FR2663345A1 - Cathode compartment for the electrolytic regeneration of sulphochromic and/or phosphochromic solutions - Google Patents
Cathode compartment for the electrolytic regeneration of sulphochromic and/or phosphochromic solutions Download PDFInfo
- Publication number
- FR2663345A1 FR2663345A1 FR9007367A FR9007367A FR2663345A1 FR 2663345 A1 FR2663345 A1 FR 2663345A1 FR 9007367 A FR9007367 A FR 9007367A FR 9007367 A FR9007367 A FR 9007367A FR 2663345 A1 FR2663345 A1 FR 2663345A1
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- cathode compartment
- chromic
- solution
- compartment according
- cathode
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- 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
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
- C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
- C23C18/1601—Process or apparatus
- C23C18/1617—Purification and regeneration of coating baths
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D21/00—Processes for servicing or operating cells for electrolytic coating
- C25D21/16—Regeneration of process solutions
- C25D21/18—Regeneration of process solutions of electrolytes
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- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Electrochemistry (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
Abstract
Description
La présente invention concerne un compartiment ca- thodique, utile pour la régénération électrolytique de solutions sulfo-chromiques et/ou phospho-chromiques usagées consistant en un volume ouvert seulement à sa face supérieure et constitué d'un matériau support solide inerte chimiquement dans les conditions de l'électrolyse et bon isolant de l'électricité, dans lequel sont ménagées des découpes ou fenêtres munies de façon étanche d'éléments d'occultation composés d'un matériau présentant une très bonne résistance chimique aux oxydants et aux réducteurs en milieu fortement acide et jusqu'à une température d'environ 110-1200C, une porosité comprise entre 0,02 et 50 ,uet de préférence entre 0,02 et 15 > k, une résistance électrique inférieure à environ 0,2 t /dm2 et une résistance mécanique suffisante pour supporter au minimum une différence de pression de 0,2 kg/cm2 Un tel compartiment est décrit dans FR-A-2354399. The present invention relates to a cathodic compartment, useful for the electrolytic regeneration of used sulfo-chromic and / or phospho-chromic solutions consisting of an open volume only at its upper side and consisting of a solid carrier material chemically inert under the conditions electrolysis and a good insulator of electricity, in which are provided cutouts or windows sealed with concealment elements composed of a material having a very good chemical resistance to oxidants and reducing agents in a strongly acidic medium and up to a temperature of about 110-1200 ° C., a porosity of between 0.02 and 50, and preferably of between 0.02 and 15 ° C., an electrical resistance of less than about 0.2 t / dm 2 and a resistance of sufficient mechanical to withstand at least a pressure difference of 0.2 kg / cm 2 Such a compartment is described in FR-A-2354399.
Dans le brevet principal FR-A-2354399, les éléments d'occultation sont des éléments en verre fritté notamment des disques en verre fritté. In the main patent FR-A-2354399, the occulting elements are sintered glass elements including sintered glass discs.
Ces éléments donnent satisfaction, cependant ils nécessitent l'application de moyens de fixation qui sont relativement onéreux. These elements are satisfactory, however they require the application of fastening means which are relatively expensive.
Ces éléments d'occultation sont, de plus, relativement fragiles et il convient de procéder à diverses révisions annuelles pour vérifier le bon état du compartiment cathodique. These concealment elements are, moreover, relatively fragile and it is appropriate to conduct various annual revisions to check the good condition of the cathode compartment.
Ces diverses révisions annuelles posent également des problèmes en ce qui concerne le coût. These various annual revisions are also problematic in terms of cost.
Dans la présente invention, on a recherché un moyen pour obtenir une diffusion moindre de l'acide chromique du compartiment anodique vers le compartiment cathodique afin d'obtenir une économie importante en acide chromique. In the present invention, a means has been sought to obtain a lower diffusion of the chromic acid from the anode compartment to the cathode compartment in order to obtain a significant saving in chromic acid.
De façon surprenante, on a trouvé qu'il était possible de remplacer les éléments en verre fritté par un tissu poreux pour occulter les fenêtres du compartient cathodique. Surprisingly, it has been found that it is possible to replace the sintered glass elements with a porous fabric to obscure the windows of the cathode compartment.
