EP0607535B1 - Electrolytic dissolution process for platinum, platinum metal impurities and/or platinum alloys - Google Patents
Electrolytic dissolution process for platinum, platinum metal impurities and/or platinum alloys Download PDFInfo
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- EP0607535B1 EP0607535B1 EP93118980A EP93118980A EP0607535B1 EP 0607535 B1 EP0607535 B1 EP 0607535B1 EP 93118980 A EP93118980 A EP 93118980A EP 93118980 A EP93118980 A EP 93118980A EP 0607535 B1 EP0607535 B1 EP 0607535B1
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B11/00—Obtaining noble metals
- C22B11/04—Obtaining noble metals by wet processes
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
Definitions
- the present invention relates to an electrolytic process for dissolving platinum, platinum metal impurities and / or platinum metal alloys, in particular those with a proportion of Rh, Pd, Ir, Au and Ag in aqueous hydrochloric acid.
- the platinum metals are usually in solid form, such as granules, sheets, chips, wires, etc.
- the method according to the invention can also be used to dissolve powders, sludges and precious metals which are located on ceramics, quartz parts, aluminum oxide or silicates.
- platinum metals in the form of granules, sheets or wires are digested with chlorine and hydrochloric acid.
- the platinum metal salts or platinum metal acids formed are rinsed off with aqueous hydrochloric acid.
- the addition of hydrochloric acid and the introduction of Chlorine gas takes place alternately. The process works with a continuously decreasing platinum surface. A targeted addition of hydrochloric acid is not possible. Therefore, no concentrated precious metal solutions can be produced. If the amount of platinum metal is reduced, a high excess of chlorine must be used.
- the invention was therefore based on the object of providing a method for dissolving platinum, platinum metal impurities and / or platinum metal alloys, which works with little outlay in terms of apparatus and safety technology and an acceptable ecological burden.
- platinum metal salts and / or platinum metal acids in hydrochloric acid, the solubility of the platinum or the platinum metal alloys increases sharply and that this dissolving process can be carried out electrolytically.
- the invention therefore relates to an electrolytic process for dissolving platinum, platinum metal impurities and / or platinum metal alloys, in particular from those with a proportion of Rh, Pd, Ir, Au and Ag in aqueous hydrochloric acid, which is characterized in that the dissolving process in an electrolysis cell, which is divided by a cation exchange membrane, optionally in the presence of platinum metal salts or platinum metal acids at temperatures between 50 to 110 ° C and under potentiostatic or voltage-controlled conditions of 2.5 V to 8 V and a current density of 0.3 to 7.0 A / dm 2 .
- the platinum metal to be dissolved is switched as an anode in the electrolysis cell, while platinum, titanium or graphite is used as the cathode.
- the cathode and anode compartment is filled with 6 to 8 N hydrochloric acid and the voltage selected so that the chlorine gas required for better dissolution develops electrolytically.
- the method according to the invention preferably works under potentiostatic or voltage-controlled conditions of 5 V to 7.5 V and a current density of 4.4 to 6.6 A / dm 2 and in a temperature range from 60 to 100 ° C., in particular at 80 ° C.
- the solution is only heated in the anode and cathode compartments at the beginning of the electrolysis.
- the dissolving temperature then sets itself because the process according to the invention works exothermic.
- the platinum metal solution has a concentration between 1 to 700 g / l.
- concentration between 1 to 700 g / l.
- concentrated platinum metal solutions preferably between 10 and 150 g / l.
- the dissolving process must be stopped because the platinum metal salts or acids crystallize out.
- a Teflon membrane (Nafion® membrane) is generally used as the preferred cation exchange membrane loaded with sulfonic acid groups.
- hydrochloric acid is consumed in the anode compartment due to the development of chlorine gas, its concentration remains constant because water molecules are transported into the cathode compartment with the hydrogen ions.
- the dilute hydrochloric acid is withdrawn periodically in the cathode compartment and the loss of concentration is replaced by the addition of concentrated hydrochloric acid.
- the diluted acid is used to dilute concentrated hydrochloric acid for the anode compartment.
- Rh Pd, Ir, Au, Ag, Cu, Fe, Co, Ni, Sb, As, Pb, Cd, Al, Mn, Mo, Si, Zn, Sn, Zr, as components of the platinum metal impurities or platinum metal alloys. W, Ti and Cr in question.
