Arrangement for recovering metal from waste slag
By combining granulation and separation units, the problem of low metal recovery efficiency in electronic waste slag is solved, realizing a low-energy, low-cost, and environmentally friendly metal recovery process, especially the efficient separation of precious metals such as copper, silver, gold, and palladium.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- METSO METALS LTD
- Filing Date
- 2025-01-26
- Publication Date
- 2026-05-01
AI Technical Summary
Existing technologies are difficult to efficiently and cost-effectively recover metals from electronic waste slag, and they also suffer from high energy consumption and high CO2 emissions.
By employing a granulation arrangement and separation unit, including granulation and magnetic/gravimetric separation steps, rapid granulation and separation of slag are achieved, avoiding solidification and crushing processes and reducing energy consumption and CO2 emissions.
It achieves low-cost, low-energy-consumption, and environmentally friendly metal recycling, and improves metal recycling efficiency, especially the separation effect of precious metals such as copper, silver, gold, and palladium.
Smart Images
Figure CN224186227U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an arrangement for recovering metal from waste slag. Background Technology
[0002] Electronic waste slag is formed during the smelting process of electronic waste, including, for example, electronic scrap and circuit boards. Due to impurities in the slag, it is difficult to find direct uses for it, such as as a building material. Because of the highly reducing environment during the smelting of electronic waste, the properties of electronic waste slag differ from those of typical primary copper smelting furnace slag. The loss of copper and other metals during the smelting of electronic waste is primarily due to the physical inclusions of metal droplets within the electronic waste slag. Due to the high viscosity of electronic waste slag, pyrometallurgical settling furnaces are not ideal for separating metals from the remaining portion of the slag. Solidification and crushing of electronic waste slag are also not ideal solutions due to long process preparation times, high equipment costs, and high energy consumption. Summary of the Invention
[0003] From a first perspective, an arrangement for recovering metals from waste slag can be provided, the arrangement comprising a granulation arrangement and a first separation unit, the granulation arrangement being configured to receive slag in at least a partially molten state and granulate the slag in the at least partially molten state, the first separation unit being configured to separate the granulated slag into at least two fractions, wherein the metal content in the first fraction of the at least two fractions is higher than the metal content in the second fraction of the at least two fractions.
[0004] Therefore, an arrangement can be implemented that provides short process lead times and low energy consumption, while still achieving the same process results as known arrangements. Furthermore, this arrangement requires low capital expenditure and is environmentally friendly, as it does not produce any direct CO2 emissions.
[0005] Utility model embodiments are also disclosed in the specification and drawings of this patent application. The invention may also consist of several separate inventive creations, particularly when the invention is examined based on explicit or implicit sub-tasks or on the benefits or groups of benefits obtained. Within the scope of the basic inventive concept, features of different embodiments of the invention can be applied to other embodiments.
[0006] Various embodiments of the first aspect may include at least one feature from the following paragraphs.
[0007] In one embodiment, the slag is received from a furnace (such as a top-blown rotary converter).
[0008] The advantage is that the slag has a high temperature, which can prevent it from solidifying prematurely.
[0009] In one embodiment, the slag is discharged from the furnace into a vessel and then discharged from the vessel to granulate the slag.
[0010] The advantage is that it allows for a certain degree of flexibility in the layout of the arrangement.
[0011] In one embodiment, at least a portion of the slag originates from at least one source selected from: electronic waste, cable waste, plastic waste from electrical or electronic devices, incinerator bottom ash, copper waste, and copper alloys.
[0012] The advantage is that these sources often contain precious metals with recycling value.
[0013] In one embodiment, granulation includes blowing fluid into a slag stream that is at least partially molten to produce granules.
[0014] The advantage is that it can achieve rapid granulation and cooling of slag.
[0015] In one embodiment, granulation includes blowing steam or gas, such as air.
[0016] The advantage is that the produced granules are at least substantially dry.
[0017] In one embodiment, granulation includes blowing a liquid, such as water.
[0018] The advantage is that the particles can be effectively cooled and solidified.
[0019] In one embodiment, the separation includes a magnetic separation phase.
[0020] The advantage is that it can achieve a separation stage with low energy consumption and no direct CO2 emissions.
[0021] In one embodiment, the magnetic separation stage is performed by a low-intensity magnetic separator.
