IMPROVED PROCESS FOR THE PRODUCTION OF SCRAP PRODUCTS WITH A HIGH DEGREE OF PURITY FROM NON-HOMOGENEOUS STARTING MATERIAL

Abstract

The invention relates to a process for the production of recycled scrap metal, comprising the following steps: a) producing or providing a non-homogeneous ferrous scrap composition, b) crushing the non-homogeneous ferrous scrap composition in a crushing unit to obtain a crushed material, c) separating organic and / or inorganic impurities from the crushed material to obtain a previously cleaned material, d) analyzing the previously cleaned material with one or more first detection devices to detect at least initial information about the material and separating the components of the previously cleaned material to obtain a purified material, the separation being carried out based on the initial information about the material, e) analyzing the purified material with one or more second detection devices to detect at least additional information about the material.f) compare the second piece of material information detected with a predetermined material criterion assigned to the second piece of material information, wherein the cleaned material becomes recycled scrap if the second piece of material information meets the assigned predetermined material criterion.

Description

[0001] Process for producing scrap products with a high degree of purity from inhomogeneous input material

[0002] Description

[0003] The invention relates to a process for producing recycled scrap, a recyclable scrap with a particularly high iron content that can be produced by this process, a plant for recycling scrap that is optimized for carrying out the process, and an improved comminution unit for use in corresponding processes and plants.

[0004] The subject matter of the invention is defined in the appended claims.

[0005] Scrap metal, a valuable resource, is obtained by dismantling old metal products. Iron and steel scrap, in particular, has always been viewed not only as waste, but also as an important secondary raw material that can be used in numerous applications to reduce the demand for newly manufactured metals. Using scrap metal as a raw material not only reduces industry's dependence on scarce raw materials and reduces the amount of otherwise superfluous waste. The reduced demand for newly mined metals and alloys, whose large-scale production regularly requires considerable energy and other resources, also enables more sustainable economic activity.

[0006] Particularly in the manufacture of products for high-performance applications, ferrous scrap has particularly stringent requirements. If scrap is to be used instead of newly mined metals, it must reliably possess material properties that are at least similar to those of newly mined metals.

[0007] Fundamentally, there is therefore a great need for many industrial applications to obtain particularly pure scrap compositions that ideally also exhibit a favorable bulk density. However, this is notoriously challenging, as the starting materials for producing such scrap compositions are inherently heterogeneous. For example, two scrapped washing machines from different manufacturers can result in scrap of different compositions despite the similarity of the products.

[0008] To obtain correspondingly pure scrap compositions, various, mostly very complex, processes are known in the state of the art, which in principle can extend to manual sorting processes in which only particularly suitable parts of a scrap composition are isolated by workers.

[0009] Operators of large-scale shredding plants often achieve the production of comparatively pure scrap compositions in practice by passing the processed scrap through the processing plant and the shredder several times, ie the scrap passes through two or more

[0010] Crushing steps, if necessary with downstream sorting, in order to achieve improved purities and / or more favorable bulk densities in the material.

[0011] The prior art processes have the disadvantage of being comparatively time-consuming and / or costly, for example, because they require double processing of the materials, which increases waste and at least halves the plant's material throughput. Furthermore, with this approach, material may remain in the plant during the first pass and only be transported to the discharge point during the second pass through the plant, meaning that the resulting material at the outlet may regularly contain parts that have not even undergone the necessary double shredding step.

[0012] Furthermore, a common disadvantage of the state-of-the-art processes is that comparatively little data is available on the resulting product. This is problematic because for many high-performance applications, it is often not sufficient to simply provide scrap of a certain quality. For many applications, it is essential to be able to reliably demonstrate this quality, for example, for liability reasons.

[0013] In addition, with the state-of-the-art processes, it is often difficult to actively control product quality during operation, for example, to adapt it as quickly as possible to customer requirements. As a result, with the state-of-the-art processes, it is often not possible to produce, for example, two different scrap products with different specifications directly one after the other in continuous operation and / or without retooling the plant.

[0014] In addition, conventional processes often do not allow for the production of high bulk densities that are advantageous for certain applications within a production time that allows for efficient large-scale product manufacturing.

[0015] The primary object of the present invention was to provide an improved process for producing recycled scrap, with which the disadvantages known from the prior art can be eliminated or at least reduced.

[0016] The object of the present invention was therefore to provide an improved process for the production of recycled scrap of high quality and with a high bulk density, with which a particularly pure scrap product with a particularly favorable bulk density can be obtained from the usual scrap fractions, ie an inhomogeneous and particularly challenging starting material.

[0017] The task was to specify a process for the production of recycled scrap that would ideally produce correspondingly high-quality products in a single pass. This would make the time- and cost-efficient process particularly suitable for the large-scale production of these high-quality scrap products in large quantities and at a low price. Compared to the state of the art, the process for the production of recycled scrap should also make it possible to achieve significantly higher purity at industrially relevant volumes than was possible with previous processes.

[0018] An additional requirement was that the process to be specified for producing recycled scrap should be capable of being operated using conventional scrap fractions as starting material and that it should be operable, as far as possible, with equipment that is already available in conventional scrap processing plants.

[0019] It was a supplementary object of the present invention that the method to be specified for producing recycled scrap should be designed in such a way that more comprehensive information about the properties of the respective scrap batches produced should be obtained automatically.

[0020] Furthermore, the specified process for producing recycled scrap should be highly flexible and easily adaptable, and thus be particularly efficient in adapting to changing quality requirements on the part of the customer, ideally even during ongoing operations. In this respect, it was a supplementary object of the present invention that the specified process for producing recycled scrap should enable flexible adaptation of the chemical composition and / or particle shape and / or bulk density of the recycled material.

[0021] In addition, it was desirable that the process to be specified for the production of recycled scrap should also reduce the risk of defective scrap batches that are unusable for the customer.

[0022] It was an additional object of the present invention that the method to be specified for producing recycled scrap should be particularly safe and low-emission in order to reduce the risks and burdens on humans and the environment.

[0023] Furthermore, it was a secondary object of the present invention to provide a recycled scrap which is a high-quality scrap product that is also suitable for high-performance applications.

[0024] Furthermore, it was a secondary object of the present invention to provide an improved plant for recycling scrap and a novel comminution unit, each of which should be particularly optimized for use in the process to be specified.

