EP1567689A1 - Procede de phosphatation de surfaces metalliques presentant un meilleur taux de recuperation de phosphate - Google Patents

Procede de phosphatation de surfaces metalliques presentant un meilleur taux de recuperation de phosphate

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Publication number
EP1567689A1
EP1567689A1 EP03795846A EP03795846A EP1567689A1 EP 1567689 A1 EP1567689 A1 EP 1567689A1 EP 03795846 A EP03795846 A EP 03795846A EP 03795846 A EP03795846 A EP 03795846A EP 1567689 A1 EP1567689 A1 EP 1567689A1
Authority
EP
European Patent Office
Prior art keywords
phosphating
permeate
rinse water
water
solution
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Withdrawn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
EP03795846A
Other languages
German (de)
English (en)
Inventor
Jan-Willem Brouwer
Peter Kuhm
Iradj Peirow
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.)
Henkel AG and Co KGaA
Original Assignee
Henkel AG and Co KGaA
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 Henkel AG and Co KGaA filed Critical Henkel AG and Co KGaA
Publication of EP1567689A1 publication Critical patent/EP1567689A1/fr
Withdrawn legal-status Critical Current

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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
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F9/00—Multistage treatment of water, waste water or sewage
    • 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
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
    • 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
    • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C22/86—Regeneration of coating baths
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/28—Treatment of water, waste water, or sewage by sorption
    • C02F1/281—Treatment of water, waste water, or sewage by sorption using inorganic sorbents
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/42—Treatment of water, waste water, or sewage by ion-exchange
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C02F1/444—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by ultrafiltration or microfiltration
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/72—Treatment of water, waste water, or sewage by oxidation
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/42—Treatment of water, waste water, or sewage by ion-exchange
    • C02F2001/422—Treatment of water, waste water, or sewage by ion-exchange using anionic exchangers
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/105—Phosphorus compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/20—Heavy metals or heavy metal compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/16—Nature of the water, waste water, sewage or sludge to be treated from metallurgical processes, i.e. from the production, refining or treatment of metals, e.g. galvanic wastes

