Method and system for determining waste metal batch composition considering differences between surface and internal composition - Patents.com

Abstract

This document describes a method for recycling aluminum alloy wheels. The method includes providing a supply of aluminum alloy wheels made from a particular alloy; fragmenting the aluminum alloy wheels into a plurality of pieces, with newly exposed surfaces in the plurality of pieces having an internal composition; determining a newly exposed surface signature to distinguish each newly exposed surface in the aluminum alloy wheel supply; determining an overall composition estimate by determining a plurality of composition measurements for the piece material in the plurality of pieces; and providing the plurality of pieces and the overall composition estimate for use in manufacturing at least one component formed from the aluminum alloy.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 856,818, filed June 4, 2019, which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE INVENTION The embodiments described herein relate to the field of recycling, and in particular to the field of recycling waste metals and determining batch compositions of recyclable waste metals. [Background technology]

[0003] In modern waste management, it is important to recycle what would otherwise be waste materials to form new materials or products. Many different materials can be recycled, such as glass, paper, cardboard, metal, plastic, tires, textiles, batteries, and electronics. Typical methods for recycling waste materials include picking, sorting, cleaning, and processing. Summary of the Invention [Means for solving the problem]

[0004] This Summary is intended to introduce the reader to various aspects of Applicant's teachings, but is not intended to limit the scope of any particular embodiment. Generally, disclosed herein are one or more methods for recycling waste metals.

[0005] In a first aspect, some embodiments of the present invention provide a method for recycling aluminum alloy wheels, the method including: (1) providing a supply of aluminum alloy wheels made of a particular alloy, each aluminum alloy wheel in the aluminum alloy wheel supply having a surface composition and an internal composition, the surface composition being the composition at an outer surface of the aluminum alloy wheel and the internal composition being the composition at an interior of the aluminum alloy wheel; (2) fragmenting the aluminum alloy wheels into a plurality of pieces, such that newly exposed surfaces of the plurality of pieces have the internal composition; (3) determining a newly exposed surface signature to distinguish each newly exposed surface in the aluminum alloy wheel supply from the outer surface; (4) determining a plurality of composition measurements for piece material in the plurality of pieces, at least some of the plurality of composition measurements being from the newly exposed surfaces of the plurality of pieces, and then determining an overall composition estimate by estimating the composition of the piece material based on the plurality of composition measurements for the piece material and the newly exposed surface signature; and (5) providing the plurality of pieces and the overall composition estimate for use in manufacturing at least one component formed from the aluminum alloy.

[0006] In some embodiments, the newly exposed surface index is a surface volume / internal volume of the aluminum alloy wheel supply determined based on the difference between the surface composition and the internal composition predicted for the aluminum alloy wheel supply.

[0007] In some embodiments, determining multiple composition measurements for a fragment material in the multiple fragments includes (1) heating the material to a point (temperature) at which the material emits a characteristic radiation (characteristic radiation) while cooling, (2) operating a sensor to detect the characteristic radiation, and (3) operating a processor to analyze the characteristic radiation to determine a composition measurement for the material.

[0008] In some embodiments, determining the surface / internal content of the aluminum alloy wheel supply includes, for each of at least one segment of an aluminum alloy wheel made from a particular alloy, (1) determining a surface composition of the segment; (2) determining an internal composition of the segment; and (3) determining the surface / internal content from the surface composition and the internal composition.

[0009] In some embodiments, the surface / internal amount includes a differentiation criterion for distinguishing surface composition measurements from internal composition measurements.

[0010] In some embodiments, determining the overall composition estimate includes, for each composition measurement of the plurality of composition measurements for the fragment material in the plurality of fragments, using a classification criterion that determines that the composition measurement is an internal composition measurement, and if the composition measurement is an internal composition measurement, using the composition measurement in determining the overall composition estimate, and if the composition measurement is not an internal composition measurement, determining the overall composition estimate without using the composition measurement.

[0011] In some embodiments, the surface / internal content further comprises a surface-internal correlation for calculating the internal composition of a fragment from the surface composition of the fragment.

[0012] In some embodiments, determining the overall composition estimate includes, for each of a plurality of composition measurements for the fragment material in the plurality of fragments, using a fractionation criterion to determine that the composition measurement is an internal composition measurement. If the composition measurement is an internal composition measurement, the composition measurement is used in determining the overall composition estimate without adjusting the composition measurement using surface-to-internal correlation. If the composition measurement is a surface composition measurement, the composition measurement is adjusted using surface-to-internal correlation when used to determine the overall composition estimate.

[0013] In some embodiments, the fractionation criteria include different fractionation criteria for different elements.

[0014] In some embodiments, segmenting the aluminum alloy wheel into a plurality of pieces further comprises shot blasting the plurality of pieces to remove non-aluminum impurities from the plurality of pieces.

