SK962002A3 - Method for selectively separating predetermined materials in mixtures of materials - Google Patents

Abstract

The invention concerns a method for selectively separating predetermined materials contained in mixtures of materials, in particular mixtures formed by waste and containing other materials with characteristics similar to said predetermined materials. The method is characterised in that the mixtures of materials are subjected, according to a known operation, to at least a process of automatic separation by density, the materials whereof the mass density is within a first range of values being separated from those within a second range of values. Before or while they are being treated, the predetermined materials are enriched with at least an additive providing them a with mass density within the first range of values. Said method enables simple and economical separation for example of high value or biodegradable synthetic materials contained in waste mixtures, such that they can be subsequently treated in accordance with prescribed rules or upgraded during removal.

Description

14794

A method of selectively separating the present substances from a mixture of substances

Technical field

The invention relates to a method of selectively separating the present substances from a mixture of substances that fall out (are susceptible to waste to fall out) is understood to be the commodity only when producing the entire area from to waste recovery. Under the production of waste collection or waste, eventually up to recycling.

BACKGROUND OF THE INVENTION

In this application field, a large number of methods are missing which allow further or re-utilization of waste materials, in particular of high-value plastics. High-quality material recovery of plastic waste presupposes the recovery of sufficiently type and secondary pure plastic fractions from the waste. This is particularly widespread in the case of heterogeneous waste mixtures in that the plastics lack the sorting properties on the basis of which separation by means of cost-effective technological fractionation or sorting methods or processes could be carried out. As far as costs are concerned, the specialized methods of separation are not economically logical (meaningful) for individual plastics.

Known automatic separation processes which work at advantageous costs include separation methods according to density differences. Fractionation by specific masses or densities assumes sufficiently large differences in these densities between the dividing fractions. As a rule, however, the specific weights of the plastics in the important mixtures existing in the wastes are not sufficiently distinguished so that sufficient type and species-pure plastic fractions can be obtained by separation according to the specific masses.

For species-pure plastic fractions, the plastics contained in the fraction must be chemically identical for the base thermoplastics. In the case of type (generic) pure plastic fractions, the plastics contained in the base thermoplastic are chemically and physically-structurally identical and, in addition, uniformly added.

Another cost-effective dividing process that works automatically is by magnetic properties. The fraction according to magnetic properties assumes bound magnetic properties of the components separating from the mixture, but which do not exist in the plastics.

At the same time, the plastics are, at the same time, primarily sorted by hand or separated by air (wind) screens. Although specific gravity separation processes are also used, they, however, fail or only yield less valuable, poorly type or species-pure fractions in small specific gravity differences between plastics. The air or wind screening method separates large surface plastic parts from parts with a small specific surface. The method is therefore able to perform a division according to types or types of plastics in which the surface criterion coincides with the type or species criterion. This is the case, for example. for large packaging films, which are often made of LDPE and LLDPE. Manual sorting is costly and economically only applicable to large parts plastics.

The German Packaging Ordinance (Verpack V) foresees that sales packaging and catering utensils (serving for one-time catering) must be valued to a specified proportion. The industrial, manual sorting of plastic packaging takes place under the pressure of this packaging regulation in Germany, which applies to different types of goods, respectively. Article. This presupposes separate recording of certain packaging, respectively. packaging fractions and catering waste fractions. The packaging waste is divided into "large hollow bodies", "foils" and "mixed plastics". However, "large hollow bodies" and "foils" are neither type nor species-pure fractions.

The hollow body fraction and foil fraction are subjected to a small proportion by specific gravity and are always divided into light (specific gravity <1.0 g / cm ³ ) and heavy fraction (specific gravity »1.0 g / cm ³ ). using saline solutions instead of pure water, the separating layer moves to higher specific weights). The light fraction comprises a blend consisting essentially of 30-50% PP (polypropylene), 50-70% PE (polyethylene) and, depending on the sharpness of the separation or the selectivity of the PS fractionation process. This PE-PP mixture can only be recovered with additional expensive compatibility agents (s). thermoplastically further processed. In the department of heavy plastics, respectively. of plastics are formed from mixed polyolefins of less valuable regranulates, which can be marketed (commercially used) with only low yield, respectively. sales, partly even with a surcharge. The heavy fraction, which consists of PET, PVC, PC, PA and PS fractions, is usually heat treated or deposited.

