EP0157190B1 - Etching process for aluminium - Google Patents

Etching process for aluminium Download PDF

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Publication number
EP0157190B1
EP0157190B1 EP19850102400 EP85102400A EP0157190B1 EP 0157190 B1 EP0157190 B1 EP 0157190B1 EP 19850102400 EP19850102400 EP 19850102400 EP 85102400 A EP85102400 A EP 85102400A EP 0157190 B1 EP0157190 B1 EP 0157190B1
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Prior art keywords
process according
bath
pickling
aluminium
pickling bath
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Expired - Lifetime
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EP19850102400
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German (de)
French (fr)
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EP0157190A1 (en
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Prof. Dr. E. Plattner
Ch. Dr. Comninellis
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Cessione metallgesellschaft AG
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Individual
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Priority claimed from CH1325/84A external-priority patent/CH660201A5/en
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    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23FNON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F1/00Etching metallic material by chemical means
    • C23F1/10Etching compositions
    • C23F1/14Aqueous compositions
    • C23F1/32Alkaline compositions
    • C23F1/36Alkaline compositions for etching aluminium or alloys thereof
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23FNON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F1/00Etching metallic material by chemical means
    • C23F1/46Regeneration of etching compositions
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23GCLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/14Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions
    • C23G1/22Light metals
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23GCLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/36Regeneration of waste pickling liquors

Definitions

  • the low concentration of the pickling bath in dissolved substances also helps to keep the chemical loss caused by entrainment at a low level. The loss decreases even further if the pickled pieces are drained properly and the rinsing water is recycled.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)

Description

Die Erfindung betrifft ein Beizverfahren für Aluminium in einem Alkalilaugebad.The invention relates to a pickling process for aluminum in an alkali bath.

Die meisten Oberflächenveredelungsverfahren für Aluminium, z.B. die Eloxierung, setzen ein chemisches Beizen des Metalls voraus. Zur Durchführung des Beizens werden die entfetteten Aluminiumstücke z.B. in ein Natronlaugebad bei 50°C bis 70°C während 5 bis 15 Minuten getaucht. Dabei löst sich das Metall unter Bildung von Natriumaluminat und Wasserstoff auf nach der Gleichung:

Figure imgb0001
Das Lösen von 27 g Aluminium (1 mol) verbraucht 40 g Natronlauge (1 mol) und 18 g Wasser (1 mol) unter Bildung von 82 g gelöstem Natriumaluminat (1 mol) und 3 g Wasserstoff (1,5 mol).Most surface finishing processes for aluminum, such as anodizing, require chemical pickling of the metal. To carry out the pickling, the degreased aluminum pieces are immersed, for example, in a sodium hydroxide solution at 50 ° C. to 70 ° C. for 5 to 15 minutes. The metal dissolves with the formation of sodium aluminate and hydrogen according to the equation:
Figure imgb0001
Dissolving 27 g of aluminum (1 mol) consumes 40 g of sodium hydroxide solution (1 mol) and 18 g of water (1 mol) to form 82 g of dissolved sodium aluminate (1 mol) and 3 g of hydrogen (1.5 mol).

Die Badkonzentration an Natriumaluminat nimmt dabei zu, die Natronlauge und die entsprechende Beizkraft nehmen ab.The bath concentration of sodium aluminate increases, the sodium hydroxide solution and the corresponding pickling power decrease.

Die Badaktivität kann durch periodische Zugabe von zusätzlicher Natronlauge aufrechterhalten werden. Um die Bildung von festen anhaftenden Krusten von Aluminiumhydroxid zu vermeiden, wird ein Komplexbildner zugegeben.The bath activity can be maintained by periodically adding additional sodium hydroxide solution. A complexing agent is added to avoid the formation of solid adherent crusts from aluminum hydroxide.

Normalerweise ist eine mit 70 g/I Aluminium beladenes Bad abgenützt und muß durch eine frisches Bad ersetzt werden. Dieser Ersatz ist kostspielig und stellt ein Abwasserproblem dar, dessen Lösung erhebliche Kosten verursachen kann. Die stets sich verändernde Badzusammensetzung und aktivität führen außerdem zu einer unregelmäßigen Qualität der gebeizten Aluminiumstücke.A bath loaded with 70 g / l aluminum is normally worn out and must be replaced by a fresh bath. This replacement is costly and is a wastewater problem, the solution of which can be costly. The constantly changing bath composition and activity also lead to an irregular quality of the pickled aluminum pieces.

