System and method for recovering desired material using a pan mill

Abstract

A method for recovering metals from waste by screening materials to separate non-fibrous raw materials. These non-fibrous raw materials are then crushed using a pan mill and further separated to obtain a mixture consisting of a metal fraction and a non-metallic residue. The metal fraction can then be recovered. Systems employing this method are used to efficiently process such materials.

Description

Technical Field

[0001] This application relates to a system for separating desired substances from waste such as automotive shredder residue (ASR), electronic waste, incineration ash, etc. More specifically, this application relates to a system for recovering iron-based materials and non-ferrous materials by reducing the size of waste materials to facilitate the separation process using a pan mill.

Background Art

[0002] In the United States, more than 15 million vehicles reach the end of their service life every year. Due to economic and environmental protection requirements, the importance of recovering metals and other materials from these scrapped vehicles is increasing. The recycling process of automobiles and white goods (e.g., refrigerators and electronic devices) in the United States and Europe usually begins with crushing these items after removing specific components (especially bulk refrigerants). After crushing, the metal components in the crushed materials are separated and recycled. On the other hand, non-metallic residues, which were historically regarded as waste and disposed of in landfill sites, are now being recovered, separated, washed, and recycled. This residue is usually composed of various types of plastics including polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), high impact polystyrene (HIPS), ABS / polycarbonate (ABS / PC) blend, polycarbonate (PC), and various nylons. To reduce the environmental impact by utilizing incinerator waste, treatment methods have been introduced, and waste is classified and sorted to promote recovery.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Therefore, there is always a need for an improved method for separating and classifying waste.

Means for Solving the Problems

[0004] This application discloses a process for recovering and separating materials from waste streams containing both ferrous and non-ferrous materials, which is particularly designed for high efficiency and lower operating costs. This process can utilize either a compression mill or a pan mill.

[0005] In one embodiment, the process begins by introducing the crushed residue into a concentration unit, where the residue is separated into light and heavy fractions by air classification or gravity separation techniques. Subsequently, both fractions are screened to separate the material based on size, improving the efficiency of subsequent processing steps, including processing with a pan mill.

[0006] After screening, the material is transferred to a hopper or surge hopper, and the flow can be adjusted to ensure a consistent supply into the pan mill. The pan mill helps to break and grind the material into finer particles, which is particularly effective for hard materials such as metals, reducing loss and promoting regeneration. The material can also be crushed.

[0007] Following crushing and grinding in a pan mill, the material can undergo secondary screening to remove oversized and flattened material, ensuring that particles of the appropriate size pass through. This process may include a dehydration step to remove excess water, followed optionally by clarification to separate solid particles from the water, allowing for the recovery of fine material.

[0008] Another embodiment includes a system having a batch feeder and screening mechanism for feeding and sorting initial waste material. Material larger than a certain size threshold is processed in a wet pan mill to reduce its size to below a set threshold, improving the efficiency of material recovery and separation.

[0009] Another embodiment involves a process for separating ferrous and non-ferrous materials from a waste stream. The waste stream may contain automotive crushing residue (ASR) and water, and the ASR is separated using a pan mill. The waste stream can be mixed with water, and a wet pan mill may be used to crush and grind the waste material. A wet pan mill can stretch metal particles to 3 to 20 times their original size, which can enhance the separation and recovery process.

[0010] Another embodiment includes a method for recycling components from automotive shredder residue (ASR), comprising the steps of: concentrating the shredder residue into a light fraction and a heavy fraction; screening both fractions to remove particles of different sizes; transferring the screened material to a surge hopper; and shredding and grinding the material in a wet pan mill.

[0011] Another embodiment includes a method comprising the steps of: performing a secondary screening to remove oversized and flattened articles; dehydrating the treated material to reduce its moisture content; and optionally, clarifying the dehydrated material to separate solid particles from the water.

[0012] Another embodiment includes a method for recovering metal from metallic waste, comprising the steps of: separating fibrous material from metallic waste to leave non-fibrous raw material; mixing the raw material with water; applying a pan mill to the raw material to separate metal from the non-fibrous raw material; and recovering the metal fraction and residue. The pan mill may include a crevis structure. The method may include the step of using a density separator or a magnetic drum.