When the fraction of mixed plastics, respectively. The mixture of substances (mixed fraction of plastics or plastics) is removed directly, processed to the appropriate agglomerate. It is used mostly (approx. 94%) as raw material and only to a small extent (approx. 6%) as inferior (inferior) material. The ecological and economic use of these products is extremely limited due to their low material quality.

Also, the centrifugal separation process, which is currently being tested (being tested) and is applied primarily to the mixed plastics fraction, i.e., in the test. The methods of KAKTUS, in terms of the division of plastics, work on the basis of differences in density (specific gravity). It primarily separates, as mentioned above, polyolefins from non-polyolefins. Furthermore, PVC is electrostatically separated from the heavy fraction. The remaining part contains PET, PA, PC etc. and can be used for energy or as a raw material.

The separation or separation method of electrostatic separation (separation) is based on a different charge (charge) of plastics (plastics) in the electric field. The charged particles are in the free fall on the basis of the electric high-voltage field in the so-called. free-fall separators (utilizing free-fall) directed towards the corresponding electrodes and in this way separated from each other. The method is applicable, inter alia, for separating PE from a PE / PP mixture, PC from a PC / PMMA mixture, and separating filled PP from a PP / ABS / PVC mixture.

The material recovery (recovery) of PP / PE mixtures is very limited due to material intolerance, or is associated with additional costs. Although it would be technically possible to separate PE from the electrostatic separation method from PP, this method is relatively inferior, resp. inferior end-products too cost intensive to be widely used.

Also, the heavy fraction contained in high-grade PET cannot be recovered materially, but is heat treated or deposited.

So far, there is no classification criterion for biodegradable materials, resp. Plastics (BAW). Biodegradable materials, resp. plastics containing packaging plastics have a density (specific gravity) between 1.1 g / cm ³ and 1.4 g / cm ³ . In the above, the particles to which the classification applies are BAW (biodegradable materials) mainly in the mixed plastics fraction. In the case of the fractionation of mixed plastics by separating (separating) on the basis of different densities, BAWs mostly get into the heavy fraction. Thus, they are recovered in a raw or energy manner or simply disposed of, but will not be recovered materially or biologically as intended.

However, BAW, in particular, cannot be separated by known methods inexpensively from mixed catering wastes which, in addition to disposable utensils or containers, also contain packaging, food residues, printed matter, hygiene articles and the like, and thus disposed of as intended.

In the future, 95% of old vehicles are planned to be used according to the voluntary commitment of car manufacturers. This means that, in this area, the light fraction of traditional plastics (plastics) falling from a shredder or shredder device has to achieve a higher recovery rate than hitherto, in particular material recovery. Due to the high degree of mixing, this plastic waste fraction can only be recovered for energy or raw materials. However, inexpensive selective separation and thus the material recovery of the high-quality technical plastic contained in the light fraction from the shredder is not possible by known methods in the prior art.

In summary, the prior art methods used hitherto present the problem that these methods do not allow any inexpensive separation, respectively. Separation of generic or generic pure plastic materials from fabric mixtures, such as those occurring in packaging waste or in the disposal of cars. Such plastics in fabric mixtures can therefore no longer be made available for any high-value material or other material-specific recovery or disposal. evaluation.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for selectively separating said substances from a waste mixture which can be recovered, simply and inexpensively - according to the target, the various substances of the substance mixtures so that they can then be further processed or disposed.

The method according to the invention is intended to ensure that a certain or several certain plastics can be separated from the mixture of materials, either individually or as a substance class, so that the plastic or family of plastics can, for example, be further utilized specifically.

This applies in particular to cases where it has not yet been possible, without further measures, to divide other plastics in the absence of sufficient use of them cheaply.

significant material categories of plastics that would

Furthermore, the method according to the invention is intended to allow the inexpensive properties of this plastic / this separation of biodegradable materials or plastics (BAW) from the waste mixtures.

Said object is solved by the method according to claim 1. Preferred embodiments or application of the method are the subject of further claims.

In order to solve this problem, a method is proposed in which the substance mixtures pass through at least one density dividing method which separates substances whose specific weight lies within the first value range as the first property and separates them from substances whose specific weight lies within the second value range as the second property separated from the mixture of substances is the specific value of the substances during processing; or

Said substances, i. according to the invention, before being enriched with the additive, moves to be separated separately from similar substances of the zone. In this way, the separation method according to the densities of the first substance of the substances can be used. For this purpose, the additives must be aligned with the separation method used and the partitioning task. Therefore, the substance mixture and the properties of the substances involved are analyzed, a suitable density-based separation method is determined, and the type and amount of ingredients required to allow the desired separation by the selected separation method is determined.