[0015] In some embodiments, the fractionation criteria include an elemental concentration range for an element, and each composition measurement value of the plurality of composition measurements for the fragment material in the plurality of pieces includes an elemental measurement value for the element. In this embodiment, determining the overall composition estimate includes using the fractionation criteria to determine, for each composition measurement value of the plurality of composition measurements for the fragment material in the plurality of pieces, whether the elemental measurement value for that composition measurement value is an internal composition measurement value or a surface composition measurement value by determining whether the elemental measurement value for that composition measurement value is within an elemental concentration range for that element.

[0016] In some embodiments, the fractionation criteria include a plurality of elemental concentration ranges, and for each of the plurality of elements, the fractionation criteria includes an elemental concentration range for the element. Each composition measurement of the plurality of composition measurements for the fragment material in the plurality of pieces includes, for each of the plurality of elements, an elemental measurement value for the element. In this embodiment, determining the overall composition estimate includes using the fractionation criteria to determine, for each of the plurality of composition measurements for the fragment material in the plurality of pieces, whether the composition measurement value is an internal composition measurement value or a surface composition measurement value by determining, for each of the plurality of elements, whether the elemental measurement value for that composition measurement value is within the elemental concentration range for that element.

[0017] In some embodiments, the surface-to-interior correlation includes an elemental correlation for an element, and each composition measurement of the plurality of composition measurements for the fragment material in the plurality of fragments includes an elemental measurement for the element. In this embodiment, adjusting each surface composition measurement using the surface-to-interior correlation includes adjusting the elemental measurement based on the elemental correlation.

[0018] In some embodiments, the surface-to-interior correlation includes a plurality of elemental correlations, and for each of the plurality of elements, an elemental correlation for the element is included. In this embodiment, each composition measurement of the plurality of composition measurements for the fragment material in the plurality of fragments includes, for each of the plurality of elements, an elemental measurement for the element. In this embodiment, for each surface composition measurement, adjusting the composition measurement using the surface-to-interior correlation includes, for each of the plurality of elements, adjusting the elemental measurement based on the elemental correlation.

[0019] In some embodiments, segmenting the aluminum alloy wheel into a plurality of segments includes imparting at least a portion of the newly exposed surface indicia to the newly exposed surface.

[0020] According to some embodiments, a system for recycling aluminum alloy wheels includes: (1) a conveyor for providing a supply of aluminum alloy wheels made from a particular alloy, each aluminum alloy wheel in the aluminum alloy wheel supply having a surface composition and an internal composition, the surface composition being the composition at an outer surface of the aluminum alloy wheel and the internal composition being the composition at an interior of the aluminum alloy wheel; (2) a fragmentation device for receiving the aluminum alloy wheel supply from the conveyor and fragmenting the aluminum alloy wheels into a plurality of pieces, such that newly exposed surfaces of the plurality of pieces have the internal composition; and (3) a sensing device for sensing the plurality of pieces produced by the fragmentation device. (a) at least one sensor for determining a newly exposed surface indicator for distinguishing each newly exposed surface in the aluminum alloy wheel supply from an outer surface, and (b) a plurality of composition measurements for fragment material in the plurality of fragments, at least some of the plurality of composition measurements being derived from the newly exposed surfaces of the plurality of fragments; and (4) at least one processor for determining an overall composition estimate by estimating the composition of the fragment material based on the plurality of composition measurements and the newly exposed surface indicator for the fragment material, the processor being connected in communication with the at least one sensor.

[0021] In some embodiments, the system further includes a laser for heating a portion of at least one of the plurality of fractions to a point where the at least one portion emits a characteristic radiation while cooling. The at least one sensor includes a spectrometer for measuring the characteristic radiation. The spectrometer is communicatively connected to the at least one processor for communicating the measured characteristic radiation to the at least one processor. During operation, the one of the at least one processors analyzes the characteristic radiation to determine a composition measurement of the at least one fraction.

[0022] In some embodiments, the system further comprises a blast chamber for receiving the plurality of fragments from the fragmentation device and subjecting the plurality of fragments to shot blasting before the plurality of fragments are provided to the at least one sensor.

[0023] These and other advantages of the present invention will be more fully and completely understood from the following detailed description of embodiments and aspects of the invention taken in conjunction with the drawings. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a flow chart illustrating a method for determining a batch composition of a scrap metal flake supply.

[0025] [Figure 2] 1 is a flowchart illustrating a method for recycling aluminum alloy wheels.

[0026] [Figure 3] 3 is a flowchart showing an alternative method for recycling the aluminum alloy wheel shown in FIG. 2.

[0027] [Figure 4] 3 is a flowchart showing an alternative method for recycling the aluminum alloy wheel shown in FIG. 2.

[0028] [Figure 5] 3 is a flowchart showing an alternative method for recycling the aluminum alloy wheel shown in FIG. 2.

[0029] [Figure 6] 1 is a block diagram illustrating a system for recycling scrap metal pieces. DETAILED DESCRIPTION OF THE INVENTION

[0030] It will be appreciated that numerous specific details are set forth to provide a thorough understanding of the exemplary embodiments described herein. However, it will be understood by those skilled in the art that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the embodiments described herein. Furthermore, the description and drawings herein should not be construed in any way as limiting the scope of the embodiments described herein, but merely as illustrating the implementation of various embodiments described herein.

[0031] Referring initially to FIG. 1 , a method 100 for determining a batch composition of a scrap metal scrap supply is shown. The method 100 begins at step 102, in which a scrap metal scrap supply is provided. The scrap metal scrap provided in step 102 is made of a particular alloy type. For example, the scrap metal scrap supply may be an aluminum alloy supply. In other examples, the scrap metal scrap supply may be any one of a bismuth alloy, a brass alloy, a cobalt alloy, a copper alloy, a gallium alloy, a gold alloy, an indium alloy, an iron alloy, a lead alloy, a magnesium alloy, a mercury alloy, a nickel alloy, a potassium alloy, a silver alloy, a steel alloy, a tin alloy, a titanium alloy, a zinc alloy, a zirconium alloy, etc.

[0032] In some examples of the method 100, each piece of waste metal in the feed is made of the same alloy type, but each piece may have a composition that is different from the composition of at least one of the other pieces in the feed. In some examples, a piece may have one of two different compositions present in the feed. In other examples, a piece of waste metal may have one of any number of different compositions present in the waste metal feed. A batch of waste metal pieces has an overall or batch composition based on the different compositions of the different waste metal pieces and their relative masses. For example, if all the waste metal pieces were melted and mixed to provide a homogeneous mass or mixture, the overall or batch composition would be the composition of that homogeneous mixture. This batch composition of the waste metal piece feed may not be known when the waste metal pieces are initially fed.

[0033] This scrap metal supply may all come from the same type of component being recycled. For example, a supply of aluminum alloy wheels made from a particular alloy, such as aluminum alloy 356.2. Even though all the wheels are made from a particular alloy type, they may still vary slightly in composition. Also, some elements, such as iron and silicon, tend to migrate toward or away from the surface of the component being recycled, so there may be compositional variations within a particular fragment or scrap metal piece. Thus, the surface of the scrap metal pieces, which were the outer surfaces of the wheels from which these metal stem pieces came, may have higher or lower concentrations of elements, such as silicon, than would be measured within the interior of those pieces.

[0034] In step 104 of method 100, the scrap metal pieces are fragmented into a plurality of pieces. Fragmenting the scrap metal pieces can expose the interior surfaces of the scrap metal pieces. The interior surfaces of the scrap metal pieces can have a surface composition that is equal to or nearly equal to the interior composition of each scrap metal piece. Because the interior composition of the scrap metal pieces can more accurately represent the overall composition of the pieces, the batch composition of the scrap metal pieces can be more accurately estimated using measurements of the interior surface composition.

[0035] The surface composition of the outer surface may also differ from the inner composition because the outer surface may be oxidized, rusted, or doped with impurities during the original manufacturing process of the scrap metal pieces.

[0036] In step 106, a new exposed surface indicator is determined to distinguish each newly exposed surface in the scrap metal supply. Determining the new exposed surface indicator may be used to detect newly exposed surfaces during the remaining steps of method 100.

[0037] In one example, distinguishing each newly exposed surface involves fragmenting the scrap metal pieces in a way that allows the newly exposed surfaces to be geometrically distinguished from other, longer-exposed surfaces (which may have been surfaces of components to be recycled and therefore may have been exposed for a significantly longer period of time than the newly exposed surfaces). For example, if a piece is fragmented along its long axis, the long axis can provide a newly exposed surface indicator to indicate the newly exposed surface at a location midway between the two ends of the piece along the long axis. In a second example, a signature can be applied to the newly exposed surface of the fragmented scrap metal pieces during the fragmentation step. In this example, the location of the newly exposed surface can be determined by searching for and detecting the signature. The signature can be, for example, a specific shape, cut line, stamp, or pattern placed on the newly exposed surface of the piece. In a third example, described in more detail below, the newly exposed surface indicator can be a surface volume / internal volume.

[0038] In step 108 of method 100, an estimate of the overall composition of the scrap metal scrap supply is determined. The estimate of the overall composition may be determined by taking multiple composition measurements for the fragment material in the multiple fragments at the newly exposed surface and calculating an average composition. The composition measurement for the fragment material may be estimated based on the multiple composition measurements for the fragment material and the newly exposed surface indicator.

[0039] For example, suppose the composition of a piece of material is measured at the surface of the piece. If the newly exposed surface indicator is used to identify the surface on which the composition measurement was made as a newly exposed surface, the composition measurement can be classified as an internal composition measurement that can be used in calculating the average composition without adjusting the measured composition value. However, if the newly exposed surface indicator is used to identify the surface on which the composition measurement was made as a newly exposed surface, the composition measurement for the piece of material can be classified as an external surface composition measurement using the newly exposed surface indicator, and the composition measurement can be ignored or adjusted when determining the batch composition, because the external surface composition does not accurately reflect the internal composition. In some embodiments, the newly exposed surface indicator can be the composition measurement itself, such that whether a surface is a newly exposed surface can be determined from the composition measurement itself based on the concentrations of different elements, such as iron and silicon, as described in more detail below.

[0040] In some examples of method 100, a laser scanner can be used to determine composition measurements. This may involve using a laser to heat material at a point on the surface of the piece to a temperature where the material emits characteristic radiation while cooling. A sensor can then be operated to detect the characteristic radiation and provide a spectrum of signal magnitude at various frequencies. This spectrum of signal magnitude at various frequencies can then be analyzed by a computer processor to estimate the relative concentrations of various elements in the alloy. This is described, for example, in U.S. Pat. No. 10,220,418, which is incorporated herein by reference.

[0041] In one example of method 100, a "Laser-Induced Breakdown Spectroscopy" ("LIBS") composition analyzer manufactured by Laser Distance Spectrometry can be applied as a laser scanner and sensor. The LIBS composition analyzer can include a radiation emitter, such as a Nd:YAG laser. The laser emits light in the frequency range of 1 to 20 hertz, thereby raising the temperature of the fragment at the contact point between the fragment and the laser to above 30,000 degrees Celsius and generating a plasma. The plasma rapidly cools, returning the excited ions to a lower energy state. Upon returning to the lower energy state, the ions emit characteristic radiation. The LIBS composition analyzer can include one or more sensors that detect the characteristic radiation. The sensor measurements are then analyzed by a processor, and the results can be used to determine the concentrations of components contained in the material undergoing the temperature change. The processor can be located within the composition analyzer. Alternatively, the processor can be a remote processor.

[0042] Other suitable composition analyzers may include those that use other systems that rely on laser spectroscopy or other methods to induce characteristic radiation emitted by each fragment material at the surface of the fragment and then detect and analyze the characteristic radiation to determine the composition of the material. The composition analyzer may detect the characteristic radiation by using any suitable sensor. Suitable sensors may include, for example, complementary metal-oxide semiconductor (CMOS), high-density short-channel metal-oxide semiconductor (HMOS), charge-coupled device (CCD), and other types of sensors.

[0043] A suitable composition analyzer may, for example, use a radiation emitter such as a plasma or electron beam, or any other radiation emitter suitable for heating each piece of material at at least one point on the surface of the piece to a point where the material emits a characteristic radiation of sufficient quantity and quality during cooling to enable a sensor to detect the characteristic radiation and a processor to determine the composition of the material from the characteristic radiation. The composition analyzer may be adapted to withstand continuous use and typical conditions that may be present in certain aluminum alloy rim recycling operations. Such conditions may include vibrations resulting from operation of the aluminum alloy rim transport mechanism and dust and other particles generated in the recycling process.

[0044] Referring to Figure 2, a method 200 for recycling aluminum alloy wheels is shown therein. The method 200 for recycling aluminum alloy wheels is an application of the method 100 for determining a batch composition of a scrap metal scrap feed. Thus, any of the examples discussed below may be applied to the method 100, and any of the examples discussed above with reference to the method 100 may be applied to the method 200. Furthermore, the discussion below is not meant to limit the methods described herein to recycling aluminum alloy wheels. For example, the methods described herein may be applied to methods for recycling steel alloys, copper alloys, or any other suitable metallic objects.

[0045] In step 202 of method 200, a supply of aluminum alloy wheels made from a particular alloy is provided. Similar to the scrap metal products described above, although aluminum alloy wheels are made from a particular alloy, the composition of the wheels may vary. Thus, the overall composition of a batch of aluminum alloy wheels may not be known when the batch is first provided.

[0046] In step 204, the aluminum alloy wheel is fragmented into a plurality of pieces. As described above, fragmenting the aluminum alloy wheel exposes new surfaces, which may have a surface composition approximately equal to the internal composition of each of the aluminum alloy wheels. In some examples, step 204 may include shot blasting the plurality of pieces to remove non-aluminum impurities from the plurality of pieces.

[0047] In step 206 of method 200, a new exposed surface index is determined to distinguish each newly exposed surface in the aluminum alloy wheel supply. The new exposed surface index may be determined as described above. In some examples, the new exposed surface index may be a surface volume / internal volume for the aluminum alloy wheel supply. The surface volume / internal volume may be determined based on the difference between the predicted surface composition and the internal composition for the aluminum alloy wheel supply. The surface volume / internal volume is described in more detail below.

[0048] In step 208, an estimate of the overall composition of the batch is determined. In some examples of method 200, as described above with reference to method 100, the estimate of the overall composition may be determined by obtaining multiple composition measurements for the fragment material in the multiple fragments at their newly exposed surfaces and calculating an average composition of these composition measurements. The composition measurement for the fragment material may be estimated based on the multiple composition measurements for the fragment material and the newly exposed surface indicator.

[0049] 3, in some examples of method 200, determining multiple composition measurements for the piece material in the multiple pieces, i.e., step 208, may include heating the material to a point where the material emits a characteristic radiation while cooling. Step 208 may further include operating a sensor to detect the characteristic radiation and operating a processor to analyze the characteristic radiation to determine a composition measurement for the material.

[0050] 2, after the overall composition estimate is determined, the plurality of pieces may be provided along with the overall composition estimate for use in manufacturing at least one component formed from the aluminum alloy in step 210. For example, if the overall composition of the batch is determined to be suitable for manufacturing motorcycle wheels, the batch may be recycled into motorcycle wheels. If the overall composition of the batch is determined to be suitable for manufacturing semi-truck wheels, the batch may be recycled into semi-truck wheels.

[0051] By determining batch composition using the methods described herein, melting and mixing of the pieces to determine the batch composition is unnecessary. Not having to melt and mix the pieces to determine the batch composition can increase the efficiency of the recycling process. For example, if the recycling facility and the wheel manufacturing facility are different entities in different locations, the pieces may otherwise have to be melted twice, increasing the cost of the recycling process because (1) the pieces must be melted at the recycling facility to determine the batch composition, and (2) the pieces must be melted at the manufacturing facility during the molding / die-casting process. Alternatively, by utilizing the methods described herein, the pieces may only need to be melted once at the manufacturing facility, where fine-tuning of the batch composition can be performed as needed. The pieces can be provided by the recycling facility to the manufacturing facility along with the batch composition, allowing the manufacturing facility to make the best decisions about how to use the pieces and, if desired, what other materials to combine them with.

[0052] Referring to FIG. 4 , as described above, in step 206, the new exposed surface index can be the surface / internal volume for the aluminum alloy wheel supply. The surface / internal volume for the aluminum wheel supply can be determined based on the difference between the predicted surface composition and the internal composition for the aluminum alloy wheel supply. For example, to determine the surface / internal volume for the supply, first, in step 206a, the outer surface composition of at least one piece can be determined; second, in step 206b, the internal composition of at least one piece can be determined; and third, in step 206c, the surface / internal volume for each piece can be determined from the surface composition and the internal composition of the piece. The batch surface / internal volume, i.e., the new exposed surface index, can be determined from the surface / internal volume of each piece, for example, by averaging. The surface / internal volume can be used to determine whether a composition measurement is an inner surface measurement or an outer surface measurement depending on how the measurement compares to the surface / internal volume, so the surface / internal volume can be the new exposed surface index.

[0053] In some examples, the surface / internal amounts may include compositional measurements of individual elements found within the aluminum alloy wheel, such as silicon, while in other examples, the surface / internal amounts may include a spectrum of the composition of all of the individual elements, or a subset of the individual elements, found within the aluminum alloy wheel.

[0054] In some examples of method 200, the surface / internal quantities may include a differentiation criterion for distinguishing surface composition measurements from internal composition measurements. For example, an aluminum alloy wheel made of a particular alloy may be determined to typically have an internal silicon composition ranging from X to Y and an external surface silicon composition ranging from A to B. These ranges, or differentiation criteria, can be used to identify whether a composition measurement is an internal or external surface composition measurement. The surface / internal quantities may be a representation of an individual element, as described above, or may be a representation of a spectrum of elements found within the aluminum alloy wheel. In examples with differentiation criteria for individual elements, there may be more than one differentiation criterion, and the differentiation criterion may vary depending on the element. For example, in addition to an internal silicon composition range and an external silicon composition range, an aluminum alloy wheel made of a particular alloy may be determined to typically have an internal iron composition ranging from X' to Y' and an external surface iron composition ranging from A' to B'.

[0055] In an example of method 200 in which the fractionation criteria include an elemental concentration range for a particular element, each of the plurality of composition measurements for the fragment material in the plurality of fragments determined in step 208 can include an elemental measurement value for that element. Thus, in this example, determining the overall composition estimate can include using the fractionation criteria to determine, for each of the plurality of composition measurements for the fragment material in the plurality of fragments, whether the composition measurement is an internal or surface composition measurement. Whether a composition measurement is an internal or surface composition measurement can be determined by determining whether the elemental measurement value for that composition measurement is within an elemental concentration range for that element. In other examples, the fractionation criteria can include multiple elemental concentration ranges, or spectra, and each composition measurement can include one measurement value for multiple elements, and the fractionation criteria can be used to estimate the overall composition to determine whether the composition measurement is an internal or external surface composition measurement, thereby calculating the overall internal composition.

[0056] In summary, in some examples, referring to, for example, FIG. 5 , determining an overall composition estimate in step 208 of method 200 may include: (a) step 208a using a discrimination criterion to determine whether the composition measurement is an internal composition measurement; (b) step 208b using the composition measurement in determining the overall composition estimate when the composition measurement is an internal composition measurement; and (c) step 208c determining an overall composition estimate without using the composition measurement when the composition measurement is not an internal composition measurement.

[0057] In other examples of method 200, the surface / internal amount can include a surface-to-internal correlation for calculating the internal composition of a fragment from its surface composition. In these embodiments, just because a composition measurement is not an internal composition measurement does not mean that the composition measurement is not used to determine an overall composition estimate; instead, an estimate of the internal composition can be provided by multiplying or dividing the external surface composition measurement by the surface-to-internal correlation, thereby determining an overall composition estimate. For example, it may be found that the concentration of element "A" for an internal composition measurement is typically about 90% of the concentration of element "A" in the external surface composition measurement. In this case, if a particular composition measurement is classified as an external surface composition measurement (e.g., using a classification standard), it can be adjusted by multiplying it by 0.9 before using it to determine an overall composition estimate. In other examples of method 200 that include an elemental correlation for elements with surface-to-internal correlation, when a surface measurement is detected, the composition measurement can be adjusted by using the surface-to-internal correlation based on the elemental correlation.

[0058] In yet another example of method 200, the surface-to-interior correlation can include a plurality of elemental correlations, including an elemental correlation for each of a plurality of elements. In this example, each of the plurality of composition measurements for the fragment material in the plurality of fragments can include an elemental measurement for each of a plurality of elements. Thus, for each surface composition measurement, adjusting the composition measurement using the surface-to-interior correlation can include adjusting the elemental measurement for each of the plurality of elements based on the elemental correlation. For example, it may be found that the concentration of element "A" for the interior composition measurement is typically about 90% of the concentration of element "A" in the outer surface composition measurement, while the concentration of element "B" for the interior composition measurement is typically about 95% of the concentration of element "B" in the outer surface composition measurement. Finally, it may be found that the concentration of element "C" for the interior composition measurement is typically about 110% of the concentration of element "C" in the outer surface composition measurement. In this case, if a particular composition measurement is classified as an exterior surface composition measurement, it may be adjusted by multiplying its element "A" concentration by 0.9, its element "B" concentration by 0.95, and its element "C" concentration by 1.1 before using these measurements to determine the overall composition estimate.

[0059] In yet another example of method 200, determining the overall composition estimate can include (a) using a classification criterion to determine whether the composition measurement is an exterior surface composition measurement; (b) when the composition measurement is an exterior surface composition measurement, using the composition measurement in determining the overall composition estimate; and (c) when the composition measurement is not an exterior surface composition measurement, determining the overall composition estimate without using the composition measurement. In this example of method 200, for each exterior surface composition measurement, the surface-to-interior correlation can be used to calculate the corresponding interior composition of the piece having that exterior surface composition measurement. That is, as described above, for each element in the plurality of element correlations of the surface-to-interior correlation, and for each exterior surface composition measurement, the exterior surface composition measurement of that element can be adjusted by multiplying the exterior surface composition measurement by the corresponding element correlation in the plurality of element correlations of the surface-to-interior correlation.

[0060] According to these three aspects of the present invention, an overall composition estimate can be determined based on i) internal composition measurements alone, ii) external surface composition measurements alone, or iii) both internal and external surface composition measurements. In all three aspects, the internal and external surface composition measurements can be distinguished from each other using a differentiation criterion. In aspects ii) and iii), where external surface composition measurements are used to determine the overall composition estimate, these external surface composition measurements can be adjusted by multiplying the external surface composition measurements by the corresponding element correlation in a surface-to-internal correlation.

[0061] 6, there is shown a block diagram of a system for recycling waste metal pieces 300. As shown, the system for recycling waste metal pieces 300 may include a conveyor 302, a fragmentation device 304, at least one sensor 306, and at least one processor 308.

[0062] Conveyor 302 provides a supply of scrap metal pieces, such as, but not limited to, aluminum alloy wheels made from a particular alloy. The scrap metal pieces are placed on conveyor 302 by any suitable means, such as, but not limited to, a truck that deposits the scrap metal pieces into a hopper connected to one end of conveyor 302, or manually by an operator who places the scrap metal pieces on the conveyor. As discussed above with reference to FIGS. 1-5 , each scrap metal piece provided by conveyor 302 has a surface composition and an internal composition. The surface composition is the composition of the outer surface of the scrap metal piece, i.e., the surface that has been exposed for some time, which may be, for example, the outer surface of a component to be recycled. The internal composition may be the composition of the interior of the scrap metal piece. This internal composition measurement may be derived from the interior of the component to be recycled.

[0063] In some examples of the system 300 for recycling scrap metal pieces, the fragmenter 304 receives the scrap metal piece feed from the conveyor 302. The fragmenter 304 can fragment the scrap metal pieces into multiple pieces, with newly exposed surfaces of the multiple pieces having an internal composition. In some examples, the fragmenter can be a shredder or cutter that uses multiple blades to cut the scrap metal pieces into multiple pieces. In other examples, the fragmenter can be a water jet cutter. In some examples, the cutting pattern can be random, and in other examples, the cutting pattern can be designed to place a signature on each of the multiple pieces.

[0064] At least one sensor 306 of system 300 may be used to sense the plurality of fragments fragmented by the fragmentation device and (1) determine a newly exposed surface signature for distinguishing each newly exposed surface in the aluminum alloy wheel supply, and (2) determine a plurality of compositional measurements for various fragment materials in the plurality of fragments. At least some of the plurality of compositional measurements may be derived from the newly exposed surfaces of the plurality of fragments. As noted above, in some examples of system 300, at least one sensor 306 may comprise a laser spectroscopy device. In other examples, at least one sensor 306 may comprise a system for locating and detecting a signature disposed on each fragment of the plurality of fragments during fragmentation. In yet another example, at least one sensor 306 may comprise a system for detecting the largest surface of the fragment.

[0065] At least one processor 308 of the system 300 is used to determine an overall composition estimate by estimating the composition of the fraction material based on multiple composition measurements and the newly exposed surface indicia for the fraction material. The at least one processor 308 can be communicatively coupled to the at least one sensor 306.

[0066] In examples where the at least one sensor 306 includes a laser spectroscopy device, the system may also include a laser 310 for heating a portion of the scrap metal pieces to a point where the material emits a characteristic radiation while cooling. In this example, the laser spectroscopy device may be connected to at least one processor 308 for measuring the characteristic radiation, analyzing the characteristic radiation, and determining a composition measurement of the material. In some examples, the laser spectroscopy device may include a first processor of the at least one processor 308. The first processor may analyze the spectrum and determine the percentage composition of various elements. A second processor, separate from the first processor of the at least one processor 308, may determine the overall batch composition. Alternatively, a single processor 308 may analyze the spectrum, determine the percentage composition of various elements, and further determine the overall batch composition.

[0067] The system 300 for recycling waste metal pieces may also include a blast chamber 312. Within the blast chamber 312, an abrasive material such as shot is propelled toward the waste metal pieces to clean their surfaces (shot blasting). Collision between the shot and these surfaces can remove debris from the surfaces. Debris removed by shot blasting can include paint, clear coat, and organic compounds such as rubber, as well as copper and chrome. In some examples of the system 300, the blast chamber 300 can be a centrifugal blasting device. ½-inch or larger S330 steel shot can be used.

[0068] The centrifugal blasting apparatus may include a housing that completely encloses a conveying means formed of a plurality of flights extending across an endless chain for movement along a predetermined path. The housing may be divided into four compartments, including an entrance chamber, two blast chambers, and a shakeout chamber. The flights in the blast chamber may be formed from blast-resistant manganese rod, while the flights in the shakeout and entrance chambers may be formed from a less expensive, lighter material. Debris removed from the waste metal pieces may be discharged from the shakeout chamber and removed from the system, and the spent abrasive may be recycled back to the blast wheel.

[0069] The present invention has been described herein by way of example only. Various changes and modifications can be made to these exemplary embodiments without departing from the spirit and scope of the invention, which is limited only by the appended claims.

Claims

1. 1. A method for recycling aluminum alloy wheels, the method beginning with a feeding step, and proceeding through a fragmentation step, an index determination step, a composition measurement detection step, an overall composition estimation step, and a regeneration step; the providing step comprising providing a supply of aluminum alloy wheels made from a particular alloy, each aluminum alloy wheel of the aluminum alloy wheel supply having a surface composition and an interior composition, the surface composition being the composition at an exterior surface of the aluminum alloy wheel and the interior composition being the composition at an interior of the aluminum alloy wheel; the fragmenting step occurs after the providing step, fragmenting the aluminum alloy wheel into a plurality of pieces, exposing an interior of the aluminum alloy wheel supply by fragmenting, and wherein newly exposed surfaces of the plurality of pieces have the interior composition; the index determining step is performed after the fragmenting step, and includes determining a newly exposed surface index for distinguishing each newly exposed surface in the aluminum alloy wheel supply from the outer surface; the composition measurement detection step is performed after the fragmentation step, and includes determining a plurality of composition measurements of fragment material in the plurality of fragments, at least some of the plurality of composition measurements being derived from newly exposed surfaces in the plurality of fragments fragmented in the fragmentation step; The overall composition estimation step is performed after the indicator determination step and the composition measurement detection step, and is a step of determining an overall composition estimate by estimating the composition of the fragment material based on the plurality of composition measurements of the fragment material detected in the composition measurement detection step and the newly exposed surface indicator determined in the indicator determination step; the regeneration step is performed after the overall composition estimation step, and is a step of providing a plurality of the fractional materials, for which the overall composition estimates have been determined, together with their overall composition estimates for use in manufacturing at least one component formed of an aluminum alloy; method.

2. the newly exposed surface index is a surface / internal amount for the aluminum alloy wheel supply determined based on a difference between the surface composition and the internal composition predicted for the aluminum alloy wheel supply; The method of claim 1.

3. Determining the plurality of composition measurements of the fragment material for the plurality of fragments includes heating the fragment material to a point where the fragment material emits a characteristic radiation while cooling, operating a sensor to detect the characteristic radiation, and operating a processor to analyze the characteristic radiation to determine the composition measurements of the fragment material. The method of claim 2.

4. Determining the surface / internal content for the aluminum alloy wheel supply includes, for each of at least one section of the aluminum alloy wheels made from the particular alloy, determining the surface composition of the fragment; determining the internal composition of the fragment; determining the surface amount / internal amount from the surface composition and the internal composition; The method according to claim 2 or 3.

5. The method of claim 4 , wherein the surface / internal quantities include a discrimination criterion for distinguishing surface composition measurements from internal composition measurements.

6. Determining the overall composition estimate includes, for each of a plurality of the composition measurements of the fraction material for the plurality of fractions, using the discrimination criteria to determine that the composition measurement is an internal composition measurement; when the composition measurement is an internal composition measurement, using the composition measurement in determining the overall composition estimate; and when the composition measurement is not an internal composition measurement, determining the overall composition estimate without using the composition measurement. The method according to claim 5.

7. The surface amount / internal amount further includes a surface-internal correlation for calculating the internal composition of a fragment from the surface composition of a fragment. The method according to claim 5.

8. Determining the overall composition estimate includes, for each of a plurality of the composition measurements of the fraction material for the plurality of fractions, using the discrimination criteria to determine that the composition measurement is an internal composition measurement; when the composition measurement is an internal composition measurement, using the composition measurement in determining the overall composition estimate without adjusting the composition measurement using the surface-to-internal correlation; if the composition measurement is a surface composition measurement, adjusting the composition measurement with the surface-to-internal correlation when using the composition measurement to determine the overall composition estimate; The method of claim 7, comprising:

9. The fractionation criteria include different fractionation criteria for different elements; The method according to claim 5.

10. and wherein segmenting the aluminum alloy wheel into a plurality of segments further comprises shot blasting the plurality of segments to remove non-aluminum impurities from the plurality of segments. The method according to claim 1 or 2.

11. The separation criteria include an elemental concentration range for an element; each composition measurement of the plurality of composition measurements of the fraction material in the plurality of fractions includes an elemental measurement for the element; determining the overall composition estimate includes using the fractionation criteria to determine, for each of the plurality of composition measurements of the fragment material in the plurality of fragments, whether the composition measurement is an internal composition measurement or a surface composition measurement by determining whether the elemental measurement for that composition measurement is within the elemental concentration range for that element. The method according to claim 5.

12. The separation criteria include a plurality of elemental concentration ranges, the elemental concentration ranges including an elemental concentration range for each of the plurality of elements; each composition measurement of the plurality of composition measurements for the fragment material in the plurality of fragments includes, for each of a plurality of elements, an elemental measurement for the element; determining the overall composition estimate includes using the fractionation criteria to determine, for each of a plurality of the composition measurements of the fragment material in the plurality of fragments, whether the composition measurement is an internal composition measurement or a surface composition measurement by determining, for each of a plurality of elements, whether the elemental measurement for that composition measurement is within the elemental concentration range for that element; The method according to claim 5.

13. The surface-internal correlation includes an element correlation for an element; each composition measurement of the plurality of composition measurements for the piece material in the plurality of pieces includes an elemental measurement for the element; and for each surface composition measurement, adjusting the composition measurement using the surface-to-interior correlation includes adjusting the elemental measurement based on the elemental correlation. The method of claim 7.

14. The surface-internal correlation includes a plurality of element correlations, the element correlation including, for each of the plurality of elements, an element correlation for the element; each composition measurement of the plurality of composition measurements for the fragment material in the plurality of fragments includes, for each of a plurality of elements, an elemental measurement for the element; and for each surface composition measurement, adjusting the composition measurement using the surface-to-interior correlation includes, for each of a plurality of elements, adjusting the elemental measurement based on the elemental correlation. The method of claim 7.

15. and segmenting the aluminum alloy wheel into a plurality of segments includes imparting at least a portion of the newly exposed surface indicia to the newly exposed surface. The method of claim 1.

16. A system for recycling aluminum alloy wheels using the method of claim 1, comprising: a conveyor for providing a supply of aluminum alloy wheels made from a particular alloy, each aluminum alloy wheel in the supply having a surface composition and an interior composition, the surface composition being the composition at an exterior surface of the aluminum alloy wheel and the interior composition being the composition at an interior of the aluminum alloy wheel; a fragmentation device for receiving the aluminum alloy wheel supply from the conveyor and fragmenting the aluminum alloy wheels into a plurality of segments, the newly exposed surfaces of the plurality of segments having the internal composition; at least one sensor for detecting the plurality of fragments produced by the fragmentation device; determining a newly exposed surface index for distinguishing each newly exposed surface in said aluminum alloy wheel supply from said outer surface; a sensor that determines a plurality of compositional measurements for fragment material in the plurality of fragments, at least some of the plurality of compositional measurements being derived from newly exposed surfaces of the plurality of fragments; at least one processor configured to determine an overall composition estimate by estimating a composition of the fragment material of the fragment based on a plurality of the composition measurements and the newly exposed surface indicator for the fragment material of the fragment, the processor being communicatively connected to at least one of the sensors; A system including:

17. a laser for heating a portion of at least one of the plurality of segments to a point where the at least one portion emits a characteristic radiation while being cooled; At least one of the sensors includes a spectrometer for measuring the characteristic radiation; the spectrometer is communicatively coupled to at least one of the processors for communicating the measured characteristic emissions to the at least one of the processors; and wherein one of the at least one processors, during operation, analyzes the characteristic radiation to determine the composition measurement of at least one fraction.

17. The system of claim 16.

18. a blast chamber for receiving the plurality of fragments from the fragmentation device and for subjecting the plurality of fragments to shot blasting prior to providing the plurality of fragments to the at least one sensor.

17. The system of claim 16.

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