Die periodische Beseitigung der abgenützten Beizbäder kann vermieden werden, indem man die Konzentration an gelöstem Aluminium bis auf etwa 110 g/I steigen läßt. Bei dieser Konzentration enthält die mit den behandelten Stücken mitgeschleppte Badflüssigkeit so viel gelöstes Aluminium wie durch Beizen der entsprechenden Stücke im Bad entstanden ist. Ein stationärer Zustand wird erreicht; der Natronlauge- und Komplexbildnerverbrauch muß durch Zugabe entsprechender frischer Chemikalien ergänzt werden; die Gesamtmenge an gelöstem Aluminium gelangt mit dem Spülwasser in das Abwasser und muß aus einer verdünnten Lösung entfernt werden. Die praktisch konstante Beizbad-Zusammensetzung sorgt zwar für eine konstante Qualität der behandelten Stücke, die hohe Salzkonzentration führt aber oft zu Fleckenbildung auf den gebeizten Stücken während ihres Transports vom Beiz- zum Spülbad (vgl. J. H. Dailey, Plating and surfaces finishing, July 1982 S 22 und 45.The periodic removal of the worn pickling baths can be avoided by letting the concentration of dissolved aluminum rise to about 110 g / l. At this concentration, the bath liquid carried along with the treated pieces contains as much dissolved aluminum as was produced by pickling the corresponding pieces in the bath. A steady state is reached; the sodium hydroxide and complexing agent consumption must be supplemented by adding appropriate fresh chemicals; the total amount of dissolved aluminum gets into the wastewater with the rinse water and must be removed from a dilute solution. The practically constant pickling bath composition ensures a constant quality of the treated pieces, but the high salt concentration often leads to the formation of stains on the pickled pieces during their transport from the pickling to the rinsing bath (cf.JH Dailey, Plating and surfaces finishing, July 1982 p 22 and 45.

Ein weiterer Weg, das Problem der abgenützten Beizbäder zu lösen, besteht darin, einen Teil des Beizbades in einen separaten Behälter zu überführen und dort durch Temperaturänderung und Zugabe von beträchtlichen Mengen an Aluminiumhydroxid als Impfkeime die Fällung des Aluminiumhydroxids aus der Natronlaugelösung zu bewirken nach der Gleichung:

Figure imgb0002
Dabei wird Natronlauge in gleicher Menge regeneriert wie sie beim Beizen des Aluminiums verbraucht wurde. Nach Filtration und Waschung des Aluminiumhydroxids wird die so erhaltene alkalische Lösung wieder in das Beizbad rezyklisiert. Der Nachteil dieses Verfahrens liegt darin, daß eine aus Fäll- und Dekantierbehältern sowie Filterapparaten bestehende aufwendige Anlage in der Nähe des Beizbades installiert werden muß (vgl. C. J. Brown, Plating and surfaces finishing, June 1982, S 102).Another way to solve the problem of worn pickling baths is to transfer part of the pickling bath into a separate container and to cause the precipitation of the aluminum hydroxide from the sodium hydroxide solution by changing the temperature and adding considerable amounts of aluminum hydroxide as inoculants according to the equation :
Figure imgb0002
Sodium hydroxide solution is regenerated in the same amount as was used when pickling the aluminum. After filtration and washing of the aluminum hydroxide, the alkaline solution thus obtained is recycled back into the pickling bath. The disadvantage of this method is that a complex system consisting of precipitation and decanting containers and filter apparatus must be installed in the vicinity of the pickling bath (cf. CJ Brown, Plating and surface finishing, June 1982, p. 102).

Aus der EP-A-O 143 715 ist ein Beizbad bekannt, das neben NaOH oder KOH zwingend eine Komponente enthält, die ausgewählt ist aus Sulfiden, Thiosulfaten und/oder Sulfaten.EP-A-O 143 715 discloses a pickling bath which, in addition to NaOH or KOH, contains a component which is selected from sulfides, thiosulfates and / or sulfates.

Aus der DE-A-24 39 202 ist ein alkalisches Bad zum Ätzen von Aluminium und Aluminiumlegierungen bekannt, das neben Ätznatron und/oder Ätzkali und/oder weiteren für Beizbäder üblichen Zusätzen zwingend Polyhydroxycarboxylate enthält.From DE-A-24 39 202 an alkaline bath for the etching of aluminum and aluminum alloys is known which, in addition to caustic soda and / or caustic potash and / or other additives customary for pickling baths, contains polyhydroxycarboxylates.

In der DE-B-1 073 272 wird eine wäßrige Lösung zum Ätzen von Aluminium und seinen Legierungen beschrieben, die neben einem Alkalihydroxid und Weinsäure zwingend ein lösliches Phosphat enthält.DE-B-1 073 272 describes an aqueous solution for etching aluminum and its alloys, which in addition to an alkali hydroxide and tartaric acid necessarily contains a soluble phosphate.