[0025] The inventors of the present invention have developed a novel and efficient process and the associated systems with which the above objects can be achieved. In simplified terms, this process is based on a comprehensive modification of existing process technology, with a particular focus on a specific coupling of the separation technology with process analytics, as defined in the claims.

[0026] According to the inventors' assessment, the process according to the invention makes it possible, for the first time, to produce a high-quality scrap product in industrially relevant quantities in a single process in a time- and cost-efficient manner. Despite the use of inhomogeneous starting materials, i.e., the usual scrap fractions, iron contents of 97% and more, a near freedom from organic contaminants and advantageous bulk densities can be achieved, which, according to the inventors' assessment, could not be achieved with comparable large-scale, prior-art processes, at least not with comparable material throughput and / or with comparable reproducibility. As a synergistic advantage, the material information obtained during processing can also be used to document the material properties, thus enabling certification of the scrap products produced without major additional effort.In the inventors' own experiments, scrap recycled on an industrial scale had an iron content of more than 97% and, by using a preferred plant according to the invention, bulk densities of approximately 1.5 t / m. 3with approximately spherical particles. The above-mentioned objects are thus achieved by a process for producing recycled scrap, the scrap that can be produced thereby, plants for recycling scrap, and comminution units, as defined in the claims. Preferred embodiments of the invention emerge from the subclaims and the following explanations. Those features of embodiments of the invention that are referred to as preferred below are combined in particularly preferred embodiments with other features referred to as preferred. Combinations of two or more of the embodiments referred to as particularly preferred below are therefore very particularly preferred.Also preferred are embodiments in which a feature designated as preferred to any extent is combined with one or more further features designated as preferred to any extent. Features of preferred recycled scrap, preferred scrap recycling plants, and preferred comminution units are derived from the features of preferred methods.

[0027] The invention relates to a method for producing recycled scrap, comprising the following steps: a) producing or providing an inhomogeneous iron-containing scrap composition, b) comminuting the inhomogeneous, iron-containing scrap composition in a comminution unit to obtain a comminution material, c) separating organic and / or inorganic contaminants from the comminution material to obtain a pre-cleaned material, d) analyzing the pre-cleaned material with one or more first detection devices for detecting at least one first piece of material information and separating components of the pre-cleaned material to obtain a purified material, wherein the separation takes place depending on the first piece of material information, and e) analyzing the purified material with one or more second detection devices for detecting at least one second piece of material information,f) comparing the detected second material information with a predetermined material criterion associated with the second material information, wherein the purified material is output as recycled scrap if the second material information meets the associated predetermined material criterion.

[0028] The process according to the invention is, in principle, also suitable for small scale applications. For example, it has been demonstrated on a pilot plant scale that the process according to the invention can produce excellent scrap products. However, at small throughput rates, the process according to the invention competes more economically with more complex manual processes, where, for example, a physical-chemical separation of a

[0029] Scrap composition on a laboratory scale could potentially also yield pure scrap products. The great advantages of the process according to the invention are evident in large-scale processes, which are accordingly particularly preferred. Very particular preference is given to processes according to the invention in which 30,000 kg or more, preferably 60,000 kg or more, particularly preferably 75,000 kg or more of recycled scrap are output per hour. The person skilled in the art understands that the large-scale implementation and in particular the specified

[0030] In practice, throughput rates imply very specific requirements for the process, the machines used, and the raw materials employed. For example, the demand for starting scrap to produce the inhomogeneous ferrous scrap composition increases, so the selection may be less selective, and the inhomogeneity of the starting material generally increases. In step a) of the process according to the invention, an inhomogeneous ferrous scrap composition is provided or produced directly in the process.

[0031] In practice, production can be achieved, for example, by mixing scrap from several ferrous scrap fractions. This mixing can be achieved, for example, by feeding the appropriate quantities of different scrap fractions into the shredding unit one after the other or by feeding them together into a single feed to the shredding unit so that they enter the shredding unit at the same time. This form of production has proven to be particularly efficient in practice. Furthermore, the integrated production by mixing several scrap fractions into the process advantageously allows the composition of the mixture to be controlled by adjusting the mixing ratio.A method according to the invention is therefore preferred, wherein the production of the inhomogeneous, iron-containing scrap composition in step a) is carried out by mixing scrap from several iron-containing scrap fractions, wherein the mixing preferably takes place substantially in the comminution unit.

[0032] The term scrap fraction is clear to the expert in the field of metal processing. The expert can easily distinguish between different ferrous scrap fractions. These are usually

[0033] Scrap fractions are collections of similar materials that are compiled according to specific selection criteria and are collected and / or processed together. The composition of the various iron-containing

[0034] Scrap fractions vary due to changing legal regulations or industry-specific specifications. A scrap fraction consisting, for example, of so-called white goods, i.e. washing machines and ovens, must always be distinguished by the expert from a scrap fraction consisting, for example, of pressed vehicle bodies or returned scrap from metalworking companies. In accordance with the expert's understanding, a ferrous scrap fraction is therefore a classification criterion for compiling scrap that is as similar as possible. This scrap fraction, although in most cases also inhomogeneous in terms of scrap composition, exhibits a smaller deviation in the material properties of the scrap contained in the scrap fraction than the scrap in a second ferrous scrap fraction, in which other similar scrap is grouped together.In practice, corresponding scrap fractions are usually collected separately in accordance with applicable regulations and stored separately by the recycler. In the inventors' experiments, a wide range of common scrap fractions were used to produce the inhomogeneous iron-containing scrap composition. Of these, certain scrap fractions are particularly advantageous due to their ready availability and comparatively high iron content. A preferred process according to the invention is one in which the one or more iron-containing scrap fractions are selected from the group consisting of returned scrap, white goods, and composite materials.

[0035] Waste incineration scrap, shredder materials, and end-of-life vehicles. In accordance with the expert understanding, the term "white goods" is the technical term for household appliances such as refrigerators, washing machines, dishwashers, or stoves, and is distinguished from so-called "brown goods," which refers to consumer electronics devices such as televisions or mobile phones. Shredder materials, for example, come from waste disposal companies or sorting facilities and regularly include bicycles, awnings, and similar items.