[0013] Another embodiment includes a system comprising an ASR source containing water, a pan mill for separating metal from the ASR, and a recovery machine for recovering the separated metal. The system may have a screen, or a density separator may be connected to the pan mill to separate the material by specific gravity. The system may have multiple dewatering screens installed within the system to remove excess (oversized) material.

[0014] Another embodiment includes a method for recovering metals from automotive crushing residue (ASR) or incinerator ash, comprising the steps of: separating the ASR or incinerator ash into groups of different particle sizes; mixing the ASR or incinerator ash with water; concentrating the ASR or incinerator ash; sending the ASR or incinerator ash to a pan mill for crushing and metal separation; screening the ASR or incinerator ash for a predetermined size; dewatering the ASR or incinerator ash; and recovering metals from the ASR or incinerator ash. The predetermined size may be less than 1 mm. The concentrator can separate the material into a material of a first density and a material of a second density.

[0015] Another embodiment includes a pan milling stage having a clevis setup that includes a clevis bracket and a clevis pin for securing the clevis bracket to a corresponding mounting point. The clevis setup allows for easy adjustment of the angle and position of the wheel relative to the milling pan.

[0016] Another embodiment includes a pan mill comprising a milling pan for containing a grinding medium and a material to be ground, a central rotating shaft positioned vertically within the milling pan, one or more grinding elements attached to the central rotating shaft for grinding the material, and a clevis setup with a clevis bracket.

[0017] This process utilizes a wet pan mill to provide a systematic approach for recycling, recovering, and obtaining desired materials from various waste flows, ensuring high-volume processing at low operating costs. Because this method can handle a wide variety of waste flows, it is particularly versatile and economically beneficial for the recycling industry. [Brief explanation of the drawing]

[0018] [Figure 1] This document describes one embodiment of a method for using a pan mill to separate materials such as automotive shredder residue (ASR). [Figure 2] Another embodiment is shown in which a pan mill is used to separate materials such as ASR. [Figure 3] Another embodiment is shown in which a pan mill is used to separate a material similar to ASR. [Figure 4A] Here is a typical example of a bread mill. [Figure 4B] Another example of a pan mill is shown, which features a clevis setup. [Modes for carrying out the invention]

[0019] This application provides a system and method for recovering metals from waste streams. It covers both wet and dry process applications, including streams from pre-concentrators, water-level concentrators, vibrating ore-separating tables for gold (such as those from Diester and Wilfery), gravity separators, snail drums, barrel washers, and processes using heavy media, DMS separators, hydrocyclones, etc. Similarly, dry processes may include coarse sorters such as the air aspirator Z-box, widely used in Europe for pre-concentrating automotive crushing residues. These methods are well known to those skilled in the art.

[0020] One embodiment involves separating iron-based materials from non-iron-based materials, with applications ranging from automotive shredder residue (ASR) to different types of incineration ash. Specific methods include using a wet pan mill, known for its large capacity and low operating costs, to regenerate, recover, and obtain valuable materials from metal-containing waste streams. Also called a wet pan grinding mill or a wheel pan mill, an example is a quartz mill or a Chile mill. This device utilizes the principle of unevenness to crush ore, resulting in a product of well-polished particles with minimal slime and no discoloration. This ensures an improved recovery rate (especially for sulfides and gold). The wet pan mill functions as an all-inclusive grinding and mixing device, performing various operations such as crushing, breaking, and compression through a grid. It effectively flattens the metal, reduces losses, and enables further recycling.

[0021] Waste streams applicable here include not only ASR but also electronic waste and incineration ash. Water or other liquids facilitate the separation of various material fractions. In particular, the wet pan mill can stretch the length of metal by 3 to 20 times.

[0022] Figure 1 shows a material recovery process for separating and recycling components from ASR, which typically contains a mixture of metal, plastic, glass, and fiber. This process begins with concentrating (120) an exemplary input material ASR (input material (110)) with water. This initial stage involves dividing the residue into a light fraction and a heavy fraction, often employing techniques such as air classification or gravity separation. The light materials typically consist of plastic, foam, and fiber, while the heavy materials consist of metal, glass, and other high-density substances. At this stage, water can be added to the materials or water can be present with the materials.