[0022] The advantage is that it can achieve lower maintenance requirements and operator attendance.
[0023] In one embodiment, separation includes a weight separation stage.
[0024] The advantages are that it can be operated at low cost, requires simple equipment, and is environmentally friendly.
[0025] In one embodiment, the first fraction comprises 10% to 90% by weight of metal.
[0026] The advantage is that it allows for cost-effective separation of stages.
[0027] In one embodiment, the metal includes at least one of copper, silver, gold, palladium, and platinum.
[0028] The advantage is that it allows for cost-effective separation of stages.
[0029] In one embodiment, the metal is in a mixture known as black copper that is attracted by a magnet.
[0030] The advantage is that non-magnetic metals, such as copper, contained in black copper can be separated through a magnetic separation stage.
[0031] In one embodiment, the second fraction is ground, and thus a ground second fraction is provided, and the ground second fraction is separated into at least two ground fractions such that the metal content in the first fraction of the at least two ground fractions is higher than the metal content in the second fraction of the at least two ground fractions.
[0032] The advantage is that it still allows one or more metals in the waste to be separated from the slag during the separation stage.
[0033] In one embodiment, the separation stage of the milled second fraction includes separating the milled second fraction by weight into a first sub-fraction and a second sub-fraction.
[0034] The advantages are that it can be operated at low cost, requires simple equipment, and is environmentally friendly.
[0035] In one embodiment, the first milled fraction is further separated by flotation.
[0036] The advantage is that it still allows one or more metals in the waste to be separated from the slag during the separation stage.
[0037] In one embodiment, the arrangement includes: a grinding arrangement configured to grind the second fraction and provide the ground second fraction; and a second separation unit configured to perform a separation stage of separating the ground second fraction into at least two ground sub-fractions, such that the metal content in the first sub-fraction of the at least two ground sub-fractions is higher than the metal content in the second sub-fraction of the at least two ground sub-fractions.
[0038] The advantage is that it still allows one or more metals in the waste to be separated from the slag during the separation stage.
[0039] In one embodiment, the second separation unit includes a weight separation device.
[0040] The advantage is that it can realize a second separation unit that is low-cost, requires simple equipment, and is environmentally friendly.
[0041] In one embodiment, the second separation unit includes a magnetic separation device.
[0042] The advantage is that it enables the creation of a second separation unit with low energy consumption and no direct CO2 emissions.
[0043] In one embodiment, the arrangement includes a flotation arrangement configured to perform further separation of the second milled fraction.
[0044] The advantage is that it can further improve the separation capability of the arrangement.
[0045] Based on the above, it should be noted that the different embodiments mentioned in the above paragraphs can be combined in any possible suitable manner to implement this utility model. Attached Figure Description
[0046] Some embodiments of this disclosure are illustrated in more detail in the accompanying drawings, wherein:
[0047] Figure 1 This is a partial cross-sectional schematic diagram of the arrangement used for recovering metal from waste slag.
[0048] Figure 2 A partial cross-sectional side view schematic diagram of the separation unit used in the arrangement for recovering metal from waste slag, and
[0049] Figures 3a-3c This is a side view schematic diagram of other separation units used in the arrangement for recovering metals from waste slag.
[0050] In the figures, some embodiments are shown in a simplified manner for clarity. Similar parts are labeled with the same reference numerals in the figures. Detailed Implementation
[0051] Figure 1 This is a partial cross-sectional schematic diagram of the arrangement used for recovering metal from waste slag. Figure 2 A partial cross-sectional side view schematic diagram of the separation unit used in the arrangement for recovering metal from waste slag, and Figures 3a-3c This is a side view schematic diagram of other separation units used in the arrangement for recovering metals from waste slag.
[0052] The method performed in the arrangement operates in arrangement 100, the main parts or components of which include granulation arrangement 3 and first separation unit 4.
[0053] Arrangement 100 is controlled by control unit 14, which may be a computer, computing unit, or device including at least one processor and memory.
[0054] In one embodiment, the granulation arrangement 3 is arranged to receive slag directly from the furnace 1, the slag having already been melted in the furnace 1.
[0055] In one embodiment, such as Figure 1 As shown, the slag is first placed in a container 15, such as a ladle, and then, if necessary, M is moved to the position where the slag is poured from the container 15 into the granulation arrangement 3.
