EP0575699A2 - Process and apparatus for regenerating metal ions and sulfuric acid containing aqueous solutions and use thereof - Google Patents

Process and apparatus for regenerating metal ions and sulfuric acid containing aqueous solutions and use thereof Download PDF

Info

Publication number
EP0575699A2
EP0575699A2 EP93104001A EP93104001A EP0575699A2 EP 0575699 A2 EP0575699 A2 EP 0575699A2 EP 93104001 A EP93104001 A EP 93104001A EP 93104001 A EP93104001 A EP 93104001A EP 0575699 A2 EP0575699 A2 EP 0575699A2
Authority
EP
European Patent Office
Prior art keywords
sulfuric acid
anolyte
ions
catholyte
solution containing
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.)
Withdrawn
Application number
EP93104001A
Other languages
German (de)
French (fr)
Other versions
EP0575699A3 (en
Inventor
Ulrich Dr. Ströder
Lothar Schneider
Wolfgang Dr. Blatt
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.)
De Nora Deutschland GmbH
Original Assignee
Heraeus Elektrochemie GmbH
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 Heraeus Elektrochemie GmbH filed Critical Heraeus Elektrochemie GmbH
Publication of EP0575699A2 publication Critical patent/EP0575699A2/en
Publication of EP0575699A3 publication Critical patent/EP0575699A3/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING 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
    • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
    • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
    • C23G1/36—Regeneration of waste pickling liquors

Definitions

  • the invention relates to a method for regenerating an aqueous solution containing metal ions and sulfuric acid, in particular a solution containing zinc ions, nickel ions, iron ions and / or copper ions, in an electrolytic cell, the metal ions being deposited on the surface of the cathode and on the anode by water decomposition Oxygen and protons are formed, as well as the use of the method and device.
  • Such a direct regeneration of a zinc chloride solution is known from DE-OS 25 39 137, according to which the chloride ion-containing solution is introduced into a cathode chamber of an electrolysis cell, which is divided into 3 chambers, namely an anode chamber, a cathode chamber and an electrolyte chamber arranged between them ; the anode chamber is bounded by a porous diaphragm of low permeability, which separates the anolyte from the electrolyte, the anolyte containing sulfuric acid.
  • the anions of the anolyte have an oxidation potential that is high enough to ensure that essentially only the decomposition of water at the anode takes place under operating conditions, while the cathode chamber is delimited by a relatively high permeability through a diaphragm.
  • the anolyte has a substance capable of combining with the chloride ions entering the anode chamber so as to prevent oxidation of chloride ions at the anode.
  • the liquid level of the anolyte if necessary, is always kept so that the liquid level lies above the liquid level of the neighboring electrolyte, so as to maintain the desired flow rate through the diaphragm in order to achieve the technical purposes.
  • the anolyte contains a silver sulfate additive to ensure the precipitation of the chloride as silver chloride.
  • a problem with this arrangement is the comparatively complex division of the electrolyte space into 3 chambers and the use of diaphragms, the permeability of which can change significantly in the course of the electrolytic process.
  • Other problems include the addition of chemicals to silver sulfate, the formation of silver chloride and its removal from the cell, and the risk of diaphragm blockages due to silver chloride precipitation.
  • the object of the invention is to provide a method and a device by means of which sulfuric acid pickling or extraction solutions which are heavily contaminated with metal ions are to be demetallized to the greatest possible extent, at the same time a pure, highly concentrated sulfuric acid is to be obtained.
  • the cathodic deposition of hydrogen as can occur in particular in aqueous solutions with a relatively low metal ion concentration, should be avoided with certainty.
  • the process is to be used as an intermediate stage of a chlorine gas-free regeneration of pickling or extraction solutions.
  • the invention is achieved in that the solution containing metal ions is introduced as a catholyte into an electrolysis cell which is subdivided using an anion exchange membrane which is stable to sulfuric acid, sulfate ions from the catholyte passing through the anion exchange membrane due to the voltage applied to the electrodes in the solution Anolytes migrate and sulfuric acid is generated with the anodically formed protons and the sulfuric acid concentration in the anolyte is constantly increased.
  • the concentrated sulfuric acid is removed from the anolyte.
  • a major advantage of the process is that the concentrated sulfuric acid can be returned to the pickling or extraction process as a fresh solution component in the manner of a cycle, and that the cathodically deposited metal can also be recycled.
  • the process can be carried out either batchwise or continuously, with a solution being supplied as catholyte in batch operation, the sulfuric acid concentration of which corresponds in each case to the initial concentration of the anolyte; on the other hand, if the solution is fed continuously as catholyte, its sulfuric acid concentration must generally always be below the sulfuric acid concentration of the anolyte.
  • a solution with a sulfuric acid concentration in the range from 60 to 80 g / l is supplied as the catholyte.
  • the cathodic deposition takes place at a current density in the range from 250 to 1500 A / m 2.
  • the cathode is removed from the catholyte space after the metal deposition has reached a predetermined layer thickness.
  • the electrolytic cell is divided into an anolyte space and a catholyte space by means of an anion exchange membrane which is stable with respect to sulfuric acid, in that the catholyte space has at least one opening for supplying the solution containing metal ions and the anolyte space has at least one opening for removing electrolysis formed sulfuric acid, the cathode being electrically and mechanically detachable for removing the deposited metal.
  • the process according to the invention is preferably used as a subsequent process step in a pickling or extraction process, in which, in a first process step, a solution containing chloride ions is converted into a solution containing sulfate ions by means of the ion exchange process.
  • a major advantage of the invention is the fact that the metal can be separated from a metal ion-containing sulfate solution in a simple, inexpensive manner, at the same time a concentration of the sulfuric acid of the anolyte takes place in the form of a cycle, which in turn is used to continue the regeneration process .
  • Figure 1 shows schematically in longitudinal section an electrolysis cell.
  • Figure 2 shows schematically the process flow in the form of a circuit.
  • the electrolysis device has a trough 1, the interior of which is divided into an anolyte space 3 and a catholyte space 4 by means of an anion exchange membrane 2.
  • the anode 5 located in the anolyte compartment 3 consists of a dimensionally stable valve metal electrode, in particular titanium electrode, which is connected to the positive pole 6 of a DC voltage source 7.
  • the basic structure of such dimensionally stable valve metal electrodes, in particular titanium electrodes, is known from chloralkali electrolysis and is described, for example, in DE-OS 20 41 250.
  • the cathode 8 located in the catholyte space 4 is made of expanded copper, it is connected via a detachable electrical connection 9 to the negative pole 10 of the direct voltage source.
  • an aqueous sulfuric acid solution which is fed in at the beginning of the process via feed line 11 to produce the ion conduit, water possibly being added during the electrolysis process and the additional sulfuric acid formed being able to be removed via outlet 12 of the anolyte compartment 3 and the regeneration process, for example pickling can be fed again.
  • the sulfate solution containing zinc ions is fed continuously to the catholyte space 4 via feed line 13, the sulfuric acid concentration of the catholyte generally corresponding at most to that of the anolyte; the sulfuric acid concentration of the anolyte is in the range of 70 g / l.
  • the electrolysis process begins, the charge being transported by applying the voltage source 7 during the electrolysis through the ion exchange membrane 2 by means of the sulfate ions, which are symbolically designated by reference number 13.
  • the zinc ions are symbolically provided with reference number 14 and are discharged at the cathode 8, metallic zinc being deposited.
  • the anolyte compartment 3 there is a decomposition of the water portion of the anolyte solution, the oxygen being removed as gas from the open trough 1 and the hydrogen ions being recombined together with the sulfate ions to form sulfuric acid, which is concentrated in the course of the electrolysis process and via the outlet 12 is removed to the pickling process.
  • the sulfuric acid concentration of the anolyte is adjusted with the aid of pH-value meters and a control circuit, which maintains the predetermined sulfuric acid concentration or the sulfuric acid by removing the concentrated sulfuric acid and supplying water via line 11 adjusts the concentration of the catholyte.
  • the catholyte supplied as a pickling solution has a zinc ion concentration of approximately 170 g / l and a sulfuric acid concentration in the range of 70 g / l.
  • the cathode 8 is made in the form of a copper expanded metal, while the anode 5 consists of the dimensionally stable titanium anode already mentioned. Zinc is applied to the cathode 8 in a compact deposition quality.
  • the current density of the cathode is in the range from 250 to 1500 A / m 2 .
  • the same electrolysis device can also be used for batchwise operation, in which case the anolyte is removed batchwise or continuously within certain concentration ranges, while the catholyte side is replenished in batches.
  • the sulfate solution containing zinc ions flowing out of outlet 21 of a pickling device 20 is fed via feed line 13 to the catholyte compartment 4 of the electrolysis cell having a trough 1 with an anion exchange membrane 2, the zinc deposited in the catholyte compartment - represented schematically by reference number 22 - from the catholyte compartment 4 is discharged.
  • the concentrated aqueous sulfuric acid solution which forms in the anolyte compartment 3 is fed via outlet 12 and line 23 as a fresh component for the pickling process via feed 24 to the pickling device 20.
  • the process cycle of the solution containing sulfuric acid is shown in FIG. 2, the used pickling solution being fed as an aqueous sulfate solution containing metal ions to the electrolytic cell via outlet 21 of the pickling device 20 and feed line 13 of the cell, while the practically pure concentrated sulfuric acid is in turn fed via line 23 to the cell Pickling process is supplied.
  • the deposited zinc is removed from this cell cycle by removal from the cell; it can also be used again.
  • a membrane of the ARA type from MORGANE (France) is used as the anion exchange membrane.

