METHOD AND DEVICE FOR ANALYZING AND SORTING MATERIAL PARTS

Description

[0001] The invention relates to a method for analyzing and sorting material parts, in particular scrap parts made of aluminum, according to claim 1. Furthermore, the invention relates to a device according to claim 9.

[0002] Methods for analyzing and sorting are known from the prior art. For example, WO 2022 / 172238 describes a method for analyzing and sorting steel scrap. This document describes a two-stage process for analyzing and sorting material parts, particularly scrap parts. The first stage involves pre-sorting, and the second stage involves post-sorting. In the first stage, the material parts are sorted according to a predefinable material property. In the second stage, the material parts are then allocated to either a first or a second fraction, depending on their respective material properties.and wherein, in the second stage, in a first step, the material components of one of the two fractions are transferred into a continuous flow and subjected to a prompt gamma neutron activation analysis, and in a second step of the second stage, the flow is diverted to individual subfractions depending on an element determination obtained by the PGNAA, as well as a corresponding device.

[0003] Another method for analyzing and sorting rocks is described in US Patent 2013 / 0292307 A1. This method aims to sort rocks or ores immediately after their extraction from open-pit mines. Pre-sorting based on rock size can be performed. A key feature of this method is that no segregation or singulation of the material is required, which would limit sorting capacity. High sorting efficiency is achieved by sorting the unsegregated, unsingled rock in a large number of sorting stages using various sensor / sorting units. The number of stages and the sensor / sorting units to be selected are determined by a mathematical model that incorporates the characteristic properties of the rock. The large number of sorting stages is necessary because each individual stage yields insufficient sorting results.

[0004] A well-established method for analyzing and sorting material parts, particularly scrap aluminum, enables sorting based on laser-induced plasma spectroscopy, also known as LIBS (laser-included breakdown spectroscopy). In this process, laser-induced plasma spectroscopy is used to determine the elemental composition of a material part, i.e., a sample, using a plasma. The plasma is generated on a surface of the material part using high-intensity, focused laser radiation. Light emitted by the plasma is detected and spectrally analyzed to deduce the elemental composition of the material part.

[0005] A method of the type described above is known, for example, from EP 3 352 919 B1, which also discloses a generic device for carrying out the method.

[0006] According to EP 3 352 919 B1, material parts to be sorted are fed to a feeding device. This feeding device can, for example, be vibrating plates that provide a feeding surface along which the material parts are moved.

[0007] The material samples to be analyzed and sorted are fed into a chute via a feeding device. Following the pull of gravity, the samples slide down the chute and exit over a lower edge. From there, they fall freely through the surrounding atmosphere. The feeding device and the chute serve to separate the samples and, after they exit the chute, to guide them through a spatially defined fall corridor.

[0008] During free fall, each piece of material exiting the slide undergoes laser-induced plasma spectroscopy. For this purpose, a laser device is provided, configured to generate a plasma on the surface of a material piece using a laser beam propagating along a beam axis. Furthermore, a spectrometer system is provided, configured to perform a spectral analysis of the plasma light emitted by the laser-induced plasma and to generate an output signal based on the results of this spectral analysis.

[0009] This output signal, in combination with a sorting criterion, is then used by a sorting unit to direct the material particles exiting the chute into one of two fractions. For example, an air nozzle, controlled by a control device, can be used as the sorting unit. Under the influence of air pressure, specific material particles can be sorted out from the stream of particles leaving the chute. The result is one fraction of sorted particles and one fraction of unsorted material particles.

[0010] Typically, the aforementioned process serves to identify material components of a specific composition and separate them from those of a different composition. This separation occurs either because a material component with an undesired composition is identified and rejected by the sorting unit, or because the composition of a material component could not be reliably determined, necessitating its rejection by the sorting unit. The fraction of rejected material components thus consists of, on the one hand, material components whose composition is clearly identified and undesired, and, on the other hand, material components whose composition is not clearly identified.

[0011] The fraction of material components that are clearly identified and desired is also referred to as the "good fraction". The other fraction, that is, the fraction of material components that are clearly identified but not desired on the one hand, and material components that are not clearly identified on the other, is also referred to as the "residual fraction".