- 500 g of platinum granules are dissolved in an electrolysis cell, which is divided by a cation exchange membrane.
- the anode compartment is filled with 1 l of 8 N HCl.
- the cathode compartment also contains 8 N HCl.
- the platinum to be dissolved serves as the anode, platinum, titanium or carbon is used as the cathode.
- the electrolysis bath is heated to a temperature of 80 ° C. A voltage of 5 V is applied to the cell and work is carried out at a current density of 6.6 A / dm 2 .
- the hydrochloric acid concentration in the cathode and anode compartments is checked and readjusted.
- the hydrochloric platinum solution contained in the anode compartment has a concentration of 650 g platinum / l.
- the platinum granules are dissolved to a residual content of 3% platinum.
- 250 g of platinum-iridium-1 granules are placed in an electrolysis cell, which is divided by a cation exchange membrane filled and 500 ml of 8 N hydrochloric acid in the anode compartment and 250 ml of 8 N hydrochloric acid in the cathode compartment.
- a titanium sheet serves as the cathode and the platinum-iridium-1 granules to be dissolved as the anode.
- the hydrochloric acid in the anode and cathode compartments is heated to 80 ° C.
- a voltage of 6 V is applied to the electrolysis cell and work is carried out at a current density of 5.25 A / dm 2 .
- the electrolysis is stopped after 12 hours.
- the hydrochloric acid platinum-iridium solution has a platinum metal content of 550 g / l.
- the platinum-iridium granules are 95% dissolved.
- 250 g of platinum-rhodium-10 wire residues are placed in the anode compartment of the electrolytic cell, which is divided by a cation exchange membrane.
- a titanium sheet is used as the cathode, and the platinum-rhodium-10 to be dissolved serves as the anode.
- the electrolytic cell is filled with 8 N hydrochloric acid.
- the temperature of the bath is set at 80 to 100 ° C.
- a voltage of 7.5 V is applied to the apparatus and work is carried out at a current density of 6.6 A / dm 2 .
- the hydrochloric acid concentration is checked during the electrolysis and the specified starting concentration is maintained by adding hydrochloric acid.
- the concentration of the platinum metal solution is 330 g / l.
- the platinum-rhodium-10 wires are 90% dissolved.
- 300 g of platinum metal sponge with a composition of 59% platinum, 1% rhodium and 40% palladium are placed in an electrolysis cell which is divided by a cation exchange membrane.
- a titanium sheet serves as the cathode and the platinum metal sponge as the anode.
- the anode compartment is filled with 1 l and the cathode compartment with 500 ml of 6 N hydrochloric acid.
- the hydrochloric acid is heated to 60 ° C.
- a voltage of 5 V is applied to the electrolysis cell and the current density is 4.4 A / dm 2 .
- the hydrochloric acid concentration is kept constant during the electrolysis.
- the electrolysis is stopped after 10 hours.
- the concentration of the platinum metal solution is 635 g / l.
- the platinum metal sponge is 98% dissolved.
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Abstract
Description
Die vorliegende Erfindung betrifft ein elektrolytisches Verfahren zum Lösen von Platin, Platinmetallverunreinigungen und/oder Platinmetallegierungen, insbesondere von solchen mit einem Anteil von Rh, Pd, Ir, Au und Ag in wäßriger Salzsäure.The present invention relates to an electrolytic process for dissolving platinum, platinum metal impurities and / or platinum metal alloys, in particular those with a proportion of Rh, Pd, Ir, Au and Ag in aqueous hydrochloric acid.
Die Platinmetalle liegen in der Regel in massiver Form, wie Granalien, Blechen, Spänen, Drähten usw. vor.The platinum metals are usually in solid form, such as granules, sheets, chips, wires, etc.
Das erfindungsgemäße Verfahren kann aber auch zum Lösen von Pulvern, Schlämmen und Edelmetallen, die sich auf Keramik, Quarzteilen, Aluminiumoxid oder Silikaten befinden, angewendet werden.However, the method according to the invention can also be used to dissolve powders, sludges and precious metals which are located on ceramics, quartz parts, aluminum oxide or silicates.