Landscapes

  • 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)
  • Electrolytic Production Of Metals (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)

Abstract

For regeneration, an aqueous solution containing metal ions and sulphuric acid, in particular a solution containing zinc ions, iron ions and/or copper ions, for the purpose of cathodic separation of the metal ions, is introduced into the catholyte chamber of an electrolysis cell subdivided by an anion exchanger membrane into an anolyte and catholyte chamber, sulphate ions migrating from the catholyte chamber through the anion exchanger membrane because of the voltage applied to the electrodes into the anolyte chamber and sulphuric acid being formed there by means of the protons formed by anodic water decomposition, the concentration of which sulphuric acid continuously increases in the anolyte. In the anolyte chamber a pure highly concentrated sulphuric acid is formed which can be reused for pickling or extraction processes. The regeneration is intended to be used as an intermediate stage of a chlorine-gas-free regeneration of pickling or extraction solutions.

Description

Die Erfindung betrifft ein Verfahren zur Regenerierung einer Metallionen und Schwefelsäure enthaltenden wässrigen Lösung, insbesondere einer Zinkionen, Nickelionen, Eisenionen und/oder Kupferionen enthaltenden Lösung, in einer elektrolytischen Zelle, wobei die Metallionen auf der Oberfläche der Kathode abgeschieden werden und an der Anode durch Wasserzersetzung Sauerstoff und Protonen gebildet werden, sowie die Verwendung des Verfahrens und eine Vorrichtung.The invention relates to a method for regenerating an aqueous solution containing metal ions and sulfuric acid, in particular a solution containing zinc ions, nickel ions, iron ions and / or copper ions, in an electrolytic cell, the metal ions being deposited on the surface of the cathode and on the anode by water decomposition Oxygen and protons are formed, as well as the use of the method and device.

Aus dem Lehrbuch "Praktische Galvanotechnik" aus dem Leuze Verlag, Saulgau/Württemberg, 1970 ist es gemäß der Seiten 537, 538 bekannt, Zink aus Sulfat-Elektrolyten kathodisch abzuscheiden. Solche Sulfat-Elektrolyte entstehen bei der Umwandlung von Zinkchlorid-Lösungen in Zinksulfat-Lösungen mittels lonenaustauscher-Verfahren, wobei dieser vorgeschaltete Verfahrensschritt eine elektrolytische Behandlung von Chlorid-Elektrolyten vermeiden soll, weil bei der elektrolytischen Aufbereitung von Zinkchlorid-Elektrolyten Chlor entstehen würde und ein erhebliches Gefahrenpotential mit sich bringen würde.From the textbook "Practical Electroplating" from Leuze Verlag, Saulgau / Württemberg, 1970 it is known according to pages 537, 538 to cathodically deposit zinc from sulfate electrolytes. Such sulfate electrolytes are formed during the conversion of zinc chloride solutions into zinc sulfate solutions by means of the ion exchange process, this preceding process step being intended to avoid electrolytic treatment of chloride electrolytes, because chlorine would be formed during the electrolytic treatment of zinc chloride electrolytes and a considerable amount Would bring potential danger.

