System and method for recycling magnetic materials and rare earth elements contained therein

Abstract

Methods and systems are disclosed for extracting magnetic materials from magnet-containing materials and for extracting rare earth elements (REEs) from magnetic materials. Exemplary systems include a grinding / washing unit for magnet-containing materials such as used motors, hard drives, partially disassembled motors, magnet-containing used products, or parts thereof, and output magnetic components by taking advantage of the magnetic properties of ferromagnetic and paramagnetic materials in the presence and absence of an electromagnetic field, along with other physical properties such as size and density. The system also includes a chemical processing unit that receives the magnetic components to extract rare earth elements from the materials. A chemical process for separating rare earth elements from the magnetic components is disclosed.

Description

Technical Field

[0001] The present disclosure generally relates to recycling, and more particularly to systems and methods for recycling magnets and valuable elements contained therein, including rare earth elements.

Background Art

[0002] Many elements contained in such materials, including magnetic materials and rare earth elements (REEs), are playing an increasingly important role in the manufacture of many tools necessary for the prosperity of advanced economies, from smartphones and high-performance magnets to electric vehicles.

[0003] The availability of REEs is constrained by increasing demand and insufficient production capacity, and as a result, the world economy is at increasing risk of facing a severe shortage of rare earth elements.

[0004] In addition, as the importance of climate change increases, there is also a growing recognition that green technologies will be more widely adopted as the only means of achieving sustainability in energy production and consumption.

[0005] Therefore, the recycling of valuable materials contained in magnets, such as but not limited to rare earth elements, alleviates and complements the above-mentioned problems. Recycling is an inherently sustainable resource production method and significantly reduces the need for new sources of REEs. As a result, supply chain constraints are eased.

[0006] One of the main challenges in the recycling of rare earth elements is the cost required to purify the mixtures obtained from consumer devices and other waste devices containing REEs.

[0007] Therefore, it is desirable to improve the recovery and recycling of important rare earth elements in order to mitigate the environmental impact of the global energy transition.

Summary of the Invention

[0008] According to one aspect of the present invention, a system for generating a magnet concentrate containing rare earth elements is provided. The system includes: i) a size reduction unit for receiving a disposed waste containing a magnetic material and outputting a mixed scrap, the mixed scrap containing a magnetic component and a non-magnetic component; ii) a target magnetic material extraction block for receiving the mixed scrap and separating it into a target magnetic material and a non-target material; and iii) a chemical treatment unit including: a) an input section for receiving a mixed feed containing the target magnetic material; b) an acid leaching unit for acid leaching the mixed feed; c) a rare earth element removal unit for precipitating and removing rare earth elements from the mixed feed as oxalates, carbonates, or other rare earth salts; d) a firing unit for firing the rare earth salts into rare earth oxides; and e) one or more particle removal units for: 1) iron removal by pH adjustment and precipitation; 2) removal of one or more of nickel, cobalt, and other transition metals by solvent extraction, pH adjustment, and precipitation as hydroxides; 3) copper removal by precipitation, solvent extraction, or ion exchange; 4) boron removal by solvent extraction or ion exchange, wherein the target magnetic material includes rare earth elements contained in magnets such as, but not limited to, neodymium magnets and samarium cobalt magnets, and cobalt and / or nickel contained in magnets such as, but not limited to, aluminum nickel cobalt magnets, or any combination thereof, and boron removal.

[0009] According to another aspect, a method for obtaining rare earth elements is provided. The method includes: (i) crushing a mixed scrap material containing magnets into a crushed material of a predetermined size; (ii) capturing the dust generated by crushing with a dust collector; (iii) remagnetizing the crushed material; (iv) vibrating the crushed material to promote mixing; (v) passing the crushed material over a set of N sieves to produce N + 1 product fragments, the fragments including an oversized fragment containing a first set of magnet blocks and a fine dust fragment; (vi) combining the fine dust fragment with the dust from the dust collector to form a dust stream; (vii) passing the dust stream through a circuit including remagnetization-aggregation-screening to output fine particles including a second set of magnet blocks; (viii) briefly crushing the magnetic mass and then screening to capture the magnetic material in the small-sized fragments of the sieve as a mixed feed; (ix) subjecting the mixed feed to acid leaching; (x) removing rare earth elements by precipitation as oxalates, carbonates, or other rare earth salts; (xi) firing the rare earth salts into rare earth oxides; (xii) removing iron by pH adjustment, temperature adjustment, and precipitation; (xiii) removing one or more of nickel and cobalt by solvent extraction, pH adjustment, and precipitation as oxides or hydroxides; (xiv) removing copper by precipitation or solvent extraction; and (xv) removing boron by solvent extraction or ion exchange.

[0010] According to yet another aspect of the present disclosure, there is provided a system comprising: (i) a size reduction unit for receiving one or more of a magnet-containing used product, a discarded electric motor (including subcategories known as ELMOs), a hard disk drive, and a meatball (also known as SHELMO, a partially disassembled or cut electric motor) and outputting a mixed scrap having a magnetic component and a non-magnetic component; and (ii) a target magnetic material extraction block for receiving the magnetic component and separating the magnetic component into a target magnetic material and a non-target material, the target magnetic material being a final product to be processed separately.

[0011] According to yet another aspect of the present disclosure, a method for preparing a magnet concentrate is provided. The method includes obtaining a feed material containing a magnetic material, where the magnetic material includes a ferromagnetic material and a non-ferromagnetic material, reducing the size of the feed material, separating the feed material of reduced size into a ferromagnetic material and a non-ferromagnetic material, and separating the ferromagnetic material into a target magnetic material concentrate (also referred to as a "magnet concentrate") and a non-target magnetic material-deficient scrap.

