EP0500837A1

EP0500837A1 - Process for recovering metals and coatings from composite materials

Info

Publication number: EP0500837A1
Application number: EP91914746A
Authority: EP
Inventors: Dagmar Mertens-Gottselig; Gerd Rauser; Werner Löffler
Original assignee: RWE Entsorgung AG
Current assignee: RWE Entsorgung AG
Priority date: 1990-09-13
Filing date: 1991-08-29
Publication date: 1992-09-02
Also published as: BR9106175A; JPH05501134A; CA2050767A1; WO1992005215A1; NZ239670A; AU652772B2; AU8337191A; US5232489A; JPH0765124B2

Abstract

Selon un procédé de récupération de métaux et de matériaux d'enduction contenus dans des matériaux composites, on traite les matériaux composites avec des solvants donnés à une température élevée. Dans le cas de matériaux composites en métaux/matières plastiques, on peut dissoudre les matières plastiques et les récupérer dans la solution, alors que le métal est quantitativement séparée sous une forme purifiée de la solution et peut être réutilisé. Dans le cas de matériaux composites en métaux/papier et en métaux/matières plastiques/papier, on peut également récupérer les métaux sous forme purifiée en éliminant le papier avec de l'eau, à laquelle on ajoute le cas échéant des quantités réduites d'alcools C1 à C3 et/ou de cétones C3 à C4.According to a process for recovering metals and coating materials contained in composite materials, the composite materials are treated with given solvents at an elevated temperature. In the case of composite materials made of metals / plastics, the plastics can be dissolved and recovered in the solution, while the metal is quantitatively separated in a purified form from the solution and can be reused. In the case of composite materials made of metals / paper and metals / plastics / paper, the metals can also be recovered in purified form by eliminating the paper with water, to which reduced quantities of, if necessary, are added. C1 to C3 alcohols and / or C3 to C4 ketones.

Description

Process for the recovery of metals and coating materials from composite materials

The present invention relates to a method for the recovery of metals and coatings of the metals from composite materials by treating the composite materials with certain solvents at elevated temperatures, the coating being brought into solution and recovered from this solution and the metal quantitatively and in pure form from the Solution is separated and can be reused.

The present invention also relates to an apparatus for performing the method.

The recovery of metals from composite materials, in particular from aluminum laminates, is of considerable economic importance, since such laminates are widely used for packaging purposes.

Composite materials are used as packaging materials e.g. B. for coffee, tea, toothpaste, chemicals, drinks and. a. in large quantities on the market.

Metal foils in such composite materials are mostly made of aluminum, while the coating can be made of numerous plastic materials.

Examples are films made of various polyethylenes, of polypropylene, of polyesters, of polycamonates, of copolymers such as. B.

Ethylene vinyl acetate, ethylene propylene, from polyvinyl chloride or from

Called epoxy resins. Outside multilayer composites containing films made of various plastics are on the market. Furthermore, the metal foil with cellulose-containing materials such. B. be shrewd with paper. Paper coatings can also be combined with plastic layers. The foils can be made with or without Kleoer or

Adhesion promoter to be connected. Metal containing composite materials, however, are not only used as packaging material. Examples outside the packaging area are cables, coated wires, Closing lid, plastic-coated items such as. B. door handles or tools, further electrical devices, circuit boards and numerous other items. A recovery of metals present in the composite materials is of greater interest, the more valuable the metal is, there is also considerable interest in the recovery of copper. An important aspect for recovery can also be the separation of the metals for environmental reasons, since it is known that heavy metals get into the atmosphere in small quantities when the entire composite material is burned.

Numerous recovery processes have been described in the literature.

A process is described in DD-PS 218313 in which aluminum and polyvinyl chloride are recovered from an aluminum / polyvinyl chloride film by grinding and mechanical separation.

A mechanical separation process is also described in FR-PS 2528351 for composite materials such as power cables and wires and the like.

Japanese patent JP-PS 57043941 discloses a method according to which composites are subjected to pyrolysis, in which the plastic decomposes and the pyrolysis gases are used as fuel to maintain the pyrolysis temperature.

According to JP-PS 54127983, polyvinylchloride-laminated aluminum foils are treated with carbon tetrachloride, producing two layers of solvent, the lower one containing the aluminum and the upper one containing the polyvinyl chloride.

