparatus for control of electroplating bath composition | |
US4555317A (en) | Cathode for the electrolytic production of hydrogen and its use | |
EP0369732A1 (fr) | Réaction d'oxydo-réduction électrochimique et dispositif | |
US5173170A (en) | Process for electroplating metals | |
EP0346981B1 (fr) | Procédé pour métalliser par voie électrolytique un substrat métallique en forme de bande et dispositif pour réaliser ledit procédé | |
US4560453A (en) | Efficient, safe method for decoppering copper refinery electrolyte | |
US4627899A (en) | Electrolytic cell and methods combining electrowinning and electrochemical reactions employing a membrane or diaphragm | |
EP0501547B1 (fr) | Procédé de dépôt électrolytique sur une bande d'acier d'une couche métallique composé au moins partiellement de zinc | |
US5173168A (en) | Method of making iron foil by electrodeposition | |
US5198095A (en) | Method for continuously manganese-electroplating or manganese-alloy-electroplating steel sheet | |
Dew et al. | The effect of Fe (II) and Fe (III) on the efficiency of copper electrowinning from dilute acid Cu (II) sulphate solutions with the chemelec cell: Part I. Cathodic and anodic polarisation studies | |
WO1999010564A3 (fr) | Procede et dispositif pour reguler la concentration de substances dans des electrolytes | |
EP0435835B1 (fr) | Procédé d'électroplacage d'un alliage de zinc et dispositif utilisé dans ce but | |
Dubrovsky et al. | An investigation of fluidized bed electrowinning of cobalt using 50 and 1000 amp cells | |
JPS6141799A (ja) | 電気錫メツキ浴への錫イオン補給法 | |
EP0550002B1 (fr) | Procédé d'étamage électrolytique | |
Nidola | Electrode materials for oxygen evolution cobalt treated lead vs. commercial lead and lead alloys | |
Murase et al. | Measurement of pH in the vicinity of a cathode during the chloride electrowinning of nickel | |
JPS6340868B2 (fr) | ||
Expósito et al. | Use of a hydrogen‐diffusion electrode in the electrochemical removal of lead from effluents of lead electrowinning processes | |
Wilcox et al. | The kinetics of electrode reactions III practical aspects | |
JPH07316874A (ja) | クロムめっき方法 | |
US4367128A (en) | Energy efficient self-regulating process for winning copper from aqueous solutions | |
JPH07150377A (ja) | 電気めっき液中のFe3+イオンおよび/またはCr6+イオンの還元方法 | |
JPH01212788A (ja) | 高純度電解鉄およびその製造方法ならびに電解槽 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 19920210 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE DE ES FR GB IT LU NL |
|
17Q | First examination report despatched |
Effective date: 19940726 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE DE ES FR GB IT LU NL |
|
REF | Corresponds to: |
Ref document number: 125887 Country of ref document: AT Date of ref document: 19950815 Kind code of ref document: T |
|
ITF | It: translation for a ep patent filed |
Owner name: JACOBACCI & PERANI S.P.A. |
|
REF | Corresponds to: |
Ref document number: 69203752 Country of ref document: DE Date of ref document: 19950907 |
|
ET | Fr: translation filed | ||
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2075587 Country of ref document: ES Kind code of ref document: T3 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: NL Payment date: 19951231 Year of fee payment: 5 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: BE Payment date: 19960116 Year of fee payment: 5 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: AT Payment date: 19960117 Year of fee payment: 5 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 19960119 Year of fee payment: 5 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 19960124 Year of fee payment: 5 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: LU Payment date: 19960201 Year of fee payment: 5 Ref country code: FR Payment date: 19960201 Year of fee payment: 5 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: ES Payment date: 19960213 Year of fee payment: 5 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19970210 Ref country code: GB Effective date: 19970210 Ref country code: AT Effective date: 19970210 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: ES Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19970211 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Effective date: 19970228 |
|
BERE | Be: lapsed |
Owner name: HOOGOVENS GROEP B.V. Effective date: 19970228 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Effective date: 19970901 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19970210 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Effective date: 19971030 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19971101 |
|
NLV4 | Nl: lapsed or anulled due to non-payment of the annual fee |
Effective date: 19970901 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FD2A Effective date: 19990405 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED. Effective date: 20050210 |