Die Anwendung von Chlorgas und Salzsäure zum Lösen von Platin und/oder Platinmetallegierungen ist allgemein bekannt (Gmelin, Platin, Teil C, Seite 77).The use of chlorine gas and hydrochloric acid to dissolve platinum and / or platinum metal alloys is generally known (Gmelin, platinum, part C, page 77).
Im Ullmann, Enzyklopädie der Chemie, Bd. 18, 1979, Seite 708, wird Chlor und Salzsäure für Pulver, Schlämme und Erzkonzentrate eingesetzt. Es wird mit einer 6 bis 8 N Salzsäure bei einer Temperatur von 80°C gearbeitet. Dabei wird u. a. festgestellt, daß gelöste Platinmetalle die Lösegeschwindigkeit nicht verringern.In Ullmann, Encyclopedia of Chemistry, Vol. 18, 1979, page 708, chlorine and hydrochloric acid are used for powders, slurries and ore concentrates. It works with a 6 to 8 N hydrochloric acid at a temperature of 80 ° C. Here u. a. found that dissolved platinum metals do not decrease the rate of dissolution.
Nach der DD-63880 werden Platinmetalle in Form von Granalien, Blechen oder Drähten mit Chlor und Salzsäure aufgeschlossen. Dabei werden die gebildeten Platinmetallsalze oder Platinmetallsäuren mit wäßriger Salzsäure abgespült. Die Zugabe von Salzsäure und das Einleiten von Chlorgas erfolgen im Wechsel. Das Verfahren arbeitet mit einer ständig abnehmenden Platinoberfläche. Eine gezielte Salzsäurezugabe ist nicht möglich. Daher können auch keine konzentrierten Edelmetallösungen hergestellt werden. Bei Verringerung der Platinmetallmenge muß mit hohem Chlorüberschuß gearbeitet werden.According to DD-63880, platinum metals in the form of granules, sheets or wires are digested with chlorine and hydrochloric acid. The platinum metal salts or platinum metal acids formed are rinsed off with aqueous hydrochloric acid. The addition of hydrochloric acid and the introduction of Chlorine gas takes place alternately. The process works with a continuously decreasing platinum surface. A targeted addition of hydrochloric acid is not possible. Therefore, no concentrated precious metal solutions can be produced. If the amount of platinum metal is reduced, a high excess of chlorine must be used.
Die in der DD-63880 beschriebene erreichbare Konzentration von 500 g/l Platinmetall und die Lösegeschwindigkeit von 1000 g/h werden, bedingt durch den Verfahrensablauf, nur in Ausnahmefällen erreicht. Außerdem müssen bei diesem Verfahren mindestens 4 bis 6 kg Platinmetall vorgelegt werden.The achievable concentration of 500 g / l platinum metal and the dissolving rate of 1000 g / h described in DD-63880 are only reached in exceptional cases due to the process sequence. In addition, at least 4 to 6 kg of platinum metal must be presented in this process.
Alle beschriebenen Verfahren des Standes der Technik haben den Nachteil, daß sie, bedingt durch die Arbeit mit Chlorgas und seine schwierige Dosierbarkeit, einen hohen apparativen und sicherheitstechnischen Aufwand erfordern. Sie sind sehr teuer und ökologisch nicht mehr verantwortbar.All of the prior art methods described have the disadvantage that, owing to the work with chlorine gas and its difficult meterability, they require a high level of equipment and safety engineering. They are very expensive and no longer environmentally responsible.
Der Erfindung lag daher die Aufgabe zugrunde, ein Verfahren zum Lösen von Platin, Platinmetallverunreinigungen und/oder Platinmetallegierungen zur Verfügung zu stellen, das mit geringem apparativen und sicherheitstechnischen Aufwand sowie einer vertretbaren ökologischen Belastung arbeitet. Überraschenderweise wurde nun gefunden, daß bei Anwesenheit von Platinmetallsalzen und/oder Platinmetallsäuren in der Salzsäure die Löslichkeit des Platins oder der Platinmetallegierungen stark ansteigt und daß sich dieser Löseprozeß elektrolytisch durchführen läßt.The invention was therefore based on the object of providing a method for dissolving platinum, platinum metal impurities and / or platinum metal alloys, which works with little outlay in terms of apparatus and safety technology and an acceptable ecological burden. Surprisingly, it has now been found that in the presence of platinum metal salts and / or platinum metal acids in hydrochloric acid, the solubility of the platinum or the platinum metal alloys increases sharply and that this dissolving process can be carried out electrolytically.