A preferred use of the method according to the invention relates to the separation of certain resp. of said plastics from fabric blends. Plastic (plastic) in this specification also refers to plastic-like materials that are biodegradable or non-biodegradable, which are based on synthetic or natural polymers and are thermoplastic processable.

In this method, the appropriate additive for later separation of a certain base thermoplastic is carried out with the respective additive - or mixture of additives - which is specifically much heavier than the base thermoplastic or is ferromagnetic. The additive is admixed to the base thermoplastic in the molten state. In this way, the granulate of the base thermoplastic is altered in density. This granulate is then available for the production of special articles to be selectively separated from the waste mixtures later on. The separation is carried out by a suitable separation method known in the art based on different densities.

The granulate can also advantageously be used to make articles that improve haptic properties, as will be explained below.

It is preferable to use a fine-grained mineral, in particular also metallic, metal-oxide (from the corresponding metal oxide) or salt filler, as an additive. If desired, an adjuvant or mixture of adjuvants is further admixed to improve the miscibility of the additive and the base thermoplastic. It may also be a second thermoplastic.

The amount of base thermoplastic per unit weight of admixed additive (additive) is determined according to the invention such that the plastic or plastic additive (s) is (are). objects created from it, crushing, event. The debris produced by grinding could be separated by cheap separation methods, as known in the art, from articles of plastics of initially similar density. This includes, in particular, dividing, respectively. separation processes, which in carrier media such as e.g. water, aqueous solutions, air or carrier gases operate according to the gravitational or centrifugal principle in the presence or absence of other current-dynamic effects that favor or hinder the density distribution.

Examples of suitable fillers are dolomite (MgCa (CO ₃ ) ₂ ) with a specific gravity of 2.8-2.9 g / cm ³ , calcium carbonate (CaCO ₃ ) with a specific gravity of 2.7-2.9 g / cm ³ , barium sulphate (BaSOJ with a specific gravity of 4,0 - 4,9 g / cm ³ or ferromagnetic iron powder (Fe) with a specific gravity of 7,8 - 7,9 g / cm ³ .

It is known from other fields to add mineral fillers to polymers, for example to specifically adjust the mechanical properties or color of the plastic or to "stretch" the material, i.e., to reduce material costs. In addition, barriers, resp. threshold properties of polymers against vapors and permeation gases with increasing mineral filling degree (filling degree). This, however, applies only to specific, for use related properties of polymers.

In the present method, on the other hand, the respective plastics, respectively. mineral fillers admixed for the purpose of selective separability from the respective mixtures, in particular waste mixtures, in order to increase its material density (specific gravity). It is very little known to add such fillers to improve the haptic, i.e. to improve the haptic properties. the sense or direction of sensing (contact) of the reactive properties of the plastic, made from it.

This method allows the species-specific separation of certain resp. predetermined plastics from the waste mixture by means of a separating or resp. a dividing method based on a different density, e.g. swimming and settling method. The method according to the invention contributes to meeting the appreciation quotas required by the legislature, for example for a light fraction from the shredder, sales packaging or catering utensils, in particular for material recovery, later cheaper and at the option of

When enriching a predetermined size.

Surprisingly, in addition to increasing the specific gravity of the haptic properties, plastics with fillers also result in articles made from these plastic improvements.

Disposable drill modified by safer in hand.

the heavier material is produced and the material is more adhering and the crockery of the invention is made of plastic

In addition, the article of manufacture is made by hand so that the present method can be easily slipped.

achieved by simple and cheap technological separation of biodegradable plastics, event. plastic-like materials (BAW) from non-degradable plastics, the first of which are enriched by the additive before processing.

Tab. 1 shows, by way of example, a list of biodegradable and non-biodegradable thermoplastic plastics (plastics) and their specific weights depending on the degree of filling with dolomite as a filler.