Definitions

  • the invention is in the field of phosphating metal surfaces, as is carried out as a widespread corrosion protection measure in the metalworking industry such as, for example, the automotive industry and the household appliance industry, but also in part in steelworks. It relates to a process for the improved recovery of active components that were previously discharged via the wastewater. In a preferred embodiment of the process, so much wastewater is additionally saved that the process works almost wastewater-free.
  • the aim of phosphating metals is to create crystalline metal phosphate layers that are firmly adhered to the metal surface, which in themselves improve corrosion resistance and, in conjunction with paints and other organic coatings, contribute to a significant increase in adhesion and resistance to infiltration when exposed to corrosion.
  • Such phosphating processes have long been known in the prior art.
  • the low-zinc phosphating processes are particularly suitable, in which the phosphating solutions have comparatively low zinc ion contents of e.g. B. 0.5 to 2 g / l.
  • phosphate layers with significantly improved corrosion protection and paint adhesion properties can be formed.
  • z. B. 0.5 to 1.5 g / l of manganese ions and z. B. 0.3 to 2.0 g / l of nickel ions as a so-called trication process for the preparation of metal surfaces for painting, for example for the cathodic electrodeposition of car bodies, wide application.
  • a phosphating solution contains layer-forming components such as zinc and possibly other divalent metal ions as well as phosphate ions.
  • a phosphating solution contains non-layer-forming components, such as accelerators in particular and their degradation products.
  • the degradation products of the accelerator result from the fact that it reacts with the hydrogen formed on the metal surface by the pickling reaction.
  • the non-layer-forming components, such as alkali metal ions, which accumulate over time in the phosphating bath, and in particular the degradation products of the accelerator, can only be removed from the phosphating solution by discharging and discarding part of the phosphating solution and replacing it continuously or discontinuously with new phosphating solution.
  • Phosphating solution can be discharged, for example, by operating the phosphating bath with an overflow and discarding the overflow. As a rule, however, an overflow is not necessary since the phosphated metal parts discharge a sufficient amount of phosphating solution as an adhering liquid film.
  • the phosphating solution adhering to the phosphated parts, such as automobile bodies, is rinsed off with water. Since the phosphating solution contains heavy metals and possibly other ingredients that must not be released into the environment in an uncontrolled manner, the rinsing water must be subjected to a water treatment. This must be done in a separate step before being discharged into a biological sewage treatment plant, as otherwise the functioning of the sewage treatment plant would be endangered.
  • EP-A-414 301 relates to a wastewater-free process for producing phosphate coatings on metal surfaces by means of aqueous zinc phosphate solutions containing iron (II) and nitrate ions.
  • the phosphating bath is followed by a rinsing bath cascade consisting of at least 2 rinsing baths, low-salt, preferably salt-free water is fed into the last rinsing bath, the water overflow is led into the preceding rinsing bath or the phosphating bath and at least as much low-salt or salt-free water is withdrawn from the phosphating bath that it the rinse water enriched with phosphate can absorb from the cascade.
  • undesirable ingredients such as degradation products of the accelerator, accumulate in the phosphating bath.
  • WO 99/48819 describes a process for the treatment of phosphating bath overflow and / or rinsing water after the phosphating, the phosphating using a acidic aqueous phosphating solution which contains 3 to 50 g / l phosphate ions, calculated as PO 4 3 -, 0.2 to 3 g / l zinc ions, optionally further metal ions and accelerators, characterized in that the phosphating bath overflow and / or the rinsing water contain a Nanofiltration is subjected.
  • the layer-forming cations of the phosphating process accumulate in the retentate of nanofiltration. The retentate is therefore preferably returned to the phosphating solution directly or after enrichment with further active ingredients.
  • the permeate from nanofiltration can be used as rinsing water after cleaning the parts to be phosphated before phosphating.
  • This document therefore already describes extensive recycling of recyclable materials from the rinsing water into the phosphating solution and a method for saving fresh water and thus also for reducing the amount of waste water.
  • a further development of this method is proposed in the unpublished German patent application DE 101 42 933.
  • premature blocking of the nanofiltration membrane is prevented, for example, by acidifying the rinsing water before the nanofiltration, preferably with phosphoric acid.
  • the phosphate ions partially get into the permeate of the membrane filtration. These can be reused by raising the pH of the permeate to such an extent that it can be used to supplement the cleaning solutions before phosphating.
  • Membrane filtration removes contaminants from the cleaning solution, sometimes together with surfactants, and returns water and builder salts to the cleaning solution.
  • Such processes are described in more detail, for example, in the following literature reference: N. Rajagopalan, T. Lindsey and J. Sparks, "Recycling of Aqueuos Cleaning Solutions with Membrane Filtration: Issues and Practice", Met. Finish (1999), 97 (3), SS 39-40, 42-44, 46-51. Although such processes return water and some of the valuable substances in the cleaning solution to them, valuable substances in the phosphating solution that have entered the cleaning solution are lost.