[0023] First, the materials are screened (130) and separated based on particle size into a light fraction and a heavy fraction. This separation, by employing a mechanical screen that classifies the materials into groups of various sizes, helps make subsequent processing steps more efficient.

[0024] After screening, the material can optionally be transferred to a hopper or surge hopper, which function as buffers to regulate the flow and ensure a consistent supply to the downstream process. This step helps manage the supply of material to the pan mill.

[0025] Subsequently, the screened material, or the material from the hopper, is crushed in a pan mill (140). Here, the material is mixed with water to produce a slurry, and individually sized portions from the surge hopper are introduced into the pan mill. This mill is extremely effective in breaking large pieces into smaller, more manageable pieces and is particularly useful for hard materials such as metals and high-density plastics.

[0026] After crushing, the material from the pan mill (140) is subjected to re-screening (150) to remove oversized and flat articles that may interfere with further processing. This step adds value to the process as only appropriately sized particles proceed while larger metals and flat materials are recovered for possible recycling or sale.

[0027] Subsequently, the material can be dehydrated (160) to remove excess moisture, reduce the moisture content, and facilitate handling and processing. This stage often includes techniques such as centrifugation, filtration, and pressing. Metals can then be recovered or further processed for recovery (170).

[0028] Figure 2 shows another embodiment of a method (200) including a crushing step. Here, the input material is mixed with water to produce a slurry (21), processed through a pan mill (220), and then metals are recovered (230).

[0029] Figure 3 shows a simplified version of method (300), where the input material (310) is fed into a concentrator, mixed with water to produce a slurry (210), which is then processed through a pan mill (220) and the metal is recovered (230).

[0030] Optionally, the material can be subjected to a clarification process. Following dewatering, the slurry can be transferred to a clarification apparatus, where the solid settles from the water, and then the fine material, including recyclable metal particles, is recovered.

[0031] The material can be screened first (130). After separation, both the light and heavy fractions are screened to remove particles of different sizes. This helps separate the material based on size, making subsequent processing steps more efficient. Screening typically involves mechanical screens that classify the material into different size categories.

[0032] The screened material can optionally be fed into a hopper or surge hopper. The hopper acts as a buffer, regulating the material flow to ensure a consistent supply to downstream processes. The combination of a hopper or surge hopper allows for control over the material supply to the pan mill.

[0033] In one embodiment, a system for separating materials to obtain a desired material may include a batch feeder for feeding incinerator ash, ASR, or other similar waste containing materials of various sizes into a screen. The screen has a screen that allows materials of a size of millimeters (mm) or larger or smaller to pass through. Fractions of various sizes of material can be removed from the system or further processed manually and / or automatically. In this example, materials larger than 2 mm can be fed into a wet pan mill and reduced to less than 2 mm after processing. In another example, the material may have sizes larger than 1 mm or smaller than 1 mm after processing.

[0034] Figure 3 shows another exemplary method in which the initial material (310) is supplied to a concentrator (320). Light material is removed, and heavy material is screened into different size categories such as 0-2 mm, 2-6 mm, 6-12 mm, and over 12 mm (330). The screened material is then supplied to a pan mill (340) as batches of more uniform size. After this, secondary screening is used to obtain the material, or the material is further processed. The material can then be dewatered (360), and excess material, such as metal, from the screening process can be recovered.

[0035] Figure 4A shows an example of a pan mill (400) within a frame (405). Each pan mill (400) includes a large circular pan (420) supported by a central drive shaft (430) with bearings. This pan base (421), along with the grinding chamber (425), is made of steel or another sturdy material. A vertical shaft (430) is mounted in the center of the pan, and a mixing and grinding element (420), such as a wheel or müller, is mounted on it. These grinding components are made of a material that is both strong and wear-resistant. The grinding element (420) may have a raised or other uneven structure at its base to enhance the grinding action within the grinding base (421). The operation of the pan mill (410) is powered by an engine (540) connected via a belt (455), which drives a mechanism including a crank arm (460) (and crankshaft (468)) and a wheel hub (465). This configuration allows the pan mill to operate based on the principle of low speed and high pressure applied to the ore particles. As the material is fed into the rotating pan, the grinding wheels roll over the material, crushing and grinding it effectively against the base of the pan (421).