[0012] According to yet another aspect, a method for preparing a magnet concentrate is provided. The method includes grinding a mixed scrap material containing magnets into a ground material of a predetermined size, capturing the dust generated by the grinding in a dust collector, remagnetizing the ground material, vibrating the ground material to promote mixing, passing the ground material over a set of N sieves to produce N + 1 product fragments, where the fragments include an oversize fragment containing a first set of magnet chunks and a fine dust fragment, combining the fine dust fragment with the dust from the dust collector to form a dust stream, passing the dust stream through a circuit including remagnetization-aggregation-screening to output fine particles containing a second set of magnet chunks, rapidly grinding and screening the magnet chunks to collect the minimum size fragments as the target magnetic material concentrate, and combining the fine particles to form the magnet concentrate, including one or more of these steps.

[0013] According to another aspect of the present disclosure, a system for obtaining rare earth elements is provided, comprising (i) a grinding / washing block for receiving swarf and discarded magnet material and outputting a magnetic component, and (ii) a chemical treatment unit for receiving the magnetic component from one or more of a target magnetic material extraction block and the grinding / washing unit and extracting rare earth elements from the material.

[0014] In another aspect, a process for obtaining rare earth elements from a mixed feed is provided, the method comprising acid leaching the mixed feed, removing the rare earth elements by precipitation as oxalates, carbonates, or other rare earth salts, firing the rare earth salts to rare earth oxides, removing iron by pH adjustment and precipitation, removing one or more of nickel, cobalt, and other transition metals by solvent extraction, pH adjustment, and precipitation as hydroxides, removing copper by precipitation, solvent extraction, or ion exchange, and removing boron by solvent extraction, ion exchange, or precipitation.

[0015] Other technical advantages may become readily apparent to those skilled in the art after consideration of the following drawings and description.

Brief Description of the Drawings

[0016] To better understand the embodiments described herein and to more clearly show how the embodiments can be implemented, reference is made herein to the accompanying drawings by way of example only.

[0017]

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[0018] Unless otherwise specified, the articles depicted in the drawings are not necessarily drawn to scale.

Best Mode for Carrying Out the Invention

[0019] The disclosed technology processes various used devices and captures value from the contents of the materials contained therein. Such devices include, but are not limited to, electric motors, hard drives, and / or meatballs (partially disassembled motors), and any magnet-containing used products or parts thereof.

[0020] For simplicity and clarity of explanation, where appropriate, reference numerals may be repeated between the drawings to indicate corresponding or similar elements. Further, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments described herein. However, it will be understood by those of ordinary skill 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. Exemplary embodiments are illustrated in the drawings and described below, but it should first be understood that the principles of the present disclosure may be implemented using any number of techniques, whether currently known or not. The present disclosure should in no way be limited to the exemplary embodiments and techniques shown in the drawings and described below.

[0021] Throughout this specification, various terms are to be read and construed as follows, unless the context indicates otherwise. The "or" used throughout is inclusive as if written "and / or". The singular articles and pronouns used throughout include their plural forms and vice versa. Similarly, gender pronouns include their corresponding pronouns, so pronouns should not be construed as limiting anything described herein to use, implementation, performance, etc. by a single gender. "Exemplary" should be understood as "illustrative" or "exemplifying" and not necessarily "preferred" over other embodiments. Further definitions of terms can be set forth in this specification, and these can apply to the examples before and after those terms as would be understood upon reading this specification. Note also that the use of the term "a" or "an" indicates "at least one" in all cases, unless specifically stated otherwise or where it is clear that it must mean "one".

[0022] Modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein without departing from the scope of the disclosure. For example, the components of the systems and apparatuses may be integrated or separated. Further, the operations of the systems and apparatuses disclosed herein may be performed by more, fewer, or other components, and the methods described may include more, fewer, or other steps. Further, the steps may be performed in any suitable order. As used herein, "each" refers to each member of a set or each member of a subset of a set.

[0023] System Overview A simplified block diagram of a system 10 for reusing materials containing magnets and rare earth elements from discarded motors, hard disk drives, and other electromechanical waste is shown in FIG. 1, according to one embodiment.

[0024] As shown, system 10 includes a first subsystem 30 that receives the disposal waste 12 and separates them into a magnetic component and a non-magnetic component, and a second subsystem 32 that receives the magnet concentrate, swarf, and defective magnets from the subsystem 30 and obtains a rare earth element concentrate.

[0025] The subsystem 30 includes a size reduction block 14 and a target magnetic material extraction block 16. The size reduction block 14 reduces the size of the received waste 12 in a controlled manner suitable for further processing so that most of the magnets are preserved. In an uncontrolled environment, crushing, pulverizing, or grinding a material containing magnets in the conventional way may result in loss of magnets and may adhere to surrounding objects exhibiting ferromagnetic properties.

[0026] In the target magnetic material extraction block 16, the target magnetic material 24 is separated or extracted from the material reduced at the output of the block 14. The target magnet material 24 includes magnets containing rare earth elements such as, but not limited to, neodymium magnets and samarium cobalt magnets, and magnets containing cobalt and / or nickel such as, but not limited to, aluminum nickel cobalt magnets, or any combination thereof. The target magnetic material extraction block 16 can extract the non-target material 18 and the target magnetic material 24 separately. The non-target material 18 includes a non-magnetic material 18a (such as plastic, aluminum, copper, etc.) and a non-target magnetic material 18b such as steel. The non-target material 18 may include steel, copper, aluminum, and plastic as well as non-metallic forms.

[0027] System 10 also includes a second subsystem 32, an example of an embodiment of the present disclosure, which receives disposal waste 20 in the form of swarf, defective products, and / or currently unusable magnets. The grinding / washing block 22 of the subsystem 32 receives the swarf, defective magnets, and / or currently unusable magnets and outputs a target magnetic material 24. These target magnetic materials 24 may include diamagnetic, ferromagnetic, and paramagnetic components. As used herein, target magnetic materials include, but are not limited to, magnets containing rare earth elements such as neodymium magnets and samarium cobalt magnets, as well as magnets containing cobalt and / or nickel such as aluminum nickel cobalt magnets, or any combination thereof. Swarf does not require grinding and may be presented directly as forming part of the target magnetic material 24 by bypassing the grinding / washing block 22. Defective magnets and large magnets may or may not need to be demagnetized before being supplied to the grinding / washing block 22.