Aufgabe der vorliegenden Erfindung war die Bereitstellung eines Beizverfahrens für Aluminium, das die vorstehend aufgezeigten Nachteile weitestgehend vermeidet und auf einfache und wirtschaftliche Weise zu einem gebeizten Aluminium von möglichst gleichbleibender Qualität führt.The object of the present invention was to provide a pickling process for aluminum, which largely avoids the disadvantages indicated above and leads in a simple and economical manner to a pickled aluminum of as constant a quality as possible.

Diese Aufgabe wird mit der vorliegenden Erfindung gelöst.This object is achieved with the present invention.

Gegenstand der Erfindung ist ein Beizverfahren für Aluminium in einem Alkalilaugebad gemäß Patentanspruch 1.The invention relates to a pickling process for aluminum in an alkali bath according to claim 1.

Zweckmäßigerweise wird mit einem verdünnten Beizbad gearbeitet, und vorzugsweise enthält das erfindungsgemaß eingesetzte Beizbad 1 bis wenigen als 10 g/I und insbesondere 3 bis 6 g/I Natron- oder Kalilauge; die Konzentration an gelöstem Aluminium liegt bevorzugt bei 2 bis 20 g/I, insbesondere 2 bis 15 g/I, besonders bevorzugt bei 4 bis 8 g/I. Diese geringen Alkalikonzentrationen ermöglichen die Ausfällung eines leicht filtrierbaren Aluminiumhydroxids und eine leichte Laugenregeneration direkt im Beizbad.It is expedient to work with a dilute pickling bath, and the pickling bath used according to the invention preferably contains 1 to a few than 10 g / l and in particular 3 to 6 g / l of sodium or potassium hydroxide solution; the concentration of dissolved aluminum is preferably 2 to 20 g / l, in particular 2 to 15 g / l, particularly preferably 4 to 8 g / l. These low alkali concentrations enable the precipitation of an easily filterable aluminum hydroxide and an easy regeneration of the alkali directly in the pickling bath.

Die geringe Konzentration des Beizbades an gelösten Stoffen trägt außerdem dazu bei, den durch Mitschleppen verursachten Chemikalienverlust auf einem geringen Wert zu halten. Der Verlust nimmt noch weiter ab, wenn man die gebeizten Stücke richtig abtropfen laßt und das Spülwasser rezyklisiert.The low concentration of the pickling bath in dissolved substances also helps to keep the chemical loss caused by entrainment at a low level. The loss decreases even further if the pickled pieces are drained properly and the rinsing water is recycled.

Die Temperatur des Beizbades liegt vorzugsweise zwischen 50 und 75°C.The temperature of the pickling bath is preferably between 50 and 75 ° C.

Die Konzentration an gelösten Stoffen bleibt während des Beizens des Aluminiums im wesentlichen konstant, weil das Aluminiumhydroxid laufend ausfällt, und soll vorzugsweise in dem oben als bevorzugt angegebenen Konzentrationsbereich liegen. Dies ermöglicht eine regelmäßige Beizgeschwindigkeit von 3 bis 7 g Aluminium pro m2 und Minute bei einer Badtemperatur von 50 bis 75°C. Die Qualität der behandelten Stücke ist gleichbleibend gut.The concentration of dissolved substances remains essentially constant during the pickling of the aluminum, because the aluminum hydroxide continuously fails, and should preferably be in the concentration range given above as preferred. This enables a regular pickling rate of 3 to 7 g aluminum per m 2 and minute at a bath temperature of 50 to 75 ° C. The quality of the treated pieces is consistently good.

Das während des Beizens gebildete Aluminiumhydroxid reichert sich im Beizbad an, ohne das Beizen zu stören. Es ist aber wünschenswert, den Feststoffgehalt des Bades zwischen 10 und 30 g/I zu halten, indem der Feststoff z.B. durch Dekantieren und/oder Filtrieren abgetrennt wird. Die Feststoffabtrennung kann chargenweise oder kontinuierlich durchgeführt werden, und wird zweckmäßigerweise jeweils in einem Teil des Beizbades durchgeführt. Die nach dem erfindungsgemäßen Verfahren erhaltene Filtrierform (Filtrationsrückstand) ist gut; der Filtrationskuchen ist leicht zu waschen und enthält mehr als 50% Feststoff, was die Auswertung des Aluminiumhydroxids erleichtert.The aluminum hydroxide formed during pickling accumulates in the pickling bath without disturbing the pickling. However, it is desirable to keep the solids content of the bath between 10 and 30 g / l by e.g. is separated by decanting and / or filtering. The solids separation can be carried out batchwise or continuously, and is expediently carried out in part of the pickling bath. The filtration form (filtration residue) obtained by the process according to the invention is good; The filtration cake is easy to wash and contains more than 50% solids, which makes it easier to evaluate the aluminum hydroxide.