Gegenstand der Erfindung ist daher ein elektrolytisches Verfahren zum Lösen von Platin, Platinmetallverunreinigungen und/oder Platinmetallegierungen, insbesondere von solchen mit einem Anteil von Rh, Pd, Ir, Au und Ag in wäßriger Salzsäure, welches sich dadurch auszeichnet, daß der Löseprozeß in einer Elektrolysezelle, die durch eine Kationenaustauschermembran unterteilt ist, gegebenenfalls in Anwesenheit von Platinmetallsalzen oder Platinmetallsäuren bei Temperaturen zwischen 50 bis 110°C und unter potentiostatischen oder spannungskontrollierten Bedingungen von 2,5 V bis 8 V und einer Stromdichte von 0,3 bis 7,0 A/dm2 erfolgt.The invention therefore relates to an electrolytic process for dissolving platinum, platinum metal impurities and / or platinum metal alloys, in particular from those with a proportion of Rh, Pd, Ir, Au and Ag in aqueous hydrochloric acid, which is characterized in that the dissolving process in an electrolysis cell, which is divided by a cation exchange membrane, optionally in the presence of platinum metal salts or platinum metal acids at temperatures between 50 to 110 ° C and under potentiostatic or voltage-controlled conditions of 2.5 V to 8 V and a current density of 0.3 to 7.0 A / dm 2 .
In der Elektrolysezelle wird das zu lösende Platinmetall als Anode geschaltet, während als Katode Platin, Titan oder auch Graphit eingesetzt wird.The platinum metal to be dissolved is switched as an anode in the electrolysis cell, while platinum, titanium or graphite is used as the cathode.
Der Katoden- und Anodenraum wird mit 6 bis 8 N Salzsäure gefüllt und die Spannung so gewählt, daß das zum besseren Lösen benötigte Chlorgas sich elektrolytisch entwickelt.The cathode and anode compartment is filled with 6 to 8 N hydrochloric acid and the voltage selected so that the chlorine gas required for better dissolution develops electrolytically.
Durch eine entsprechende Gestaltung der Löseeinheit kommt es zu einer impulsweisen Berührung des Platinmetalls mit der platinmetallhaltigen Säure und dem elektrolytisch erzeugten Chlorgas.Appropriate design of the dissolving unit causes the platinum metal to come into contact with the platinum metal-containing acid and the electrolytically generated chlorine gas.
Bevorzugt arbeitet das erfindungsgemäße Verfahren unter potentiostatischen oder spannungskontrollierten Bedingungen von 5 V bis 7,5 V und einer Stromdichte von 4,4 bis 6,6 A/dm2 und in einem Temperaturbereich von 60 bis 100°C, insbesondere bei 80°C. Nur zum Beginn der Elektrolyse wird die Lösung im Anoden- und Katodenraum erwärmt. Danach stellt sich die Lösetemperatur selbst ein, da das erfindungsgemäße Verfahren exotherm arbeitet.The method according to the invention preferably works under potentiostatic or voltage-controlled conditions of 5 V to 7.5 V and a current density of 4.4 to 6.6 A / dm 2 and in a temperature range from 60 to 100 ° C., in particular at 80 ° C. The solution is only heated in the anode and cathode compartments at the beginning of the electrolysis. The dissolving temperature then sets itself because the process according to the invention works exothermic.
Die Platinmetallösung weist eine Konzentration zwischen 1 bis 700 g/l auf. Die besten Löseergebnisse wurden mit konzentrierten Platinmetallösungen, bevorzugt zwischen 10 und 150 g/l, erreicht. Bei einer Platinmetallkonzentration von >700 g/l muß der Lösevorgang abgebrochen werden, da die Platinmetallsalze oder -säuren auskristallisieren.The platinum metal solution has a concentration between 1 to 700 g / l. The best results were achieved with concentrated platinum metal solutions, preferably between 10 and 150 g / l. At a platinum metal concentration of> 700 g / l, the dissolving process must be stopped because the platinum metal salts or acids crystallize out.
Als bevorzugte, mit Sulfonsäuregruppen beladene Kationenaustauschermembran wird in der Regel eine Teflonmembran (Nafion®-Membran) eingesetzt.A Teflon membrane (Nafion® membrane) is generally used as the preferred cation exchange membrane loaded with sulfonic acid groups.