  • the prior art thus contains numerous suggestions for saving rinsing water and for recycling valuable materials from the rinsing water after the phosphating in the phosphating solution.
  • active ingredients in the phosphating solution reach into the first rinsing water or into the cleaning solution.
  • phosphating solution can be introduced into the first rinse water and thus indirectly into the cleaning solution due to incorrectly set nozzles. This can be determined, for example, by lowering the pH of the first rinse water by introducing the acidic phosphating solution.
  • zinc ions can accumulate in the alkaline cleaning solution and subsequently also in the first rinse water, which are detached during the cleaning of galvanized surfaces. Zinc ions are a valuable substance for the phosphating solution.
  • German patent application 102 36 293 which has not been published beforehand, has the task of returning phosphating agents which have reached the cleaning solution and / or the first rinsing water to the phosphating solution.
  • Appropriate process control should preferably also allow further savings in rinsing water, so that the phosphating process can be operated almost wastewater-free.
  • a process for phosphating metal surfaces a) cleaned with at least one cleaning solution, b) rinsed with at least a first rinse water, c) phosphated with a phosphating solution which is 3 to 50 g / l phosphate ions, calculated as PO 4 3 -, 0.2 to 3 g / l zinc ions, optionally containing further metal ions and optionally accelerators, and d) rinsing with at least one second rinse water and wherein e) continuously or batchwise at least a portion of the first rinse water is transferred to the cleaning solution, characterized in that f) continuously or batchwise at least a portion of the cleaning solution and / or a portion of the first rinse water is treated with a first cation exchanger which is selective for Zinc, nickel and / or manganese anions, g) regenerating this first cation exchanger after loading with an acid to obtain a first regenerate, and h) converting
  • cleaning anions such as phosphate ions can be recovered from the solution obtained after sub-step f). These can either be reused for cleaning purposes or converted into other products, such as fertilizers for agriculture. Because of the cation exchange step f), the recovered phosphate-containing valuable substances contain only such small amounts of heavy metals that they do not interfere with further use. However, this presupposes that sub-step f) is carried out according to the method described above.
  • the ion exchanger provided there has the disadvantage that traces of surfactant and / or oil are retained on the exchange resin in the feed to the ion exchanger. When the loaded exchanger is regenerated, the surfactants and / or the oil are released again and thus reach the regenerates in an enriched form. In this way, the regenerates are contaminated and can no longer be used or can only be reused after a high level of cleaning.
  • the present invention has the task of working up cleaning or rinsing solutions in such a way that cleaning-active anions such as phosphate ions can also be recovered even if one does without the cation exchanger step.
  • This object is achieved by a method for phosphating metal surfaces, the metal surfaces being sprayed and / or dipped a) cleaned with at least one cleaning solution, b) rinsed after cleaning with at least a first rinse water, c) phosphated with a phosphating solution, the 3 to 50 g / l phosphate ions, calculated as PO 4 3 -, 0.2 to 3 g / l zinc ions, optionally further metal ions as well optionally contains accelerator, and d) after the phosphating rinsing with at least one second rinse water and wherein e) continuously or discontinuously at least a portion of the second rinse water is transferred into the first rinse water or into the cleaning solution, characterized in that f) continuously or discontinuously removes at least part of the cleaning solution and / or part of the first rinse water, mixed with a precipitation reagent which forms compounds which are difficult to dissolve with heavy metal cations, and then g) subject to filtration, giving a first permeate.
  • This filtration can be carried out as a "dead end” filtration, in which all the liquid is filtered, a filter cake being built up on the filter.
  • the filtrate is referred to here as "permeate” because of the uniformity of the designations.
  • the resulting filter cake can increase the separation properties of the filter.
  • one uses cross-flow filtration over a membrane, in which only part of the liquid passes through the membrane as permeate and another part remains as retentate.
  • a membrane filtration is preferably used as the filtration in this step, and contains a first retentate and a first permeate.
  • a cleaning solution or “at least” one rinsing water is used, this means that instead of a single cleaning or rinsing step, several cleaning or rinsing steps connected in series can be provided. In practice, this is quite common. For the present invention, this means that the measures described are in each case carried out on at least one of these cleaning or rinsing stages.
  • the phrase "part of the cleaning solution” or “part of the first rinse water” means that not all of the first cleaning solution or all of the first rinse water is subjected to the treatment mentioned. Rather, a portion of each is removed and fed to the treatment mentioned: this can be, for example, the overflow that is led out of the cleaning solution or the first rinse water.