[0036] For the process according to the invention, the actual composition of the scrap fractions used for production or the inhomogeneous iron-containing scrap composition, i.e., the iron-containing scrap composition that is inhomogeneous, particularly with regard to the composition of various individual components, is ultimately not decisive. However, for the purposes of the present invention, the iron-containing scrap composition should be inhomogeneous, since processing homogeneous starting materials would be significantly less demanding. This criterion can be readily determined by a person skilled in the art.In accordance with the understanding of those skilled in the art, a ferrous scrap composition is considered inhomogeneous in any case if the ferrous scrap composition was produced by mixing two or more ferrous scrap fractions and / or if it comprises parts obtained by scrapping two or more items from different categories selected from the group consisting of household appliances from the white goods sector, vehicles, and scrap from metalworking companies. In step b) of the method according to the invention, the ferrous scrap composition is comminutioned. This is carried out according to the invention using a comminution unit. Step b) thus corresponds, for example, to the shredding step known to those skilled in the art from the prior art.

[0037] Even if a variety of comminution units are possible, for example scrap shears, condirators and disintegrators, the use of a shredder or disintegrator has proven particularly advantageous, especially for processing large quantities of material. For the purposes of the present invention, disintegrators are understood to be comminution units that have an outlet area for the shredded material in the floor of the comminution chamber, usually covered by a grate, although disintegrators can optionally also have a further outlet area in the upper part of the comminution chamber. In contrast, the term shredder is understood to mean comminution units that do not have an outlet area for the shredded material in the floor of the comminution chamber, but in which the outlet area, usually covered by a grate,

[0038] Exit area for the shredded material is located in the upper part of the shredding chamber.

[0039] Particularly preferred is the use of a comminution unit according to the invention which, thanks to its design with an adjustable base plate and / or cover plate, enables the available exit area of ​​the particles from the comminution chamber to be varied. This makes it possible to reduce the exit of the comminuted particles, thereby increasing the average residence time of the particles in the comminution unit. This advantageously allows the intensity of comminution to be controlled externally, even during ongoing operation. By increasing the average residence time, which can even extend to a temporary complete blockage of the exit area, an increase in cleaning performance and / or a reduction in the particle diameter as well as an increase in the bulk density is possible, depending on the need and requirement.Thus, a method according to the invention is explicitly preferred, wherein the comminution unit has a comminution chamber with at least one outlet area for comminuted material, wherein adjustable elements, preferably an adjustable base plate and / or cover plate, particularly preferably a hydraulically adjustable base plate and / or cover plate, are arranged in the outlet area, with which the available exit area of ​​the particles from the comminution chamber can be changed.

[0040] The inventors of the present invention have come to the conclusion that the above-mentioned method can be most advantageously implemented by means of the adjustable base plate and / or cover plate, which are mounted, for example, inside or on the outside of the comminution chamber, preferably on the outside of the comminution chamber. The adjustable elements are preferably adjustable by remote control. In light of the above explanations, a method according to the invention is therefore fundamentally preferred, wherein in step b) the residence time of the scrap composition in the comminution unit, in particular the average residence time, is controlled in order to control the average particle size of the comminuted material, preferably by adjustable elements arranged in the outlet region.

[0041] If the comminution unit is a shredder, preferably at least one adjustable element, for example an adjustable flap, is provided at the outlet region arranged in the upper part of the comminution chamber. If the comminution unit is a crusher, preferably at least one adjustable element is provided at the outlet region arranged in the floor of the comminution chamber. However, it is particularly preferred if a preferred comminution unit according to the invention is used which has at least a first adjustable element at an outlet region arranged in the upper part of the comminution chamber and a second adjustable element at an outlet region arranged in the floor of the comminution chamber.In addition to the advantageous possibility of controlling the residence time of the scrap composition in the shredding unit using two different adjustable elements, it is advantageously possible to completely close the outlet area located in the floor of the shredding chamber by adjusting the adjustable elements positioned in the lower outlet area. This advantageously makes it possible to operate the shredding unit flexibly both as a shredder and as a decomposer. For example, demanding scrap compositions can be shredded with a closed base plate in shredding mode. However, if a less demanding scrap composition is used, which primarily comprises metallic sheets, for example, the base plate can be opened to increase throughput in decomposer mode.

[0042] The inventors of the present invention were able to identify particularly suitable operating parameters for the comminution unit. A preferred method according to the invention is one in which the rotor of the comminution unit, equipped with hammers, is driven by an electric motor, the power of the electric motor preferably being more than 2000 kW, more preferably more than 2400 kW, and most preferably more than 2800 kW.

[0043] Particularly with large material throughputs, considerable dust development can occur in step b). In particular, when the process is carried out with control of the available exit area of ​​the particles from the comminution chamber, particle sizes can be achieved even in continuous operation that are regularly smaller than those achieved in conventional processes. In this respect, the dust problem in processes according to the invention is particularly pronounced in many cases. As a result of their own experiments, the inventors of the present invention propose providing a dedusting system directly at the comminution unit in order to avoid environmental pollution as best as possible. A process according to the invention is therefore preferred, wherein the comminution unit comprises a dedusting system, preferably a dry dedusting system, preferably with one or more activated carbon filters.In step c), a first processing stage takes place, in which organic and / or inorganic contaminants are removed from the shredded material obtained from the shredding unit. This basic separation step is partly found in prior art processes, where in many cases a single, comparatively simple separation device represents the processing.

[0044] This separation advantageously captures as many, mostly macroscopic, impurities as possible. In accordance with the expert's understanding, step c) does not define the separation of all impurities, so it is an at least partial separation. A process according to the invention is preferred, wherein the inorganic impurities are metallic or mineral impurities, preferably metallic impurities.

[0045] Even if it would be conceivable, at least in theory, to carry out the separation in step c) manually, for example by sorting on an assembly line, this requires for the large-scale industrial process that is particularly relevant here

[0046] Scrap processing requires large amounts of labor, making it uneconomical, at least in most industrialized nations. Accordingly, a method according to the invention is preferred, wherein the separation in step c) is carried out using one or more separation devices, preferably automated separation devices.

[0047] The inventors of the present invention have identified among the various separation processes those that are particularly suitable for the process according to the invention. These are long part separation, air separation, magnetic separation, and sieving, which are basically known to the person skilled in the art, as are the methods used for this purpose.