Die Ausfällung von Aluminiumhydroxid kann durch Zugabe von Alkalisalzen, z.B. von Natriumcarbonat, vorzugsweise in einer Menge von 5 bis 100 g/I, insbesondere 20 bis 60 g/I, begünstigt werden. Der Aggregatzustand und damit die Filtrierbarkeit des gefällten Aluminiumhydroxids wird durch die Anwesenheit von Natriumgluconat beeinflußt. Zweckmäßig wird das Natriumgluconat in einer Menge Zugegeben, daß seine Konzentration im Bad zwischen 0,01 bis 1,0 g/I, insbesondere 0,1 bis 0,5 g/I beträgt.The precipitation of aluminum hydroxide can be carried out by adding alkali salts, e.g. of sodium carbonate, preferably in an amount of 5 to 100 g / l, in particular 20 to 60 g / l, favored. The physical state and thus the filterability of the precipitated aluminum hydroxide is influenced by the presence of sodium gluconate. The sodium gluconate is expediently added in an amount such that its concentration in the bath is between 0.01 to 1.0 g / l, in particular 0.1 to 0.5 g / l.

Die Lebensdauer des erfindungsgemäßen Beizbades ist praktisch unbegrenzt, wenn die durch Mitschleppen verursachten Verluste durch Zugabe der entsprechenden Mengen an frischen Chemikalien ergänzt werden. Diese Verluste und die entsprechenden Chemikalienkosten lassen sich auf einem Minimum halten, wenn man Filtrat und Waschwasser der Aluminiumhydroxid-Filtration sowie das Spülwasser der gebeizten Stücke in das Beizbad ganz oder teilweise zurückführt. Dieses Rückführen des Wasch- und Spülwassers dient ebenfalls zur Ergänzung des durch die Bildung des Aluminiumhydroxids und des durch Verdampfung entstandenen Wasserverlusts.The service life of the pickling bath according to the invention is practically unlimited if the losses caused by entrainment are supplemented by adding the appropriate amounts of fresh chemicals. These losses and the corresponding chemical costs can be kept to a minimum if the filtrate and washing water from the aluminum hydroxide filtration and the rinsing water of the pickled pieces are returned in whole or in part to the pickling bath. This return of the washing and rinsing water also serves to supplement the water loss caused by the formation of the aluminum hydroxide and the evaporation.

Der Ersatz und die Beseitigung der abgenützten Beizbäder ist nicht mehr erforderlich, wodurch eine beträchtliche Einsparung der Beizkosten erreicht werden kann. Die zur Durchführung des erfindungsgemäßen Beizverfahrens nötigen Zusatzinvestitionen sind gering und bestehen im wesentlichen aus den Kosten für eine Filtrationsanlage.The replacement and removal of the worn pickling baths is no longer necessary, which means that a considerable saving in pickling costs can be achieved. The additional investments required to carry out the pickling process according to the invention are low and essentially consist of the costs for a filtration system.

Claims (13)

1. Pickling process for aluminium in an alkali lye bath with simultaneous precipitation of aluminium hydroxide in situ and regeneration of the alkali lye consumed during pickling, wherein a pickling bath is used which contains less than 10 g/I caustic soda or caustic potash solution and also contains sodium gluconate as the complexing agent, and is free of sulphides, sulphates, phosphates and thiosulphates, and wherein the aluminium hydroxide occurring in the pickling bath is precipitated without alteration of the temperature of the pickling bath.
2. Process according to claim 1 characterised in that a pickling bath is used which contains 3 to 6 g/I caustic soda solution or caustic potash solution and 2 to 20 g/I dissolved aluminium.
3. Process according to claim 1 or 2 characterised in that an alkali salt is added to the pickling bath.
4. Process according to claim 3 characterised in that sodium carbonate is added as the alkali salt.
5. Process according to claim 4 characterised in that the sodium carbonate is added in a volume of 5 to 100 g/I.
6. Process according to one of the preceding claims characterised in that the sodium gluconate is added in a volume of 0.01 to 1.0 g/I.
7. Process according to one of the preceding claims characterised in that the temperature of the bath amounts to 50 to 75°C.
8. Process according to one of the preceding claims characterised in that the precipitated aluminium hydroxide is removed continually or batchwise from the pickling bath.
9. Process according to claim 8 characterised in that the aluminium hydroxide is removed when the solid content of the pickling bath exceeds 10 to 30 g/I.
10. Process according to claim 8 or 9 characterised in that the removal of the aluminium hydroxide is undertaken from a part of the bath.
11. Process according to one of claims 8 to 10 characterised in that the removal of the aluminium is carried out by decanting and/or filtering.
12. Process according to one of the preceding claims characterised in that the filtrate which arises on removing the aluminium hydroxide, and the washing water as well as the rinsing water of the pickled aluminium parts are returned wholly or partially to the pickling bath.
13. Process according to one of the preceding claims characterised in that the chemical losses of the pickling bath are replaced by adding corresponding amounts of fresh chemicals.
EP19850102400 1984-03-16 1985-03-04 Etching process for aluminium Expired - Lifetime EP0157190B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT85102400T ATE54679T1 (en) 1984-03-16 1985-03-04 PICKLING PROCESS FOR ALUMINUM.