Eine solche direkte Regeneration einer Zinkchlorid-Lösung ist aus der DE-OS 25 39 137 bekannt, wonach die chloridionenhaltige Lösung in eine Kathodenkammer einer Elektrolysezelle eingeführt wird, die in 3 Kammern unterteilt ist, nämlich in eine Anodenkammer, eine Kathodenkammer und eine dazwischen angeordnete Elektrolytkammer; die Anodenkammer ist dabei von einem porösen Diaphragma von geringer Permeabilität umgrenzt, welche den Anolyten vom Elektrolyten trennt, wobei der Anolyt schwefelsäurehaltig ist. Die Anionen des Anolyten weisen ein Oxidationspotential auf, das hoch genug ist, um zu gewährleisten, das im wesentlichen nur die Zersetzung von Wasser an der Anode unter Betriebsbedingungen stattfindet, während die Kathodenkammer von einem Diaphragma verhältnismäßig hohe Permerabilität umgrenzt ist. Der Anolyt weist eine Substanz auf, die imstande ist, sich mit den Chloridionen, die in die Anodenkammer eintreten, zu verbinden, um so eine Oxidation von Chloridionen an der Anode zu verhindern. Der Flüssigkeitspegel des Anolyten wird ggf. durch Anolytnachführung stets so gehalten, daß der Flüssigkeitspegel oberhalb des Flüssigkeitspegels des benachbarten Elektrolyten liegt, um so die gewünschte Strömungsgeschwindigkeit durch das Diaphragma zur Erreichung der technischen Zwecke aufrechtzuerhalten. Um zu verhindern, daß Chloridionen die durch das Anodendiaphragma einsickern, zu Chlorgas oxidiert werden, enthält der Anolyt einen Silbersulfatzusatz, um die Ausfällung des Chlorids als Silberchlorid sicherzustellen.Such a direct regeneration of a zinc chloride solution is known from DE-OS 25 39 137, according to which the chloride ion-containing solution is introduced into a cathode chamber of an electrolysis cell, which is divided into 3 chambers, namely an anode chamber, a cathode chamber and an electrolyte chamber arranged between them ; the anode chamber is bounded by a porous diaphragm of low permeability, which separates the anolyte from the electrolyte, the anolyte containing sulfuric acid. The anions of the anolyte have an oxidation potential that is high enough to ensure that essentially only the decomposition of water at the anode takes place under operating conditions, while the cathode chamber is delimited by a relatively high permeability through a diaphragm. The anolyte has a substance capable of combining with the chloride ions entering the anode chamber so as to prevent oxidation of chloride ions at the anode. The liquid level of the anolyte, if necessary, is always kept so that the liquid level lies above the liquid level of the neighboring electrolyte, so as to maintain the desired flow rate through the diaphragm in order to achieve the technical purposes. To prevent chloride ions that seep through the anode diaphragm from being oxidized to chlorine gas, the anolyte contains a silver sulfate additive to ensure the precipitation of the chloride as silver chloride.

Als problematisch erweist sich bei dieser Anordnung, die verhältnismäßig aufwendige Aufteilung des Elektrolytraumes in 3 Kammern, sowie der Einsatz von Diaphragmen, deren Permeabilität sich im Laufe des elektrolytischen Prozesses stark verändern kann. Weitere Probleme sind in der Chemikalienzugabe von Silbersulfat, der Bildung von Silberchlorid und dessen Entfernung aus der Zelle sowie in der Gefahr von Diaphragmaverstopfungen durch Silberchlorid-Ausfällungen zu sehen.A problem with this arrangement is the comparatively complex division of the electrolyte space into 3 chambers and the use of diaphragms, the permeability of which can change significantly in the course of the electrolytic process. Other problems include the addition of chemicals to silver sulfate, the formation of silver chloride and its removal from the cell, and the risk of diaphragm blockages due to silver chloride precipitation.

Weiterhin sind in dem Buch "Angewandte Elektrochemie" von A. Schmidt, Verlag Chemie Weinheim 1976, auf Seite 210 Voraussetzungen genannt, nach denen Zink aus wässrigen Lösungen trotz seines elektronegativen Standardpotentials von -0,763V wegen der hohen Überspannung des Wasserstoffs am Zink abgeschieden werden kann; hierzu wird angeführt, daß für die Abscheidung von Zink eine relativ hohe Zink-Ionenkonzentration an der Kathode erforderlich ist, da sonst wegen der ansteigenden Schwefelsäure-Konzentration von einem gewissen Zeitpunkt ab an Stelle von Zink Wasserstoff kathodisch abgeschieden würde. Auf Seite 213 des gleichen Buches sind verschiedene Beispiele von Zink-ElektrolyseVerfahren angegeben.Furthermore, in the book "Applied Electrochemistry" by A. Schmidt, Verlag Chemie Weinheim 1976, on page 210, conditions are mentioned under which zinc can be separated from aqueous solutions despite its electronegative standard potential of -0.763V due to the high overvoltage of the hydrogen on the zinc ; for this purpose it is stated that a relatively high zinc ion concentration at the cathode is required for the deposition of zinc, since otherwise hydrogen would be deposited cathodically instead of zinc at a certain point in time because of the increasing sulfuric acid concentration. Various examples of zinc electrolysis processes are given on page 213 of the same book.

Die Erfindung stellt sich die Aufgabe, ein Verfahren und eine Vorrichtung anzugeben, mittels derer stark mit Metallionen belastete schwefelsaure Beiz- oder Extraktions-Lösungen möglichst weitgehend entmetallisiert werden sollen, wobei gleichzeitig eine reine, hochkonzentrierte Schwefelsäure gewonnen werden soll. Dabei soll die kathodische Abscheidung von Wasserstoff, wie sie insbesondere bei wässrigen Lösungen mit relativ geringer Metall-lonenkonzentration auftreten kann, mit Sicherheit vermieden werden.The object of the invention is to provide a method and a device by means of which sulfuric acid pickling or extraction solutions which are heavily contaminated with metal ions are to be demetallized to the greatest possible extent, at the same time a pure, highly concentrated sulfuric acid is to be obtained. The cathodic deposition of hydrogen, as can occur in particular in aqueous solutions with a relatively low metal ion concentration, should be avoided with certainty.

Das Verfahren soll als Zwischenstufe einer chlorgasfreien Regeneration von Beiz- oder Extraktions-Lösungen verwendet werden.The process is to be used as an intermediate stage of a chlorine gas-free regeneration of pickling or extraction solutions.