[0048] Devices. To optimize the quality of the resulting scrap product, the inventors of the present invention propose combining two or more of these steps. Accordingly, a process according to the invention is preferred, wherein the separation of organic and / or metallic contaminants in step c) comprises two or more, preferably three or more, particularly preferably four or more, different steps selected from the group consisting of long-part separation, air separation, magnetic separation, and screening.

[0049] In previous experiments, the inventors of the present invention have largely ignored questions of cost efficiency and concentrated on achieving the highest possible product quality from the recycled scrap, thereby identifying a particularly suitable design for the process and plant according to the invention. According to the inventors' assessment, a process according to the invention is preferred, wherein the separation of organic and / or metallic contaminants comprises long part separation, wall separation, preferably with an air classifier with two or more cascades, magnetic separation, and screening, preferably in this order, wherein the magnetic separation preferably takes place using two magnetic separators, which are preferably designed as electromagnets, wherein the field strength of the electromagnet is particularly preferably adjustable.

[0050] In the process according to the invention, it is special that the pre-cleaned material obtained in step c), ie the comminuted material from which organic and / or inorganic contaminants have already been at least partially separated, is analyzed in step d) with a first detection device.

[0051] At least one piece of material information, preferably several pieces of material information, is detected. This means that the pre-cleaned material is automatically examined after pre-cleaning. The first piece of material information determined in this process is, in most cases, expediently selected so that it correlates with the chemical composition and / or the shape and / or size of the particles in the pre-cleaned material. The material information can, for example, be spectroscopic measurements or optical images of the pre-cleaned material. Subsequently, in step d), components are separated from this pre-cleaned material based on the detected material information.This means, for example, that a part contained in the pre-cleaned material for which initial material information was obtained that does not meet the specified criteria or specifications, for example, with regard to chemical composition or shape, is rejected based on this material information. Step d) of the method according to the invention thus represents a rejection process supported by a detection device. The detection devices used for this purpose can be any detection devices known to those skilled in the art, in particular spectroscopic and optical detection devices.

[0052] Since the number of interfering particles to be separated is usually comparatively low due to prior separation, it seems, at least in theory, easier to perform the separation in step d) manually. In this case, the initial material information is expediently displayed to the workers, for example, via a screen or other interface, through which the worker receives the information about which part of the pre-cleaned material is to be removed. However, with regard to the achievable material throughput and, in particular, the accuracy of the separation, it is explicitly preferred if the separation is carried out automatically. The inventors have succeeded in identifying particularly powerful devices in their own plant that are connected to the first detection device for this purpose, for example, via a data processing device or a network.A method according to the invention is therefore preferred, wherein the separation in step d) is carried out by an automated device, preferably by a compressed air gun, for example in the form of a bar with several compressed air nozzles, or a robot arm, preferably by a robot arm. In the method according to the invention, the material purified in this way passes through a further detection device which detects at least one second piece of material information, preferably several pieces of material information. According to the invention, this second piece of material information is compared with a material criterion assigned to the material information or to the material criterion assigned to each piece of material information. This means, for example, that spectroscopically determined measured values ​​are compared with limit values ​​or the optically determined shape of particles is compared with a template of an accepted particle shape.Only if the second piece of material information satisfies the associated predefined material criterion is the purified material output in the process according to the invention as recycled scrap, i.e. as a product of the process which can, for example, be transported via conveyor belts to a suitable storage facility. In other cases, the purified material is, for example, disposed of, fed to downstream plants for post-processing or recycled in the process according to the invention, the latter being generally preferred. For reasons of efficiency, however, it is advantageous not to reuse the recyclate in the comminution unit, but rather to use it in steps c) or d). A process according to the invention is therefore preferred, wherein the purified material is used again in step b) or step c) or step d) if the at least one second piece of material information does not satisfy the predefined material criterion.

[0053] It is preferred if the comparison is carried out by a

[0054] A data processing device, for example a computer, is also preferred in this respect, wherein the predetermined material criterion is transmitted in the method by a data processing device and / or retrieved from a storage unit.

[0055] A method according to the invention is preferred, wherein the purified material is output as recycled scrap if all of the second material information fulfills the respectively assigned predetermined material criterion.

[0056] The analysis in steps d) and e) has many similarities.

[0057] For efficient process control in the preferred continuous or semi-continuous process, it is desirable that the detection devices also be operated continuously. A method according to the invention is preferred, wherein the analysis in step d) and / or step e), preferably in step d) and step e), is carried out continuously, in particular in an inline analysis. To achieve the best possible material properties, in particular to simultaneously optimize the iron content, the content of organic contaminants, and / or the particle shape, it has proven particularly advantageous to detect multiple pieces of material information independently of one another using the first detection device and / or the second detection device.A method according to the invention is therefore preferred, wherein in step d) at least two, preferably at least three, first pieces of material information are detected and / or wherein in step e) at least two, preferably at least three, second pieces of material information are detected. Against this background, a method according to the invention is also preferred, wherein the at least one first piece of material information and / or the at least one second piece of material information, preferably all of the material information, correlate with the chemical composition and / or the particle shape and / or the mechanical properties of the analyzed material, preferably with the chemical composition of the analyzed material. For this purpose, it is preferred for the vast majority of the methods according to the invention if at least one of the first pieces of material information and at least one of the second pieces of material information correlate with the same material or particle property.

[0058] According to the inventors of the present invention, it is particularly advantageous if the detection is carried out with spatial and / or temporal resolution, which depends primarily on the remaining structure of the plant and whether it is operated continuously. Such a resolution is particularly advantageous in step d), as it enables more precise separation of contaminants and minimizes material waste. However, a corresponding resolution is also advantageous in step e), as a deviation from the material criterion may, for example, only exist locally, so that at least parts of the processed material can be output as recycled scrap. A temporal resolution also enables, in continuous or semi-continuous operation of the process, a correlation of the material information with the respective output fraction of the recycled scrap. Consequently, a process according to the invention is preferred, wherein the at least one first

[0059] Material information and / or the at least one second piece of material information, preferably all material information, are detected with a spatial and / or temporal, preferably a spatial and temporal, resolution, so that a spatially and / or temporally resolved information profile is obtained in each case. Accordingly, a method according to the invention is also preferred, wherein the analysis in step d) and / or step e), preferably in step d) and step e), is carried out using spatially and temporally resolved measurement methods.