[0012] Experience has shown that the amount of residual fraction is significantly smaller compared to the amount of usable fraction. Since the composition of the residual fraction is undefined and therefore unknown, the material components belonging to the residual fraction cannot be economically recycled.

[0013] Analyzed and sorted material components can then be used, in particular, to feed into the furnace of a melting plant in order to provide the desired alloy composition for a subsequent casting. For example, with material components that are available as scrap aluminum, the primary goal of sorting is to select the correct aluminum alloy for the proper operation of a remelting plant.

[0014] To ensure optimal utilization of both the usable and residual fractions, analytical evaluation is necessary. The results of such an analysis can then be used to plan the charging of a remelting furnace. This is done while taking into account a "safety buffer" necessary to reliably remain within a specific target alloy range. While this can partially compensate for analytical inaccuracies, it also negatively reduces the maximum possible amount of scrap metal that can be used.

[0015] The analytical inaccuracy of the evaluation stems from the fact that only a few samples are used for analysis, representing only a fraction of the total material to be processed. The probability of analytical uncertainty increases with heterogeneously structured fractions. Consequently, the remaining fraction is essentially not economically viable, or if it is, only to a very limited extent and with a high probability of analytical inaccuracies.

[0016] Based on the foregoing, the object of the invention is to provide a method for analyzing and sorting material parts, in particular scrap aluminum parts, which helps to minimize possible analysis errors and to maximize the further usability of material parts, especially in remelting plants. Furthermore, a device for analyzing and sorting material parts, in particular scrap aluminum parts, is to be proposed.

[0017] To solve the above problem, a method according to claim 1 is proposed.

[0018] To solve the above problem, a device according to claim 9 is proposed.

[0019] The process according to the invention is carried out in two stages. A pre-sorting stage and a post-sorting stage are provided. The pre-sorting stage serves to form at least two material fractions: a good fraction and a residual fraction.

[0020] According to the invention, fractionation is carried out depending on a predefinable material property of the material components. For this purpose, a predefinable material property of the material components is determined in a first step. In a second step of the first stage, the material components are then sorted, i.e., divided into at least two fractions, namely a first fraction and a second fraction. This fractionation is carried out depending on the respective determined material property of the material components. The material components are thus fractionated depending on the result of the determination of the material property according to the first step.

[0021] According to the invention, fractionation is carried out in such a way that at least two fractions are formed, wherein one of the two fractions contains more material parts that have the specified material property, whereas the other fraction is mainly composed of material parts that do not have this material property.

[0022] As a material property within the meaning of the invention, a material property can generally be selected that expediently contributes to optimizing the desired sorting result. Particularly suitable material properties in this sense are the respective density, absorption capacity, and / or chemical composition of the material components.

[0023] The pre-sorting fraction formation can also include further stages. In particular, it is possible to perform sorting based on a plurality of material properties to be determined. For example, it may be possible to determine a first predefinable material property of the material parts in a first step and, in a second step, to assign the material parts to either a first or a second fraction depending on the determined first material property. One of the two resulting fractions is then subjected to further pre-sorting according to the invention by determining a second predefinable material property of the material parts in a third step and, in a fourth step, assigning the material parts to either a third or a fourth fraction depending on the determined second material property.

[0024] The essential aspect of the invention is therefore not the pre-sorting as such, but the combination of pre-sorting and post-sorting, wherein at least two fractions of material parts are present upon completion of the pre-sorting and at least one of these two fractions is subjected to a PGNAA.

[0025] According to a particular embodiment of the invention, it is provided that in the first stage, the respective chemical composition of the material parts is determined in a first step by checking for each material part whether a predefinable chemical component is a component of the material part, and in a second step of the first stage, the material parts are each supplied to either a first fraction or a second fraction depending on the presence of the predefinable chemical component as a component of the material part.

[0026] Fractionation is preferably carried out based on the chemical composition of the material components. For this purpose, the chemical composition of each component is determined in a first step by checking whether a predefined chemical component is present. If so, this component is added to the good fraction; otherwise, it is added to the residual fraction. If a material component cannot be clearly identified, it is added to the residual fraction.