Weiterhin soll eine Verwendung angegeben werden, wonach die in der Lösung enthaltenden Substanzen möglichst weitgehend wiederverwendet werden können.Furthermore, a use is to be specified according to which the substances contained in the solution can be reused as far as possible.

Die Erfindung wird verfahrensgemäß dadurch gelöst, daß in eine, unter Verwendung einer gegen Schwefelsäure stabilen Anionen-Austauschermembran unterteilte Elektrolysezelle die Metallionen enthaltende Lösung als Katholyt eingebracht wird, wobei Sulfationen aus dem Katholyten durch die Anionen-Austauschermembran aufgrund der an den Elektroden anliegenden Spannung in den Anolyten wandern und mit den anodisch gebildeten Protonen Schwefelsäure erzeugt wird und die Schwefelsäurekonzentration im Anolyten ständig erhöht wird.According to the method, the invention is achieved in that the solution containing metal ions is introduced as a catholyte into an electrolysis cell which is subdivided using an anion exchange membrane which is stable to sulfuric acid, sulfate ions from the catholyte passing through the anion exchange membrane due to the voltage applied to the electrodes in the solution Anolytes migrate and sulfuric acid is generated with the anodically formed protons and the sulfuric acid concentration in the anolyte is constantly increased.

In einer bevorzugten Ausführungsform des Verfahrens wird die aufkonzentrierte Schwefelsäure aus dem Anolyten abgeführt.In a preferred embodiment of the process, the concentrated sulfuric acid is removed from the anolyte.

Weitere vorteilhafte Ausgestaltungen des Verfahrens sind in den Ansprüchen 3 bis 7 angegeben.Further advantageous embodiments of the method are given in claims 3 to 7 ben.

Ein wesentlicher Vorteil des Verfahrens ist darin zu sehen, daß die aufkonzentrierte Schwefelsäure nach Art eines Kreislaufs dem Beiz- oder Extraktionsvorgang als frischer Lösungsbestandteil wieder zugeführt werden kann und daß das kathodisch abgeschiedene Metall ebenfalls einer Wiederverwertung zugeführt werden kann.A major advantage of the process is that the concentrated sulfuric acid can be returned to the pickling or extraction process as a fresh solution component in the manner of a cycle, and that the cathodically deposited metal can also be recycled.

Das Verfahren kann sowohl chargenweise als auch kontinuierlich durchgeführt werden, wobei im Chargenbetrieb eine Lösung als Katholyt zugeführt wird, deren Schwefelsäurekonzentration jeweils der Anfangskonzentration des Anolyten entspricht; wird dagegen die Lösung als Katholyt kontinuierlich zugeführt, muß deren Schwefelsäurekonzentration in der Regel stets unterhalb der Schwefelsäurekonzentration des Anolyten liegen. Als Katholyt wird eine Lösung mit einer Schwefelsäurekonzentration im Bereich von 60 bis 80 g/I zugeführt. Die kathodische Abscheidung erfolgt bei einer Stromdichte im Bereich von 250 bis 1500 A/m2. Die Kathode wird nach Erreichen einer vorgegebenen Schichtstärke der Metallabscheidung aus dem Katholytraum entnommen.The process can be carried out either batchwise or continuously, with a solution being supplied as catholyte in batch operation, the sulfuric acid concentration of which corresponds in each case to the initial concentration of the anolyte; on the other hand, if the solution is fed continuously as catholyte, its sulfuric acid concentration must generally always be below the sulfuric acid concentration of the anolyte. A solution with a sulfuric acid concentration in the range from 60 to 80 g / l is supplied as the catholyte. The cathodic deposition takes place at a current density in the range from 250 to 1500 A / m 2. The cathode is removed from the catholyte space after the metal deposition has reached a predetermined layer thickness.

Die Aufgabe wird vorrichtungsgemäß dadurch gelöst, daß die Elektrolysezelle mittels einer gegenüber Schwefelsäure stabilen Anionen-Austauschermembran in einen Anolytraum und einen Katholytraum unterteilt ist, daß der Katholytraum wenigstens eine Öffnung zur Zufuhr der Metallionen enthaltenden Lösung und der Anolytraum wenigstens eine Öffnung zur Abfuhr der mittels Elektrolyse gebildeten Schwefelsäure aufweist, wobei die Kathode zur Entnahme des abgeschiedenen Metalls elektrisch und mechanisch lösbar ist.The object is achieved according to the device in that the electrolytic cell is divided into an anolyte space and a catholyte space by means of an anion exchange membrane which is stable with respect to sulfuric acid, in that the catholyte space has at least one opening for supplying the solution containing metal ions and the anolyte space has at least one opening for removing electrolysis formed sulfuric acid, the cathode being electrically and mechanically detachable for removing the deposited metal.

Weitere vorteilhafte Ausgestaltungen der Vorrichtung sind in den Ansprüchen 10 bis 12 angegeben.Further advantageous refinements of the device are specified in claims 10 to 12.

Die Verwendung des erfindungsgemäßen Verfahrens erfolgt vorzugsweise als nachgeschalteter Verfahrensschritt in einem Beiz- oder Extraktionsvorgang, bei dem in einem ersten Verfahrensschritt eine Chloridionen enthaltende Lösung mittels lonenaustauscherverfahren in eine Sulfationen enthaltende Lösung umgewandelt wird.The process according to the invention is preferably used as a subsequent process step in a pickling or extraction process, in which, in a first process step, a solution containing chloride ions is converted into a solution containing sulfate ions by means of the ion exchange process.

Ein wesentlicher Vorteil der Erfindung ist darin zu sehen, daß aus einer metallionenhaltigen Sulfat- Lösung das Metall auf einfache, kostengünstige Weise abgeschieden werden kann, wobei gleichzeitig in Form eines Kreislaufs eine Aufkonzentration der Schwefelsäure des Anolyten erfolgt, welche wiederum zur Weiterführung des Regenerationsprozesses gebraucht wird.A major advantage of the invention is the fact that the metal can be separated from a metal ion-containing sulfate solution in a simple, inexpensive manner, at the same time a concentration of the sulfuric acid of the anolyte takes place in the form of a cycle, which in turn is used to continue the regeneration process .

Im folgenden ist der Gegenstand der Erfindung anhand der Figuren 1 und 2 näher erläutert.The subject matter of the invention is explained in more detail below with reference to FIGS. 1 and 2.