[0060] In particular, this preferred procedure makes it possible, in a synergistic manner, to use the specific material information, in particular the second material information, simultaneously for the specification, certification and qualification of the recycled scrap output, so that it can also be used in applications that place high demands on the scrap product, in particular for safety reasons.

[0061] A method according to the invention is therefore preferred, wherein the at least one first piece of material information and / or the at least one second piece of material information, preferably the at least one second piece of material information, is stored on the storage unit of a data processing device, wherein the material information is preferably correlated with at least one piece of operational information, preferably time information, so that the respective material information can be assigned to a part of the recycled scrap, wherein the respective material information is preferably attached to the respectively issued part of the recycled scrap via a certificate, preferably a digital certificate.

[0062] In the course of their own experiments, the inventors of the present invention were able to identify particularly suitable detection methods and the corresponding detection devices associated with them. Excellent purity levels were achieved using these methods, and it has proven particularly advantageous to provide multiple measurement methods in each case. A method according to the invention is preferred, wherein the analysis in step d) and / or step e), preferably in step d) and step e), is carried out using one or more, preferably two or more, different methods selected from the group consisting of X-ray fluorescence analysis, optical image recognition, preferably using artificial intelligence, and IR absorption spectroscopy, in particular NIR absorption spectroscopy.X-ray fluorescence analysis, for example, is used to determine the elemental content, and IR / NIR absorption spectroscopy, for example, is used to determine the organic content.

[0063] In principle, it is possible to use the same types of detection devices in steps d) and e) and to detect the same types of measured values ​​as the first and second material information or to derive them from the same data types, for example, images. However, the inventors of the present invention have recognized that it is advantageous to use different detection methods, especially if they can detect material information that correlates with the same material or particle property. This makes it possible, in a synergistic manner, to minimize measurement errors and compensate for any deficiencies of the various methods, thereby achieving even greater accuracy in processing.Consequently, a method according to the invention is preferred, wherein the first and second pieces of material information are detected using different detection methods, wherein the first and second pieces of material information preferably correlate with the same material or particle property. As explained above, it can be considered a major advantage of the method according to the invention that excellent results can be achieved even in continuous operation, thereby enabling particularly time- and cost-efficient process control. A method according to the invention is therefore particularly preferred, wherein the method is a continuous or semi-continuous process, wherein preferably the comminuted material and / or the pre-cleaned material and / or the cleaned material, preferably all of these materials, are guided at least partially via conveyor belts and / or vibrating conveyor troughs.The process according to the invention advantageously allows large quantities of recycled scrap to be obtained, which reproducibly exhibits particularly favorable iron contents, shape factors, and / or bulk densities. Accordingly, it is particularly advantageous to operate the process according to the invention in such a way that the corresponding parameters are achieved, since in these cases the advantages over the prior art are particularly evident.

[0064] Accordingly, a process according to the invention is preferred, wherein the recycled scrap has a maximum particle size of 100 mm or less, preferably 80 mm or less, particularly preferably 60 mm or less. A process according to the invention is also preferred, wherein the recycled scrap has an average particle size in the range of 60 to 250 mm, preferably 80 to 200 mm, particularly preferably 100 to 150 mm.

[0065] Also preferred is a process according to the invention, wherein the recycled scrap has an average shape factor of length / width in the range from 1 to 5, preferably from 1 to 2.5, particularly preferably from 1 to 1.25, wherein the particles of the recycled scrap are very particularly preferably substantially spherical.

[0066] In particular, a process according to the invention is preferred, wherein the recycled scrap has a bulk density of 1.0 t / m 3 or more, preferably 1.2 t / m 3 or more, particularly preferably 1.5 t / m 3or more. Also preferred is a method according to the invention, wherein the recycled scrap has an iron content of 97% or more, preferably 98% or more, particularly preferably 99% or more, based on the mass of the recycled scrap. Starting from the method according to the invention, the inventors of the present invention have also identified a particularly advantageous further development which interacts synergistically with the structure of the method according to the invention. This involves up to three so-called feedback loops via which the method can be controlled and optimized. In the first two feedback loops, the material information already detected during the processing of the scrap in the method according to the invention is used to also control the individual steps of the method according to the invention depending on the recorded material information.A method according to the invention with a so-called first feedback is preferred, wherein the composition of the inhomogeneous iron-containing scrap composition is controlled as a function of the first material information and / or the second material information, preferably the first material information and the second material information, particularly preferably by changing the relative mass ratio of two or more iron-containing scrap fractions in the inhomogeneous iron-containing scrap composition.

[0067] This process makes it possible to actively respond to deviations in the quality of the scrap, particularly its chemical composition, and to actively control the selection of starting materials in the initial part of the process. This is preferably done using a data processing device, preferably comprising a neural network or a comparable artificial intelligence, preferably a neural network, which is trained to respond to registered deviations of the material information from the corresponding predetermined target values, particularly the material criterion, by changing the relative mass ratio of two or more ferrous scrap fractions during the production of the inhomogeneous ferrous scrap composition, which is suitable for correcting the detected deviation.Since the first material information is detected earlier in the process, it may be advantageous to perform this first feedback based on the first material information due to the faster reaction of the process.

[0068] A method according to the invention with a so-called second feedback is preferred, wherein the comminution in step b) is controlled as a function of the first material information and / or the second material information, preferably the first material information and the second material information, wherein preferably one or more operating parameters of the comminution unit are changed, which are selected from the group consisting of the size of the comminution chamber, the size of the exit area available in the exit region and the speed of the rotor equipped with hammers.Although the basic idea is comparable to that of the first feedback loop, in the second feedback loop, it is not the composition of the inhomogeneous iron-containing scrap that is controlled based on the detected material information, but rather the operating parameters of the comminution unit, with the size of the particle outlet being the preferred control variable. This feedback loop can be used particularly efficiently when the method according to the invention is operated with the comminution unit according to the invention.The control of step b) is also preferably carried out using a data processing device, which preferably comprises a neural network or a comparable artificial intelligence, preferably a neural network, which is trained to react to registered deviations of the material information from the corresponding predetermined target values, in particular the material criterion, with a change in the operating parameters of the comminution unit that is suitable for correcting the detected deviation. The remaining third feedback accesses material information that is not detected in the method according to the invention, but rather in the course of further processing, wherein in principle the same statements apply as those made above for the detection of the first and second material information. This is carried out on a product, e.g.a composition or a reaction product obtained by processing the recycled scrap is detected, and can, for example, relate to the material composition or strength. The at least one third piece of material information is thus regularly provided to the company using the method according to the invention from outside, for example, by buyers of cooling scrap for use in the converter.