[0027] Individual elements, such as zinc, copper, iron, or manganese, can be selected as predefined chemical components. Alternatively, groups of elements can be specified, for example, certain aluminum alloys, such as the 5000 series or the 6000 series.

[0028] It is particularly preferred to carry out the aforementioned pre-sorting using LIBS. However, other methods can also be used, as the primary goal is simply to analyze material components according to their chemical composition and then assign them to two fractions based on that specific chemical composition.

[0029] Pre-sorting can also be carried out using X-ray sorting, for example by X-ray transmission, instead of LIBS, especially if other material properties of the parts are to be used as sorting criteria for pre-sorting. For example, a two-stage X-ray sorting process is also possible, in which a first stage involves X-ray sorting for aluminum enrichment and a second stage involves X-ray sorting for separation into cast and wrought alloys.

[0030] According to the invention, pre-sorting is followed by post-sorting. In this post-sorting, the material components of at least one fraction are sorted. However, the material components of both fractions can also be sorted separately. Preferably, the remaining fraction is also sorted.

[0031] The subsequent sorting is carried out using PGNAA, i.e., prompt gamma neutron activation analysis. This enables online quality control, whereby all material components belonging to a fraction are analyzed, unlike in the prior art where only individual samples are analyzed. This offers the particular advantage of extremely reliable measurement, thus avoiding the inaccuracies inherent in sample analysis according to the invention. The "safety buffer" to be considered when optimizing batches for furnace loading can be reduced due to the analytical accuracy achieved with the process according to the invention. This, in turn, allows for a higher proportion of usable, lower-grade scrap and consequently lower costs for the use of primary metals and / or alloys.

[0032] Furthermore, a particular advantage of PGNAA is that the material components of the analyzed fraction can be added to sub-fractions, depending on the average chemical composition, which is determined in real time by PGNAA.

[0033] The residual fraction, in particular, contains material components that vary considerably in their chemical composition. The economic value of the residual fraction's recyclability is determined by the content of its alloying elements, especially elements such as zinc and copper. The inventive method allows the actual chemical composition of the material components to be determined online, i.e., in real time. This then enables the material components to be separated into individual subfractions. In this way, separate subfractions are produced which, due to their known chemical composition, have a higher economic value than an unseparated mixture.The process according to the invention can therefore contribute to increasing the economic usability of the material components contained in the fractions, thereby simultaneously reducing undesirable downcycling. Furthermore, it provides an additional quality assurance measure.

[0034] Prompt gamma neutron activation analysis (PGNAA) enables multi-element measurement of material particles of a fraction moving in a conveying stream. According to the invention, a first step of the second stage provides that the material particles of one of the two fractions are transferred into a continuous conveying stream. The material particles are then subjected to PGNAA. The advantage of PGNAA is that measurements are taken continuously across the entire cross-section of the conveying stream, allowing for representative element determination. Elements such as copper can be measured with an accuracy of up to 0.02% copper, thus making it possible to form subfractions that are clearly distinguishable from one another.

[0035] In a second step of the second stage, the flow of material parts is directed to individual subfractions, depending on the element determination obtained using PGNAA.

[0036] The advantageous result of the inventive process is that material components can be sorted according to the economic value of selected alloying elements such as copper, zinc, iron, or manganese. This is achieved not through analysis based on representative samples, but rather through a complete analysis of all material components belonging to a given fraction, performed in real time, thus enabling online operation. This minimizes analytical inaccuracies, allowing for a reduction in the "safety buffer" required for the proper operation of a foundry, which in turn permits a reduced use of primary metals.

[0037] According to a further feature of the invention, the two stages are carried out immediately one after the other. Thus, a pre-sorting stage is immediately followed by a post-sorting stage. The fractions resulting from the pre-sorting stage are then further processed and subjected to the second sorting stage provided for in the invention. This allows for a temporally and spatially optimized process execution.

[0038] Alternatively, it is of course also possible to decouple the two process stages according to the invention in time. In particular, it is permissible to temporarily store the fractions resulting from a pre-sorting of the intended type and only subject them to a subsequent sorting of the invention at a later time. Such a time-delayed two-stage sorting can prove particularly advantageous for logistical reasons. In particular, fractions from the pre-sorting can be collected and then sorted together in the manner described above.