Figur 1 zeigt schematisch im Längsschnitt eine Elektrolysezelle.Figure 1 shows schematically in longitudinal section an electrolysis cell.

Figur 2 zeigt schematisch den Verfahrensablauf in Form eines Kreislaufs.Figure 2 shows schematically the process flow in the form of a circuit.

Die Elektrolysevorrichtung weist gemäß Figur 1, einen Trog 1 auf, dessen Innenraum mittels einer Anionen-Austauschermembran 2 in einen Anolytraum 3 und einen Katholytraum 4 unterteilt ist. Die im Anolytraum 3 befindliche Anode 5 besteht aus einer dimensionsstabilen Ventilmetall-Elektrode, insbesondere Titan-Elektrode, die mit dem positiven Pol 6 einer Gleichspannungsquelle 7 verbunden ist. Der prinzipielle Aufbau solcher dimensionsstabilen Ventilmetall-Elektroden, insbesondere Titan-Elektroden ist aus der ChloralkaliElektrolyse bekannt und beispielsweise in der DE-OS 20 41 250 beschrieben.According to FIG. 1, the electrolysis device has a trough 1, the interior of which is divided into an anolyte space 3 and a catholyte space 4 by means of an anion exchange membrane 2. The anode 5 located in the anolyte compartment 3 consists of a dimensionally stable valve metal electrode, in particular titanium electrode, which is connected to the positive pole 6 of a DC voltage source 7. The basic structure of such dimensionally stable valve metal electrodes, in particular titanium electrodes, is known from chloralkali electrolysis and is described, for example, in DE-OS 20 41 250.

Die im Katholytraum 4 befindliche Kathode 8 besteht aus Kupfer-Streckmetall, sie ist über einen lösbaren elektrischen Anschluß 9 mit dem negativen Pol 10 der Gleichspannungsquelle verbunden. Im Anolytraum 3 befindet sich eine wässrige Schwefelsäure-Lösung, die zu Beginn des Verfahrens über Zuleitung 11 zur Erzeugung der lonenleitung zugeführt wird, wobei während des Elektrolyseprozesses gegebenenfalls Wasser nachgeführt und die zusätzlich entstehende Schwefelsäure über Auslaß 12 des Anolytraumes 3 abführbar und dem Regenerationsprozeß beispielsweise Beizvorgang wieder zuführbar ist.The cathode 8 located in the catholyte space 4 is made of expanded copper, it is connected via a detachable electrical connection 9 to the negative pole 10 of the direct voltage source. In the anolyte compartment 3 there is an aqueous sulfuric acid solution which is fed in at the beginning of the process via feed line 11 to produce the ion conduit, water possibly being added during the electrolysis process and the additional sulfuric acid formed being able to be removed via outlet 12 of the anolyte compartment 3 and the regeneration process, for example pickling can be fed again.

Die Zinkionen enthaltende Sulfat-Lösung wird über Zuleitung 13 dem Katholytraum 4 beispielsweise kontinuierlich zugeführt, wobei die Schwefelsäurekonzentration des Katholyten in der Regel höchstens der des Anolyten entspricht; die Schwefelsäurekonzentration des Anolyten liegt im Bereich von 70 g/I. Nach Auffüllung von Anolyt- und Katholytraum beginnt der Elektrolyseprozeß, wobei durch Anlegungen der Spannungsquelle 7 der Ladungstransport während der Elektrolyse durch die lonenaustauschermembran 2 mittels der Sulfationen erfolgt, welche symbolisch mit Bezugsziffer 13 bezeichnet sind. Die Zinkionen sind symbolisch mit Bezugsziffer 14 versehen und werden an der Kathode 8 entladen, wobei metallisches Zink abgeschieden wird.The sulfate solution containing zinc ions is fed continuously to the catholyte space 4 via feed line 13, the sulfuric acid concentration of the catholyte generally corresponding at most to that of the anolyte; the sulfuric acid concentration of the anolyte is in the range of 70 g / l. After the anolyte and catholyte spaces have been filled, the electrolysis process begins, the charge being transported by applying the voltage source 7 during the electrolysis through the ion exchange membrane 2 by means of the sulfate ions, which are symbolically designated by reference number 13. The zinc ions are symbolically provided with reference number 14 and are discharged at the cathode 8, metallic zinc being deposited.

Im Anolytraum 3 erfolgt eine Zersetzung des Wasser-Anteils der Anolyt-Lösung, wobei der Sauerstoff als Gas aus dem oben offenen Trog 1 abgeführt wird und die Wasserstoffionen zusammen mit den Sulfationen zu Schwefelsäure rekombiniert werden, welche im Laufe des Elektrolyseprozesses aufkonzentriert wird und über Auslaß 12 zum Beizvorgang abgeführt wird. Die Einstellung der Schwefelsäurekonzentration des Anolyten erfolgt mit Hilfe von pH-Wert-Messern und einem Regelkreis, welcher durch Abfuhr der aufkonzentrierten Schwefelsäure und Zufuhr von Wasser über Leitung 11 die vorgegebene Schwefelsäure- konzentration aufrechterhält bzw. der Schwefelsäurekonzentration des Katholyten anpaßt. Der zugeführte Katholyt als BeizLösung weist eine Zinkionenkonzentration von ca. 170 g/I und eine Schwefelsäurekonzentration im Bereich von 70 g/I auf. Die Kathode 8 wird in Form eines Kupferstreckmetalls ausgeführt, während die Anode 5 aus der bereits vorerwähnten dimensionsstabilen Titananode besteht. Auf der Kathode 8 wird Zink in einer kompakten Abscheidungsqualität aufgebracht. Die Stromdichte der Kathode liegt im Bereich von 250 bis 1500 A/m 2.In the anolyte compartment 3 there is a decomposition of the water portion of the anolyte solution, the oxygen being removed as gas from the open trough 1 and the hydrogen ions being recombined together with the sulfate ions to form sulfuric acid, which is concentrated in the course of the electrolysis process and via the outlet 12 is removed to the pickling process. The sulfuric acid concentration of the anolyte is adjusted with the aid of pH-value meters and a control circuit, which maintains the predetermined sulfuric acid concentration or the sulfuric acid by removing the concentrated sulfuric acid and supplying water via line 11 adjusts the concentration of the catholyte. The catholyte supplied as a pickling solution has a zinc ion concentration of approximately 170 g / l and a sulfuric acid concentration in the range of 70 g / l. The cathode 8 is made in the form of a copper expanded metal, while the anode 5 consists of the dimensionally stable titanium anode already mentioned. Zinc is applied to the cathode 8 in a compact deposition quality. The current density of the cathode is in the range from 250 to 1500 A / m 2 .