Le tissu poreux est fixé entre deux plaques du compartiment cathodique. The porous tissue is fixed between two plates of the cathode compartment.
Il présente une porosité comprise entre 0,02 et 50 tet une résistance électrique inférieure à 0,2 J\~ /dm2. It has a porosity of between 0.02 and 50 t and an electrical resistance of less than 0.2 J / dm2.
La présente invention a donc pour objet un compartiment cathodique selon la revendication de FR-A-2354399 qui est caractérisé en ce que les éléments d'occultation sont constitués par un tissu poreux en polytétra fluoroéthylène appliqué entre deux plaques parallèles du compartiment cathodique. The present invention therefore relates to a cathode compartment according to claim FR-A-2354399 which is characterized in that the occultation elements are constituted by a porous polytetrafluoroethylene fabric applied between two parallel plates of the cathode compartment.
La présente invention concerne également les caractéristiques ci-après considérées isolément ou selon toutes leurs combinaisons techniquement possibles:
- l'épaisseur du tissu poreux est comprise dans la gamme de 0,1 à 3,0 mm;
- le compartiment cathodique présente une forme de parallélépipède-rectangle vertical,
- le compartiment cathodique est au moins partiellement rempli d'une solution aqueuse d'acide sulfurique et/ou phosphorique;
- la solution est une solution d'acide sulfurique et/ou phosphorique à O-95%, et de préférence, à 5-95% en volume dans l'eau;;
- La présente invention a encore pour objet la cellule électrolytique utile pour la régénération de solutions sulfo-chromiques et/ou phospho-chromiques usagées qui est caractérisée en ce qu'elle comporte un compartiment cathodique selon les caractéristiques mentionnées plus haut, immergé dans la solution à régénérer dans laquelle plonge au moins une anode et à titre de milieu électrolytique entourant la ou les cathodes plongeant dans ledit compartiment cathodique, une solution aqueuse d'acide sulfurique et/ou phosphorique.The present invention also relates to the characteristics hereafter considered in isolation or in all their technically possible combinations:
the thickness of the porous fabric is in the range of 0.1 to 3.0 mm;
the cathode compartment has a parallelepiped-vertical rectangle shape,
- The cathode compartment is at least partially filled with an aqueous solution of sulfuric acid and / or phosphoric acid;
the solution is a solution of sulfuric acid and / or phosphoric acid at 0-95%, and preferably at 5-95% by volume in water;
The subject of the present invention is also the electrolytic cell useful for the regeneration of used sulfo-chromic and / or phosphochromic solutions which is characterized in that it comprises a cathode compartment according to the characteristics mentioned above, immersed in the solution regenerating in which plunges at least one anode and as an electrolytic medium surrounding the cathode or cathodes immersed in said cathode compartment, an aqueous solution of sulfuric acid and / or phosphoric acid.
Divers avantages et caractéristiques de la présente invention ressortiront de la description détaillée ci-après faite en regard des dessins annexés sur lesquels:
Figure 1 est une vue en perspective d'un compartiment cathodique selon l'invention.Various advantages and characteristics of the present invention will emerge from the detailed description given below with reference to the appended drawings, in which:
Figure 1 is a perspective view of a cathode compartment according to the invention.
Figure 2 est une vue en coupe d'une cellule électrolytique avec le compartiment cathodique de l'invention. Figure 2 is a sectional view of an electrolytic cell with the cathode compartment of the invention.
Aux dessins annexés où les mêmes symboles de référence désignent des parties analogues, 1 est une anode avantageusement au plomb ou tout alliage de plomb plongeant dans la solution sulfo-chromique et/ou phospho-chromique à régénérer 3. 2 est une cathode plongeant dans un compartiment cathodique 5. In the appended drawings in which the same reference symbols denote similar parts, 1 is an advantageously lead anode or any lead alloy dipping into the sulpho-chromic and / or phosphochromic solution to be regenerated. cathode compartment 5.
Le compartiment cathodique 5 est constitué de plusieurs plaques parallèles 7, 7', 7", 7"' comportant un certain nombre de fenêtres 8. Le compartiment cathodique 5 est rempli, jusqu'à un niveau, de préférence au moins égal à celui de la solution sulfo-chromique et/ou phospho-chromique 3 avec une solution aqueuse d'acide sulfurique et/ou phosphorique 4. The cathode compartment 5 consists of several parallel plates 7, 7 ', 7 ", 7"' having a number of windows 8. The cathode compartment 5 is filled, to a level, preferably at least equal to that of the sulpho-chromic and / or phosphochromic solution 3 with an aqueous solution of sulfuric and / or phosphoric acid 4.