Table 1:

Plastic (plastic) Špec.hmotn. unfilled plastic g / cm ³ Specific g / cm ³ for 10% weight (calculated) in dolomite with weight 20% 30% 1.Biodegradable (BAW) BIOPOL (PHB / V) Monsanto 1.25 1.32 1.41 1, 50 TONE (Polycaprolactone, PCL), Union Carbide 1, 15 1.22 1.31 1, 40 BAK (polyesteramide) BAS F 1.07 1.14 1.22 1.32 ECOFLEX (polyester), BAS F 1.25-1.27 1.32 to 1.34 1.41 to 1.43 1.50-1.52 Polylactic Lactic Acid (PLA), MTC 1.26 1.33 1.42 1, 51 DIOMAX (polyester), Du Pont 1, 35 1.43 1.51 1.60 Bionolle, Showa Highpolymer 1.23-1.32 1.30-1.39 1.39-1.48 1.48-1.57 MATER-BI (starch / PCL mixtures), Novamont 1, 12 1.19 1.27 1.37 BIOCETA (cellulose diacetate), Rhone Poulenc 1.27-1.32 1.34-1.39 1.43 to 1.48 1.52-1.57 2.Biologically non-degradable Polyethylene PE 0.91-0.97 0.98 to 1.04 1.05-1.12 1.14 to 1.21 Polypropylene PP O, 90-0.94 0.97 to 1.01 1,04-1,09 1.13-1.18 Polystyrene PS 1.05-1.08 1.12 to 1.15 1.20 to 1.23 1.30-1.33 Polyamide PA 1.05-1.20 1.12-1.27 1.20-1.36 1.30-1.45 Polycarbonate PC 1.20 to 1.23 1.27-1.30 1.36 to 1.39 1.45-1.48 polyethylene terephthalate PET 1.35-1.40 1.43 to 1.48 1.51 to 1.56 1.60-1.65

Polyvinyl chloride PVC 1.34-1.43 | 1.41-1.50 1.50 to 1.59 1.59-1.68

From this table, it is apparent how, when enriching biodegradable substances with a suitable amount of filler, such as dolomite, the specific gravity of these substances can be brought to an area which allows the biodegradable plastics to be separated by an automatic separation process based on specific weights.

Just in the field of packaging and related applications, such as. catering, there is a great market potential for BAW. In the foreseeable future, biodegradable and non-biodegradable materials will occur side by side, especially in packaging waste as well. as mixed waste in catering and fast food operations. These materials can be separated cheaply from each other in accordance with the method of the invention for the purpose of their material-specific utilization or recovery.

This method further allows a cheap technological separation of the respective plastic or group of plastics from the mixture.

The source for such mixtures is, for example, the plastic fractions falling into the packaging waste according to the aforementioned sorting criteria, but also the light fraction components from the automobile recycling crushers, or the plastic from the casings and components from electronic scrap.

In addition, the proposed enrichment of the above-mentioned substances with the appropriate additives causes an improvement in the haptic properties of the processed plastics according to the corresponding inventive roughness, and the coefficients of friction are increased. The material in question mediates the invention unfilled except in lie of the plastic of it

Dishes of plastic modified in comparison with dishes with better hand. By modification, the surface microscopic grip and the sliding grip change the pleasant dry feel (perception), it is rougher and does not slide as easily from hand as traditional plastic dishes. The modification of the plastics according to the invention therefore increases their roughness and thus advantageously guarantees a safer and more sensationally comfortable handling of the articles made from them.

In particular, utensils of daily use are often made of plastics. The disposable disposable tableware is produced especially with thin walls due to the constant effort to save material. Catering irreversible stable in terms of grip and lies must therefore constantly strive to avoid the load that is characterized by slipping tactile invention.

therefore the dishes are often not easily handled. The consumer is careful about handling.

is disposable plastic especially in the case of wet

In the case of hand dishes, the haptic disadvantages (relating to very smooth and surfaces. This grip) can be avoided by modifying the plastics according to

The process according to the invention is further (as follows) made clear by way of examples.

In particular, based on the five problem sets, it will be shown to perform the method using a density separation device. Said fractions refer to the state of the art sorting methods explained at the beginning of the description.

Selective separation by means of separation on the basis of different density requires, from practical, apparatus and cost-economic aspects, the difference in density or specific gravity between the separating fractions, which should not be substantially less than 10% in the case of centrifugal separation (case a) or. 20% in case of swimming and settling (case b). Examples of practical separation tasks in practice, below, take into account a density difference of a) of at least 10% and b) of at least 20%.