[0036] Figure 4B shows an alternative pan mill design (500) located within the frame (505) incorporating a clevis setup. Similar to the design shown in Figure 4A, this model mounts the grinding rollers or wheels to an arm or lever, which are then connected to a central pivot or hub using a clevis joint. The pan mill (500) features a base (520) and a grinding element (510). The clevis joint, a U-shaped bracket, secures the components (particularly the arm holding the grinding wheel) and allows for slight pivoting or rotation. This mechanism facilitates angular movement and precise adjustment of the grinding element relative to the pan, thereby improving the mill's adaptability and operational efficiency. Furthermore, this configuration significantly reduces stress on the cylinder (530) and roller bearings (560), which are optionally immersed in an oil bath (540) for increased smoothness and lifespan. The pan mill can be integrated with hydraulic cylinders of various capacities (e.g., 30 tons or 40 tons or more). The rod clevis cylinder mount provides dynamic connection to the fasteners and facilitates movement during operation. These consist of a rod with a threaded end that attaches to the cylinder and a clevis pin on the opposite end that connects to the work bracket. This arrangement helps ensure that the thrust roller is immersed in the oil bath and maintains operational connectivity with the wheel bearing. By adjusting the oil pressure, the operator can adjust the pressure and crushing force applied by the mill. Essentially, changing the hydraulic pressure changes the PSI applied to the material by the wheel, optimizing the crushing force to suit various needs. This feature allows the operator to customize the roller position and pressure, enabling a crushing operation tailored based on the material properties and the required fineness of grinding.

[0037] In another embodiment, a screen (e.g., a star screen) can be attached to the feeder. The screen may consist of small pores. These small pores are used to separate fine materials, which are less than 2 mm in size, from the waste stream. Generally, these particles are organic in nature. Particles larger than 2 mm can be moved to a wet pan mill for further grinding of the waste stream. In other examples, the screen size is larger than 4 mm, 6 mm, 8 mm, or 12 mm.

[0038] The feeder introduces a waste stream containing materials of various sizes into the first screen (e.g., a star screen or another type of screen). The initially screened material passes through the process more efficiently, thereby protecting the wet pan mill. The material can be fed to the wet pan mill in batch or continuous mode. In particular, malleable metals from the wet pan mill are planarized.

[0039] The material can be individually sized or separated. For example, equipment can be used to cut into multiple sizes such as 0-2mm, 2-6mm, 6-18mm, 18-54mm, and 54-100mm, which are considered efficient cuts. Other cuts are also suitable.

[0040] In another embodiment, the material from the pan mill ultimately proceeds to a gravity separator (e.g., a settling velocity separator, an upward flow separator, or a jig) or is further screened using, for example, a nose cone. The material from the pan mill ultimately proceeds to a density separator (e.g., a descending velocity separator, an upward flow velocity separator, or a jig) or is further screened using, for example, a nose cone. In one scenario, the material is separated by cutting at a specific gravity (SG) of approximately 1.6. Organic or non-metallic materials may be removed and discarded, or used for solidification (such as absorbing wet or hazardous materials in landfills) and / or as an inorganic medium.

[0041] In another embodiment, associating a pan mill with a screen size greater than 2 mm yields unexpected results. The inner surface of the wet pan mill is covered with a hard material. Wet pan mills are used to reduce the size of waste flow material. They function as crushers, flattening metals and crushing materials such as sand, rock, and glass.

[0042] Generally, a wet pan mill is cylindrical and rotates around a horizontal axis. Due to the internal cascade effect, the material is ground into a fine powder.

[0043] In another embodiment, heavy materials containing metals or minerals are processed by a magnetic separator (e.g., a wet magnet). This includes low, medium, and high-strength magnetic pulleys. These pulleys remove iron-containing materials from the product stream, leaving non-ferrous materials and minerals in the processing stream.