[0069] A method according to the invention with a so-called third feedback is preferred, wherein at least one third piece of material information is detected during the further processing of the recycled scrap, wherein the composition of the inhomogeneous iron-containing scrap composition, preferably the relative mass ratio of the iron-containing scrap fractions in the inhomogeneous iron-containing scrap composition, preferably as referred to above as preferred, and / or the comminution in step b), preferably as referred to above as preferred, and / or the separation in step c) is controlled as a function of the at least one third piece of material information. Here, too, the use of a neural network or a comparable artificial intelligence, preferably a neural network, is advantageous.

[0070] The method according to the invention preferably comprises at least the first and the second feedback, particularly preferably the first, the second and the third feedback.

[0071] The invention further relates to recycled scrap produced or producible by the method according to the invention, wherein the iron content in the recycled scrap is 97 wt.% or more, preferably 98 wt.% or more, particularly preferably 99 wt.% or more, based on the mass of the recycled scrap. Corresponding recycled scrap according to the invention is particularly advantageous because it is also suitable for demanding applications and, in terms of its quality, almost approaches that of newly produced metals. The invention further relates to a plant for recycling scrap, preferably for carrying out the method according to the invention, comprising: at least one comminution unit for comminuting an inhomogeneous, iron-containing scrap composition, preferably a comminution unit according to the invention,

[0072] Means for separating organic and / or metallic impurities from the crushed material,

[0073] One or more first detection devices for analyzing the material obtained after separation to detect first material information,

[0074] Means for the automated separation of parts from the material obtained after separation depending on the first material information,

[0075] One or more second detection devices for analyzing the material obtained after the separation to detect a second material information, and

[0076] A data processing device configured to compare the second material information with an associated predetermined material criterion and to output the material purified in the device as recycled scrap if the second material information satisfies the associated predetermined material criterion.

[0077] The system according to the invention is advantageous because it is suitable for carrying out the method according to the invention. Particularly preferred are systems according to the invention that comprise additional components required to carry out the method according to the invention in preferred embodiments, in particular specific comminution units, separation devices, and detection devices, as well as data processing devices designed to implement the first, second, and / or third feedback described above.The invention finally relates to a comminution unit, in particular for use in a method according to the invention or a system according to the invention, comprising: a comminution chamber with at least one outlet area for comminuted material, and at least one rotor arranged in the comminution chamber and equipped with hammers, wherein the comminution unit has an adjustable element which is designed to control the outlet area available in the outlet area for the comminuted material from the comminution chamber, wherein the comminution unit preferably has an adjustable base plate and / or cover plate, particularly preferably a hydraulically adjustable base plate and / or cover plate, with which the outlet area available in the outlet area for the comminuted particles from the comminution chamber can be changed.

[0078] In accordance with the understanding of the person skilled in the art, the comminution chamber will regularly have an inlet opening through which the scrap composition to be processed can be introduced into the comminution chamber and which is not an outlet area for comminuted material within the meaning of the present invention.

[0079] This comminution unit according to the invention is preferred because it is optimized for use in the method according to the invention and, in particular, the above-described control of method step b) and the second feedback can be implemented particularly well. Compared to the prior art, the comminution unit according to the invention is capable of influencing the average residence time of the particles in the comminution chamber even during operation and thus, for example, influencing the particle size and the degree of purification of the processed scrap.A comminution unit according to the invention is particularly preferred, wherein the comminution unit in the upper part of the comminution chamber has a first outlet area with a first adjustable element, which is designed to control the exit area available in the first exit area for the comminution material from the comminution chamber, and wherein the comminution unit in the bottom of the comminution chamber has a second exit area with a second adjustable element, which is designed to control the exit area available in the second exit area for the comminution material from the comminution chamber. This comminution unit according to the invention is particularly preferred because, in the opinion of the inventors, it is possible for the first time to obtain a comminution unit which is flexible, iefor example, even during operation, it can be adjusted between a shredder and a disintegrator. A shredding unit according to the invention is therefore particularly preferred, which can be operated as a shredder and a disintegrator by adjusting one or more elements in the exit area of ​​the shredding chamber.

[0080] Very particularly preferred is a method according to the invention which combines one or more features of the preferred methods specified above, wherein the comminution unit has a soundproof housing.

[0081] A method according to the invention which combines one or more features of the preferred methods specified above is particularly preferred, wherein the comminution unit is anchored in the ground via a foundation.

[0082] A method according to the invention that combines one or more features of the preferred methods specified above is particularly preferred, wherein the scrap composition and / or the crushed material and / or the pre-cleaned material and / or the cleaned material are weighed. A method according to the invention that combines one or more features of the preferred methods specified above is particularly preferred, wherein the method is controlled via a control unit.

[0083] A method according to the invention which combines one or more features of the preferred methods specified above is particularly preferred, wherein an acoustic or optical warning signal is emitted in the event of malfunctions.

[0084] Very particularly preferred is a method according to the invention which combines one or more features of the preferred methods specified above, wherein the comminution unit is made of steel to more than 75% by weight.

[0085] Very particularly preferred is a method according to the invention which combines one or more features of the preferred methods specified above, wherein the output recycled scrap is stored on a stockpile.

[0086] Very particularly preferred is a method according to the invention which combines one or more features of the preferred methods specified above, wherein the output recycled scrap is transported away on a truck, a freight train or a ship, preferably with a freight train or a ship.

[0087] A method according to the invention which combines one or more features of the preferred methods specified above is very particularly preferred, wherein the method can be interrupted via an emergency switch. A system according to the invention which combines one or more features of the preferred systems specified above is very particularly preferred, wherein the system comprises a signaling and / or warning device. A system according to the invention which combines one or more features of the preferred systems specified above is very particularly preferred, wherein the system comprises an emergency switch for stopping the system. A system according to the invention which combines one or more features of the preferred systems specified above is very particularly preferred, wherein the comminution unit is made of more than 75% by weight of steel.

