EP0054074B1 - Procede permettant de reduire et de regenerer un electrolyte contenant un sel d'etain - Google Patents

Procede permettant de reduire et de regenerer un electrolyte contenant un sel d'etain Download PDF

Info

Publication number
EP0054074B1
EP0054074B1 EP80901147A EP80901147A EP0054074B1 EP 0054074 B1 EP0054074 B1 EP 0054074B1 EP 80901147 A EP80901147 A EP 80901147A EP 80901147 A EP80901147 A EP 80901147A EP 0054074 B1 EP0054074 B1 EP 0054074B1
Authority
EP
European Patent Office
Prior art keywords
electrolyte
liter
grams
tin
ions
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
Application number
EP80901147A
Other languages
German (de)
English (en)
Other versions
EP0054074A1 (fr
EP0054074A4 (fr
Inventor
Yuji Fujisash Industries Ltd. Hinoda
Kazuhiro Fujisash Industries Ltd. Enmoto
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.)
Fujisash Co Ltd
Original Assignee
Fujisash Co 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 Fujisash Co Ltd filed Critical Fujisash Co Ltd
Publication of EP0054074A1 publication Critical patent/EP0054074A1/fr
Publication of EP0054074A4 publication Critical patent/EP0054074A4/fr
Application granted granted Critical
Publication of EP0054074B1 publication Critical patent/EP0054074B1/fr
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D21/00—Processes for servicing or operating cells for electrolytic coating
    • C25D21/16—Regeneration of process solutions
    • C25D21/18—Regeneration of process solutions of electrolytes