[0044] In another embodiment, the density separator can be connected directly to the wet pan mill or operably connected. The density separator consists of an inlet and an outlet for feeding in and discharging waste flow material for further processing. It operates to separate the material using a paddle wheel mounted on the central top of the density separator and specific gravity. The paddle wheel rotates to create turbulence in the water, facilitating the separation of heavy and light materials. The speed of the paddle wheel varies depending on the process and can range from 30 to 60 rpm.

[0045] In another embodiment, the material from which the iron components have been removed is then processed through one or more coarse sorting machines (e.g., jigs, concentration tables, or wet or dry density separation). The heavy material is further polished, and the light material is further processed and screened. This process separates the intermediate from the heavy material, which may include aggregate minerals and light metals (e.g., magnesium, aluminum).

[0046] A wet pan mill can be connected to either a gravity feed velocity separator or a density separator. A gravity feed velocity separator separates organic material from the waste stream remaining after star-screening. It is used to separate heavy and light particles from the waste stream and operates based on specific gravity (typically around 1.6 SG). It separates material between 2 mm and 6 mm based on the density of the material. Material with a specific gravity less than 1.6 is disposed of in a landfill, which is a designated location for waste material disposal.

[0047] Specific gravity, also known as relative density, is the ratio of the density of a substance to the density of a reference substance. Gravity separators operate based on specific gravity between 1 and 1.6 SG. Materials with a specific gravity below 1.6 SG are considered inorganic and separated from the waste stream, while materials with a specific gravity above 1.6 SG are classified as ferrous and non-ferrous. Materials with higher specific gravity are moved to a wet magnetic drum to separate ferrous materials from the waste stream. Gravity separation can be employed before the pan mill to remove organic and lighter materials.

[0048] A coarse separator can be attached to a wet magnetic drum to separate the waste stream. After passing through the wet magnetic drum, the remaining waste stream consists only of non-ferrous materials. These heavy and light materials are then separated by a coarse separator, which can be a mechanical separator, a density separator, or a separator using physical motion (e.g., a table or mechanical separator such as the one described in International Publication No. 2019222558 “Fluidized Inertia Table”), used to separate the materials from the waste stream.

[0049] The density separator includes a coarse density separator that separates light and heavy materials from the waste stream. The heavier materials are then further processed in a finishing mechanical separator (e.g., International Publication No. 2018090039, "Method and System for Recovering Metal Using a Helix Separator"). The finishing density separator is positioned after the coarse density separator to separate the heavy materials from the light materials, which are then reprocessed in the coarse density separator or mechanical separator. Heavier materials may include copper, aluminum, magnesium, or other non-ferrous materials.

[0050] Several dewatering screens and / or sedimentation screws can be attached to the system.

[0051] The crude concentrate assembly can be coupled with a coarse sorter to further separate the lighter material. This assembly includes a sand scrubber, which generates friction on the lighter material to separate any inorganic substances that may be adhering to the ferrous and non-ferrous materials present in the waste flow. The sand scrubber is essentially a wide rotating wheel with multiple pockets for holding sand particles used to scrub the lighter material. After passing through the sand scrubber, the waste flow material is separated into ferrous and non-ferrous materials. Any sand particles that may be adhering to these materials can be removed using a high-pressure slurry pump.

[0052] The high-pressure slurry pump functions as a hydrocyclone, removing sand particles from ferrous and non-ferrous materials. It may include a dewatering screen for draining the collected water into a recovery box. The collected water is filtered for reuse. An eddy current chamber is used to further separate non-ferrous materials from the waste flow.

[0053] "Intermediate" or medium-sized materials can be processed using eddy currents or sensors, which is particularly effective for removing aluminum. The residue from eddy current processing has commercial value as aggregate products (e.g., for asphalt or roadbed material). In one example, a sand washer or sand wheel may be employed for further dewatering and polishing of the material.

[0054] The terms "heavier" and "lighter" refer to materials with relatively higher and lower specific gravities, respectively. In fluid separators, absolute weight is less important than the buoyancy effect in the fluid. For example, if a 6-ounce (approximately 170-gram) item has a higher specific gravity than a 16-ounce (approximately 454-gram) item, the 16-ounce item will be lighter than the 6-ounce item.