Obwohl im Anodenraum durch die Chlorgasentwicklung Salzsäure verbraucht wird, bleibt deren Konzentration konstant, da mit den Wasserstoffionen Wassermoleküle in den Katodenraum transportiert werden.Although hydrochloric acid is consumed in the anode compartment due to the development of chlorine gas, its concentration remains constant because water molecules are transported into the cathode compartment with the hydrogen ions.
Lediglich der Volumenverlust an Salzsäure im Anodenraum muß ausgeglichen werden.Only the volume loss of hydrochloric acid in the anode compartment has to be compensated for.
Im Katodenraum wird periodisch die verdünnte Salzsäure abgezogen und der Konzentrationsverlust durch Zusatz von konzentrierter Salzsäure ersetzt. Dabei wird die verdünnte Säure zum Verdünnen von konzentrierter Salzsäure für den Anodenraum eingesetzt.The dilute hydrochloric acid is withdrawn periodically in the cathode compartment and the loss of concentration is replaced by the addition of concentrated hydrochloric acid. The diluted acid is used to dilute concentrated hydrochloric acid for the anode compartment.
Mit dem erfindungsgemäßen Verfahren sind folgende Vorteile verbunden:
- es arbeitet im Bereich der höchsten Leitfähigkeit der Salzsäure
- es erfordert einen minimalen sicherheitstechnischen und apparativen Aufwand
- es arbeitet mit minimaler ökologischer Belastung
- es ist gegenüber den herkömmlichen Verfahren wesentlich zeit- und kostensparender.
- it works in the area of the highest conductivity of hydrochloric acid
- it requires a minimal amount of security and equipment
- it works with minimal ecological impact
- it is much more time and cost saving compared to conventional processes.
Als Bestandteile der Platinmetallverunreinigungen bzw. Platinmetallegierungen kommen neben dem Rh, Pd, Ir, Au, Ag auch Cu, Fe, Co, Ni, Sb, As, Pb, Cd, Al, Mn, Mo, Si, Zn, Sn, Zr, W, Ti und Cr infrage.In addition to Rh, Pd, Ir, Au, Ag, Cu, Fe, Co, Ni, Sb, As, Pb, Cd, Al, Mn, Mo, Si, Zn, Sn, Zr, as components of the platinum metal impurities or platinum metal alloys. W, Ti and Cr in question.
Die Erfindung wird nachstehend an einigen Beispielen näher erläutert.The invention is explained in more detail below using a few examples.
500 g Platingranalien werden in einer Elektrolysezelle, die durch eine Kationenaustauschermembran unterteilt ist, gelöst. Der Anodenraum wird mit 1 l 8 N HCl gefüllt. Der Katodenraum enthält ebenfalls 8 N HCl. Als Anode dient das zu lösende Platin, als Katode wird Platin, Titan oder Kohlenstoff eingesetzt. Das Elektrolysebad wird auf eine Temperatur von 80°C erwärmt. An die Zelle wird eine Spannung von 5 V angelegt und bei einer Stromdichte von 6,6 A/dm2 gearbeitet. Während der Elektrolyse wird die Salzsäurekonzentration im Katoden- und Anodenraum überprüft und neu eingestellt.500 g of platinum granules are dissolved in an electrolysis cell, which is divided by a cation exchange membrane. The anode compartment is filled with 1 l of 8 N HCl. The cathode compartment also contains 8 N HCl. The platinum to be dissolved serves as the anode, platinum, titanium or carbon is used as the cathode. The electrolysis bath is heated to a temperature of 80 ° C. A voltage of 5 V is applied to the cell and work is carried out at a current density of 6.6 A / dm 2 . During the electrolysis, the hydrochloric acid concentration in the cathode and anode compartments is checked and readjusted.
Nach einer Elektrolysezeit von 20 Stunden wird die Elektrolyse abgebrochen. Die im Anodenraum enthaltene salzsaure Platinlösung hat eine Konzentration von 650 g Platin/l. Die Platingranalien werden bis auf einen Restgehalt von 3 % Platin gelöst.After an electrolysis time of 20 hours, the electrolysis is stopped. The hydrochloric platinum solution contained in the anode compartment has a concentration of 650 g platinum / l. The platinum granules are dissolved to a residual content of 3% platinum.