[0039] According to a further feature of the invention, it is provided that not only the material components of one fraction, but the material components of both fractions are subjected to PGNAA. The fractions are processed separately from one another, so that unintentional mixing of the material components previously divided into two fractions is reliably prevented.

[0040] According to a further feature of the invention, the chemical composition of the material components is determined in the first stage using LIBS. Since the LIBS process very reliably produces good fractions, it is particularly preferred, after pre-sorting using LIBS, to further process the remaining fraction using PGNAA. However, the good fraction produced by the LIBS process can, of course, also be subjected to further sorting using PGNAA.

[0041] According to a further feature of the invention, it is provided that a characteristic component of a specific aluminum alloy is selected as the predefinable chemical component.

[0042] Certain aluminum alloys are characterized by specific individual chemical elements. Therefore, to distinguish between aluminum alloys, it is not necessary to analyze all alloy components of a material sample to be sorted. Determining just one alloying element can suffice to clearly differentiate between two aluminum alloys. This is particularly true when the alloy composition contains expected components. For example, if a scrap mixture to be sorted primarily contains material samples of only two aluminum alloys, then only these two alloys are to be expected. If these two expected aluminum alloys differ by a characteristic alloying element, then it is sufficient to determine the chemical composition of the material samples based on this alloying element.

[0043] According to a further feature of the invention, it is provided that in the second stage of element determination using PGNAA, alloying elements from the group consisting of zinc, copper, iron, and manganese are taken into account. These alloying elements are particularly important from a business perspective, which is why it is advantageous to divide the flow of material parts into subfractions representing these alloying elements.

[0044] The device according to the invention is particularly suited for carrying out the method according to the invention. For this purpose, the device proposed by the invention has a first analysis unit and a second analysis unit. The first analysis unit serves for pre-sorting according to the first process stage, and the second analysis unit for post-sorting according to the second process stage. The two analysis units can be coupled to each other by means of a conveyor system, which makes it possible to carry out the two process stages immediately one after the other.

[0045] The first analytical device is configured to determine a predefined material property of the material components and to fractionate the material components using a sorting device. A predefined material property, in the sense of the invention, can be, in particular, density, absorbency, and chemical composition. The first analytical device is designed accordingly so that the material components can be sorted according to the desired material property.

[0046] According to a particularly preferred embodiment of the invention, the first analytical device is specifically configured to determine the chemical composition of the material parts by testing, for each material part, whether a predefinable chemical component is present. This test can preferably be carried out using LIBS, as described above.

[0047] The first analysis unit has a sorting device by which the material particles are fed into one of two fractions. This preferably results in a good fraction on the one hand and a residual fraction on the other, depending on the previously performed material analysis, for example, based on the chemical composition of the material particles.

[0048] The second analysis unit is designed to subject the material components of one of the two fractions to a PGNAA (Process Identification and Analysis of Natural Materials) and then, depending on the elemental analysis performed by the PGNAA, to the individual sub-fractions. The analysis of the material components is performed in real time, allowing for the immediate sorting of the material components moving in the conveyor stream into individual sub-fractions.

[0049] According to a further feature of the invention, the first analysis device enables analysis using LIBS, for which purpose the first analysis device comprises: a sorting unit configured to feed a material part into one of two fractions, a laser device configured to generate a plasma on a surface of the material part using a laser beam propagating along a beam axis, a spectrometer system configured to perform a spectral analysis of plasma light emitted by the laser-induced plasma and to generate an output signal in accordance with the result of the spectral analysis, and a control device configured to receive the output signal and to operate the sorting unit based on the output signal and a sorting criterion.

[0050] The spectrometer system itself comprises a spectrometer and a detection unit optically connected to the spectrometer. The detection unit has a lens to which a detection cone is assigned, forming a plasma detection area in an overlap region with the laser beam.

[0051] Using an analytical device equipped in this way, the chemical composition of a material part can be determined by LIBS in a manner known per se, whereby the device can be set to a specific predefinable element or a specific predefinable alloy, for example an aluminum alloy.