[0055] Another embodiment involves eddy currents induced by a change in a magnetic field, flowing within a closed loop. Eddy currents are perpendicular to the plane of the magnetic field and occur when a conductor moves through the magnetic field, causing a change in the strength or direction of the magnetic field, thereby generating eddy currents.

[0056] Heavy metals (such as copper, brass, zinc, lead, stainless steel, and cadmium) can be further processed and graded.

[0057] A system for regenerating, recovering, and obtaining desired materials from metal-containing waste flows features a pan mill capable of crushing and mixing, performing operations such as crushing plastic parts, breaking hard parts, and flattening metals by pushing them through a grid, thereby regenerating metals while minimizing losses as fine powder. This device is operationally connected to a concentration unit.

[0058] While specific embodiments of this disclosure have been described in detail, this description is for illustrative purposes only. It should be understood that this description illustrates aspects relevant to a clear understanding of the invention. Certain embodiments that would be obvious to those skilled in the art and therefore do not contribute to a better understanding have been omitted for the sake of brevity. While these embodiments have been described, those skilled in the art will recognize, upon reviewing the foregoing description, many modifications and variations, all of which are intended to be included in this description.

Claims

1. A process for separating ferrous and non-ferrous materials from a waste stream, wherein the waste stream comprises automotive crushing residue (ASR) and water, and the ASR is separated using a pan mill.

2. The waste stream is mixed with water, The process according to claim 1, wherein a wet pan mill is used to crush and grind waste material.

3. The wet pan mill can stretch the metal particles to 3 to 20 times their original size, thereby enhancing the separation and recovery process, according to claim 1.

4. A method for recycling components from automotive shredder residue (ASR), The steps include concentrating the crushed residue into a light fraction and a heavy fraction, The steps include screening both fractions to remove particles of different sizes, The steps include transferring the screened material to a surge hopper, The steps include crushing and grinding the aforementioned material in a wet pan mill. Methods that include...

5. The steps include: performing a secondary screening to remove oversized and flattened items, In order to reduce the moisture content, the processed material is dehydrated, Optionally, to separate solid particles from water, a step of clarifying the dehydrated material and The method according to claim 3, further comprising:

6. A method for recovering metal from metallic waste, A step of separating fibrous material from the metallic waste in order to retain non-fibrous raw materials, The steps include mixing the raw materials with water, The steps include applying a pan mill to the raw material in order to separate the metal from the non-fibrous raw material, Steps to collect metal fractions and residues and Methods that include...

7. The method according to claim 5, wherein the pan mill includes a clevis structure.

8. The method according to claim 5, comprising separating the waste stream by using a density separator.

9. The method according to claim 5, further comprising the step of separating ferrous material from the waste stream using a magnetic drum.

10. The method according to claim 5, wherein the material is crushed.

11. ASR source containing water, A pan mill for separating metal from ASR, A recovery machine for collecting separated metals and A system equipped with these features.

12. The system according to claim 11, further comprising a screen.

13. The system according to claim 10, wherein a density separator is connected to the pan mill for separating materials by specific gravity.

14. The system according to claim 11, wherein a plurality of dewatering screens are installed in the system to remove excess material.

15. A method for recovering metals from automobile shredder residue (ASR) or incinerator bottom ash, The steps include separating the ASR or incinerator bottom ash into groups of different particle sizes, The steps include mixing the ASR or incinerator bottom ash with water, The steps include concentrating the ASR or incinerator bottom ash, The steps include sending the ASR or incinerator bottom ash to a pan mill for crushing and metal separation, The steps include screening the ASR or incinerator bottom ash to a predetermined size, The steps include dewatering the ASR or incinerator bottom ash, The steps include recovering metal from the ASR or incinerator bottom ash. Methods that include...

16. The method according to claim 14, wherein the predetermined size is less than 1 mm.

17. The method according to claim 14, wherein the concentration apparatus separates the material into a material of a first density and a material of a second density.

18. The method according to claim 14, wherein the pan mill has a clevis setup including a clevis bracket and a clevis pin for securing the clevis bracket to a corresponding mounting point, the clevis setup allowing for easy adjustment of the angle and position of the wheel relative to the milling pan.

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