  • the portion of the second rinse water is not led directly into the first rinse water or into the cleaning solution, but polyvalent cations are separated as much as possible from this portion of the second rinse water.
  • the proportion of the second rinse water for example a nanofiltration, can be used for this undergo and split it into a permeate and a retentate.
  • the retentate contains the multivalent cations that have been transferred from the phosphating solution into the second rinse water.
  • the retentate is preferably returned either directly or after further working up to the phosphating solution, thereby largely closing the cycle of polyvalent cations.
  • the permeate of the nanofiltration contains most of the phosphate ions from the second rinse water.
  • the zinc contents are preferably in the range from 0.4 to 2 g / l and in particular from 0.5 to 1.5 g / l, as are customary for low-zinc processes.
  • the weight ratio of phosphate ions to zinc ions in the phosphating baths can vary within a wide range, provided it is in the range between 3.7 and 30. A weight ratio between 10 and 20 is particularly preferred
  • the phosphating bath can contain other components which are currently customary in phosphating baths.
  • the phosphating solution according to the invention preferably additionally contains one or more of the following cations:
  • the phosphating solution contains 0.1 to 4 g / l of manganese ions and 0.002 to 0.2 g / l of copper ions as additional cations and not more than 0.05 g / l, in particular not more than 0.001 g / l, of nickel ions.
  • phosphating baths can be used which, in addition to zinc ions, contain 0.1 to 4 g / l manganese ions and additionally 0.1 to 2.5 g / l nickel ions.
  • the form in which the cations are introduced into the phosphating baths is in principle irrelevant. It is particularly advisable to use oxides and / or carbonates as the cation source. Because of the risk of salting in the phosphating baths, salts of acids other than phosphoric acid or nitric acid should preferably be avoided.
  • phosphating baths In addition to the layer-forming divalent cations, phosphating baths generally also contain sodium, potassium and / or ammonium ions to adjust the free acid.
  • Phosphating baths that are used exclusively for the treatment of galvanized material do not necessarily have to contain a so-called accelerator.
  • accelerators which are required for the phosphating of non-galvanized steel surfaces, are also often used in technology for the phosphating of galvanized material.
  • Accelerating phosphating solutions have the additional advantage that they are suitable for both galvanized and non-galvanized materials. This is particularly important when phosphating car bodies, as these often contain both galvanized and non-galvanized surfaces.
  • accelerators are available for phosphating baths. They accelerate the formation of layers and facilitate education closed phosphate layers, since they react with the hydrogen generated during the pickling reaction. This process is referred to as "depolarization". This prevents the formation of hydrogen bubbles on the metal surface which interfere with the layer formation.
  • depolarization This prevents the formation of hydrogen bubbles on the metal surface which interfere with the layer formation.
  • the phosphating solution can contain one or more of the following accelerators:
  • hydrogen peroxide can advantageously be used as the accelerator. This can be used as such or in the form of compounds which form hydrogen peroxide under the conditions of the phosphating bath.
  • Another accelerator to be preferably used is hydroxylamine. If this is added to the phosphating bath in free form or in the form of hydroxylammonium phosphates, hydroxylammonium nitrate and / or hydroxylammonium chloride, only degradation or by-products are created which can penetrate a nanofiltration membrane.
  • Metal surfaces to be phosphated are usually coated with oil or fat.
  • This oil or fat must be removed by the cleaning solution before phosphating. Therefore, over time, oil or fat accumulates in the cleaning bath and, due to dragging, also in the first rinse water.
  • These non-water-soluble impurities can either be emulsified in the cleaning solution or at least partially float on it.
  • these are removed by membrane filtration, such as, for example, nanofiltration or preferably ultrafiltration. Suitable membrane types for this membrane filtration step are contained, for example, in the Rajagopalan literature cited at the beginning.
  • Heavy metal cations in the cleaning solution or the first rinse water would pass into the permeate together with phosphate ions in the membrane filtration step g) and hinder a later reuse of the phosphate ions. This is prevented by adding a precipitation reagent to the removed part of the cleaning solution and / or the first rinsing water in sub-step f), which forms poorly soluble compounds with heavy metal cations. As a result, the heavy metal cations are precipitated or at least converted into a colloidal form. You will then no longer be able to penetrate the membrane in step g) and contaminate the phosphate-containing permeate.
  • pooled compounds are understood to mean that these compounds have such a low solubility that, according to the solubility product, less than 10 mg / l of heavy metal ions remain dissolved and can pass into the permeate of the membrane filtration g).
  • an acid for example hydrochloric acid
  • hydrochloric acid is added to the removed part of the cleaning solution and / or the first rinsing water in step f) before adding the precipitation reagent.
  • the strong alkaline pH of the cleaning solution should be reduced to 10 or below by adding the acid. However, it is not necessary to set a pH below 7.
  • a precipitation reagent is preferably used which contains a sulfur compound with sulfur in a negative oxidation state (i.e. from -1 or -2).