[0052] According to a further feature of the invention, the second analysis device includes a transport device with conveyor belts for transporting the material components in a continuous flow. The conveyor belts serve to transfer the material components into a flow of a predetermined width and height. The geometric design of the flow is determined, in particular, by the detection unit to be used for the PGNAA.

[0053] According to a further feature of the invention, the second analysis device comprises a detection unit with a neutron source arranged below a conveyor belt and a detector arranged above the conveyor belt and opposite the neutron source. This enables area-wide scanning of the conveyed material flow, allowing the calculation of the conveyor belt length occupied by material particles of a specific average chemical composition, given a known conveying speed. This allows for the time-controlled allocation of the conveyed material flow to individual subfractions, thus enabling the simple yet effective feeding of the material flow to separate, distinct subfractions. A reversed arrangement of the neutron source and detector is, of course, also possible.

[0054] According to a further feature of the invention, it is provided that compartments separate from one another are connected downstream of the detection unit in the transport direction of the conveyor belt, wherein the compartments each serve to receive material parts of a subfraction.

[0055] Compartments are provided to divide the conveyed material flow into different sub-fractions. These compartments represent spatially separated collection points for the material particles, with one collection point for each sub-fraction. Such a collection point can be, for example, a box, a container, and / or the like. The only important factor is that these compartments are located downstream of the detection unit in the direction of material transport, so that after PGNAA (Process Identification and Analysis), the conveyed material flow can be allocated to the individual compartments as intended.

[0056] According to a further feature of the invention, it is provided that each compartment is assigned a circumferential conveyor belt which is arranged in the vertical direction above the compartment.

[0057] The individual compartments are arranged one after the other in the direction of the material flow. Above each compartment, individual conveyor belts are provided, also arranged one after the other in the direction of transport, so that the material flow can be transferred from one conveyor belt to the next. Each compartment is assigned a conveyor belt, allowing the material flow to be transferred from compartment to compartment by means of the respective conveyor belt. The design according to the invention thus makes it possible to selectively direct the material flow to individual compartments, depending on the conveyor belts used.

[0058] According to a further feature of the invention, the conveyor belts are each inclined to the horizontal. They thus have a first end section and a second end section, the two end sections being at different heights. In this respect, an end section of one conveyor belt located further back in the conveying direction projects beyond an end section of a conveyor belt located further back in the conveying direction.

[0059] According to a further feature of the invention, the direction of travel of the conveyor belts is reversible. In combination with the inclination of the conveyor belts to the horizontal, this allows for a simple yet effective allocation of the conveyed material flow to the individual compartments. The conveyor belts running in the transport direction carry the material flow from conveyor belt to conveyor belt until they reach the conveyor belt rotating in the opposite direction. This reverse-rotating conveyor belt conveys the material placed on it into its corresponding compartment. If a different compartment is to be served, the direction of travel of this conveyor belt is reversed again. In this technically simple yet effective manner, a targeted distribution of the conveyed material flow to individual compartments is thus possible.

[0060] Further features and advantages of the invention will become apparent from the following description with reference to the figures. These show Fig. 1 shows a schematic representation of a first analysis device of the device according to the invention; Fig. 2 shows a schematic representation of a second analysis device of the device according to the invention; and Fig. 3 shows a schematic representation of a device according to the invention and its operation.

[0061] Fig. 3 The schematic representation shows a device 1 according to the invention for analyzing and sorting material parts 4. The device 1 according to the invention has a first analysis unit 2 and a second analysis unit 3. These are shown in the Figure 1 and 2 This will be explained in more detail below.

[0062] Fig. 1The schematic representation shows the first analysis device 2. This device serves to sort material parts 4 on the basis of laser-induced plasma spectroscopy, also known as LIBS, and to assign them to two fractions F1 and F2.

[0063] The in Fig. 1 The first analysis device 2 shown is configured to subject a material part 4 to laser-induced plasma spectroscopy and to sort it according to the result of the spectral analysis. In the illustrated embodiment, two fractions F1 and F2 are provided, to which the material part 4 can be assigned. Collection points 5, for example in the form of containers, serve to receive the respective fractions F1 and F2.