Division Task 1:

The heavy BAW should be separated from the heavy fraction consisting of PET, PC and PVC. Depending on case (a), the specific gravity of the BAW shall be increased to 1,57 g / cm ³ , as in case (b) to 1,72 g / cm ³ . This should be done with dolomite as a filler.

Table 2 shows the required degree of filling of the dolomite BAW when solving this separation method.

Table 2:

Plastic (plastic) (BAW) Proportion of filler required for a density difference of 10% (equivalent to 1.57 g / cm ³ ) Filling ratio required for a density difference of 20% (equivalent to 1.72 g / cm ³ ) Vol. % hm. % volume ·% hm. % BIOPOL (PHB / V) Monsanto 20, 0 36.3 29, 4 48.7 ECOFLEX (polyester), BASF 19.0 to 20.0 34.5 to 36.3 28.5 to 29.4 47.2 to 48.7 Polylactic acid Lacea (PLA), MTC 19.5 35, 4 28, 9 47, 9 BIOMAX (polyester), Du Pont 14.7 26.6 24.7 40.9 Bionolle, Showa Highpolymer 16.3 to 21.0 29.7 to 38.1 26.1 to 30.2 43.3 to 50.1 BIOCETA (cellulose diacetate), Rhone Poulenc 16.3 to 19.0 29.7 to 34.5 26.1 to 28.5 43.3 to 47.2

Separation Task 2:

Heavy BAW should be separated from the light fraction consisting of PE, PP and PS. Depending on case (a), the specific gravity shall be

BAW increased to 1.19 g / cm ³ , according to case b) to 1.30 g / cm ³ . This should be done with dolomite as a filler.

Table 3 shows the necessary degree of filling of the BAW with dolomite in the solution of this separation method.

Table 3:

Plastic (plastic) (BAW) Proportion of filler required for a density difference of 10% (equivalent to 1.19 g / cm ³ ) Proportion of filler required for a density difference of 20% (equivalent to 1.30 g / cm ³ ) obj % hm. % Vol. % hm. % TONE (Polycaprolactone) PCL), Union Carbide 2.4 5, 6 8.8 19, 3 BAK (polyesteramide), BASF 6.7 16, 1 12, 9 28.3 MATER-BI (starch / PCL mixtures), Novamont 4.0 9.7 10.4 22.8

Heavy PP, respectively. the heavy PS should be separated from the strand fraction consisting of PE, PP and PS. Depending on case (a), the density of the heavy plastic shall be increased to 1,19% or, where appropriate, (b) to 1,30 g / cm ³ . This should be done with dolomite as a filler.

The filling level of the BAW dolomite required for this purpose is shown in Table 4.

Table 4;

Plastic (plastic) (BAW) Proportion of filler required for a density difference of 10% (equivalent to 1.19 g / cm ³ ) Proportion of filler required for a density difference of 20% (equivalent to 1.30 g / cm ³ ) Vol. % hm. % vol. % hm. % PP 13.1 to 14.9 31.3 to 35.6 18.8 to 20.5 41.3 to 45.0 PS 6.2 -7.8 14.9 to 18.6 12.4-13.9 27.2 to 30.4

Separation Task 4:

The heavy PET should be separated from the heavy fraction consisting of PET, PC and PVC. According to case (a), the specific gravity must be increased to 1,57 g / cm ³ , as in case (b) to 1,72 g / cm ³ . This is to be done with iron powder as a filler.

Table 5 shows the necessary degree of iron powder filling.

Table 5:

Plastic (plastic) (BAW) Proportion of filler required for a density difference of 10% (equivalent to 1.57 g / cm ³ ) Filling ratio required for a density difference of 20% (equivalent to 1.72 g / cm ³ ) Vol. % hm. % Vol. % hm. % PET 2.7-3.4 13.2 to 16.9 5.0 to 5.7 22.7 to 26.0

Separation Task 5:

The heavy PP should be separated from the light fraction consisting of PP, PE and PS. Depending on case (a), the specific weight of the heavy plastic shall be increased to 1,19 g / cm ³ , as in case (b) to 1,30 g / cm ³ . This is to be done with barium sulfate as a filler.

Table 6 shows the required barium sulphate filling step in solving this separation process.