  • a sulfur compound with sulfur in a negative oxidation state i.e. from -1 or -2.
  • This can be, for example, inorganic or organic sulfides.
  • a product can be used that is marketed by the Gütling company under the name Katoplex. The use of such sulfur compounds in processes for treating waste water is described in DE-A-3022 679.
  • this permeate can be mixed with an oxidizing agent.
  • an oxidizing agent for example, hydrogen peroxide is suitable for this.
  • the phosphate contained in the permeate of membrane filtration g) is preferably recovered by passing the permeate obtained in sub-step g) over a selective anion exchanger which selectively binds anions of polyvalent acids, especially phosphate ions. If this selective anion exchanger is loaded with anions of polyvalent acids, for example phosphate ions, it can be regenerated with a strong alkali such as sodium or potassium hydroxide solution.
  • the regenerate contains the polyvalent anions, especially the phosphate ions.
  • this second regrind can be used as a raw material to make a cleaning solution. In the simplest case, this can mean that some or all of this second regrind is transferred to the cleaning solution. However, the regrind can also be discharged from the system and reformulated into a different cleaning solution.
  • cleaning-effective anions of polyvalent acids are recovered, for example phosphates, borates and / or silicates.
  • this closes the material cycle for these anions.
  • this prevents such anions from getting into the wastewater from which they would have to be removed.
  • a resin e.g. cross-linked polystyrene which carries quaternary amino groups as functional groups is suitable as a selective anion exchanger.
  • cleaning-effective anions are removed from the treated part of the cleaning solution and used again for cleaning purposes before, if desired, the part of the cleaning solution is freed from monovalent cations and anions.
  • the phosphate ions can be removed from the permeate of membrane filtration g) and sent for further use. At least two embodiments are available for this:
  • the first embodiment consists in subsequently precipitating the phosphate ions as calcium and / or iron phosphates from the permeate obtained in sub-step g). This can be done, for example, by contacting the portion of the cleaning solution with a slurry of calcium hydroxide and / or iron hydroxide, thereby binding the phosphate ions to the hydroxide and separating the solid.
  • a cheaper alternative to the precipitation consists in adding an aqueous solution of water-soluble calcium and / or iron (III) salts to the proportion of the cleaning solution and the poorly water-soluble phosphates formed cations mentioned, if appropriate together with hydroxides additionally formed. If the permeate has a pH above 7 after the sub-step g), hydroxides form automatically.
  • the proportion of the cleaning solution - if desired after prior acidification, for example with hydrochloric acid - can be mixed with a solution of iron (III) salts, for example iron (III) chloride, and an alkaline pH value can be set by adding an aqueous calcium hydroxide slurry. This also leads to the formation of easily separable solid flakes.
  • a further embodiment of the phosphate removal consists in that the permeate obtained in sub-step g) is then passed through a container which contains solid calcium hydroxide, iron hydroxide, or a mixture of calcium hydroxide and iron hydroxide.
  • solid hydroxides bind the phosphate ions. They can be available as a fixed bed or as a fluidized bed. Because of the better handling for this alternative method, solid, preferably crystalline or partially crystalline, iron hydroxide is preferred. For example, the iron hydroxide known as “ferrrihydrite” can be used.
  • the calcium and / or iron phosphate-containing solids formed according to the above process variants only contain such small proportions of other heavy metals or hydrocarbons that they do not have to be disposed of as waste, but as valuable materials, for example in agriculture, the cement industry or wastewater treatment (further phosphate binding) can be used.
  • This makes it possible to recycle the phosphate ions contained in the wastewater from phosphating processes, including the associated cleaning steps, instead of disposing of them costly in the form of waste materials.
  • the method according to the invention thus represents an alternative to the method described in the introductory cited unpublished patent application DE 102 36 293.
  • the solution remaining after the phosphate ions have been bound by the selective anion exchanger still contains the monovalent cations and anions of the cleaning solution or of the first rinsing water and ions or molecules of the phosphating solution which have not been removed and which pass into the first rinsing water or into the cleaning solution via the second rinsing water have arrived.
  • This solution is preferably worked up in such a way that these monovalent ions are also removed and ultimately demineralized water is obtained.
  • This can be used as rinsing water after phosphating or for other purposes.
  • the water cycle is also largely closed. So you not only recover the phosphate ions, you also save fully demineralized water.
  • the procedure is preferably such that the permeate from the membrane filtration g) which is freed of phosphate ions by the selective anion exchanger is either h) first with a second, strongly acidic cation exchanger and then with a second, strongly basic anion exchanger, or first with a second, strongly basic anion exchanger and then treated with a second, strongly acidic cation exchanger to obtain demineralized water, or h ') is subjected to reverse osmosis, demineralized water being obtained as the third permeate and a third retentate being obtained as a concentrate, which is disposed of.