[0064] As the schematic representation according Fig. 1As can be seen, the analysis device 2 has a feeder 6 followed by a chute 9. In its intended use, a material part 4 is fed into the feeder 6. The feeder 6 serves to transport the material part 4 along a feed surface 7 provided by the feeder 6, up to an upper section 8 of the chute 9. Here, the material part 4 is transferred from the feeder 6 onto the chute 9.

[0065] The feeding device 6 serves in particular to separate a plurality of material parts 4 placed on the feeding device 6, so that these can subsequently be fed to the chute 9 at a distance from one another.

[0066] A material part 4, transferred to chute 9, slides down chute 9 under the influence of gravity until it reaches the lower edge 10 of chute 9, which is located opposite the upper section 8 of chute 9. The primary function of chute 9 is to align the material part 4 and transfer it into a defined fall path. Upon exiting chute 9, the material part 4 continues its free fall through the surrounding atmosphere under the influence of gravity. During this fall, it passes through a spectrometer system 11, which analyzes the material part 4. Based on the results of the spectral analysis, the spectrometer system 11 generates an output signal. This signal is fed to a control unit 12, which, depending on this output signal and a stored sorting criterion, operates (i.e., controls) a sorting unit 13.Using this sorting unit 13, the material part 4 is either deflected during its free fall or it is not deflected. If it is not deflected, the material part 4 goes to collection point 5 for fraction F2. Otherwise, if sorting is carried out by sorting unit 13, the material part 4 goes to collection point 5 for fraction F1.

[0067] The spectrometer system 11, which is part of a LIBS module 14, is used to analyze the composition of the material part 4. The LIBS module 14 also includes a laser device 15 and the control unit 12. Preferably, the laser device 15, the spectrometer system 11, and the control unit 12 are housed in a common casing, which in Fig. 1 not shown in detail.

[0068] The laser device 15 in turn has further individual components, for example a laser beam source, an optical fiber and a focusing optic.

[0069] The spectrometer system 11 further comprises a detection unit, which in turn provides several lenses. Each of these lenses is assigned a detection cone 16, which, in an overlap region with a laser beam 17 emitted by the laser device 15, each forms a plasma detection area 18. These plasma detection areas 18 are arranged offset from one another along the beam axis of the laser beam 17 and together form a field of view of the detection unit. The field of view is thus composed of the individual plasma detection areas, thereby defining the total detection area covered by the detection unit.

[0070] As soon as a material part 4 passes through the detection area, it is bombarded with a laser beam, resulting in the generation of laser-induced plasma on the surface of the material part 4. This plasma is analyzed by the spectrometer system 11 as previously described, and depending on the analysis result, the material part 4 is deflected by the sorting unit 13. The sorting unit 13 can, in particular, include an air nozzle which, in the event of pressurization, enables the sorting out of the material part 4.

[0071] Fig. 2 Figure 1 shows a schematic representation of the second analysis device 3 of the device 1 according to the invention.

[0072] In the illustrated embodiment, the second analysis unit 3 serves to re-sort the material parts 4 of the first fraction F1 stored in a bunker 20. Such re-sorting can also be carried out for the material parts 4 of the second fraction F2.

[0073] By means of the second analysis device 3, the material components 4 are separated into subfractions, with each subfraction having a separate compartment 29, for example in the form of a container. In the illustrated embodiment, a total of eight subfractions are provided, namely subfractions A1, A2, B1, B2, B3, B4, C1, and C2. It is possible that subfractions A1 and A2 share a first alloying element but differ with respect to a second alloying element. The same applies to the remaining subfractions, with the subfractions of group B differing with respect to four possible additional alloying elements.

[0074] A transport device 23, comprising a plurality of conveyor belts 21, 24, 25 and 30, is used to transport the material parts 4 from bunker 20 to the individual compartments 29. The conveyor belts 21, 24, 25 and 30 are arranged one behind the other in the transport direction from bunker 20 to the compartments 29.