In eine Elektrolysezelle, die durch eine Kationenaustauschermembran unterteilt ist, werden 250 g Platin-Iridium-1-granalien gefüllt und 500 ml 8 N Salzsäure in den Anodenraum und 250 ml 8 N Salzsäure in den Katodenraum gegeben. Als Katode dient ein Titanblech, als Anode die zu lösenden Platin-Iridium-1-granalien. Die Salzsäure im Anoden- und Katodenraum wird auf 80°C erwärmt. An die Elektrolysezelle wird eine Spannung von 6 V angelegt und bei einer Stromdichte von 5,25 A/dm2 gearbeitet. Nach 12 Stunden wird die Elektrolyse abgebrochen. Die salzsaure Platin-Iridium-lösung hat einen Platinmetallgehalt von 550 g/l. Die Platin-Iridium-granalien sind zu 95 % gelöst.250 g of platinum-iridium-1 granules are placed in an electrolysis cell, which is divided by a cation exchange membrane filled and 500 ml of 8 N hydrochloric acid in the anode compartment and 250 ml of 8 N hydrochloric acid in the cathode compartment. A titanium sheet serves as the cathode and the platinum-iridium-1 granules to be dissolved as the anode. The hydrochloric acid in the anode and cathode compartments is heated to 80 ° C. A voltage of 6 V is applied to the electrolysis cell and work is carried out at a current density of 5.25 A / dm 2 . The electrolysis is stopped after 12 hours. The hydrochloric acid platinum-iridium solution has a platinum metal content of 550 g / l. The platinum-iridium granules are 95% dissolved.
250 g Platin-Rhodium-10 Drahtreste werden in den Anodenraum der Elektrolysezelle, die durch eine Kationenaustauschermembran unterteilt ist, gegeben. Als Katode wird ein Titanblech eingesetzt, als Anode dient das zu lösende Platin- Rhodium-10. Die Elektrolysezelle wird mit 8 N Salzsäure gefüllt. Die Temperatur des Bades wird auf 80 bis 100° C eingestellt. An die Apparatur wird eine Spannung von 7,5 V angelegt und bei einer Stromdichte von 6,6 A/dm2 gearbeitet. Die Salzsäurekonzentration wird während der Elektrolyse überprüft und durch den Zusatz von Salzsäure die vorgegebene Ausgangskonzentration eingehalten.250 g of platinum-rhodium-10 wire residues are placed in the anode compartment of the electrolytic cell, which is divided by a cation exchange membrane. A titanium sheet is used as the cathode, and the platinum-rhodium-10 to be dissolved serves as the anode. The electrolytic cell is filled with 8 N hydrochloric acid. The temperature of the bath is set at 80 to 100 ° C. A voltage of 7.5 V is applied to the apparatus and work is carried out at a current density of 6.6 A / dm 2 . The hydrochloric acid concentration is checked during the electrolysis and the specified starting concentration is maintained by adding hydrochloric acid.
Nach einer Lösezeit von 15 Stunden wird die Elektrolyse abgebrochen. Die Konzentration der Platinmetallösung beträgt 330 g/l. Die Platin-Rhodium-10-drähte sind zu 90 % gelöst.After a dissolution time of 15 hours, the electrolysis is stopped. The concentration of the platinum metal solution is 330 g / l. The platinum-rhodium-10 wires are 90% dissolved.
In eine Elektrolysezelle, die durch eine Kationenaustauschermembran unterteilt ist, werden 300 g Platinmetallschwamm mit einer Zusammensetzung von 59 % Platin, 1 % Rhodium und 40 % Palladium gegeben. Als Katode dient ein Titanblech, als Anode der Platinmetallschwamm. Der Anodenraum wird mit 1 l und der Katodenraum mit 500 ml 6 N Salzsäure gefüllt. Die Salzsäure wird auf 60°C erwärmt. An die Elektrolysezelle wird eine Spannung von 5 V angelegt und bei einer Stromdichte von 4,4 A/dm2 gearbeitet. Während der Elektrolyse wird die Salzsäurekonzentration konstant gehalten. Nach 10 Stunden wird die Elektrolyse abgebrochen. Die Konzentration der Platinmetallösung beträgt 635 g/l. Der Platinmetallschwamm ist zu 98 % gelöst.300 g of platinum metal sponge with a composition of 59% platinum, 1% rhodium and 40% palladium are placed in an electrolysis cell which is divided by a cation exchange membrane. A titanium sheet serves as the cathode and the platinum metal sponge as the anode. The anode compartment is filled with 1 l and the cathode compartment with 500 ml of 6 N hydrochloric acid. The hydrochloric acid is heated to 60 ° C. A voltage of 5 V is applied to the electrolysis cell and the current density is 4.4 A / dm 2 . The hydrochloric acid concentration is kept constant during the electrolysis. The electrolysis is stopped after 10 hours. The concentration of the platinum metal solution is 635 g / l. The platinum metal sponge is 98% dissolved.