[0056] In one embodiment, the slag originates from the recycled waste, such as recycled electronic waste. In another embodiment, at least a portion of the slag originates from at least one source selected from: electronic waste, cable waste, plastic waste from electrical or electronic devices, incinerator bottom ash, copper waste (such as copper pipes used in the construction industry), and copper alloys. Typically, the recycled waste is a combination of wastes from different sources.
[0057] In one embodiment, furnace 1 is a top-blown rotary converter, such as a Kaldo converter. The top-blown rotary converter is shaped like an open-end barrel and lined with refractory material. It can rotate about its longitudinal axis X and tilt about an axis T perpendicular to said longitudinal axis X. The molten slag in the top-blown rotary converter is discharged through an inclined port 2.
[0058] In one embodiment, furnace 1 is an Isasmelt furnace. In another embodiment, furnace 1 is an Ausmelt furnace.
[0059] In one embodiment, the device is used in batches so that the molten slag discharged from furnace 1 is processed as a batch. In another embodiment, the device is used continuously.
[0060] In one embodiment, before or after the slag is discharged from furnace 1, there is a metal discharge step in which the molten metal phase is discharged from furnace 1 to another arrangement (not shown) for further processing.
[0061] Granulation arrangement 3 receives slag in at least a partially molten state and granulates it. In addition to the flowable (molten) phase, the slag may contain solid (unmolten) particles or fragments. Granulation arrangement 3 includes devices for pressurizing a fluid, which is then blown by a blowing device into the slag stream S in at least a partially molten state. In one embodiment, the blowing device includes, for example, an opening or nozzle 17 arranged in a blowing box 16. Fluid F is blown at high speed through the opening or nozzle into the slag stream S in at least a partially molten state. In one embodiment, fluid F is blown into the slag stream S poured or discharged from furnace 1. In another embodiment, fluid F is blown into the slag stream S poured or discharged from a vessel (e.g., ladle 15).
[0062] In one embodiment, the slag stream S is fed into or onto a flow channel 8, which is arranged to guide the slag into a granulation arrangement 3.
[0063] In one embodiment, slag granulation occurs in a granulation pit 9 provided in the granulation arrangement 3. In one embodiment, the bottom of the granulation pit 9 is at least partially filled with a liquid, such as water, and the particles enter the liquid and are cooled therein.
[0064] In one embodiment, the fluid F is blown at least primarily in the horizontal direction, and the slag flow S is configured to fall through the fluid. However, it should be noted that other arrangements of the fluid F and the slag flow S can be used in slag granulation.
[0065] In one embodiment, fluid F comprises steam or gas, such as air. In one embodiment, fluid F comprises liquid, such as water. In one embodiment, fluid F provides a high-pressure turbulent liquid flow. Characteristic features of fluid F, such as its velocity, temperature, and volumetric flow rate, are selected based on, for example, the properties of molten slag and its flow characteristics.
[0066] In one embodiment, granulation arrangement 3 includes a centrifugal granulation device. In this device, a slag stream is poured onto a high-speed rotating disc. The force generated by the rotation breaks the slag into particles. In one embodiment, the rotating disc throws the particles into the air, where the particles cool and solidify. In another embodiment, the rotating disc throws the particles into a liquid, such as water, where the particles cool and solidify.
[0067] When slag is granulated, it is also cooled, resulting in small solid lumps or droplets. Some heat is removed from the slag through the evaporation of the liquid (usually water) and / or as a heating gas (usually air) and / or liquid. In water granulation, large quantities of water can be used, which can then be reused and pumped back during the granulation process.
[0068] In one embodiment, granulation arrangement 3 produces particles with an average size ranging from 0.5 mm to 5 mm. However, it should be noted that the particle size distribution can vary, for example, from a few micrometers to more than 5 mm.
[0069] Particle G, i.e., granulated slag, is delivered to the first separation unit 4. In one embodiment, a drying step and drying equipment may be present, wherein the particles are dried before being fed into the first separation unit 4. However, a drying step and drying equipment are preferably avoided. If the separation step in the first separation unit requires drying the material, the granulation step preferably uses dry granulation without any liquid.
[0070] The first separation unit 4 separates the particle G into at least two fractions. In one embodiment, such as... Figure 1 As shown, the first separation unit 4 separates particle G into two fractions, namely the first fraction A and the second fraction B, so that the first fraction A has a higher metal content than the second fraction B.
[0071] In one embodiment, first fraction A comprises 10% to 90% by weight of metal. In another embodiment, first fraction A comprises 30% to 70% by weight of metal.
[0072] In one embodiment, the metal includes at least one of copper, silver, gold, palladium, and platinum. In another embodiment, the metal is a mixture comprising copper and iron-containing and iron-free metals, typically including silver, gold, palladium, and platinum, i.e., so-called black copper. Black copper includes metallic iron, which makes the black copper phase magnetic.
[0073] In one embodiment, the first separation unit 4 includes a magnetic separation device, and the separation includes a magnetic separation stage. Figure 2 An embodiment of a magnetic separation device 12 is shown. In one embodiment, the magnetic separation device 12 is a low-intensity magnetic separator.
[0074] A low-intensity magnetic separator (LIMS) is an apparatus used to recover magnetic materials from non-magnetic materials or to recover highly magnetic materials from low-magnetic materials. In one embodiment, the magnetic separator 12 is designed to work in conjunction with a dry separation process. In another embodiment, the magnetic separator 12 is designed to work in conjunction with a wet separation process.
[0075] In one embodiment, the magnetic separation device 12 includes a separator drum 10 that rotates about its vertically arranged axis R. A magnet arrangement 11 is disposed inside the separator drum 10. The magnet arrangement 11 extends only a portion of the length of the separator drum's periphery. Magnetic or more magnetic materials are attracted to the separator drum 10 by the magnet arrangement 11 and rotate out from the non-magnetic or less magnetic particle stream on the surface of the drum. In one embodiment, the magnetic or more magnetic materials separate from the separator drum 10 upon reaching a specific boundary point (e.g., a baffle) and fall into, for example, a collection container. In one embodiment, the magnetic material is discharged from the separator drum as it rotates out of the magnetic field. Thus, particles G are separated into a first fraction A and a second fraction B based on their magnetic properties. However, it should be noted that the magnetic separation device 12 can be constructed in many alternative ways.
[0076] In one embodiment, the first separation unit 4 includes a weight separation device 13, and the separation is a weight separation stage. Figure 3a An embodiment of a gravimetric separation device 13 is shown. The working principle of this separation device 13 is based on centrifugal separation, meaning that substances with different specific gravities are separated by centrifugal force. Therefore, particles G are separated into a first fraction A and a second fraction B based on their specific gravity. However, it should be noted that the gravimetric separation device 13 can be constructed in many alternative ways. Figure 3b Another embodiment of the gravimetric separation device 13 is shown. This device 13 is a scavenging spiral, wherein the separation of different solid materials or components in a slurry is based on the density of solid particles and the hydrodynamic properties of the particles. Another embodiment of the gravimetric separation device 13 is a shaking table or gravity separation table, such as... Figure 3c As shown in the diagram. In this device, relative movement against gravity is applied to the particles.
[0077] The first fraction A provided by the separation stage performed by the first separation unit 4 has a high metal content and can be discharged from arrangement 100 for any suitable purpose.
[0078] In one embodiment, the second fraction B, provided by the separation stage and having a low metal content, can be considered waste. In another embodiment, the second fraction B is further processed to further recover metals (one or more) still present in the second fraction.
[0079] In one embodiment, the second fraction B, i.e., particles with low metal content, is ground into a ground second fraction, and then the ground second fraction BG is separated into at least two ground fractions.
[0080] The second stage, B, is ground by grinding arrangement 5, which includes a suitable grinding machine or crushing machine. The type of grinding machine or crushing machine can be, for example, a jaw crusher, a rotary crusher, a cone crusher, a ball mill, a rod mill, or an impact crusher.
[0081] In one embodiment, following the grinding arrangement 5 is a second separation unit 6, in which the ground second fraction BG is separated into at least two ground fractions. In one embodiment, the ground second fraction BG is separated into a first ground fraction BG1 and a second ground fraction BG2. The first ground fraction BG1 has a higher metal content than the second ground fraction BG2. In one embodiment, the second separation unit 6 includes a magnetic separation device 12. In one embodiment, the second separation unit 6 includes a gravimetric separation device 13. The same principles of the magnetic separation device and the gravimetric separation device already described in conjunction with the first separation unit also apply to the second separation unit 6.
[0082] The first milled fraction BG1 can be transported from arrangement 100 for any suitable purpose.
[0083] In one embodiment of the arrangement, a second milled fraction BG2, i.e., a milled fraction with a lower metal content, is fed into the flotation arrangement 7 for further refining of the fraction. The flotation arrangement 7 separates the milled fraction BG2 into two fractions such that one of the two fractions has a higher metal content than the other of the two fractions.
[0084] This invention is not limited to the embodiments described above; rather, many variations are possible within the scope of the inventive concept defined by the following claims. Within the scope of this invention, attributes of different embodiments and applications may be used in combination with or replace attributes of another embodiment or application.
[0085] The accompanying drawings and related descriptions are intended only to illustrate the concept of this invention. Variations in detail may be made within the scope of the inventive concept defined in the following claims.
[0086] List of reference numerals
[0087] 1. Furnace
[0088] 2 mouths
[0089] 3 Granulation Layout
[0090] 4 First Separation Unit
[0091] 5 Grinding arrangement
[0092] 6 Second Separation Unit
[0093] 7 Flotation Arrangement
[0094] 8 flow channels
[0095] 9 Granulation pit
[0096] 10 Separator Drum
[0097] 11 Magnet Arrangement
[0098] 12 Magnetic Separation Equipment
[0099] 13. Weight separation equipment
[0100] 14 Control Unit
[0101] 15 Vessels
[0102] 16 Blowing Box
[0103] 17 Opening
[0104] 100 Arrangement
[0105] A. First-level score
[0106] B. Second-level subdivision
[0107] BG, the second grade of grinding
[0108] The first sub-fraction in the second-stage fraction of BG1 after grinding.
[0109] BG2, the second sub-fraction of the second-stage fraction after grinding.
[0110] F fluid
[0111] G particles
[0112] M moves
[0113] R rotation
[0114] S slag flow
[0115] T tilt
Claims
1. An arrangement for recovering metals from spent smelter slag, characterized in that, The arrangement (100) includes: - Granulation arrangement (3), said granulation arrangement (3) is arranged to receive slag in at least a partially molten state and to granulate said slag in at least a partially molten state, and - First separation unit (4), the first separation unit (4) is arranged to separate the granulated slag into at least two fractions, wherein the metal content of the first fraction (A) of the at least two fractions is higher than the metal content of the second fraction (B) of the at least two fractions.
2. The arrangement according to claim 1, characterized in that, The arrangement (100) includes: - A vessel (15), said vessel (15) being arranged to hold slag in at least a partially molten state, and for use in - The slag is discharged into the first separation unit (4).
3. The arrangement according to claim 1, characterized in that, - The granulation arrangement (3) is configured to blow fluid (F) into a slag stream that is at least partially molten.
4. The arrangement according to claim 3, characterized in that, - The fluid (F) is steam or gas.
5. The arrangement according to claim 3 or 4, characterized in that, - The fluid (F) is a liquid.
6. The arrangement according to claim 1, characterized in that, - The first separation unit (4) includes a magnetic separation device.
7. The arrangement according to claim 1, characterized in that, - The first separation unit (4) includes a weight separation device.
8. The arrangement according to claim 1, characterized in that, The arrangement includes: - Grinding arrangement (5), which is arranged to grind the second fraction (B) and provide the ground second fraction (BG).
9. An arrangement according to claim 8, characterised in that, The arrangement (100) includes: - A second separation unit (6), the second separation unit (6) being arranged to perform a separation stage of separating the milled second fraction (BG) into at least two milled sub-fractions, such that - The metal content in the first sub-fraction (BG1) of the at least two milled sub-fractions is higher than the metal content in the second sub-fraction (BG2) of the at least two milled sub-fractions.
10. The arrangement according to claim 9, characterized in that, - The second separation unit (6) includes a second weight separation device.
11. The arrangement according to claim 9, characterized in that, - The second separation unit (6) includes a second magnetic separation device.
12. The arrangement according to any of claims 9-11, characterized by, The arrangement (100) includes: - Flotation arrangement (7), which is arranged to perform further separation of the milled second sub-fraction (BG2).
13. The arrangement according to claim 3, characterized in that, The fluid (F) is air or water.