[0075] By means of the transport device 23, the material parts 4 originating from bunker 20 are transferred into a continuous conveying stream, which is then subjected to a PGNAA.

[0076] Subsequently, the flow rate is directed to the individual subfractions A1 to C2 depending on the element determination obtained by the PGNAA.

[0077] The first conveyor belt 21 in the direction of transport is equipped with a belt scale 22. The belt scale 22 determines the weight of all material parts 4 discharged onto the first conveyor belt 21, so that the speed of the conveyor belt 21 can be adjusted accordingly to ensure a more even flow of material.

[0078] The conveyed material is transferred from the first conveyor belt 21 to a second conveyor belt 24. A detection unit 26 for performing a PGNAA (photon atomic nucleate analysis) is located here. For this purpose, the detection unit 26 has a neutron source 27 and a detector 28 arranged opposite the neutron source 27. In a manner known per se, the PGNAA results in an elemental determination corresponding to the chemical composition of the material components 4.

[0079] The analyzed material parts 4 are then transferred to another conveyor belt 25, to which further conveyor belts 30 are connected in the direction of transport. Each compartment 29 is assigned a conveyor belt 30. Thus, the first conveyor belt 30 in the direction of transport is assigned to sub-fraction A1, and the second conveyor belt 30 following in the direction of transport is assigned to sub-fraction A2, and so on.

[0080] The conveyor belts 30 are designed to be reversible in their direction of travel, meaning they can run clockwise as well as in the opposite direction.

[0081] By reversing the direction of travel of individual conveyor belts 30, the conveyed flow can be directed to individual compartments 29 and thus to individual subfractions.

[0082] Provided that all conveyor belts 30 rotate clockwise, the conveying flow is transferred from conveyor belt 30 to conveyor belt 30 until the last conveyor belt 30 in the direction of transport is reached, from where the conveying flow then falls into compartment 29 of subfraction C2.

[0083] As soon as the direction of rotation of one of the conveyor belts 30 is reversed, the material flow supplied to this conveyor belt 30 is no longer conveyed in the direction of transport, but in the opposite direction, with the result that it is transferred into the compartment 29 assigned to this conveyor belt 30. By changing the direction of rotation of the conveyor belts 30, a targeted allocation of the volume flow to the individual compartments 29 can therefore be carried out.

[0084] The direction of travel of the conveyor belts 30 is reversed depending on time and the transport speed. For example, if a specific average chemical composition of the conveyed stream is detected by the detection unit 26 for a runtime of, say, 10 seconds, the subfraction corresponding to this average chemical composition can be determined, and then it can be calculated how long it will take until the detected portion of the conveyed stream reaches the corresponding conveyor belt 30. Furthermore, it can be calculated how long the conveyor belt 30 must operate in the opposite direction once it reaches this conveyor belt 30, so that the previously detected portion of the conveyed stream can be fed into the corresponding compartment 29.

[0085] Fig. 3Finally, the device 1 according to the invention can be identified in a summary. As can be seen by way of example from this illustration, the material parts of both fractions F1 and F2, which originate from the first analysis unit 2, are each re-sorted by means of a second analysis unit 3. For this purpose, conveyor belts 19 are provided which feed the fractions F1 and F2 to their respective hoppers 20. From there, re-sorting then takes place in accordance with the descriptions based on Fig. 2 instead. It shows Fig. 2 the second analysis device 3 in schematic representation from the side, whereas with Fig. 3 A schematic view from above is shown. Reference sign

[0086] 1 Device 2 First analysis device 3 Second analysis device 4 Material section 5 Collection point 6 Feeding device 7 Feeding area 8 Upper section 9 Chute 10 Lower edge 11 Spectrometer system 12 Control device 13 Sorting unit 14 LIBS module 15 Laser device 16 Detection cone 17 Laser beam 18 Plasma detection area 19 Conveyor belt 20 Bunker 21 Conveyor belt 22 Belt scale 23 Transport device 24 Conveyor belt 25 Conveyor belt 26 Detection unit 27 Source 28 Detector 29 Compartment 30 Conveyor belt F1 / F1 Fraction A1-C2 Subfraction