[0088] Very particularly preferred is a system according to the invention which combines one or more features of the preferred systems specified above, wherein the system comprises a control device for controlling the system.

[0089] Very particularly preferred is a system according to the invention which combines one or more features of the preferred systems specified above, wherein the system has a total length of more than 5 m, preferably more than 10 m, particularly preferably more than 15 m.

[0090] Very particularly preferred is a comminution unit according to the invention which combines one or more features of the preferred comminution units specified above, wherein the comminution unit has a foundation, preferably a concrete foundation.

[0091] A comminution unit according to the invention is particularly preferred, which combines one or more features of the preferred comminution units specified above, wherein the comminution unit has steel hammers. A comminution unit according to the invention is particularly preferred, which combines one or more features of the preferred comminution units specified above, wherein the comminution unit comprises an operating device. A comminution unit according to the invention is particularly preferred, which combines one or more features of the preferred comminution units specified above, wherein the comminution unit has a weight of more than 100 kg, preferably more than 200 kg.Very particularly preferred is a comminution unit according to the invention which combines one or more features of the preferred comminution units specified above, wherein the comminution unit is made of more than 75 wt.% steel.

[0092] In the following, the method according to the invention and the plant according to the invention used for this purpose are explained in more detail in the preferred embodiment, which was identified by the inventors of the present invention as being particularly advantageous in the course of comprehensive optimization and with which recycled scrap can be produced on an industrial scale, which, with almost complete freedom from organic matter, has an iron content of more than 97% and bulk densities of about 1.5 t / m 3 with approximately spherical particles, i.e. a shape factor of about 1 and a maximum particle size of about 80 mm.

[0093] The process is operated as a continuous process, with the processed material being conveyed via conveyor belts.

[0094] The starting material is an inhomogeneous ferrous scrap composition. Production takes place in the inlet of a shredding unit by mixing scrap from several ferrous scrap fractions, namely white goods, returned scrap, shredder precursors, and compacted end-of-life vehicles.

[0095] The inhomogeneous iron-containing scrap composition is crushed in a comminution unit according to the invention as shown in Fig. 1, which has a hydraulically adjustable base plate and cover plate with which the available exit area of ​​the crushed material from the comminution chamber can be varied. This allows the average residence time of the particles in the comminution chamber and the average particle size of the crushed material to be controlled. The adjustable base plate arranged in the floor of the comminution chamber allows the lower exit area to be closed, so that only the exit area arranged in the upper part of the comminution chamber remains. This allows the comminution unit according to the invention to be operated as a shredder and as a crusher. In the tests carried out, the comminution unit is mostly operated as a shredder.

[0096] In addition, the shredding unit features a dry dust extraction system with several activated carbon filters.

[0097] The shredded material is passed through a separation arrangement to separate organic and inorganic contaminants from the shredded material and to obtain a pre-cleaned material.

[0098] The separation system comprises, in sequence, a conventional long-part separation system, an air classifier with three cascades, two magnetic separators with adjustable electromagnets for magnetic separation, and a sieve. The material flow is analyzed using two initial detection devices. A camera detects material information regarding the shape and size of the parts in the pre-cleaned material, and a continuously operating NIR spectrometer determines measured values ​​that correlate with the chemical composition of the material being examined. This spatially and temporally resolved material information is transmitted via a computer control system to a robot sorter, which, based on the provided data, separates out identified contaminants or parts that do not meet predetermined requirements as part of the sensor-assisted sorting process.The purified material then passes through another section on the conveyor belt where it is analyzed again. The detection devices used here are again a continuously operating NIR spectrometer and an additional X-ray fluorescence spectrometer, the latter providing complementary information on the chemical composition (a further check of the particle dimensions, e.g., with a camera, is not carried out in this process, but can be provided). The material information recorded in this process is compared using a data processing device with assigned predefined material criteria, which in this case were focused on the presence of selected organic and metallic contaminants, particularly copper.

[0099] If all material criteria were met, the resulting material was classified as recycled scrap and transported via a conveyor belt to a storage dump.

[0100] The detected secondary material information is stored on a computer and linked to the time of production or issue. This material information is linked to the corresponding batch via a digital certificate, which can be made available to the customer in the later application and which provides a qualification of the

[0101] scrap product permitted for certain applications.

[0102] The corresponding system is equipped with a computer control system that enables the implementation of various feedback loops, i.e., the control of the process depending on the detected material properties. In this embodiment, the operating parameters of the crushing unit, more precisely the power and the adjustment of the movable plates in the exit area, were controlled depending on the initial material information detected by the camera.

[0103] The composition of the inhomogeneous, ferrous scrap was adjusted based on NIR or X-ray fluorescence measurements. At the current stage of development, this adjustment is achieved through visual instructions displayed on a display to the excavator operator indicating the quantities of scrap fractions to be added. However, automated feeding is the desired solution here.

[0104] The method and system are configured to receive third material information from a recycler of the recycled material and, based on this third material information, to control the operating parameters of the shredding unit and the composition of the inhomogeneous ferrous scrap. Although this feedback can currently only be tested with fictitious empirical values ​​due to the lack of an actual recycler, the system's adaptation works according to the invention. Through the continuous detection of material information, the resulting control of the process, and the subsequent detection of the effects by the same detection devices, comprehensive data sets can advantageously be obtained, enabling the training of a neural network to make the feedback even more precise and minimize the need for expert empirical knowledge.

[0105] The shredding unit according to the invention and its preferred embodiments are explained and described in more detail below with reference to the accompanying figure. The figure shows:

[0106] Fig. 1 is a schematic cross-sectional view of a comminution unit according to the invention in a particularly preferred

[0107] Embodiment.

[0108] Fig. 1 shows, by way of example, a schematic cross-sectional view of a preferred comminution unit 10 according to the invention.

[0109] The comminution unit 10 is particularly suitable for use in a method according to the invention or in a system according to the invention and comprises a comminution chamber 12.