Un tissu poreux 6 en polytétrafluoroéthylène est appliqué sur chaque face du compartiment cathodique 5 entre deux plaques parallèles 7, 7' et respectivement 7", 7"'. A porous polytetrafluoroethylene fabric 6 is applied to each face of the cathode compartment 5 between two parallel plates 7, 7 'and 7 ", 7"', respectively.
Le tissu poreux 6 en polytétrafluoroéthylène assure une diffusion moindre dans un rapport de 1 à 5 de la solution d'acide chromique 3 du compartiment anodique vers le compartiment cathodique 5, ce qui entratne une économie importante d'acide chromique. The porous polytetrafluoroethylene fabric 6 provides less diffusion in a ratio of 1 to 5 of the chromic acid solution 3 of the anode compartment to the cathode compartment 5, resulting in a significant saving of chromic acid.
Il importe de remarquer que le tissu poreux 6 en polytétrafluoroéthylène est prévu sensiblement au milieu des plaques 7, 7', 7", 7"' dont l'épaisseur est pratiquement identique. It should be noted that the porous polytetrafluoroethylene fabric 6 is provided substantially in the middle of the plates 7, 7 ', 7 ", 7"' whose thickness is substantially identical.
Toutefois il n'est pas exclu de faire varier l'épaisseur de l'une quelconque des plaques 7, 7', 7", 7"' et dans ce cas le tissu poreux 6 en polytétrafluoroéthylène n'est plus au milieu desdites plaques 7, 7', 7", 7"'. However, it is not excluded to vary the thickness of any of the plates 7, 7 ', 7 ", 7"' and in this case the porous fabric 6 polytetrafluoroethylene is no longer in the middle of said plates 7 , 7 ', 7 ", 7"'.
La mise en place du tissu poreux 6 entre les pla ques 7, 7', 7", 7"' permet un entretien réduit et une vérification annuelle est suffisante. The placement of the porous fabric 6 between the plates 7, 7 ', 7 ", 7"' allows a reduced maintenance and an annual check is sufficient.
Il suffit donc simplement de changer une fois par an ledit tissu poreux 6. L'homme de l'art réalise aisément les avantages économiques que peut procurer un tel changement annuel. It is therefore sufficient simply to change once a year said porous tissue 6. One skilled in the art easily achieves the economic benefits that can provide such an annual change.
A titre d'exemple on a réalisé un essai avec la cellule électrolytique telle que représentée sur les Figures 1 et 2 des dessins annexés. By way of example, an experiment was carried out with the electrolytic cell as shown in FIGS. 1 and 2 of the accompanying drawings.
La cuve d'électrolyse comportait douze anodes 1 en plomb et un compartiment cathodique 5 selon l'invention en polychlorure de vinyle surchloré. The electrolysis cell comprised twelve lead anodes 1 and a cathode compartment 5 according to the invention made of super chlorinated polyvinyl chloride.
Ce compartiment cathodique 5 de forme parallélépipédique-rectangle comprenait douze fenêtres 8 circulaires d'environ 90 mm de diamètre. Dans les plaques 7 et 7' ainsi que dans les plaques 7" et 7"' on a interposé un tissu poreux 6 en polytétrafluoroéthylène. Le compartiment cathodique 5 a été rempli avec une solution aqueuse à 50% d'acide sulfurique 4 jusqu a un niveau sensiblement identique à celui de la solution sulfo-chromique 3 dans laquelle plonge les anodes 2 après immersion du compartiment cathodique 5 dans cette solution sulfo-chromique. This parallelepiped-rectangle cathode compartment 5 comprised twelve circular windows 8 approximately 90 mm in diameter. In the plates 7 and 7 'as well as in the plates 7 "and 7", a porous fabric 6 made of polytetrafluoroethylene was interposed. The cathode compartment 5 was filled with a 50% aqueous solution of sulfuric acid 4 up to a level substantially identical to that of the sulfo-chromic solution 3 in which the anodes 2 dip after immersion of the cathode compartment 5 in this sulfo solution. -chromique.