  • demineralized water being obtained as the permeate
  • the retentate (concentrate) contains the enriched monovalent cations and anions and is discharged from the system as (only) waste water.
  • sub-step h) is carried out as an ion exchanger step
  • the loaded cation and anion exchangers must be regenerated.
  • the cation exchanger is preferably regenerated with hydrochloric acid, the anion exchanger with sodium hydroxide solution.
  • the regenerates obtained here are mixed for mutual neutralization. These regenerates are disposed of. They represent the only wastewater that leaves the water cycle of the overall process in this embodiment. In comparison to the total volume of the water cycle, this represents only a very small proportion, so that the statement is justified that the process sequence according to the invention can be operated largely free of waste water.
  • the regenerates do not contain fluoride ions, they can be fed directly into the sewer network. For environmental reasons, fluoride ions should be precipitated and disposed of separately, for example by precipitation in the form of calcium fluoride.
  • the second rinse water obtained after the phosphating is preferably worked up by one of the methods known in the prior art. For example, this can be done by ion exchange, as described in WO 00/64817 or in further training according to DE 100 56 629.
  • the layer-forming cations are recovered during the regeneration of the cation exchangers and can be used again for the phosphating.
  • the procedure is preferably that i) continuously or discontinuously a portion of the second rinse water
  • the second permeate is preferably transferred to the first rinse water after the pH has been raised to about 7 to 8.
  • a portion of the first rinse water is transferred to the cleaning solution.
  • This proportion is preferably supplemented with surfactant and lye, for example sodium hydroxide solution, so that a cleaning solution with a pH in the range from 9 to 12 is obtained which has a sufficient surfactant content.
  • the second rinse water can be supplemented with the largely demineralized water which is obtained in the further processing of the cleaning solution described above. This largely closes the water cycle.
  • the pH of the second retentate is preferably raised by adding at least of a neutralizing compound of zinc, nickel and / or manganese before the second retentate is transferred to the phosphating solution.
  • Oxides and carbonates are particularly suitable as such compounds having a neutralizing effect. For reasons of easy handling, these are preferably used as an aqueous slurry.
  • the phosphated metal surfaces are subjected to a post-passivation after rinsing with the second rinsing water. To do this, they are brought into contact with a post-passivation solution.
  • Post-passivation solutions of this type are known in the prior art.
  • a post-passivation solution as described in more detail in WO 00/73536 is particularly suitable.
  • the metal surfaces phosphated in sub-step c) and rinsed in sub-step d) are passivated in a further step m) by contacting them with an aqueous solution which is the only two or contains polyvalent cations of nickel ions and the anions are selected from nitrate ions, fluoride ions, phosphate ions and anions of complex fluorides of B, Ti and Zr and then n) with at least a third rinse water.
  • the post-passivation solution is preferably a solution of nickel dihydrogen phosphate and contains 50 to 500 mg / l of nickel ions and 200 to 1 500 mg / l of phosphate ions. Both nickel ions and dihydrogen phosphate ions are valuable substances in a phosphating solution. These valuable substances accumulate in the third rinsing water and can ultimately be transferred from there to the phosphating solution via the second rinsing water by treating it via cation exchange or nanofiltration.
  • the sequence of processes according to the invention preferably further provides that a portion of the third rinse water is added continuously or discontinuously the second rinse water is transferred and the third rinse water is supplemented by adding fresh water.
  • the largely demineralized water can be used, which is obtained when a part of the cleaning solution is completely worked up as described above.
  • the water cycle and the material cycle can therefore be largely closed even using a post-passivation solution and a third rinse water. This leads to a saving of raw materials and reduces the amount of waste and waste water.
  • the sequence of processes according to the invention accordingly has particular economic and ecological advantages.
  • Granodine R 952 tri-cation phosphating (Henkel KGaA), nitrite accelerated post-passivation: nickel phosphate passivation according to WO00 / 73536
  • composition of rinsing water see a)
  • composition of retentate / permeate after nanofiltration Composition of retentate / permeate after nanofiltration:
  • composition permeate after ultrafiltration is a composition permeate after ultrafiltration
  • Retentate must be disposed of: contains hydrocarbons ("KW”) and heavy metals d) Processing permeate ultrafiltration: removal P0 4
  • Adsorber resin Lewatit MP 500
  • Fraction 1 (20 l) contains: PO 4 : 50 g / l
  • Fraction 1 is used as a raw material for the manufacture of degreasing products.
  • Fractions 2 + 3 are used in the next regeneration: fractionated regeneration.
  • This sludge is not classified as hazardous waste and can be reused in agriculture or the cement industry.
  • Adsorber resin cation exchanger: SP 112, 20 I resin
  • Anion exchanger MP 500, 20 I resin Operating conditions: 200 l / h
  • regenerates can be introduced into the waste water system after filtering the bag with Lofclear 523 D (Hayward) (pH 6-9).
  • Lofclear 523 D Hyward