Analogously, according to JP-PS 54026871, copper is obtained from a formaldehyde-phenolic resin / copper laminate by treatment with trichlorethylene.

According to JP-PS 51020976, mixtures of aluminum foils laminated with various thermoplastics are treated with xylene at various temperatures and with phenol. The laminates contain polypropylene, ethylene-vinyl 1-acetate copolymer, poly (ethylene) terephthalate, polycarbonate and polyethylenes. The thermoplastics can be partially separated from one another by using the solvents under different conditions.

According to JP-PS 60212434, an aluminum / polyvinyl chloride laminate bonded with an ethylene / vinyl acetate copolymer adhesive is mixed with a solvent mixture of ethyl acetate, isopropanol, acetone and tol 30 ml. treated at room temperature. Here, the adhesive dissolves, so that subsequently aluminum foil and polyvinyl chloride are separated.

U.S. Patent 4,168,199 discloses the removal of paper from an aluminum / paper laminate. For this, the material is treated for 10 minutes at 120 ° C. with water under nitrogen pressure.

A similar method is described in JP-PS 54088817.

Although in Japanese Patent JP-PS 51020976 xylene is used as a solvent for the coating materials polyethylene, polypropylene, ethylene-vinyl acetate copolymer and polycarbonate, the latter two thermoplastics already at room temperature and the thermoplastics polyethylene and polypropylene at 120 ° C. To dissolve hot xylene up to 130 ° C, the investigations of the applicant have shown that under these conditions the plastic coatings do not completely detach and therefore no pure aluminum is obtained.

Rather, it was found that a pure sheet of Verbuno, such. B. packaging made of aluminum / polyethylene or polypropylene or Etnvien, propylene copolymer films or multi-layer films are on the market, which only completely dissolve in xylene at about 200 ° C under autogenous pressure of the xylene, wherein the causes of the poor solubility are not known, while for other polyethylene and polypropylene laminates at least the boiling point of xylene must be present. A process has been published by Titalyse in which the aluminum is dissolved in acids so that the plastic film is retained.

The object of the invention is to provide a method for separating and recovering aer coating materials and metals from composite materials, which allows in a simple and economical manner, as well as that To recover metal as well as the coating agent as quantitatively and in pure form as possible and to be able to reuse the solvent used.

The applicant has now found a process for recovering metals and coating materials from composite materials by removing the coatings on the metal with solvents, characterized in that the composite material is used to remove non-polar layers with dimethyl and / or trimethyl and / or tetramethylbenzenes and / ooer ethylbenzene and / or isopropylbenzene to 40 ° C to 280 ° C, preferably to 75 ° C to 220 ° C and particularly preferably to 138.4 ° C to 204 ° C without pressure or under pressure during a residence time of 0.5 to 360 minutes, preferably from 5 to 120 minutes and particularly preferably from 5 to 60 minutes, that the composite materials are removed to 40 with tetrahydrofuran and / or its methylated derivatives and / or dioxane and / or its methylated derivatives in order to detach polar layers ° C to 280 ° C, preferably to 60 ° C to 200 ° C without pressure or under pressure for a residence time of 0.5 to 360 min., Preferably of 5 b is 120 minutes and particularly preferably from 5 to 60 minutes.

heated.

The applicant has also found a process for recovering metals and coating material from composite materials by removing the coatings present on the metal with solvent, characterized in that the composite material is removed with C ₃ -C ₁₈ ketones and / or C to remove the layers ₃ -C ₁₈ polyketones at 40 ° C to 280 ° C, preferably at 75 ° C to 220 ° C and particularly preferably at 100 ° C to 220 ° C without pressure or under pressure during a residence time of 0.5 to 360 minutes, preferably from 5 heated to 120 min. and particularly preferably from 5 to 60 min.

Finally, the applicant has found a device for performing the aforementioned methods.