On a ensuite amené le jeu de quatre cathodes 1 en position presque totalement immergée dans le compartiment cathodique 5 et on a fermé le circuit alimenté par un générateur de courant continu. La solution sulfo-chromique 3 représentait 1000 1 ayant servi à l'attaque de matière plastique métallisable et contenant 20 g/l d'ions chromiques et 400 g/l d'acide chromique. Après 50 heures de fonctionnement sous une tension de 8 à 9 volts et une intensité de 250 A on a arrêté l'électrolyse et on a recueilli une solution sulfo-chromique neuve renfermant plus de 15 g/l d'ions chromiques et environ 403,5 g/l d'acide chromique. The set of four cathodes 1 was then brought into position almost completely immersed in the cathode compartment 5 and the circuit powered by a DC generator was closed. The sulfo-chromic solution 3 represented 1000 l used for etching metallizable plastic and containing 20 g / l of chromic ions and 400 g / l of chromic acid. After 50 hours of operation at a voltage of 8 to 9 volts and an intensity of 250 A, the electrolysis was stopped and a fresh sulfo-chromic solution containing more than 15 g / l of chromic ions and about 403 was collected. 5 g / l of chromic acid.
L'invention n'est pas limitée au mode de réalisation représenté et décrit en détails et diverses modifica tions peuvent y être apportées sans sortir de son cadre. The invention is not limited to the embodiment shown and described in detail and various modifications can be made without departing from its scope.
Les signes de référence insérés après les caractéristiques techniques mentionnées dans les revendications ont pour seul but de faciliter la compréhension de ces dernières et n'en limitent aucunement la portée. The reference signs inserted after the technical features mentioned in the claims are only intended to facilitate the understanding of the latter and in no way limit the scope.
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9007367A FR2663345A1 (en) | 1990-06-13 | 1990-06-13 | Cathode compartment for the electrolytic regeneration of sulphochromic and/or phosphochromic solutions |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9007367A FR2663345A1 (en) | 1990-06-13 | 1990-06-13 | Cathode compartment for the electrolytic regeneration of sulphochromic and/or phosphochromic solutions |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| FR2663345A1 true FR2663345A1 (en) | 1991-12-20 |
Family
ID=9397565
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| FR9007367A Pending FR2663345A1 (en) | 1990-06-13 | 1990-06-13 | Cathode compartment for the electrolytic regeneration of sulphochromic and/or phosphochromic solutions |
Country Status (1)
| Country | Link |
|---|---|
| FR (1) | FR2663345A1 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3450623A (en) * | 1965-10-08 | 1969-06-17 | Great Lakes Carbon Corp | Electrolytic apparatus for the regeneration of chromium salt solutions |
| US3595765A (en) * | 1965-10-08 | 1971-07-27 | Great Lakes Carbon Corp | Process for the electrolytic regeneration of reduced chromium compounds |
| JPS4986227A (en) * | 1972-12-21 | 1974-08-19 | ||
| JPS4990638A (en) * | 1972-12-29 | 1974-08-29 |
-
1990
- 1990-06-13 FR FR9007367A patent/FR2663345A1/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3450623A (en) * | 1965-10-08 | 1969-06-17 | Great Lakes Carbon Corp | Electrolytic apparatus for the regeneration of chromium salt solutions |
| US3595765A (en) * | 1965-10-08 | 1971-07-27 | Great Lakes Carbon Corp | Process for the electrolytic regeneration of reduced chromium compounds |
| JPS4986227A (en) * | 1972-12-21 | 1974-08-19 | ||
| JPS4990638A (en) * | 1972-12-29 | 1974-08-29 |
Non-Patent Citations (2)
| Title |
|---|
| CHEMICAL ABSTRACTS, vol. 82, 1975, page 417, abrégé no. 49294f, Columbus, Ohio, US; & JP-A-74 86 227 (YUASA BATTERY CO., LTD) 19-08-1974 * |
| CHEMICAL ABSTRACTS, vol. 82, 1975, page 419, abrégé no. 117870t, Columbus, Ohio, US; & JP-A-74 90 638 (YUASA BATTERY CO., LTD) 29-08-1974 * |
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