Im Prinzip läßt sich die gleiche Elektrolysevorrichtung auch für den chargenweisen Betrieb einsetzen, wobei dann der Anolyt chargenweise oder kontinuierlich innerhalb bestimmter Konzentrationsbereiche entnommen wird, während die Katholytseite chargenweise nachgefüllt wird.In principle, the same electrolysis device can also be used for batchwise operation, in which case the anolyte is removed batchwise or continuously within certain concentration ranges, while the catholyte side is replenished in batches.

Gemäß Figur 2 wird die aus Auslaß 21 einer Beizvorrichtung 20 strömende Zinkionen enthaltende Sulfatlösung über Zuleitung 13 dem Katholytraum 4 der einen Trog 1 mit Anionen-Austauschermembran 2 aufweisenden Elektrolysezelle zugeführt, wobei das im Katholytraum abgeschiedene Zink - schematisch durch Bezugsziffer 22 dargestellt - aus dem Katholytraum 4 abgeführt wird. Die im Anolytraum 3 sich bildende aufkonzentrierte wässrige Schwefelsäurelösung wird über Auslaß 12 und Leitung 23 als frischer Bestandteil für den Beizvorgang über Zulauf 24 der Beizvorrichtung 20 zugeführt.According to FIG. 2, the sulfate solution containing zinc ions flowing out of outlet 21 of a pickling device 20 is fed via feed line 13 to the catholyte compartment 4 of the electrolysis cell having a trough 1 with an anion exchange membrane 2, the zinc deposited in the catholyte compartment - represented schematically by reference number 22 - from the catholyte compartment 4 is discharged. The concentrated aqueous sulfuric acid solution which forms in the anolyte compartment 3 is fed via outlet 12 and line 23 as a fresh component for the pickling process via feed 24 to the pickling device 20.

Anhand der Figur 2 ist der verfahrensmäßige Kreislauf der Schwefelsäure enthaltenden Lösung gezeigt, wobei über Auslaß 21 der Beizvorrichtung 20 und Zuleitung 13 der Zelle die verbrauchte Beizlösung als Metallionen enthaltende wässrige Sulfatlösung der Elektrolysezelle zugeführt wird, während die praktisch reine aufkonzentrierte Schwefelsäure über Leitung 23 wiederum dem Beizvorgang zugeführt wird.The process cycle of the solution containing sulfuric acid is shown in FIG. 2, the used pickling solution being fed as an aqueous sulfate solution containing metal ions to the electrolytic cell via outlet 21 of the pickling device 20 and feed line 13 of the cell, while the practically pure concentrated sulfuric acid is in turn fed via line 23 to the cell Pickling process is supplied.

Das abgeschiedene Zink wird durch Entnahme aus der Zelle diesem Kreislaufprozeß entnommen, es kann ebenfalls wieder verwendet werden. Als Anionen-Austauschermembran wird eine Membran des Typs ARA der Firma MORGANE (Frankreich) eingesetzt.The deposited zinc is removed from this cell cycle by removal from the cell; it can also be used again. A membrane of the ARA type from MORGANE (France) is used as the anion exchange membrane.

Claims (12)