Claims (10)
- Electrolytic process for dissolving in aqueous hydrochloric acid platinum, platinum metal impurities and/or platinum metal alloys, in particular those containing Rh, Pd, Ir, Au and Ag, characterised in that the platinum metal to be dissolved is connected as the anode and that the dissolution process takes place in an electrolytic cell which is subdivided by a cation exchange membrane, optionally in the presence of platinum metal salts or platinum metal acids, at temperatures between 50 and 110 °C and under potentiostatic or voltage-controlled conditions of from 2.5 V to 8 V and at a current density of from 0.3 to 7.0 A/dm2.
- Process according to Claim 1, characterised in that platinum, titanium or graphite is utilised as the cathode.
- Process according to Claims 1 to 2, characterised in that a Teflon membrane is utilised as the cation exchange membrane.
- Process according to Claims 1 to 3, characterised in that the cathode and anode chamber of the electrolytic cell is charged with 6N to 8N hydrochloric acid, and the voltage is selected such that there is generated chlorine gas, with the platinum metal of the anode making contact in pulse-wise manner with the platinum metal-containing acid and the chlorine gas.
- Process according to at least one of Claims 1 to 4, characterised in that the dissolution process takes place under potentiostatic or voltage-controlled conditions of from 5 V to 7.5 V and at a current density of from 4.4 to 6.6 A/dm2.
- Process according to at least one of Claims 1 to 5, characterised in that the hydrochloric acid concentration in the anode chamber remains constant, with the evolution of chlorine gas compensating in continuous manner for the reduction in hydrochloric acid volume.
- Process according to at least one of Claims 1 to 6, characterised in that the dilute hydrochloric acid in the cathode chamber is removed periodically, and the addition of concentrated hydrochloric acid compensates for the reduction in concentration.
- Process according to at least one of Claims 1 to 7, characterised in that the dissolution process takes place within the temperature range 60 to 100 °C.
- Process according to Claim 8, characterised in that the dissolution process takes place at a temperature of 80 °C.
- Process according to at least one of Claims 1 to 9, characterised in that the platinum metal solution exhibits a concentration of from 1 to 700 g/l.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE4243698 | 1992-12-18 | ||
| DE4243698A DE4243698C1 (en) | 1992-12-18 | 1992-12-18 | Electrolytic dissolving of platinum@, platinum@ metal impurities and platinum@ metal alloys - using electrolytic cell with platinum metal salt or acid in the hydrochloric acid in the anode and cathode chambers of the cell |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0607535A1 EP0607535A1 (en) | 1994-07-27 |
| EP0607535B1 true EP0607535B1 (en) | 1996-07-03 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP93118980A Expired - Lifetime EP0607535B1 (en) | 1992-12-18 | 1993-11-25 | Electrolytic dissolution process for platinum, platinum metal impurities and/or platinum alloys |
Country Status (9)
| Country | Link |
|---|---|
| US (1) | US5423957A (en) |
| EP (1) | EP0607535B1 (en) |
| JP (1) | JP3229988B2 (en) |
| AT (1) | ATE140043T1 (en) |
| CA (1) | CA2111791C (en) |
| DE (2) | DE4243698C1 (en) |
| FI (1) | FI100606B (en) |
| RU (1) | RU2094534C1 (en) |
| ZA (1) | ZA938996B (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5783062A (en) * | 1995-08-04 | 1998-07-21 | Rhone-Poulenc Chimie | Process for the treatment, by an electrochemical route, of compositions containing precious metals with a view to their recovery |