Claims

1. Method for analyzing and sorting parts of material, in particular aluminum scrap parts, the method being carried out in two stages, wherein presorting takes place in a first stage and post-sorting takes place in a second stage, wherein, in a first step of the first stage, a specifiable material property of the parts of material (4) is determined by means of an analysis device (2) and the parts of material (4) are either fed to a first fraction (F1) or to a second fraction (F2), depending on the respectively determined material property, and wherein, in a first step of the second stage, the parts of material (4) of one of the two fractions (F1), (F2) are fed into a continuous conveying stream and subject to prompt gamma neutron activation analysis (PGNAA) and wherein, in a second step of the second stage, the conveying stream is directed to individual subfractions (A1 through C2) depending on an element determination obtained by the PGNAA.

2. Method according to claim, characterized in that both stages are carried out directly following each other.

3. Method according to claim 1 or 2, characterized in that the parts of material (4) of both fractions (F1, F2) are respectively subjected to PGNAA.

4. Method according to any one of the preceding claims, characterized in that the respective density, the absorption capacity, the chemical composition and / or the like of the parts of material (4) are chosen as a specifiable property of the parts of material (4).

5. Method according to claim 4, characterized in that, in the first step of the first stage, the respective chemical composition of the parts of material (4) is determined by verifying for each part of material (4) whether a specifiable chemical component is a constituent part of the part of material (4) and, in a second step of the first stage, the parts of material (4) are fed either to the first fraction (F1) or the second fraction (F2), depending on whether the specifiable chemical component is present as a constituent of the material component (4).

6. Method according to claim 5, characterized in that the determination of the chemical composition of the parts of material (4) takes place in the first stage by means of LIBS.

7. Method according to claim 5 or 6, characterized in that a characteristic component of a specific aluminum alloy is choses as a specifiable chemical component.

8. Method according to any one of the preceding claims 5 to 7, characterized in that in the second stage of element determination using PGNAA, especially alloying elements from the group consisting of Zn, Cu, Fe, and Mn are taken into account.

9. Device for analyzing and sorting parts of material, in particular aluminum scrap parts, the device comprising a first analysis device (2) and a second analysis device (3), wherein the first analysis device (2) is configured to determine a specifiable material property of the parts of material (4) and to feed the parts of material (4) to one of two fractions (F1, F2) using a sorting device (12), wherein the second analysis device (3) is configured to subject the parts of material (4) of one of the two fractions (F1, F2) to PGNAA and to feed the parts of material (4) to individual subfractions (A1 to C2) depending on a determination of elements using PGNAA.

10. Device according to claim 9, characterized in that the first analysis device (2) is configured to determine the chemical composition of the parts of material (4) by verifying for each part of material (4) whether a specifiable chemical component is a constituent part of the part of material (4).

11. Device according to claim 10, characterized in that the first analysis device (2) comprises: - a sorting unit (13) configured to feed the part of material (4) to one of two fractions (F1, F2), - a laser device (15) configured to generate a plasma on a surface of the part of material (4) by means of a laser beam (17) propagating along a beam axis, - a spectrometer system (11) configured to perform a spectral analysis of plasma light emitted by a plasma induced by the laser and to generate an output signal corresponding to a result of the spectral analysis performed, and - a control device (12) configured to receive the output signal and to operate the sorting unit (13) based on the output signal and a sorting criterion.

12. Device according to any one of the preceding claims 9 to 11, characterized in that the second analysis device (3) includes a detection unit (26) that has a neutron source (27) and a detector (28) positioned opposite the neutron source (27), or just a detector (28), wherein the detector (28) is arranged above, below or laterally of the conveyor belt (24).

13. Device according to any one of the preceding claims 9 to 12, characterized in that compartments (29) which are separate from each other are arranged downstream of the detection unit (26) in the transport direction of the transport device (23), wherein the compartments (29) each serve to receive parts of material (4) of a subfraction (A1 to C2).

14. Device according to claim 13, characterized in that each compartment (29) is assigned a continuous conveyor belt (30) that is arranged above the compartment (29) in the height direction.

15. Device according to claim 14, characterized in that the running direction of the conveyor belts (30) is reversible.