1. Verfahren zur Regenerierung einer Metallionen und Schwefelsäure enthaltenden wässrigen Lösung, insbesondere einer Zinkionen, Nickelionen, Eisenionen und/oder Kupferionen enthaltenden Lösung, in einer elektrolytischen Zelle, wobei die Metallionen auf der Oberfläche der Kathode abgeschieden werden und an der Anode durch Wasserzersetzung Sauerstoff und Protonen gebildet werden, dadurch gekennzeichnet, daß in eine unter Verwendung einer gegen Schwefelsäure stabilen Anionen-Austauschermembran unterteilte Elektrolysezelle die Metallionen enthaltende Lösung als Katholyt eingebracht wird, wobei Sulfationen aus dem Katholyten durch die Anionen-Austauschermembran aufgrund der an den Elektroden anliegenden Spannung in den Anolyten wandern und mit den anodisch gebildeten Protonen Schwefelsäure erzeugt wird und die Schwefelsäurekonzentration im Anolyten ständig erhöht wird.1. A process for the regeneration of an aqueous solution containing metal ions and sulfuric acid, in particular a solution containing zinc ions, nickel ions, iron ions and / or copper ions, in an electrolytic cell, the metal ions being deposited on the surface of the cathode and oxygen and Protons are formed, characterized in that the solution containing metal ions is introduced as a catholyte into an electrolysis cell subdivided using an anion exchange membrane that is stable to sulfuric acid, sulfate ions from the catholyte through the anion exchange membrane due to the voltage applied to the electrodes in the anolytes migrate and with the anodically formed protons sulfuric acid is generated and the sulfuric acid concentration in the anolyte is constantly increased. 2. Verfahren nach Anspruch 1 , dadurch gekennzeichnet, daß die aufkonzentrierte Schwefelsäure aus dem Anolyten abgeführt wird.2. The method according to claim 1, characterized in that the concentrated sulfuric acid is removed from the anolyte. 3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß der Elektrolysezelle als Katholyt chargenweise eine Lösung zugeführt wird, deren Schwefelsäurekonzentration jeweils der Anfangskonzentration des Anolyten entspricht.3. The method according to claim 1 or 2, characterized in that the electrolytic cell is supplied as a catholyte batchwise a solution whose sulfuric acid concentration corresponds to the initial concentration of the anolyte. 4. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß der Elektrolysezelle als Katholyt kontinuierlich eine Lösung zugeführt wird, deren Schwefelsäurekonzentration stets unterhalb der Schwefelsäurekonzentration des Anolyten liegt.4. The method according to claim 1 or 2, characterized in that the electrolytic cell is continuously supplied as a catholyte, a solution whose sulfuric acid concentration is always below the sulfuric acid concentration of the anolyte. 5. Verfahren nach einem der Ansprüche 1 bis 4 dadurch gekennzeichnet, daß als Katholyt eine Lösung mit einer Schwefelsäurekonzentration im Bereich von 60-80 g/I zugeführt wird.5. The method according to any one of claims 1 to 4, characterized in that a solution with a sulfuric acid concentration in the range of 60-80 g / l is supplied as the catholyte. 6. Verfahren nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die kathodische Abscheidung bei einer Stromdichte im Bereich von 250 bis 1500 A/m2 erfolgt.6. The method according to any one of claims 1 to 5, characterized in that the cathodic deposition takes place at a current density in the range from 250 to 1500 A / m 2 . 7. Verfahren nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß die Kathode nach Erreichen einer vorgegebenen Schichtstärke der Metallabscheidung aus der Zelle entnommen wird.7. The method according to any one of claims 1 to 6, characterized in that the cathode is removed from the cell after reaching a predetermined layer thickness of the metal deposition. 8. Verwendung des Verfahrens nach einem der Ansprüche 2 bis 7 zur Regenerierung einer Beizlösung nach einem Beizvorgang, wobei die dem Anolyten entnommene Schwefelsäure wiederum dem Beizvorgang zugeführt wird.8. Use of the method according to one of claims 2 to 7 for the regeneration of a pickling solution after a pickling process, the sulfuric acid removed from the anolyte in turn being fed to the pickling process. 9. Vorrichtung zur Regenerierung einer Metallionen und Schwefelsäure enthaltenden wässrigen Lösung in einer wenigstens jeweils eine Anode und eine Kathode aufweisenden Elektrolysezelle, dadurch gekennzeichnet, daß die Elektrolysezelle mittels einer gegenüber Schwefelsäure stabilen Anionen-Austauschermembran in einen Anolytraum und einen Katholytraum unterteilt ist, daß der Katholytraum wenigstens eine Öffnung zur Zufuhr der Metallionen enthaltenden Lösung und der Anolytraum wenigstens eine Öffnung zur Abfuhr der mittels Elektrolyse gebildeten Schwefelsäure aufweist, wobei die Kathode zur Entnahme des abgeschiedenen Metalls elektrisch und mechanisch lösbar ist.9. Device for the regeneration of an aqueous solution containing metal ions and sulfuric acid in an electrolytic cell having at least one anode and one cathode each, characterized in that the electrolytic cell by means of an opposite Anion exchange membrane which is stable to sulfuric acid is subdivided into an anolyte space and a catholyte space such that the catholyte space has at least one opening for supplying the solution containing metal ions and the anolyte space has at least one opening for removing the sulfuric acid formed by means of electrolysis, the cathode being electrical for removing the deposited metal and is mechanically detachable. 10. Vorrichtung nach Anspruch 9, dadurch gekennzeichnet, daß die Anode im wesentlichen aus Ventilmetall besteht.10. The device according to claim 9, characterized in that the anode consists essentially of valve metal. 11. Vorrichtung nach Anspruch 9 oder 10, dadurch gekennzeichnet, daß die Anode eine dimensionsstabile Elektrode auf der Basis von Titan ist.11. The device according to claim 9 or 10, characterized in that the anode is a dimensionally stable electrode based on titanium. 12. Vorrichtung nach einem der Ansprüche 9 bis 11, dadurch gekennzeichnet, daß der Anolytraum eine Öffnung zur Zufuhr von Wasser oder einer wässrigen Lösung aufweist.12. Device according to one of claims 9 to 11, characterized in that the anolyte space has an opening for the supply of water or an aqueous solution.
EP19930104001 1992-06-10 1993-03-12 Process and apparatus for regenerating metal ions and sulfuric acid containing aqueous solutions and use thereof Withdrawn EP0575699A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19924218915 DE4218915A1 (en) 1992-06-10 1992-06-10 Method and device for regenerating an aqueous solution containing metal ions and sulfuric acid, and use
DE4218915 1992-06-10

Publications (2)

Publication Number Publication Date
EP0575699A2 true EP0575699A2 (en) 1993-12-29
EP0575699A3 EP0575699A3 (en) 1994-06-01

Family

ID=6460669

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19930104001 Withdrawn EP0575699A3 (en) 1992-06-10 1993-03-12 Process and apparatus for regenerating metal ions and sulfuric acid containing aqueous solutions and use thereof

Country Status (4)

Country Link
EP (1) EP0575699A3 (en)
JP (1) JPH0688275A (en)
CA (1) CA2097868A1 (en)
DE (1) DE4218915A1 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19521132C1 (en) * 1995-06-09 1996-10-17 Poligrat Holding Gmbh Demetallising used, highly acidic electropolishing baths
DE19521596C1 (en) * 1995-06-14 1996-11-28 Ksd Innovations Gmbh Umwelt U Recovery of zinc@ from copper@-contg sulphuric or phosphoric acid pickling solutions
DE19850524C2 (en) * 1998-11-03 2002-04-04 Eilenburger Elektrolyse & Umwelttechnik Gmbh Nitrate-free recycling pickling process for stainless steels
DE19850525A1 (en) * 1998-11-03 2000-05-04 Eilenburger Elektrolyse & Umwelttechnik Gmbh Regeneration of sulfuric acid-iron(III) sulfate pickling solution, used especially for special steels, involves perdisulfuric acid production in a spent solution electrolysis cell
BRPI0911653B1 (en) * 2008-04-11 2019-07-30 François Cardarelli ELECTROCHEMICAL PROCESS FOR RECOVERY OF METAL IRON AND SULFURIC ACID VALUES FROM IRON-RICH SULPHATE RESIDUES, MINING WASTE AND STRAPPING LIQUIDS
DE102008056776A1 (en) * 2008-11-11 2010-05-12 Enthone Inc., West Haven Galvanic bath and method for the deposition of zinciferous layers
WO2022070119A1 (en) * 2020-10-02 2022-04-07 Zincovery Process Technologies Limited Process to electrochemically extract dissolved metals and an apparatus thereof
EP4313868A1 (en) 2021-03-24 2024-02-07 Electrasteel, Inc. Ore dissolution and iron conversion system