| DE19829274C2 (en) * | 1998-07-01 | 2002-06-20 | Otb Oberflaechentechnik Berlin | Process for the recovery of precious metals |
| RU2164554C1 (en) * | 2000-01-26 | 2001-03-27 | Карманников Владимир Павлович | Method of recovery of noble metals from solution |
| US7255798B2 (en) * | 2004-03-26 | 2007-08-14 | Ion Power, Inc. | Recycling of used perfluorosulfonic acid membranes |
| GB0408805D0 (en) * | 2004-04-08 | 2004-05-26 | Accentus Plc | Precious metal recovery |
| RU2307203C1 (en) * | 2006-02-14 | 2007-09-27 | Государственное образовательное учреждение высшего профессионального образования "Воронежский государственный технический университет" | Method of the electrolytic dissolution of the alloys of the platinum metals |
| DE102006056017B4 (en) * | 2006-11-23 | 2016-02-18 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Process for the recovery of precious metals |
| JP5431909B2 (en) * | 2009-12-22 | 2014-03-05 | 田中貴金属工業株式会社 | Electrolytic elution method and electrolytic treatment apparatus for platinum |
| JP7275629B2 (en) * | 2018-05-16 | 2023-05-18 | 住友金属鉱山株式会社 | Method for producing sulfuric acid solution |
| CN114892016A (en) * | 2022-05-12 | 2022-08-12 | 昆明理工大学 | A kind of method for leaching gold, platinum and palladium from high silver-containing material by coordinating sodium chlorate in stages |
| CN115976545A (en) * | 2022-12-23 | 2023-04-18 | 西安汇创贵金属新材料研究院有限公司 | A kind of electrochemical dissolution method of platinum sheet |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DD63880A (en) * | ||||
| US1467202A (en) * | 1921-02-26 | 1923-09-04 | Slatineanu Eulampiu | Process of and apparatus for separating platinum from platiniferous materials |
| SU496239A1 (en) * | 1974-05-23 | 1975-12-25 | Институт физико-органической химии АН Белорусской ССР | Method for extracting platinum from spent alumina-platinum catalyst |
| US4382845A (en) * | 1981-08-10 | 1983-05-10 | Chevron Research Company | Selective electrowinning of palladium |
| JPS6230827A (en) * | 1985-04-25 | 1987-02-09 | Chlorine Eng Corp Ltd | Method for melting and recovering noble metal |
| EP0242111B1 (en) * | 1986-04-07 | 1992-07-01 | Tosoh Corporation | Method for producing a metal salt by electrolysis |
-
1992
- 1992-12-18 DE DE4243698A patent/DE4243698C1/en not_active Expired - Fee Related
-
1993
- 1993-11-25 AT AT93118980T patent/ATE140043T1/en not_active IP Right Cessation
- 1993-11-25 EP EP93118980A patent/EP0607535B1/en not_active Expired - Lifetime
- 1993-11-25 DE DE59303139T patent/DE59303139D1/en not_active Expired - Fee Related
- 1993-12-01 ZA ZA938996A patent/ZA938996B/en unknown
- 1993-12-16 FI FI935660A patent/FI100606B/en not_active IP Right Cessation
- 1993-12-17 RU RU9393056628A patent/RU2094534C1/en not_active IP Right Cessation
- 1993-12-17 CA CA002111791A patent/CA2111791C/en not_active Expired - Fee Related
- 1993-12-17 JP JP34328993A patent/JP3229988B2/en not_active Expired - Fee Related
- 1993-12-20 US US08/170,423 patent/US5423957A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2111791C (en) | 2003-11-04 |
| FI100606B (en) | 1998-01-15 |
| DE59303139D1 (en) | 1996-08-08 |
| DE4243698C1 (en) | 1994-03-24 |
| EP0607535A1 (en) | 1994-07-27 |
| ATE140043T1 (en) | 1996-07-15 |
| CA2111791A1 (en) | 1994-06-19 |
| FI935660L (en) | 1994-06-19 |
| JP3229988B2 (en) | 2001-11-19 |
| RU2094534C1 (en) | 1997-10-27 |
| US5423957A (en) | 1995-06-13 |
| ZA938996B (en) | 1994-08-03 |
| FI935660A0 (en) | 1993-12-16 |
| JPH06280076A (en) | 1994-10-04 |
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