The present invention now makes it possible, by using special solvents and by using special conditions, to obtain the metals in such a pure form that they can be used without further treatment for new applications or for reuse in composite materials can be set. The investigations by the applicants in have shown that from the very common packaging films consisting of a metal film, in particular aluminum and a non-polar one. Coating such as a polyethylene or polypropylene film, the metal can be obtained quantitatively in a very pure form if the compounding material is heated with di-, tri-, tetramethylbenzenes, ethylbenzene and isopropylbenzene or mixtures of these hydrocarbons until the coating material has dissolved and then separating the metal and generally subjecting it to aftertreatment with at least one of the hydrocarbons mentioned. Since the boiling points of di-, tri- and tetramethylbenzenes are between 138.4 ° C and 203.2 ° C to 204 ° C, the solvent can be selected so that the solvent treatment can be carried out without pressure. This is a procedural advantage. However, according to the invention, it is also possible to work under pressure in closed vessels.

For example, one can use xylenes at 200 ° C

Own pressure of 5 to 6 bar. The xylenes are advantageously used as an industrial mixture, it being known that industrial mixtures have very different compositions, depending on the point at which the mixture is drawn in a xylene plant and the process used to obtain pure xylenes .

In addition to small amounts of trimethylbenzene, such mixtures often also contain small amounts of ethylbenzene and non-aromatic hydrocarbons.

A suitable C ₈ mixture consists, for example, of 1 to 4% by weight of non-aromatics, 19 to 28% by weight of ethylbenzene, 16 to 20% by weight of p-xylene, 40 to 45% by weight of m-xylene and 10 to 15 % By weight o-xylene, which add up to 100 -2- depending on the mixture. Here, however, depending on the plastic to be dissolved, two phases can occur with different plastic concentrations instead of a uniform, highly concentrated solution.

In principle, the individual aromatic hydrocarbons or other mixtures can also be used.

In the case of trimethylbenzenes as well, the individual isomers and mixtures can be used. The same applies to the tetramethylbenzenes, the mixtures may also contain 1,2,4,5-tetramethylbenzene, although in pure form it is solid at normal temperature and melts at 81ºC to 82ºC.

The boiling points of the aromatic hydrocarbons are 143.6 ° C for o-xylene, 139 ° C for m-xylene and 138.4 ° C for b-xylene. 1.3.5-trimethyloenzene has a boiling point of 164.6 ° C, 1.2.4-trimethylbenzene has a boiling point of 170.2 ° C, 1.2.3-trimethylbenzene has a boiling point of 175.6 ° C, 1.2.3.5-tetramethylbenzene has a boiling point of 195 ° C to 197 ° C, 1.2.3.4-tetramethylbenzene has a boiling point of 203 ° C to 204 ° C, ethylbenzene has a boiling point of 136.1 ° C and isopropylbenzene nat has a boiling point of 152.5 ° C. According to the invention, any mixtures of at least two of the hydrocarbons mentioned can also be used. In the presence of, for example, the xylenes or ethyloenzene or their mixtures, it is not possible to work at 200 ° C. without pressure. However, it was surprisingly found that in the presence of the higher methylated methyloenzene the solvent power in the same temperature range compared to the lower methylated methylbenzenes z. B. a xylene mixture, which is used under boiling conditions, is much better, so that relatively short residence times can be chosen. A residence time of 5 to 10 minutes should generally not be undercut. Another group of solvents which are very suitable according to the invention are ketones and polyketones. namely C ₃ -C ₁₈ ketones and polyketones. pierper can be both open-chain and rinc-shaped ketones. such as B. Cyclopentanone, boiling point 129 ° C, cyclohexanone, boiling point 155.7 ° C, cycloheptanone, boiling point 179-81 ° C, cyclooctanone and higher derivatives, acetylacetone, boiling point 194 ° C, 2,7-octanedione, boiling point 114 ° C (18 mo ).

According to the invention, any mixtures from groups a) dimethyl, trimethyl, tetramethylbenzene, ethylbenzene, isopropylbenzene;

b) tetranydrofuran, methylated tetrahydrofuran, dioxane, methylated dioxane; c) C ₃ -C ₁₈ ketones, C ₃ -C ₁₈ polyketones are used in coordinated proportions. The dissolution temperatures can be from 40 ° C to 280 ° C, preferably from 75 ° C to 220 ° C and particularly preferably from 138.4 ° C to 204 ° C in the case of aromatic solvents and particularly preferably from 100 ° C to 220 ° C in The case of the ketone compounds, while the preferred temperature for tetrahydrofuran and dioxane and their derivatives is 60 ° C to 200 ° C.