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2810686A (en) * 1954-11-09 1957-10-22 Rohm & Haas Electrolytic treatment of waste sulfate pickle liquor
DE1621577A1 (en) * 1966-01-22 1971-07-08 Gewerk Keramchemie Process for the selective removal of zinc ions from strongly hydrochloric iron pickles
JPS50151793A (en) * 1974-05-29 1975-12-05
DE2539137A1 (en) * 1974-09-04 1976-03-25 Atok Platinum Mines Proprietar METHOD FOR ELECTROLYTIC EXTRACTION OF NICKEL AND ZINC, AND ELECTROLYSIS CELLS FOR THEREFORE
US4148700A (en) * 1976-10-14 1979-04-10 David B. Dean Method for purifying the liquor of a galvanizing process plant after contamination
US4149951A (en) * 1978-05-22 1979-04-17 Eddleman William L Frame filter press and apparatus
FR2645044A1 (en) * 1989-03-30 1990-10-05 Morgane Ion exchange membrane for electrodialysis and process for recovery of inorganic acids using such a membrane
EP0435382A1 (en) * 1989-12-28 1991-07-03 METALLGESELLSCHAFT Aktiengesellschaft Electrolytic process for treating waste pickling solutions or product streams containing metallic ions

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5021541B2 (en) * 1972-08-22 1975-07-23
FR2273082B1 (en) * 1974-05-28 1978-03-31 Seprac
JPS5411153B2 (en) * 1974-10-04 1979-05-12
JPS51135173A (en) * 1975-05-19 1976-11-24 Asahi Glass Co Ltd Method of treating waste liquor containing acids and metal salts there of
JPS52101690A (en) * 1976-02-24 1977-08-25 Asahi Glass Co Ltd Separation of acid and metal from solution containing acid and its met al salts and recovery of them
JPS5311814A (en) * 1976-07-21 1978-02-02 Nakamura Minoru Electrolytic recovering method of nickel using ion exchange membranes
JPS5544588A (en) * 1978-09-26 1980-03-28 Sumitomo Metal Ind Ltd Recovering method for mixture of hydrofluoric acid and nitric acid

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2810686A (en) * 1954-11-09 1957-10-22 Rohm & Haas Electrolytic treatment of waste sulfate pickle liquor
DE1621577A1 (en) * 1966-01-22 1971-07-08 Gewerk Keramchemie Process for the selective removal of zinc ions from strongly hydrochloric iron pickles
JPS50151793A (en) * 1974-05-29 1975-12-05
DE2539137A1 (en) * 1974-09-04 1976-03-25 Atok Platinum Mines Proprietar METHOD FOR ELECTROLYTIC EXTRACTION OF NICKEL AND ZINC, AND ELECTROLYSIS CELLS FOR THEREFORE
US4148700A (en) * 1976-10-14 1979-04-10 David B. Dean Method for purifying the liquor of a galvanizing process plant after contamination
US4149951A (en) * 1978-05-22 1979-04-17 Eddleman William L Frame filter press and apparatus
FR2645044A1 (en) * 1989-03-30 1990-10-05 Morgane Ion exchange membrane for electrodialysis and process for recovery of inorganic acids using such a membrane
EP0435382A1 (en) * 1989-12-28 1991-07-03 METALLGESELLSCHAFT Aktiengesellschaft Electrolytic process for treating waste pickling solutions or product streams containing metallic ions

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, vol. 84, no. 16, 19. April 1976, Columbus, Ohio, US; abstract no. 109068p, KANAGAWA 'Recovery of iron and acid from waste acid' Seite 226 ; & JP-A-50 151 793 (KANAGAWA) *
INDUSTRIAL AND ENGINEERING CHEMISTY Bd. 47, Nr. 1 , 1. Januar 1955 Seiten 67 - 70 BRAMER H. C. 'Electrolytic Regeneration of Spent Pickling solutions' *

Also Published As

Publication number Publication date
JPH0688275A (en) 1994-03-29
EP0575699A3 (en) 1994-06-01
CA2097868A1 (en) 1993-12-11
DE4218915A1 (en) 1993-12-16

Similar Documents

Publication Publication Date Title
EP0638664A1 (en) Process and apparatus for regenerating solutions containing metal ions and sulfuric acid
DE1496886A1 (en) Method and device for the preparation of metal treatment solutions
DE3739580C2 (en)
DE19856840A1 (en) Wastewater treatment process and treatment apparatus therefor
DE2523950A1 (en) ELECTROCHEMICAL DEVICE AND ITS USE
EP1264010A1 (en) Method and device for the regulation of the concentration of metal ions in an electrolyte and use thereof
DE602004009572T2 (en) METHOD FOR REGENERATING IRON-BASED SOLID SOLUTIONS FOR USE IN THE PAINTING OR REFURBISHING OF COPPER OR COPPER ALLOYS AND DEVICE FOR CARRYING OUT THE METHOD
EP0575699A2 (en) Process and apparatus for regenerating metal ions and sulfuric acid containing aqueous solutions and use thereof
EP1015667B1 (en) Method and device for regulating the concentration of substances in electrolytes
EP0801692A2 (en) Electroplating plant
EP0613398B1 (en) Process, medium and device for electrodialytically regenerating the electrolyte of a galvanic bath or the like
EP0717791B1 (en) Electrolytic cell with multiple partial electrodes and at least one antipolar counter-electrode
DE2607512A1 (en) METAL POWDER MANUFACTURING METHOD
DE2818306A1 (en) PROCEDURE FOR IN-SITU REDUCTION OF ELECTRODE OVERVOLTAGE AND ELECTROLYSIS CELL FOR PERFORMING THE PROCEDURE
DE4407448A1 (en) Electrolytic process to regenerate iron-chloride or -sulphate soln.
DE69210828T2 (en) ELECTROLYTIC DEVICE AND METHOD WITH POROUS, STIRRED ELECTRODES
DE19506242C2 (en) Process for the direct electrochemical oxidation of sulfite-containing solutions, in particular waste water from gas cleaning plants
DE2836353B1 (en) Process for the extraction of hydrogen and sulfuric acid by electrochemical decomposition of an electrolyte and electrode for carrying out the electrochemical decomposition
DE69204644T2 (en) Process for galvanic tinning.
DE3135195A1 (en) METHOD FOR THE ELECTROCHEMICAL DECOMPOSITION OF Nitric Acid
DE4218916C2 (en) Use of a grid anode for electrolytic detoxification or regeneration of an aqueous solution containing cyanide
EP0079032B1 (en) Apparatus for electroplating a metallic workpiece
DE3330838C2 (en)
DE19653273C2 (en) A method for recovering at least one metal deposited on a substrate
DE1273498B (en) Process for the manufacture of electrodes for electrochemical purposes

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: 19930325

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE

17Q First examination report despatched

Effective date: 19941206

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19950419