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CH1325/84A CH660201A5 (en) 1984-03-16 1984-03-16 PROCESS FOR STRIPPING ALUMINUM IN AN ALKALINE LAUNDRY BATH.
CH1325/84 1984-03-16
DE3426114 1984-07-16
DE19843426114 DE3426114A1 (en) 1984-03-16 1984-07-16 Pickling process for aluminium

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Publication Number Publication Date
EP0157190A1 EP0157190A1 (en) 1985-10-09
EP0157190B1 true EP0157190B1 (en) 1990-07-18

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1932948A1 (en) * 2006-12-07 2008-06-18 Italtecno S.R.L. Apparatus and method for recovering caustic soda from caustic solutions
DE102008063729A1 (en) * 2008-11-03 2010-05-06 König, Thomas Process for pickling workpiece made of aluminum or aluminum alloy that is subjected to a sting bath with an alkaline pickling solution, comprises continuous or sectional drawing-off a partial quantity of the pickling solution from the bath
WO2010060408A2 (en) 2008-11-03 2010-06-03 Koenig Thomas Pickling method and pickling plant
DE102013108375A1 (en) * 2013-01-31 2014-07-31 Thomas König Process for the preparation of a pickling and / or anodizing bath and anodizing arrangement

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5512129A (en) * 1990-03-15 1996-04-30 Josef Gartner & Co. Method for regenerating alkaline solutions for pickling aluminum
DE4008379A1 (en) * 1990-03-15 1991-09-19 Gartner & Co J METHOD AND SYSTEM FOR REGENERATING ALUMINUM ALUMINUM SOLUTIONS WITH ALKALINE
CN112921316A (en) * 2021-01-20 2021-06-08 福建省闽发铝业股份有限公司 Green environment-friendly aluminum profile spraying pretreatment process

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1073272B (en) * 1960-01-14 Amchem Products Ine Ambler Pa (V St A) andsdale Mounted Route Pa (V St A) I solution and means for etching aluminum
US2653861A (en) * 1953-03-09 1953-09-29 Enthone Etching aluminum using hexahydroxyheptanoic acid as a modifier
US2884728A (en) * 1954-08-16 1959-05-05 Turco Products Inc Apparatus and method for removing metal from the surface of a metal object
FR1582144A (en) * 1968-06-24 1969-09-26
GB1420920A (en) * 1971-12-30 1976-01-14 Diversey Ltd Etching compositions
DE2439202C3 (en) * 1974-08-16 1979-09-27 Friedr. Blasberg Gmbh & Co Kg, 5650 Solingen Alkaline aqueous bath for etching aluminum and aluminum alloys
FR2555615B1 (en) * 1983-11-24 1990-05-11 Diversey France ALUMINUM PROCESSING BATH AND METHOD OF IMPLEMENTING SAID BATH AND CHEMICAL MACHINING

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1932948A1 (en) * 2006-12-07 2008-06-18 Italtecno S.R.L. Apparatus and method for recovering caustic soda from caustic solutions
DE102008063729A1 (en) * 2008-11-03 2010-05-06 König, Thomas Process for pickling workpiece made of aluminum or aluminum alloy that is subjected to a sting bath with an alkaline pickling solution, comprises continuous or sectional drawing-off a partial quantity of the pickling solution from the bath
WO2010060408A2 (en) 2008-11-03 2010-06-03 Koenig Thomas Pickling method and pickling plant
DE102013108375A1 (en) * 2013-01-31 2014-07-31 Thomas König Process for the preparation of a pickling and / or anodizing bath and anodizing arrangement

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