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Metallurgy (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)
  • Chemical Treatment Of Metals (AREA)
  • Treatment Of Water By Ion Exchange (AREA)

Abstract

L'invention concerne un procédé de phosphatation de surfaces métalliques consistant à introduire de l'eau de rinçage dans une solution de nettoyage après phosphatation, ou à recycler l'eau de rinçage avant phosphatation ; à prélever une partie de la solution de nettoyage additionnée d'un réactif de précipitation de cations de métaux lourds ; à soumettre la solution à une filtration, de préférence à une filtration sur membrane ; et, à récupérer et réemployer éventuellement des anions à effet nettoyant, notamment des ions phosphate, à partir du perméat de la filtration essentiellement libre de métaux lourds, par échange anionique, osmose inverse ou réaction de précipitation.
EP03795846A 2002-12-05 2003-11-26 Procede de phosphatation de surfaces metalliques presentant un meilleur taux de recuperation de phosphate Withdrawn EP1567689A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10256884A DE10256884A1 (de) 2002-12-05 2002-12-05 Verfahren zur Phosphatierung von Metalloberflächen mit verbesserter Phosphat-Rückgewinnung
DE10256884 2002-12-05
PCT/EP2003/013284 WO2004050949A1 (fr) 2002-12-05 2003-11-26 Procede de phosphatation de surfaces metalliques presentant un meilleur taux de recuperation de phosphate

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EP1567689A1 true EP1567689A1 (fr) 2005-08-31

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AU (1) AU2003298143A1 (fr)
DE (1) DE10256884A1 (fr)
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DE10354563B4 (de) * 2003-11-21 2006-05-04 Henkel Kgaa Abwasserreduziertes Phosphatierverfahren durch Aufarbeitung von Entfettungslösung und/oder Spülwasser
DE102005043031A1 (de) * 2005-09-10 2007-03-15 Mauer, Dieter, Dr. Verfahren zum Entfernen von Phosphaten aus Acetat-gepufferten Lösungen
CN101070215B (zh) * 2006-04-05 2012-10-24 肖应东 电镀废水回用工艺
DE102008038653A1 (de) 2008-08-12 2010-03-25 Henkel Ag & Co. Kgaa Sukzessive korrosionsschützende Vorbehandlung von Metalloberflächen in einem Mehrstufenprozess
JP5877423B2 (ja) * 2012-05-10 2016-03-08 ディップソール株式会社 亜鉛系めっき金属部材表面の硝酸活性処理溶液の再生方法及びそれを用いた再生処理装置
EP3044171A1 (fr) * 2013-09-09 2016-07-20 Kemira OYJ Procédé pour purifier l'eau
WO2015181205A1 (fr) 2014-05-28 2015-12-03 Biaqua B.V. Procédé pour l'élimination de phosphate dans des fractions d'eau
CN106587476A (zh) * 2016-12-21 2017-04-26 科迈化工股份有限公司 橡胶促进剂ns\cz\dz生产的混合污水处理方法
EP3655366A1 (fr) 2017-07-18 2020-05-27 Ecolab USA, Inc. Recyclage de courant d'eau de rinçage phosphatée d'automobile
CN109694144A (zh) * 2017-10-23 2019-04-30 宜兴市联丰化工机械有限公司 一种封头酸洗磷化污水处理工艺
CN111232944A (zh) * 2020-03-19 2020-06-05 王敏 一种低成本磷酸铁的制备方法
CN111646573B (zh) * 2020-06-23 2021-11-23 苏州科技大学 一种利用城市污水有机碳源的磷去除与回收方法

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JPS54155135A (en) * 1978-05-29 1979-12-06 Nippon Packaging Kk Treatment of metal surface cleaned water
DE3022679A1 (de) * 1980-06-18 1982-01-07 Gütling GmbH, 7012 Fellbach Verfahren und vorrichtung zum behandeln von abwaessern
DE19854431A1 (de) * 1998-11-25 2000-05-31 Henkel Kgaa Phosphatierverfahren mit Spülwasser-Einsparung
DE10115244A1 (de) * 2001-03-28 2002-10-02 Henkel Kgaa Nachpassivierung einer phosphatierten Metalloberfläche im Bandverfahren
DE10236293A1 (de) * 2002-03-20 2003-10-02 Henkel Kgaa Verfahren zur Phosphatierung von Metalloberflächen mit verbesserter Wertstoff-Rückgewinnung

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DE10256884A1 (de) 2004-06-17
WO2004050949A1 (fr) 2004-06-17
RU2005121129A (ru) 2006-01-20
AU2003298143A1 (en) 2004-06-23

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