The residence time during the dissolving process is 0.5 to 360 minutes, preferably 5 to 120 minutes and particularly preferably 5 to 60 minutes. In general, low temperatures are combined with longer residence times.

The dissolving process can take place without pressure or under pressure, but preferably without pressure, the solvents being chosen so that the boiling point is not exceeded. The ones to be processed according to the invention

Composite materials can be in any layering, and the layers can have any thickness according to the required applications. The layers can be applied as desired, such as. B. by vapor deposition, coating, etc.

The treatment according to the invention leads to the fact that thermoplastics, such as polyethylene - this applies to the various ethylene or polyethylene types, such as LD, HD and LLD polyethylene, polypropylene and ethylene / propylene copolymers - dissolve in the solvent, as does the adhesive or Adhesion promoter, if the composite material contains one. The plastics can be recovered from the process according to the invention. This can be done in a known manner, e.g. B. cases by distilling off at least part of the solvent, cases by cooling the solution or cases by adding a solvent in which the plastic is insoluble or only slightly soluble. Here it is possible to consider the plastic as fine-grained. obtain huge granules that can be used directly for processing into finished products. Particularly in the case of oem cooling, if the solubility aging is steeply dependent, rapid deposition can result in caking and sticking of the plastic particles. The heat released in the precipitation tank during this programmed crystallization can be fed to the recycled solvent via heat exchangers. A technically particularly advantageous workup is the extensive removal of the solvent, for. B. by distillation, if necessary in vacuo and extruding the concentrated plastic solution in an evacuable extruder, so that a solvent-free granulate is obtained. The metals obtained can be separated in a known manner by filtration, magnetically or by other processes.

Although the hydrocarbons mentioned also other thermoplastics, such as. B. polyester, polycarbonate, polyvinyl chloride, ethylene-vinyl acetate copolymers or epoxy resins or others can at least partially solve, it has proven to be advantageous according to the invention to use tetrahydrofuran and / or dioxane, depending on the polarity of the polymer building blocks, methylated as well Derivatives are suitable. Very good results can also be achieved here. H. very pure metals can be obtained with a residence time of 5 minutes depending on the temperature used. Temperatures of up to 280 ° C. can be used here, it being advantageous to work with self-jerk.

For multi-layer composites, e.g. B. a packaging film made of aluminum, polyethylene and polyester films, the solution processes mentioned can be carried out in succession, z. B. in the case of external polyethylene film, methylbenzenes are used first and then tetrahydrofuran and / or dioxane. In this case, total dwell times can be up to 360 min. In general, however, these can be significantly shorter per stage, as already explained above, e.g. E. 5 to 60 min. Treatment with a mixture of the polar and non-polar solvents is also possible according to the invention. Finally, according to the invention, composite materials can also be processed, which contain several metals, which can consist of the same metal or different metal.

The use of the ketone solvent has also been used for the removal of non-polar layers, depending on the structure of the ketone for polar layers, such as. B. polyacrylate-polyester copolymers, polyester and polyvinyl chloride layers proven. The plastics can often be easily obtained from these solvents by cooling them down in a pure, finely divided, granular form.

The plastic layers in composite films are very often thermoplastics, such as different types of PE and PP, polyester, polyvinyl chloride and the like. a. Composite films with these u. a. Thermoplastics are particularly well suited for the process according to the invention. However, there are also layers of resins, such as. B. epoxy resins and elastomers processable according to the invention.

The amount of solvent based on the composite material used can vary within wide limits. A suitable ratio is

Range from 1 to 15 parts by weight of the solvent per part by weight of the

Composite. Concentrated plastic solutions are preferred because that

Removing the solvent requires less effort and is therefore more economical. From business! for reasons

Solvent content should not exceed 15 parts by weight. It has surprisingly shown that C ₉ aromatics have a particularly high dissolving power for numerous thermoplastics, so that plastic concentrations of 49% by weight can easily be achieved in the solution. For example, technical C ₉ aromatics fractions from platformer and xylene plants are particularly suitable. Technical C ₁₀ aromatics fractions or mixtures of technical C ₉ and C ₁₀ aromatics fractions are also very suitable. The ratio of composite material to solvent may also be> 1.