Table 6:

Plastic (plastic) (BAW) Proportion of filler required for a density difference of 10% (equivalent to 1.19 g / cm ³ ) Proportion of filler required for a density difference of 20% (equivalent to 1.30 g / cm ³ ) Vol. % hm. % Vol. % hm. % PP 7.0-8.1 26, 6-30.5 10.1 to 11.1 35.0 to 38.5

For all five separation tasks, the filler proportion is selected depending on the separation method used and the properties of the substances involved. The mixing takes place before or during the processing of the substances.

Increasing the specific gravity with a suitable additive, respectively. mixtures of additives and, where appropriate, the additional "incorporation" of ferromagnetic substances at BAW allows for their selective separation from non-degradable components of waste and their biological recovery. For expensive biodegradable plastics, e.g. Polylactic acid (PLA), the present invention may also open up the possibility of high-value material recovery of BAW.

The material modification according to the invention can also be used for separating traditional or new, non-biodegradable plastics from the mixture, initially by the density of similar components of the mixture, by means of known technology separating techniques as to the type and / or type. species-pure fraction. As a rule, the mixtures are wastes from which the respective component is to be separated purely by species for the best possible material and biological recovery, as described in the previous examples.

The targeted use of polymer modified according to the invention as the biodegradable and non-biodegradable, it is particularly suitable for the ^one application for which it is to be installed in closed fabric cycle (production of the primary product, recirculation and treatment of the primary product, a specific, preferably high value utilization of the obtained secondary raw materials), such as e.g. in the recovery of old cars and electronic scrap, in the recovery of packaging waste, catering waste, etc.

In addition, such addition of fillers, e.g. for application in the catering area of properties. Catering compared to unfilled

Preliminary tests of dolomite showed dry grip.

micro-roughness in hand.

(PLA) achieves an improvement in the cookware made from these plastics heavier and thus the miscibility of the acid that the given haptic plastic material is safer to the pleasant surface mix-roughness and grip and sliding friction of the article.

This team

It prevents the polymilent from gaining the sensation of changing the coefficients with

Claims (9)

1. A method of selectively separating (submitting) waste substances from substance mixtures resulting from the production of waste and containing other substances with similar properties to said substances, wherein the mixture of substances undergoes at least one separation procedure based on different specific weights which substances whose specific the mass lies within the first value zone separated from the substances whose specific weight lies within the second value zone, said substances having changed their specific gravity prior to passing through the density division by the respective modification, characterized in that the change in specific gravity of said substances before or during their processing it is enriched with one or more additives which move the specific weight of the substances modified in this way into the first value zone, producing mixtures in waste production The properties of the substances and the properties of the contained substances are first analyzed and found, respectively. calculated type and quantity of the given additives, which allow selective separation, respectively. separation of the present substances by means of the method of separation according to specific weights. 17 Patent claims 1. A method of selectively separating the aforesaid substances from a slatted mixture resulting from the production of waste and containing further substances having similar properties to the above-mentioned solid substances, characterized in that the substance mixtures undergo at least one automatic separation process which: the first-class substances are separated from the second-class substances, the other substances exhibiting this latter property, and said substances are enriched before or during their processing with one or more additives which in this way impart the first-mentioned properties to the modified substances mentioned above, wherein the separation method is a separation method based on / based on different specific weights which separates substances whose specific weight lies within the first value range as the first property, separating them from substances whose specific gravity lies within the second hour / days zone, the enrichment takes place with one or more additives which move the specific weight of the flavored substances into the / first value zone. Method according to claim 1, characterized in that the specific weight of said substances is increased by enrichment with one or more additives. A method according to claim 1, characterized in that the specific weight of said substances is increased by enrichment with one or more additives so that it differs by about 10% or more from the second value range. Method according to one of Claims 1 to 3, characterized in that a mineral substance, in particular a metal, metal oxide or salt additive, is used as the additive. The process according to claim 4, characterized in that dolomite, calcium carbonate, barium sulfate, iron powder or barium ferrite is used as an additive. Method according to one of Claims 1 to 5, characterized in that said substances are thermoplastics, the enrichment being carried out by admixing said additive (s) and during which the thermoplastics are in the molten state. Method according to one of Claims 1 to 6, characterized in that the substance mixtures or the constituents separated therefrom are additionally subjected to a magnetic separation process, the said substances being optionally enriched before or during their processing with one or more other additives which are ferromagnetic. Use of said method according to one of claims 1 to 7, for separating valuable substances. Use of said method according to one of claims 1 to 7, for separating biodegradable substances.