[0110] The comminution chamber 12 comprises an inlet opening 22 through which the scrap composition can be introduced into the comminution chamber 12, which is supplied, for example, via a conveyor belt 18a. Furthermore, the comminution chamber 12 comprises two outlet areas 14a, 14b.

[0111] The first outlet area 14a is arranged in the upper part of the comminution chamber 12 and has a first adjustable element 20a, which is designed to limit the exit area of ​​the comminution material available in the outlet area 14a from the comminution chamber 12. The first adjustable element 20a is designed here as a hydraulically adjustable cover plate.

[0112] The second outlet area 14b is arranged in the floor of the comminution chamber 12 and has a second adjustable element 20b, which is designed to limit the exit area of ​​the comminution material from the comminution chamber 12 available in the outlet area 14b. The second adjustable element 20b is designed here as a hydraulically adjustable base plate, which is constructed in two parts in the form of a flap with two wings. In Fig. 1, the adjustability of the adjustable elements 20a, 20b is indicated by double arrows. The outlet areas 14a, 14b are each covered by gratings, which prevent excessively large particles from escaping from the comminution chamber 12. The gratings in the outlet areas 14a, 14b can preferably be designed with adjustable mesh sizes and / or can be reversibly and non-destructively replaced.

[0113] In the comminution chamber 12, the scrap composition is comminuted by the rotor 16 equipped with hammers. After a certain residence time in the comminution chamber 12, the comminuted particles exit the comminution unit 10 through one of the outlet areas 14a, 14b and can be fed for further processing, for example, via conveyor belts 18b, 18c.

[0114] By controlling the adjustable elements 20a, 20b, the average residence time of the particles in the comminution chamber 12 can be controlled. The second adjustable element 20b also allows the second outlet area 14b to be completely closed, allowing the comminution unit 10 to be converted from crusher mode to shredder mode.

[0115] Reference symbol

[0116] 10 Shredding unit

[0117] 12 Crushing chamber 14a-b Outlet area Rotor ac Conveyor belt ab Adjustable element Inlet opening

Claims

Claims 1. A method for producing recycled scrap, comprising the following steps: a) producing or providing an inhomogeneous, ferrous scrap composition, b) shredding the inhomogeneous, ferrous scrap composition in a shredding unit (10) to obtain a shredded material, c) separation of organic and / or inorganic impurities from the shredded material to obtain a pre-cleaned material, d) analysis of the pre-cleaned material with one or more first detection devices to detect at least one first material information and separation of components of the pre-cleaned material to obtain a purified material, wherein the separation is carried out depending on the first material information, and e) analysis of the purified material with one or more second detection devices to detect at least one second material information, f) comparison of the detected second material information with a predetermined material criterion assigned to the second material information, wherein the purified material is output as recycled scrap,if the second piece of material information matches the assigned predefined one, Material criteria met.

2. The method according to claim 1, wherein the separation of organic and / or metallic impurities in step c) involves two or more, preferably three or more, particularly preferably four or more, different The process includes steps selected from the group consisting of long part separation, air classification, magnetic separation and sieving.

3. Method according to one of claims 1 or 2, wherein the sorting in step d) is carried out by an automated device, preferably by a compressed air gun or a robot arm, preferably by a robot arm.

4. A method according to any one of claims 1 to 3, wherein the at least one first material information and / or the at least one second material information, preferably all material information, is detected with a spatial and / or temporal resolution, preferably a spatial and temporal resolution, such that a spatially and / or temporally resolved information profile is obtained in each case, and / or wherein the analysis in step d) and / or step e), preferably in step d) and step e), is carried out with one or more, preferably two or more, different methods selected from the group consisting of X-ray fluorescence analysis, optical image recognition, preferably using artificial intelligence, and IR absorption spectroscopy, in particular N IR absorption spectroscopy.

5. Method according to any one of claims 1 to 4, wherein the composition of the inhomogeneous ferrous scrap composition depends on the first material information and / or the second material information, preferably the first material information and the second Material information is controlled, particularly preferably by changing the relative mass ratio of two or more ferrous scrap fractions in the inhomogeneous ferrous scrap composition.

6. Method according to any one of claims 1 to 5, wherein the comminution in step b) is controlled depending on the first material information and / or the second material information, preferably the first material information and the second material information, wherein preferably one or more operating parameters of the comminution unit (10) are changed, which are selected from the group consisting of the size of the comminution chamber (12), the size of the discharge area available in the discharge area (14a, 14b) and the speed of the rotor (16) equipped with hammers.

7. A method according to any one of claims 1 to 6, wherein, during further processing of the recycled scrap, at least one third piece of material information is detected, and wherein the composition of the inhomogeneous ferrous scrap composition, preferably the relative mass ratio of the ferrous scrap fractions in the inhomogeneous ferrous scrap composition, and / or the comminution in step b) and / or the separation in step c) is controlled depending on the at least one third piece of material information.

8. A method according to any one of claims 1 to 7, wherein the method is a continuous or semi-continuous process, wherein, preferably, the comminutioned material and / or the pre-cleaned material and / or the purified material, preferably all of these materials, are conveyed at least partially via conveyor belts (18a, 18b, 18c) and / or vibratory conveyors.

9. Plant for recycling scrap metal, preferably for carrying out the Method according to any one of claims 1 to 8, comprising: at least one comminution unit (10) for comminuting an inhomogeneous, iron-containing scrap composition, Agents for separating organic and / or metallic impurities from the crushed material, One or more initial detection devices for analyzing the material obtained after separation to detect initial material information, Means for the automated sorting of parts from the material obtained after separation, depending on the initial material information, One or more secondary detection devices for analyzing the material obtained after sorting to detect a second material information, and A data processing device configured to compare the second material information with an associated predefined material criterion and to output the material purified in the device as recycled scrap if the second material information meets the associated predefined material criterion.

10. Comminution unit (10), in particular for use in a process according to one of claims 1 to 8 or a plant according to Claim 9, comprising: a comminution chamber (12) with at least one discharge area (14a, 14b) for comminutated material, and at least one rotor (16) arranged in the comminution chamber (12) and equipped with hammers, wherein the comminution unit (10) has an adjustable element (20a, 20b) which is configured to control the discharge area of ​​the comminutated material available in the discharge area (14a, 14b) from the comminution chamber (12).

Images