The same applies as for packaging films for other composite materials. In general, it is undesirable to use plastic-coated reusable moldings, such as. B. crush door handles. Rather, the entire composite molded part is subjected to a solvent treatment. In such cases, appropriate release containers are to be used, such as slowly curling, tumbling, draining or other dissolving devices.

The solvents used in the present invention can be returned to the solution container after at least partial separation from the dissolved plastic. The solvent can accordingly be circulated. The metal freed from the plastic foils is separated off - this can be done in a conventional manner, e.g. B. by filtering, decanting or centrifuging - and usually subjected to a washing step. To do this, use the same solvent as that used for the dissolving stage or another suitable solvent. The aftertreatment serves to detach the thinnest plastic layers from the metal, such as z. B. can arise when drying solvents from the first stage. The temperature in the aftertreatment stage can advantageously be between room temperature and 280 ° C., with residence times of 1 to 120 minutes. Short residence times are advantageously selected in combination with a sufficiently high temperature and pressure-free operation. However, the person skilled in the art has a wide range of temperatures and residence times available here.

The metal is then separated from the washing liquid, dried and is then ready for reuse.

For the recovery of metals from metal / plastic / composite pegs, composite materials from metal and cellulose-containing materials, such as paper or from composite materials from metal-plastic foils and paper, the comminuted composite material is mixed with water, which also contains small amounts of additives such as e.g. B. alcohols, such as methanol or ethanol or of ketones, such as. B. acetone or methyl ethyl ketcn or other detaching additives may be heated to 100 ° C to 200 ° C. The dwell time is 5 to 120 minutes. Depending on the type of paper, these conditions can also be varied within wide limits. Although at least a portion of the paper can result from hydrolysis of the cellulose in solution, the paper or cellulose is generally pulp, with high quality pulp that can be reused as such.

Post-treatment may also be necessary or advantageous here.

The separation of the paper from composite films is state of the art and as such will not be explained in more detail here. In the case of composite materials which consist of several layers, where at least one paper layer may also be present, the dissolving treatments according to the invention, as already described above, can be carried out in succession or, if appropriate, with thorough mixing.

The composite material can be comminuted in a conventional manner, generally comminuting to a particle size of 1 to 50 mm. However, this area is not absolutely necessary. Depending on the treatment containers, larger particles or composite parts can also be treated according to the invention. The same applies to parts <1 mm, although it must be taken into account that the size of the metal is favored by a size> 1 mm.

FIGS. 1 and 2 represent examples of greatly simplified devices for carrying out the method according to the invention.

In FIG. 1, apparatus 1 is used to shred the composite film material that has already been freed of paper. 2 is a container in which the coating material is detached from the aluminum foil or other metal. In 3 the metal is separated from the solution. The metal reaches 4, where it is rinsed again with hot solvent and dried. At 5 the pure metal is removed. In 6 the solvent is largely removed, for example by distillation or vacuum distillation. 7 represents an extruder from which the granulate is removed at 8. The solvent can be recycled from 6 to 2.

FIG. 2 shows an example of an alternative device for carrying out the method according to the invention.

Apparatus 1 in turn serves to shred the composite film material which has already been freed of paper. 2 is the release container. In 3 the metal is separated from the solution. The separated metal is rinsed in 4. At 5 the pure metal is removed. The detergent from 4 arrives at 5. In 9 wire the solvent is distilled off and returned to 2. The solution from 6 geianet in container 7, where the coating material, e.g. B. polyethylene as a granular, free-flowing material by cooling or falling with one

Case is failed and over 8 is drawn. It is obvious to the person skilled in the art that FIGS. 1 and 2 are highly simplified embodiments of the present invention, which can be varied within wide limits without leaving the scope of the invention and can be equipped with additional apparatus.