Definitions

  • This invention relates to a process for the reduction regeneration of an electro-plating bath or a coloring electrolyte for aluminum and more particularly to a process for the regeneration of an electrolyte by reducing stannic ions in the electrolyte into stannous ions through the addition of metallic tin to the used or old electrolyte.
  • a tin salt aqueous solution containing stannous ions (Sn 2+ ) is generally used as an electrolyte containing tin ions.
  • This aqueous solution containing stannous ions is very unstable since stannous ions are easily oxidized into stannic ions (Sn 4+ ) by oxygen in the air or oxygen generated during electrolysis.
  • stannic ions form in the electrolyte, the concentration of stannous ions in the electrolyte decreases and the current efficiency of electrolysis is reduced. Furthermore, it gives rise to the serious problem that the stannic ions become insoluble substances such as stannic acid, etc. which are likely to become colloids and therefore great difficulty is encountered in removing such insoluble substances by filtration. These insoluble substances attach onto the surface of the product and cause pitting thereon.
  • the regeneration of the electrolyte by the reduction thereof has been effected.
  • One of such regeneration methods is an electrolytic reduction method as described in Japanese Patent Publication No. 19856/1978.
  • this electrolytic reduction method of stannous ions and stannic ions which are present in the electrolyte, the stannous ions are first reduced into metallic tin and thereafter the stannic ions are reduced into metallic tin. Therefore, although this method is excellent, a greatly long processing time is required and equipment and operation costs are increased.
  • FR-A1 334 413 discloses the regeneration of electrolytes containing stannic and stannous fluo- borates, lead fluoborate and fluoboric acid by addition of metallic tin.
  • Object of the present invention is to provide a generally applicable method which removes the disadvantages in the prior art as described above and which permits the reduction of stannic ions in electrolytes in a short time and the formation of a regenerated electrolyte having a stable composition.
  • the stannic ions in the electrolyte are regenerated into stannous ions.
  • the unreacted metallic tin is taken out of the electrolyte and, as necessary, additional processings such as adjustment in the concentrations of other components in the electrolyte, adjustment in pH, etc are applied.
  • additional processings such as adjustment in the concentrations of other components in the electrolyte, adjustment in pH, etc are applied.
  • the thus regenerated electrolyte can be re-used.
  • the electrolyte can be repeatedly used by recycling. Furthermore, in accordance with the process of this invention, the processings can be continuously carried out and the processing time can be greatly shortened. For example, in the method as described in Japanese Patent Publication No. 19856/1978, the time required for the reduction of the stannic ions is 6 hours or more whereas in the process of this invention it is 1 hour or less and usually sufficient to be about 30 minutes.
  • the electrolyte for use in this invention is subject to no special limitations so long as it contains tin salts. In a fresh electrolyte, almost all of the tin ions are stannous ions and there are almost no stannic ions. As the electrolysis proceeds, the concentration of stannic ions increases whereas the concentration of stannous ions relatively decreases.
  • the process of this invention is applied to an electrolyte in which the concentration of stannic ions has increased to a certain extent, for example, the ratio of Sn4+/Snz+ has reached 1/2 or more.
  • the electrolyte contains a chelating agent in order to keep the stannous and stannic ions in the state that they are dissolved.
  • This control of the pH of the electrolyte is generally carried out by using acids.
  • acids releasing the same anions as those existing in the electrolyte such as sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, pyrophosphoric acid or various organic acids can be used singly or in admixtures comprising two or more thereof.
  • sulfuric acid is most preferable.
  • metallic sponge-like tin is added to the electrolyte of which the pH has been controlled as mentioned above, and the resulting electrolyte is heated.
  • the metallic sponge-like tin used has large specific surface areas.
  • Metallic sponge-like tin having such a high specific surface area can be produced as follows:
  • An acidic solution e.g., an electro-plating solution or a coloring electrolyte for aluminium
  • a direct current is passed through the electrolyte with electrically conductive material such as metal or carbon as anode and cathode whereby tin ions (Sn 2+ , Sn 4+ ) are deposited as metallic tin on the cathode.
  • electrically conductive material such as metal or carbon
  • tin ions Sn 2+ , Sn 4+
  • the thus obtained metallic tin is in a sponge form, has a high specific surface area and can be easily separated from the cathode.
  • the amount of the metallic tin added to the electrolyte is not limited and can be suitably determined depending upon the concentration of stannic ions in the electrolyte, the required concentration of stannous ions, etc. In general, it should be about 1 to 10 times moles of the amount required entirely to reduce stannic ions in the electrolyte. Even if the metallic tin is excessively added, the unreacted metallic tin precipitates in the bottom of the reactor and can easily be separated. Therefore, it imposes no specific hindrance onto the electrolyte and the metallic tin so separated can be re-used as it is.
  • the electrolyte to which the metallic tin has been added it is required to heat the electrolyte to which the metallic tin has been added at a temperature from 80°C to the boiling temperature of the electrolyte. If the electrolyte may be deteriorated in quality at high temperatures, the electrolyte to which the metallic sponge-like tin is added should be processed at the lower temperatures of the specified range.
  • the heating time it is sufficient that the reduction reaction proceeds to the desired extent. While the heating time cannot be determined unconditionally since it varies depending upon the shape and amount of the metallic tin to be added and other various conditions, it is usually sufficient to be 1 hour or less.
  • concentration of stannic sulfate is shown as a concentration converted to SnS0 4 .
  • a direct current was passed through an old or used coloring electrolyte for aluminum consisting of 9.0 grams/liter of stannous sulfate, 11.1 grams/liter of stannic sulfate, 70 grams/liter of citric acid and 20 grams/liter of sulfuric acid and having a pH of 1.5 with tin and stainless steel as anode and cathode respectively to deposit sponge-like metallic tin on the cathode.
  • Example 4 The procedure of Example 4 was repeated except that 100 mesh powdery tin reagent on the market was used in place of the sponge-like metallic tin. After heating, the obtained electrolyte contained 11.5 grams/liter of stannous sulfate and 9 grams/liter of stannic sulfate.
  • the process of this invention is greatly useful for the regeneration of an electroplating bath or a coloring electrolyte for aluminum containing tin salts.

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)

Claims (1)

  1. Procédé de régénération d'un électrolyte contenant des sels d'étain en réduisant les ions stanniques en ions stanneux en présence d'étain métallique à un pH acide, caractérisé en ce que l'électrolyte a un pH allant de 0,5 à 4, en ce qu'on ajoute de l'étain métallique spongieux dans ledit électrolyte et en ce qu'on chauffe ledit électrolyte contenant l'étain métallique ajouté à une température allant de 80°C jusqu'au point d'ébullition dudit électrolyte.
EP80901147A 1980-06-23 1980-06-23 Procede permettant de reduire et de regenerer un electrolyte contenant un sel d'etain Expired EP0054074B1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP1980/000141 WO1982000036A1 (fr) 1980-06-23 1980-06-23 Procede permettant de reduire et de regenerer un electrolyte contenant un sel d'etain

Publications (3)

Publication Number Publication Date
EP0054074A1 EP0054074A1 (fr) 1982-06-23
EP0054074A4 EP0054074A4 (fr) 1982-11-16
EP0054074B1 true EP0054074B1 (fr) 1987-05-13