[0028] Accordingly, the target magnetic material 24 can result from one or both of the target magnetic material extraction block 16 of the subsystem 30 and the grinding / washing block 22 of the subsystem 32. As shown in FIG. 1, some or all of the target magnetic material 24 can also be obtained directly from the swarf and unusable magnets in the disposal waste 20 without necessarily passing through the grinding block 22. The target magnetic material 24 is further processed in a chemical treatment block 26 to obtain rare earth element and transition metal concentrates 28. The chemical treatment block 26 can include sub-blocks for wet and non-wet smelting processes. The concentrates can include, for example, rare earth elements, cobalt, nickel, iron, copper, zinc, and boron.

[0029] Conventional operations process these used devices and separate them into base metals, generally copper, aluminum, and steel. However, embodiments of the present disclosure achieve the separation of valuable magnetic materials that move with current steel in existing processes, as shown in FIG. 1.

[0030] Some embodiments of systems and / or methods for separating valuable magnetic materials are described in the present disclosure with reference to some specific embodiments, as disclosed below.

[0031] Preliminary investigations have demonstrated that materials can be improved from less than about 6% to over 30% of the magnets with various applications of the described embodiments. By refining this technology, improvements up to 100% of the magnets can be achieved.

[0032] Embodiment 1 - Separation of Magnets from Steel Using a Ferromagnetic Focusing Surface According to a first set of embodiments, systems and methods are provided for separating magnets from steel using a ferromagnetic focusing surface. It is well known that magnetized materials are attracted to steel. In one embodiment, this property is utilized to selectively sort magnets from a mixed scrap material containing iron-based materials.

[0033] In one embodiment shown in FIG. 2, crushing is used to form small individual components of a consistent size of the mixed scrap 23. The components of the mixed scrap 23, including the non-magnetized component 23a and the magnetized component 23b, are conveyed along a non-ferromagnetic belt such as a rubber belt and pass under a rotating or revolving steel drum 25, where they may physically contact. The magnetized components adhere to the drum and are scraped off and collected by a scraper 27.

[0034] In another embodiment shown in FIG. 3, the mixed scrap 33 containing the non-magnetized component 33a and the magnetized component 33b is conveyed on a variable-speed thin non-ferromagnetic belt conveyor 36.

[0035] At the end of the conveyor 36, the belt passes over the steel idler 35, exerting a passive attraction on any magnetizable component 33b in the mixed scrap 33. As a result of the magnetic attraction, the magnetizable component 33b is flung a shorter distance from the belt, while the non-magnetizable components are thrown farther, enabling the individual components of the material to be sorted into magnetizable and non-magnetizable components in two bins 37, 38 respectively. The relative magnitude of this effect can be controlled by varying the speed of the belt.

[0036] In another embodiment shown in FIG. 4, the mixed scrap slides down a gently inclined vibrating steel plate. The magnetized particles are attracted to the steel plate and thus slide more slowly than the non-magnetized particles. The individual components of the material are split at two cuts, one of which has a strengthened magnet.

[0037] Variations of the above three embodiments can include a steel surface that is a pulsed electromagnet. A strong but temporary magnetic field exerts an attraction on all ferromagnetic materials in the mixed scrap. However, when the magnetic field is turned off, the non-magnetized iron-based components fall, while the magnetized components remain attached to the steel surface.

[0038] To facilitate the above embodiments, any part of the scrap processing line that is normally made of steel, such as the feed chute or discharge chute of the crusher, is replaced with a non-ferromagnetic material such as glass fiber or stainless steel. Next, a ferromagnetic "collection band" is added as a collection point for the lightweight magnetic particles. The magnetic particles are periodically collected with a scraper.

[0039] In other words, all of the above embodiments can be enhanced by eliminating the presence of competing ferromagnetic surfaces to which magnetic components from the mixed scrap can adhere. This can include, for example, replacing steel conveyor belt rollers with nylon rollers, replacing steel chutes with fiberglass chutes, and replacing carbon steel machine parts with stainless steel parts. Adjacent equipment such as crushers, conveyors, chutes, and storage bins may be modified or redesigned as appropriate.

[0040] In some embodiments, the fragmented magnets may be too weak magnetically to be sufficiently attracted to a steel surface or plate even if the fragmented magnets are in direct contact. Additionally, a significant amount of bulk ferrous material may be able to follow the magnets. In such cases, the embodiment is used in a partial improvement process of the scrap mixture and will be further processed.

[0041] Embodiment 2 - Separation of Magnets from Steel Using Demagnetization and Remagnetization As described above, magnetized materials are attracted to steel. Thus, in conventional scrap processing lines, magnetic components follow the steel through the process. In contrast to conventional scrap processing, in one embodiment, the magnetic components are demagnetized and then separated from the steel by taking advantage of other properties such as size and / or density, or by conventional magnetic separation.

[0042] Magnets can be demagnetized thermally, or by exposure to a reducing magnetic field that vibrates, or by the hammer action of a size reduction process. In one embodiment shown in FIG. 5, the mixed scrap material passes over an electric demagnetization pad installed under a conveyor belt. In a variation of the above embodiment, the mixed scrap material passes through an electric demagnetization cylinder. In another variation of the above embodiment, the mixed scrap material passes through a heating furnace.

[0043] Next, the obtained demagnetized material is subjected to conventional separation methods. In the downstream process, magnetic materials can be distinguished, enabling the elimination of unwanted ferrite magnets and / or steel.

[0044] In the embodiment shown in FIG. 5, remagnetization of the demagnetized magnet may be used. Ferromagnetic materials can be magnetized by exposure to a magnetic field. The material magnetized in this way can retain its magnetism either permanently or temporarily. In one embodiment, a mixed stream 53 of non-ferrous materials containing a small amount of unmagnetized magnet material 53b is remagnetized. The remagnetized magnet 53c is then selectively pulled using a ferromagnetic focusing surface as described above.

[0045] Embodiment 3 - Method for producing magnet-reinforced concentrate from scrap steel by crushing, remagnetization / demagnetization, agglomeration, and sieving In another embodiment, a method for producing a magnet-reinforced concentrate from scrap steel is provided. Magnets or magnet pieces attract ferromagnetic materials such as steel. When the mixed scrap containing magnets is crushed to a small size (e.g., less than 5 cm, less than 1 cm, less than 5 mm, or 1 mm to 50 mm), small pieces of the magnets attract steel pieces and steel dust to form larger, loosely bound fabric-like "lumps". The magnet material is concentrated inside the lumps, and the surrounding matrix material is relatively lacking in magnets. The magnet concentrate can be produced by sieving the lumps. A schematic block diagram of one embodiment of the process is shown in FIG. 6.

[0046] In a specific embodiment, process 700 shown in FIG. 7 may include one or more of the illustrated steps. In step 701, a mixed scrap material containing magnets is ground to a predetermined size (e.g., 80% passing rate of 2 inches) or for a predetermined time. In step 702, a dust collection system may be utilized on the grinder to capture the dust generated by the grinding process. As a third step 703, the material may then be remagnetized by passing over, through, or across a remagnetization device. In one embodiment, the remagnetization device may be a magnet, which may be a strong magnet, and the remagnetization step may include passing the material over or through the remagnetization device or magnet. The fourth step 704 includes agitating the ground material to promote mixing so that the magnet pieces form agglomerates. The agitation may be gentle. In a fifth step 705, the material is then passed over a set of sieves to produce several product fragments. In the illustrated embodiment, two sieves are used to produce three fragments. More generally, however, in other embodiments, N sieves may be used to produce N + 1 fragments. The order of these steps may be different from the exemplary embodiment described.

[0047] In a specific embodiment, sieves are used to produce three product fragments, namely, an oversize fragment containing magnet agglomerates, a medium-size fragment containing scrap metal lacking magnets, and fine fragments (dust). In a specific embodiment, the agglomerates are demagnetized, ground to a predetermined size or for a predetermined time, and sieved.

[0048] Process 700 may further include a sixth step 706 of combining the fine fragment dust with the dust from the dust collection system. As a seventh step 707, process 700 then passes the combined dust stream through a scavenger circuit that may also include remagnetization - aggregation - sieving, particularly calibrated for a finer particle size.

[0049] As an eighth step 708, the magnet agglomerates from steps 705 and 707 may then be combined with a magnet pre - concentrate.

[0050] In process 709, rapid pulverization and screening of the lumps are performed to collect the magnets from the fine fragments. Thereafter, the process ends.

[0051] As described above, only all or a subset of the illustrated processes of process 700 may be performed.

[0052] Iron-based and magnet materials can be further improved by pulverization and materials. Short-time pulverization has been demonstrated to rapidly reduce the size of the magnets while minimizing the size reduction of the iron-based materials. By screening this material, the magnets are further concentrated into fine fragments.

[0053] An alternative improvement method that can be used regardless of the presence or absence of the above purification is to demagnetize the agglomeration and use magnetic separation to separate the steel from the magnets while the material is in a temperature state. By performing magnetic separation at a temperature, the difference in magnetic attraction between the steel and the magnets at high temperature can be utilized to concentrate the material.

[0054] Embodiment 4 - Production of REE oxide concentrate by paramagnetic improvement of mixed oxides Iron oxide and rare earth element oxides (REE oxides) are paramagnetic and are weakly attracted to a magnetic field. By utilizing the difference in magnetic susceptibility (χm) using a very strong magnetic field, it is possible to separate different paramagnetic materials from each other. The following table shows the degree of magnetic susceptibility of different materials. [Table 1]

[0055] Embodiment 5 - Mechanical sorting of magnets from mixed scrap using magnetic field detection As is well known, permanent magnets generate a magnetic field, while steel itself does not generate a magnetic field. In one implementation, these properties are utilized as follows. An array of magnetic field sensors (e.g., magnetometers or gauss meters) is provided to construct a topographical map of the magnetic field strength of the mixed scrap on a moving conveyor. Signal processing is then used to analyze an image of the mixed scrap and infer the positions of the magnets in the mixed scrap containing magnetic components and steel pieces. Thereafter, a mechanical method such as an air jet can be used to separate the magnets based on the inferred positions.

[0056] One specific implementation includes four parts for magnet sorting: excitation, sensors, signal processing, and mechanical sorting. FIG. 8 shows one specific implementation. The mixed feed material 83 is moved in a thin layer along the conveyor belt 81, and an image of the material is captured by a sensor 85 similar to a detector or digital camera that can capture and represent the magnetic field within its field of view.

[0057] Next, an image is processed using a computing device 86 that executes a dedicated software algorithm to identify the position of the magnet. Thereafter, in this embodiment, a mechanical device 87, which may be an air gun, is used to extract the desired magnetic component. A subsystem comprising the sensor 85 and the computing device 86 including software may be formed as a stand-alone system. The stand-alone subsystem described above may be deployed for exclusive internal use as part of a conveyor, or alternatively, constructed as a separate equipment package suitable for use in a scrap yard. This embodiment may require a detector having a sensor capable of representing a magnetic field. Since the raw magnetic field map may appear to resemble a hilly terrain with undulations rather than distinct peaks, the associated signal processing may pose difficulties. Similarly, if small magnet particles and dust are widely distributed, weak signals over a wide area may be generated, which may be difficult to distinguish from background noise. A magnetic field expert would expect the signals obtained from such situations to be very noisy. Furthermore, iron-based materials are magnetically attracted to the magnet and remain attached during mechanical sorting, resulting in a high level of contamination of the magnet concentrate.

[0058] FIG. 9 shows various physical elements of the computer system 86 of FIG. 8. As shown, the computer system 86 includes a number of physical and logical components, including a processor 90, a memory 92 that can be in the form of random access memory (“RAM”), an interface circuit 96, an input / output (“I / O”) interface 94, a network interface 97, and a non-volatile storage device 98. The interface circuit 96 enables the processor 90 to communicate with the other components. The processor 90 executes at least an operating system and the above-described dedicated software for analyzing an image of a magnetic field or related characteristics captured by the sensor 85. The memory 92 provides a relatively responsive volatile storage device for the processor 90. The I / O interface 94 enables receiving input from one or more devices such as a keyboard, a mouse, etc., and outputting information to output devices such as a display and / or a speaker. The network interface 97 enables communication with other computing devices via a computer network such as the Internet. The non-volatile storage device 98 stores an operating system and programs including computer-executable instructions for implementing software. During operation of the computer system 86, the operating system, programs, and data may be retrieved from the non-volatile storage device 98 and placed in the memory 92 to facilitate execution.

[0059] Any module, unit, component, server, computer, terminal, engine, or device that executes a command as exemplified herein includes or can otherwise access a computer-readable medium such as a storage medium, a computer storage medium, or a data storage device (removable and / or non-removable) such as a magnetic disk, an optical disk, or a tape. The computer storage medium can include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk (DVD) or other optical storage devices, magnetic cassettes, magnetic tape, magnetic disk storage devices or other magnetic storage devices, or any other medium that can be used to store the desired information and that can be accessed by an application, a module, or both. Any such computer storage medium may be part of the device or may be accessible or connectable to the device. Further, unless the context clearly indicates otherwise, any processor or controller defined herein may be implemented as a single processor or as multiple processors. The multiple processors may be arranged or distributed, and any processing functions referred to herein may be executed by one processor or by multiple processors, even if only a single processor is exemplified. Any method, application, or module described herein may be implemented using computer-readable / executable instructions stored or held by such a computer-readable medium and executable by one or more processors.

[0060] Overall mechanical process In one embodiment, the overall process combines a series of individual physical processing steps in a unique combination that can output a reinforced magnet concentrate from a mixed scrap material.

[0061] Process 1200 is summarized in FIG. 12 and includes the following steps.

[0062] In step 1201, a feed material consisting of scrap containing a certain proportion of magnets is obtained.

[0063] In step 1202, the size of the mixed scrap is reduced by a grinding process such as a hammer mill.

[0064] In step 1203, separation of ferromagnetic materials (e.g., steel, magnets) from non-ferromagnetic materials (e.g., aluminum, copper, plastic, other metals) is performed using magnetic separation, and further separation of non-ferrous vapors is achieved using one or more of a eddy current separator, a shaker table, an air table, an optical sorter, a gravity separator, etc.

[0065] In step 1204, separation of ferromagnetic fragments into a "magnet concentrate" with enhanced target magnetic material and a scrap steel stream lacking non-target magnetic material is performed by one of the methods described above.

[0066] Step 1205 includes grinding of the target magnetic material reinforcing material and sieving to produce a high-purity fine reinforcing material.

[0067] Thereafter, process 1200 ends.

[0068] Chemical System / Process Some embodiments of the systems disclosed herein are characterized as chemical processes, but may include steps or processes that also utilize the physical properties of the material components. Each process component is described below, but the order and use of the process components may be changed.

[0069] Specific specific terms regarding the processes and procedures used throughout this specification, unless otherwise indicated in the context, can be read and understood as follows.

[0070] Grinding:

[0071] To promote reaction kinetics, the magnet material is ground and sieved to ensure a target particle size such that, for example, the passing rate of 100 microns is 80%. Grinding generally generates heat, and for some materials such as neodymium magnets or other metals, the resulting accompanying dust particles can be flammable and / or explosive. To eliminate or at least reduce this risk, several methods can be used, including but not limited to the addition of water, dry ice, nitrogen gas, argon, and carbon dioxide, or combinations thereof. The use of water and dry ice can act to lower the heat below the combustion temperature, the use of gases can act to limit the availability of oxygen, and the use of dry ice can act to lower the heat and limit the availability of oxygen.

[0072] Washing:

[0073] Valuable sources for magnet reuse include swarf, which is manufacturing waste. Swarf is generally mixed with a liquid used as a cutting or cooling aid, such as cutting oil. Swarf can be washed using water, heated water, surfactants such as but not limited to sodium dodecyl sulfate, Alconox®, Alcojet®, Detergent8, and Detonox®, and / or other reagents including dichloromethane that decomposes organic materials. Washing procedures have been tested, and the effectiveness ranges from 70% to 100% removal of the mixed cutting fluid.

[0074] Roasting:

[0075] To facilitate the removal of impurities, the magnet material is roasted at a temperature varying between 150 °C and 1000 °C, which can change the oxidation state of the impurities.

[0076] Leaching:

[0077] The leaching process utilizes a lixiviant that includes, but is not limited to, hydrochloric acid, sulfuric acid, nitric acid, and / or organic acids, or combinations thereof. To date, leaching tests have demonstrated extraction efficiencies of up to 100% of the valuable minerals containing rare earth elements, cobalt, and nickel by controlling temperature, reaction time, and using oxidizing agents. Some or all of these operating parameters may or may not be controlled.

[0078] Iron Removal:

[0079] Iron and other impurities can be precipitated from the process solution by adjusting the pH of the solution with calcium oxide, calcium hydroxide, calcium carbonate, magnesium oxide, magnesium hydroxide, magnesium carbonate, sodium hydroxide, or other alkaline reagents or minerals, or combinations thereof, in an oxidizing environment achieved by the use of air, oxygen gas, or hydrogen peroxide, a mixture of SO2 and oxygen or air gas, permanganate, or other oxidizing agents known in the art, or combinations thereof. The addition of copper ions or the use of solvent extraction can also be applied. To date, test work has achieved removal of up to 99% of the iron in the solution.

[0080] Oxalate Precipitation:

[0081] The production of rare earth element (REE) materials can be achieved by precipitation as oxalates or carbonates. Such precipitation can also target high-purity products by dosing the solution with 50% to 500% of the stoichiometric addition of the precipitation reagent. Solvent extraction may be used to separate the REEs. To date, laboratory studies have achieved purities of over 95% for REE products.

[0082] REE Solvent Extraction:

[0083] Using REE solvent extraction, trace levels of impurities in solution can be removed to produce a high-purity solution, from which REE can be precipitated as a high-purity product. In this process, extractants such as, but not limited to, CYANEX® 272, tributyl phosphate (TBP), di-(2-ethylhexyl) phosphoric acid (DEHPA), 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC88A), CYANEX® 801 and / or CYANEX® 905B or combinations thereof can be utilized.

[0084] Firing:

[0085] The conversion of oxalates and / or carbonates to oxides is achieved by firing. This process may include selective firing by targeting the temperature associated with the conversion of specific species, and the temperature can range from 150 °C to 1200 °C. To date, rare earth products with a purity of 95% or higher have been produced using firing at 650 °C.

[0086] Impurity removal:

[0087] Trace levels of impurities can potentially negatively impact the usefulness and value of high-purity products. The removal of aluminum, copper, zinc, and other impurities can be achieved using precipitation with calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, sodium hydroxide, other alkaline reagents, or combinations thereof. Trace impurities can also be removed using solvent extraction or ion exchange.

[0088] Removal of cobalt and nickel:

[0089] Cobalt and nickel are valuable important materials and can be separated from the process solution using solvent extraction and / or precipitation as hydroxides using reagents such as, but not limited to, lime or sodium hydroxide and magnesium hydroxide to produce a mixed cobalt-nickel hydroxide product.

[0090] Boron removal:

[0091] Boron is removed from the process solution using ion exchange or solvent extraction, and produces products such as zinc borate, boric acid, and / or sodium borate, among others.

[0092] Selective precipitation of rare earth oxalates from a high-iron-containing leaching solution by controlling the addition of oxalate In one embodiment, the process of selectively precipitating rare earth oxalates from a high-iron-containing leaching solution involves controlling the addition of oxalate. When a mixed magnet is leached with an acid, the leaching pregnant solution may contain many metals including REE, iron, aluminum, copper, nickel, etc. Separating these metals from each other is desirable to ensure that the quality of the REE product meets the pre-determined specifications for the intended use.

[0093] One method of rare earth separation is REE oxalate precipitation. Unfortunately, many other metals also precipitate as oxalates, so the resulting contaminated product needs to be further purified.

[0094] During experimental studies, it was observed that REE oxalates tend to precipitate first, followed by iron oxalate. In one embodiment of the process taking advantage of this observation, iron can be removed by carefully controlling the amount of oxalate added to the leaching solution to be approximately equal to or slightly in excess of the amount of REE. This embodiment involves combining the monitoring of the REE concentration in the leaching solution with the accurate dosing of oxalate, such that the precipitation of REE is increased / maximized and the precipitation of iron is decreased / minimized.

[0095] Selective calcination of the mixed oxalate precipitate and subsequent separation of impurities In another embodiment, after the selective firing of the mixed oxalate precipitate, a step of separating impurities follows. The REE can be recovered from the leaching solution by oxalate precipitation. This mixed oxalate precipitation process, even if tightly controlled, can result in a product containing some impurities. Conventional approaches for purifying oxalates are to calcine the oxalate to an oxide, re-leach it, and subsequently perform hydrometallurgy.

[0096] The selective firing of the mixed oxalate is a new alternative to re-leaching and can achieve the same result at a lower cost. Nickel, cobalt, and iron oxalate decompose thermally at a lower temperature than rare earth oxalates. Subsequently, the different properties of the different components of the decomposition products can be utilized to purify the product.

[0097] This embodiment has several variations. In one variation, a mixed oxalate precipitate containing rare earth elements and transition metal impurities is fired at 150°C to 1200°C. The resulting fired product is then purified by leaching, washing, magnetic separation, or slag refining. The fired product is leached with a weak acid to remove impurities, leaving the REE oxalate. Figure 2 is a schematic block diagram showing the above variation.

[0098] Washing of swarf during magnet manufacturing, and recovery of oil by solvent washing and distillation The swarf from magnet manufacturing contains metal pieces immersed in oil and water. This is then washed before it can be fed into the process of Figure 1.

[0099] In the embodiment shown in Figure 3, during the washing process, a volatile solvent or water (collectively and individually referred to as "solvent") is mixed with the swarf to dissolve and / or separate all the oil. The swarf is then separated from the solvent by sedimentation and decantation, and finally washed with more solvent.

[0100] The solvent filled with oil is then distilled to recover and reuse the solvent, and the residual oil is sold or discarded.

[0101] Non-limiting examples of volatile solvents include trichloroethylene and d-limonene.

[0102] Overall chemical process In another embodiment, the overall chemical process combines a series of chemical treatment steps to convert various magnet-containing feeds into rare earth concentrates and any secondary concentrates of iron, nickel, cobalt, boron, or other elements.

[0103] Exemplary process 1300 is summarized in FIG. 13.

[0104] Step 1301 includes acid leaching of the mixed feed materials as described above.

[0105] Step 1302 includes iron removal by pH adjustment and precipitation.

[0106] Step 1303 includes rare earth removal by precipitation as oxalates.

[0107] Step 1304 includes firing of rare earth oxalates to rare earth oxides by means described elsewhere.

[0108] Step 1305 includes impurity removal (i.e., removal of Cu, Al, Fe, and other trace impurities) by precipitation as hydroxides.

[0109] Step 1306 includes boron removal by solvent extraction or ion exchange.

[0110] Step 1307 includes removal of nickel / cobalt by pH adjustment and precipitation as hydroxides.

[0111] Step 1308 includes treatment of process water for reuse by addition of lime and / or CO2. Then, process 1300 ends.

[0112] A variant of process 1300 is shown as process 1400 depicted in FIG. 14, which includes additional steps not present in FIG. 13.

[0113] Step 1401 includes washing the feed using water, a surfactant, or a solvent.

[0114] Step 1402 includes roasting the feed at a temperature from 600 °C to 1000 °C.

[0115] Step 1403 includes acid leaching of the mixed feed materials.

[0116] Step 1404 includes purifying the solution by precipitation.

[0117] Step 1405 includes rare earth removal by precipitation as oxalate.

[0118] Step 1406 includes firing the rare earth oxalate to rare earth oxide, involving purification of the oxalate by means described elsewhere.

[0119] Step 1407 includes impurity removal (e.g., iron removal) by pH adjustment and precipitation.

[0120] Step 1408 includes nickel / cobalt removal by pH adjustment and precipitation as hydroxide.

[0121] Step 1409 includes impurity removal by precipitation as sulfide.

[0122] Step 1410 includes boron removal by solvent extraction or ion exchange.

[0123] Thereafter, process 1400 ends.

[0124] Specific advantages have been listed above, but various embodiments may include some or all of the listed advantages, or may include none.

[0125] Those skilled in the art will understand that there are further many alternative embodiments and modifications possible, and that the above examples are merely illustrative of one or more embodiments. Therefore, the scope should be limited only by the claims appended hereto and any corrections made thereto.

Claims

1. A system for generating a magnet concentrate containing rare earth elements (REE), comprising: i) a size reduction unit for receiving disposed waste containing a magnetic material and outputting a mixed scrap, wherein the mixed scrap contains a magnetic component and a non-magnetic component; ii) a target magnetic material extraction block for receiving the mixed scrap and separating it into a target magnetic material and a non-target material; iii) a chemical treatment unit, a) an input section for receiving a mixed feed containing the target magnetic material; b) an acid leaching unit for acid leaching the mixed feed; c) a rare earth element removal unit for precipitating and removing rare earth elements from the mixed feed as oxalates, carbonates, or other rare earth salts; d) a firing unit for firing the rare earth salts into rare earth oxides; e) one or more particle removal units for:

1. iron removal by pH adjustment and precipitation; 2. removal of one or more of nickel, cobalt, and other transition metals by solvent extraction, pH adjustment, and precipitation as hydroxides; 3. copper removal by precipitation, solvent extraction, or ion exchange; and 4. boron removal by solvent extraction or ion exchange, wherein the target magnetic material contains a magnet containing one or more rare earth elements, the chemical treatment unit; the system.

2. The system according to claim 1, wherein the magnet containing one or more rare earth elements includes one or more of a neodymium magnet, a samarium cobalt magnet, and a magnet containing cobalt and / or nickel.

3. The system according to claim 2, wherein the magnet containing cobalt and / or nickel includes an aluminum nickel cobalt magnet.

4. The system according to claim 1, wherein the target magnetic material is suitable for further processing in an external system for generating a magnet strengthening material having an increased magnet content.

5. The system according to claim 1, wherein the target magnetic material extraction block comprises a non-ferromagnetic belt proximate to a rotating steel drum, and the mixed scrap is conveyed along the non-ferromagnetic belt such that the magnetic component adheres to the drum and is scraped off for collection.

6. The system according to claim 5, wherein the non-ferromagnetic belt is a rubber belt.

7. The system according to claim 5, wherein a scraper is used to scrape off the magnetic component attached to the drum.

8. The system according to claim 1, wherein the target magnetic material extraction block includes a non-ferromagnetic belt passing over a steel idler adapted to exert a passive attraction force on the magnetic component so that, as a result of the magnetic attraction force, the magnetized component is flung a shorter distance from the belt while the non-magnetized component is flung a longer distance, thereby separating the magnetic component from the non-magnetic component.

9. The system according to claim 8, wherein the non-ferromagnetic belt is a rubber belt.

10. The system according to claim 1, wherein the disposed waste includes one or more of a motor, a hard disk drive, a speaker, a compressor, other electromechanical devices containing magnets, and meatballs.

11. The system according to claim 1, wherein the mixed scrap includes the target magnetic material and non-target materials, and the non-target materials include iron-based components.

12. The system according to claim 1, wherein the magnet content of the mixed scrap is at most 15%.

13. The system according to claim 12, wherein the magnet content of the target magnetic material is about 30%.

14. The system according to claim 13, wherein the magnet content of the magnet reinforcement material is from about 70% to 100%.

15. The system according to claim 1, wherein the target magnetic material is received from one or more of a target magnetic material extraction block and a grinding / washing unit.

16. The system according to claim 15, further comprising the grinding / washing unit for receiving swarf and magnets that are currently unusable and outputting at least a portion of the target magnetic material.

17. The system according to claim 1, wherein the chemical treatment unit is one of a wet smelting treatment unit or a non-wet smelting treatment unit.

18. A method for obtaining rare earth elements (REE), comprising: (i) grinding a mixed scrap material containing magnets into a ground material of a predetermined size; (ii) capturing the dust generated by the grinding with a dust collector; (iii) remagnetizing the ground material; (iv) vibrating the crushed material to promote mixing; (v) passing the crushed material over a set of N sieves to produce N + 1 product fragments, the fragments including oversize fragments containing a first set of magnet blocks and fine dust fragments; (vi) combining the fine dust fragments with the dust from the dust collector to form a dust stream; (vii) passing the dust stream through a circuit including remagnetization - aggregation - sieving to output fine particles containing a second set of magnet blocks; (viii) briefly crushing and then sieving the first and second sets of magnet blocks to capture the magnetic material in the small - size fragments of the sieves as a mixed feed; (ix) acid - leaching the mixed feed; (x) removing rare - earth elements by precipitation as oxalates, carbonates, or other rare - earth salts; (xi) firing the rare - earth salts to rare - earth oxides; (xii) removing iron by pH adjustment, temperature adjustment, and precipitation; (xiii) removing one or more of nickel and cobalt by solvent extraction, pH adjustment, and precipitation as oxides or hydroxides; (xiv) removing copper by precipitation or solvent extraction; (xv) removing boron by solvent extraction or ion exchange; A method comprising the above steps.

19. The method according to claim 18, wherein the remagnetizing step comprises passing the mixed scrap over a remagnetization device, or through a remagnetization device, or over a magnetic field.

20. The method according to claim 18, wherein N = 2, and two sieves are used to produce three product fragments.

21. The method according to claim 18, wherein the acid - leaching step comprises leaching in one or more of hydrochloric acid, nitric acid, sulfuric acid, formic acid, citric acid, or combinations thereof.

22. The method according to claim 18, wherein the removal of rare - earth elements comprises a stoichiometric addition of salts in a ratio of 50% to 500%, or separation of REEs by solvent extraction, or combinations thereof.

23. The method according to claim 18, wherein the rare - earth salt comprises oxalate.

24. The iron removal is achieved in an oxidation environment by using air, oxygen gas, or a mixture of hydrogen peroxide, SO2 and oxygen or air gas, permanganate, or other oxidants known in the art, or combinations thereof, and includes the step of using calcium oxide, calcium hydroxide, calcium carbonate, magnesium oxide, magnesium hydroxide, magnesium carbonate, sodium hydroxide, or other alkaline reagents or minerals, or combinations thereof. The method according to claim 18.

25. The method according to claim 18, wherein the firing is carried out at a temperature of 150°C to 1200°C.

26. The method according to claim 25, wherein the temperature is 650°C.

27. The method according to claim 18, further comprising the step of washing the feed with water, a surfactant, or a solvent before the acid leaching step.

28. The method according to claim 18, wherein the acid leaching step utilizes a leaching medium.

29. (i) obtaining a feed material containing a magnetic material, wherein the magnetic material includes a ferromagnetic material and a non-ferromagnetic material; (ii) reducing the size of the feed material to form a feed material of reduced size; (iii) separating the feed material of reduced size into the ferromagnetic material and the non-ferromagnetic material; (iv) separating the ferromagnetic material into a magnetically enhanced target magnetic material concentrate and a non-target magnetic material depleted scrap; The method according to claim 18, further comprising.

30. A system for obtaining rare earth elements (REE), a charging section for receiving a mixed feed containing a magnetic component; an acid leaching unit for acid leaching the mixed feed; a rare earth element removal unit for precipitating and removing rare earth elements from the mixed feed as oxalates; a firing unit for firing rare earth oxalates into rare earth oxides; iron removal by pH adjustment and precipitation, removal of one or more of nickel, cobalt, and other transition metals by solvent extraction, pH adjustment, and precipitation as hydroxides, removal of copper by precipitation, solvent extraction, or ion exchange, and removal of boron by solvent extraction or ion exchange, one or more particle removal units for A system comprising a chemical treatment unit.

31. The system according to claim 30, wherein the magnetic component is received from one or more of the target magnetic material extraction block and the grinding / washing unit.

32. The system according to claim 31, further comprising the grinding / washing unit for receiving scrap and magnets that are not currently usable and outputting the magnetic component.

33. The system according to claim 30, wherein the chemical treatment unit is one of a wet smelting treatment unit and a non-wet smelting treatment unit.

34. A system for producing a magnet concentrate, comprising: i) a size reduction unit for receiving disposal waste containing a magnetic material and outputting a mixed scrap, the mixed scrap containing a magnetic component and a non-magnetic component; and ii) a target magnetic material extraction block for receiving the mixed scrap and separating the mixed scrap into a target magnetic material and a non-target material. Comprising: The target magnetic material includes a magnet containing a rare earth element. System.

35. The system according to claim 34, wherein the magnet containing one or more rare earth elements includes one or more of a neodymium magnet, a samarium cobalt magnet, and a magnet containing cobalt and / or nickel.

36. The system according to claim 35, wherein the magnet containing cobalt and / or nickel includes an aluminum nickel cobalt magnet.

37. A system for obtaining rare earth elements, comprising: a charging section for receiving a mixed feed containing a target magnetic material; an acid leaching unit for acid leaching the mixed feed; a rare earth element removal unit for precipitating and removing rare earth elements from the mixed feed as oxalates; a firing unit for firing the rare earth oxalates into rare earth oxides; iron removal by pH adjustment and precipitation, removal of one or more of nickel, cobalt, and other transition metals by solvent extraction, pH adjustment, and precipitation as hydroxides, copper removal by precipitation, solvent extraction, or ion exchange, and boron removal by solvent extraction or ion exchange, one or more particle removal units for A system comprising a chemical treatment unit.

38. a) obtaining a feedstock containing a magnetic material, wherein the magnetic material includes a ferromagnetic material and a non-ferromagnetic material; b) reducing the size of the feedstock; c) separating the feedstock of reduced size into the ferromagnetic material and the non-ferromagnetic material; d) separating the ferromagnetic material into a magnet-enhanced target magnetic material concentrate and a non-target magnetic material-deficient scrap; A method comprising the above steps.

39. The method according to claim 38, wherein the step of reducing the size includes using a grinding process.

40. The method according to claim 38, further comprising further separating the non-ferromagnetic material using one or more of an eddy current separator, a shaker table, an air table, an optical sorter, and a gravity separator.

41. A method for preparing a magnet concentrate, comprising: (i) grinding a mixed scrap material containing a magnet into a ground material of a predetermined size; (ii) capturing the dust generated by grinding with a dust collector; (iii) remagnetizing the ground material; (iv) vibrating the ground material to promote mixing; (v) passing the ground material over a set of N sieves to produce N + 1 product fragments, the fragments including an oversize fragment containing a first set of magnet chunks and a fine dust fragment; (vi) combining the fine dust fragments with the dust from the dust collector to form a dust stream; (vii) passing the dust stream through a circuit including remagnetization - aggregation - screening to output fine particles including a second set of magnet chunks; and (viii) briefly grinding and then screening the first and second sets of magnet chunks to capture the magnetic material in the small-size fragments of the sieves as the magnetic concentrate. A method comprising one or more of the above steps.

42. A method for obtaining rare earth elements from a mixed feed, comprising: acid leaching of the mixed feed; removal of rare earth elements by precipitation as oxalates, carbonates, or other rare earth salts; calcination of the rare earth salts to rare earth oxides; iron removal by pH adjustment, temperature adjustment, and precipitation; removal of one or more of nickel and cobalt by solvent extraction, pH adjustment, and precipitation as oxides or hydroxides; removal of copper by precipitation or solvent extraction; A method including the removal of boron by solvent extraction or ion exchange, and the like.

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