According to the invention, the usual apparatuses of the prior art can be used for the various device stages, such as for comminution and for dissolving materials, that is to say stirred tanks, shaking tanks, stirred cascades, flow tanks equipped with internals and the like. Like. More are known. Numerous apparatuses are also known to those skilled in the art for flushing processes. This can be continuous countercurrent rinsing systems or rinsing cascades, stirred tanks and. a. Devices. The separation of materials need not be explained in more detail, since the person skilled in the art can use suitable devices such as centrifuges, decanders, filters and the like. Like. Are known. The same applies to apparatus for separating solvents. A large number of distillation columns with and without vacuum are available to the person skilled in the art, which can be equipped with trays, can be equipped with packings, with packing, thin-film evaporators, flasers and the like. Like., Which can also be simple stripping columns u. a. Extruding plastic materials in particular has also been state of the art for a long time. Here, too, sophisticated apparatuses are well known to the person skilled in the art. It goes without saying that further developments in apparatus can also be used according to the invention in the individual areas.

The invention is explained in more detail with the aid of the following examples.

example 1

500 g of an aluminum / polyethylene film were crushed to a particle size of approximately 10 mm, washed and dried. The comminuted aluminum foil, a layer thickness of 0.01 mm and the polyethylene foil with a sheath thickness of 0.5 mm were mixed with 500 g of a technical C ₉ -methylbenzene mixture from a platformer with a boiling range of 140 to 210 ° C. at reflux for 20 minutes Stirred 180 ° C. The solution was then treated in a tube with internals in countercurrent with the same solvent and at the same temperature. Now the aluminum was sieved and dried. Yield determinations and determinations of the purity of the separated metal were carried out in all examples in the following way by atomic absorption spectroscopy:

In order to determine the yield, a sample of the compound film was weighed out and the weight fraction of the aluminum in the film was determined in the atomic absorption spectrometer. The metal obtained by the treatment step according to the invention was weighed out, a sample was weighed and the weight fraction of the aluminum was again determined in the atomic absorption spectrometer. In all cases, the metal samples consisted of 100% aluminum. So they were completely free of foil components. The yield of aluminum was 100%.

The plastic solution was then concentrated in a flash evaporator and fed into a degassing extruder via an evaporation chamber.

This resulted in a solvent-free polyethylene granulate.

Example 2

Example 1 was repeated, but a solvent mixture of C ₉ and C ₁₀ methylbenzenes was used with a boiling range of 175 ° C

An approximately 40% by weight solution before polyethylene was obtained in the liquid container. This was passed in countercurrent through a multi-stage cascade, the aluminum-containing solution being a 3% polyethylene solution in the same

Solvent flowed against. The aluminum rinsed in this way was centrifuged in a centrifuge, rinsing at 180 ° C. using the same solvent.

As in Example 1, pure aluminum was obtained in quantitative yield, just as in Example 1, a solvent-free polyethylene granulate was obtained quantitatively.

Example 3

Example 1 was repeated, but became proprietary at 220 ° C for 2 minutes pressure stirred. The same results as in Example 1 were obtained.

Example 4

Example 1 was repeated, but the coating consisted of polypropylene. The results corresponded to those described in Example 1.

Example 5

Example 1 was repeated, but the process was carried out at a weight ratio of composite materials to solvent of 1: 5.

As in Example 1, pure aluminum and solvent-free polyethylene were obtained in quantitative yield.

Example 6

500 g of an aluminum laminate crushed to a particle size of 4 mm with an aluminum foil thickness of 0.1 mm and an LLD-PE foil thickness of 0.8 mm were mixed with 1000 g of a mixture of 50% by weight 1.2.3. Trimethyl- and 50 wt.% 1.2.4-TrimethylbenzoI at 170 ° C for 15 min. The screened metal was then treated with 1000 g of the trimethylbenzene mixture at 100 ° C. for 5 minutes. Completely pure aluminum was obtained in quantitative yield. The polyethylene solution was worked up as described in Example 1.

Example 7

Example 1 was repeated, but heating was carried out with 1000 g of 1.2.3.5-tetramethylbenzene for 0.5 min at 260 ° C. with stirring and autogenous pressure. The sieved metal was then treated for 5 minutes with 1000 g of the same tetramethylbenzene at 150 ° C. The sieved aluminum was now dried. Completely pure aluminum was obtained in quantitative yield. The polyethylene solution was worked up as described in Example 1. Example 8

Example 1 was repeated, but the film was wetted with 3000 g of isopropylbenzene for 120 minutes at 40 ° C.

The aluminum was then sieved and washed with 1000 g of isoprocylbenzene at 100 ° C.

After sieving and drying again, a very pure aluminum was obtained in quantitative yield. The polyethylene was obtained as described in Example 1.

Example 9

A steel door handle coated with polyethylene with a layer thickness of 1.5 mm was in a tumble reactor for 15 minutes with 1000 ml of a mixture of 53% by weight of 1,2.4-trimethylbenzene and 50% by weight of 1.2.3.5-tetramethylbenzene at 170 ° C treated. The door handle was then removed from the solvent, rinsed with hot solvent and dried. The steel is completely free of polyethylene. The polyethylene was recovered as described in Example 1.

Example 10

400 g of an aluminum foil with a layer thickness of 0.5 mm. a polyester film with a layer thickness of 0.2 mm and an outer polyethylene slide with a thickness of 0.5 mm was treated with a technical C ₉ cut as in Example 1.

The decanted and rinsed film, which was still coated with polyester, was then wetted with 1500 ml of tetrahydrofuran for 10 minutes at 100 ° C. under autogenous pressure. The aluminum was sieved and dried.

A completely pure aluminum was aged in duantitative yield. Polyethylene and polyester were recovered as described in Example 1. Example 11

Example 10 was repeated with dioxane with the same result.

Example 12

A laminate of a copper foil with a particle size of 10 mm and a layer thickness of 0.01 mm and a polypropylene layer with a thickness of 0.3 mm was 5 min. At 160 ° C with a 1: 1: 1 mixture of the three trimethylbenzene -Isomers treated.

The copper was then sieved and the same for 5 minutes

Post-treated solvent at 160 ° C.

Completely pure copper was obtained in quantitative yield. The polypropylene was recovered as usual.

Example 13

600 g of an aluminum foil crushed to 4 mm particle size, a layer thickness of 0.01 mm and a polyethylene foil with a layer thickness of 0.5 mm were mixed with 6000 g of a technical xylene mixture, consisting of 4% by weight non-aromatics, 20% by weight Ethylbenzene, 15% by weight of p-xylene, 40% by weight of m-xylene and 20% by weight of o-xylene were stirred at 140 ° C. for 20 minutes.

The aluminum was then sieved and stirred with 1500 g of fresh xylene added at 140 ° C for 10 minutes. Now the aluminum was sieved again and dried.

Example 14

400 g of a sheet of aluminum crushed to a particle size of 5 mm, one

Layer thickness of 0.01 mm and a polyester film with a layer thickness of 0.3 mm were stirred with 2000 g of tetrahydrofuran at 150 ° C. for 5 minutes under pressure.

The aluminum was then sieved off and added with 500 g fresh tetrahydrofuran stirred at 140 ° C under pressure for 10 min. Now the aluminum was sieved and dried.

The tetrahydrofuran was concentrated to half. The polyester was then precipitated by adding toluene and cooling to 50 ° C.

Example 15

500 g of an aluminum laminate shredded to a particle size of 4 mm with an aluminum foil thickness of 0.1 mm and an HD-PE foil thickness of 0.5 mm were treated with stirring with 2000 g of cyclohexanone at 150 ° C. and autogenous pressure for 15 minutes. The sieved metal was then treated for 10 minutes with 1000 g of cyclohexanone at 100 ° C. It became completely pure

Obtain aluminum in quantitative yield. The cyclohexanone solution was cooled to 80 ° C., the polyethylene precipitating out in granular, finely divided and free-flowing form and being able to be filtered off.

Example 16

Example 15 was repeated, but acetylacetone was used instead of cyclohexanone. As in Example 15, a very pure aluminum could be obtained in duantitati ver yield. The polyethylene was precipitated in granular form by cooling the polyethylene solution to 52 ° C.

Claims

1. A process for the recovery of metals and coating materials from composite materials by removing the coatings present on the metal with solvents, characterized in that the composite material for removing non-polar layers with dimethyl and / or trimethyl and / or tetramethylbenzenes and / or ethylbenzene and / or isopropylbenzene at 40 ° C to 280 ° C, preferably at 75 ° C to 220 ° C and particularly preferably at 138.4 ° C to 204 ° C without pressure or under pressure for a residence time of 0.5 to 360 min., preferably from 5 to 120 minutes and particularly preferably from 5 to 60 minutes, heated to remove polar layers from composite films with tetrahydrofuran and / or its methylated derivatives and / or dioxane and / or its methylated derivatives from 40 ° C. to 280 ° C, preferably to 60 ° C to 200 ° C without pressure or under pressure for a dwell time of 0.5 to 360 min., Preferably from 5 to 120 min. And particularly preferably v on 5 to 60 min., heated.

2. A process for the recovery of metals from composite materials by removing the coatings on the metal with solvents, characterized in that the composite material for removing the layers with C ₃ -C ₁₈ ketones and / or C ₃ -C ₁₈ polyketones 40 ° C to 280 ° C, preferably to 75 ° C to 220 ° C and particularly preferably to 100 ° C to 220 ° C without pressure or under pressure during a residence time of 0.5 to 360 minutes, preferably from 5 to 120 minutes. and particularly preferably from 5 to 60 minutes.

3. Process according to claims 1 and 2, characterized in that to dissolve the layer (s) at least 2 components from group a) dimethyl, trimethyl, tetramethylbenzene, ethylbenzene, isopropyl benzene; b) tetrahydrofuran, methylated tetranydrofuran, dioxane,

methylated dioxane; c) C ₃ -C ₁₈ ketones, C ₃ -C ₁₈ polyketones used in coordinated proportions.

4. Process according to claims 1 to 3, characterized in that an at least predominantly from to solve the non-polar layers

C ₉ aromatics existing solvent used.

5. Process according to claims 1 to 4, characterized in that after the separation of the metallic composite film component by cooling the solutions contained in the layer dissolved, the material forming the layer precipitates at least partially from the solvent.

6. The method according to claims 1 to 4, characterized in that the dissolved in the solvent, the layer forming material, after separating the metallic composite film component, at least partially fails by adding a precipitant.

7. Process according to claims 1 to 6, characterized in that the material forming the layer precipitates out of the solution as a fine-grained, free-flowing material.

8. The method according to oen claims 1 to 7, characterized in that the layers of thermoplastics are sine.

9. The method according to cen claims 1 to 4 and 8, dacuren characterized in that after the separation of the metallic composite film component, the solvent is removed from the solution containing the layer and the remaining material is extruded into granules in an extruder, preferably in an evacuable extruder.

10. The method according to claims 1 and 3 to 8, characterized in that an industrial xylene mixture of 1 to 4% by weight of non-aromatics, 19 to 23% by weight of ethylbenzene, 16 to 20% by weight of p-xylene, 40 up to 45% by weight of m-xylene and 10 to 15% by weight of o-xylene, whereby they each add 100% to the mixture components.

11. The method according to claims 1 to 10, characterized in that 1 to 15 parts by weight of the solvent are used per part by weight of the composite.

12. The method according to claims 1 to 11, characterized in that the separated metal of an aftertreatment with one or more of the solvents mentioned in claims 1 and 2 at 10 ° C to 200 ° C under pressure or depressurized for a residence time of 0 , 5 to 120 minutes.

13. The method according to claims 1 to 12, characterized in that one selects the solvent so that you can work without pressure.

14. The method according to claims 1 to 9 and 11 to 13, characterized in that one uses a technical C ₉ aromatics mixture.

15. The method according to claims 1 to 9 and 11 to 13, characterized in that one uses a technical C ₁₀ aromatics mixture.

16. The method according to claims 1 to 9 and 11 to 15, characterized in that one uses a technical C ₉ -C ₁₀ aromatics mixture.

17. A device for carrying out the method according to claims 1 to 16, characterized in that it contains a resolver, a metal separator downstream of the resolver, a subsequent precipitation reactor and a filter following the precipitation reactor.

18. Device for carrying out the method according to claims 1 to 16, characterized in that this is a resolver, the one

Dissolver downstream metal separator, a separating part for largely separating the solvent and a downstream extruder, preferably an evacuable extruder, contains.

19. Device according to claims 17 and 18, characterized in that the resolver is a stirred tank.