Family

ID=13706055

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80901147A Expired EP0054074B1 (fr) 1980-06-23 1980-06-23 Procede permettant de reduire et de regenerer un electrolyte contenant un sel d'etain

Country Status (3)

Country Link
EP (1) EP0054074B1 (fr)
DE (1) DE3071971D1 (fr)
WO (1) WO1982000036A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4330068A1 (de) * 1993-09-06 1995-03-09 Heraeus Gmbh W C Verfahren zum Regenerieren und Stabilisieren von cyanidischen Silber-Zinn-Bädern

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1334413A (fr) * 1962-06-25 1963-08-09 Coussinets Ste Indle Procédés de préparation ou de régénération de bains mixtes de fluoborates de plomb et d'étain
JPS5139542A (ja) * 1974-10-02 1976-04-02 Fuji Satsushi Kogyo Kk Suzuensuiyoekinioite dai 2 suzuenodai 1 suzuennisaiseisuru hoho oyobi sochi
JPS5289536A (en) * 1976-01-23 1977-07-27 Nippon Steel Corp Method of melting at high speed tin to be poured in tin plating bath

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2747750B2 (ja) * 1991-11-16 1998-05-06 住友重機械工業株式会社 屋内式ばら物払出装置
JPH05289536A (ja) * 1992-04-10 1993-11-05 Matsushita Electric Ind Co Ltd 電子写真装置の感光体・中間転写体駆動装置

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1334413A (fr) * 1962-06-25 1963-08-09 Coussinets Ste Indle Procédés de préparation ou de régénération de bains mixtes de fluoborates de plomb et d'étain
JPS5139542A (ja) * 1974-10-02 1976-04-02 Fuji Satsushi Kogyo Kk Suzuensuiyoekinioite dai 2 suzuenodai 1 suzuennisaiseisuru hoho oyobi sochi
JPS5289536A (en) * 1976-01-23 1977-07-27 Nippon Steel Corp Method of melting at high speed tin to be poured in tin plating bath

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, vol. 4, no. 178 (C-34)(660), December 10, 1980, TOKYO (JP) *

Also Published As

Publication number Publication date
EP0054074A1 (fr) 1982-06-23
WO1982000036A1 (fr) 1982-01-07
DE3071971D1 (en) 1987-06-19
EP0054074A4 (fr) 1982-11-16

Similar Documents

Publication Publication Date Title
CA1256819A (fr) Methode pour regenerer une solution ammoniacale decapante usee pour cuivre, renfermant du cuivre sous forme de solute
US3788915A (en) Regeneration of spent etchant
US4265722A (en) Method of processing the surface of workpieces including particularly the etching of surfaces containing copper or copper alloys
US4432844A (en) Process for regeneration of electrolyte containing tin salts by reducing the same
EP0054074B1 (fr) Procede permettant de reduire et de regenerer un electrolyte contenant un sel d'etain
US4297178A (en) Ruthenium electroplating and baths and compositions therefor
JP7122315B2 (ja) 電極及びその製造方法並びに再生電極の製造方法
US4164456A (en) Electrolytic process
US2578898A (en) Electrolytic removal of metallic coatings from various base metals
US3259557A (en) Method of electrodepositing aluminum
US2436244A (en) Metalworking and strippingplating process
US2182567A (en) Production of metal powders
US3458407A (en) Method of producing nickel powder
US3412000A (en) Cathodic protection of titanium surfaces
US5112447A (en) Process for electroplating
CA1186275A (fr) Methode de regeneration des electrolytes a teneur de sels stanneux par seduction de ces derniers
US1857664A (en) Treatment of gold and silver
US2831803A (en) Electro-deposition of alloys
US2131427A (en) Process of electrolytically depositing iron and nickel alloy
JPH0699178A (ja) 化学メッキ廃液の電解処理方法
JPS604280B2 (ja) 錫塩含有電解液の還元再生方法
US4240888A (en) Method of electrochemically processing metallic surfaces of workpieces
US4483752A (en) Valve metal electrodeposition onto graphite
US3640805A (en) Removal of nitrate contamination from nickel-plating solutions
JPH0438834B2 (fr)

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

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB LU SE

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: FUJISASH COMPANY

17P Request for examination filed

Effective date: 19820703

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB LU SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19870531

REF Corresponds to:

Ref document number: 3071971

Country of ref document: DE

Date of ref document: 19870619

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: 19870630

ET Fr: translation filed
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
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19890529

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19890630

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19890822

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19900623

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19910228

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19910301

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST