Material handling installation and method for using material handling installation

Abstract

In a material treatment plant for separating non-ferrous metals from slag, the plant comprises a vortex separation device having an inlet for untreated slag or mineral slag components, an outlet for mineral slag components and an outlet for separated non-ferrous metal components, a first storage container is arranged upstream of the inlet for untreated slag. The facility has an outlet for the untreated slag of the first storage container, a line leading from the outlet to the inlet of the vortex separation device, and a primary return line leading from the outlet for mineral slag components to the second storage container, the second storage container has an outlet and a line leading from the outlet to the inlet of the vortex separation device.

Description

Technical Field

[0001] Globally, the negative environmental impacts of landfilling are receiving increasing attention. Proper landfilling requires vast amounts of land, which are only available in limited urban areas or on islands. Waste can also have adverse environmental impacts, including on groundwater, as chemicals and heavy metals contained in the waste can contaminate groundwater. However, negative environmental impacts are not limited to landfills; inadequate separation and treatment of waste for recycling as potential secondary materials in various industrial applications also have negative consequences.

[0002] This invention relates to a method for separating non-ferrous metals from grate ash (so-called slag) in a waste incineration facility, the method serving as a subsystem of a complete slag treatment process. Background Technology

[0003] The separation of non-ferrous metals using eddy current separators is known in existing technology. This method is also used to process slag from waste incineration facilities. After being discharged from the incinerator, the slag consists primarily of mineral slag particles and various metals. After discharge, the slag is typically stored to reduce its moisture content before being supplied to slag processing facilities. To date, there is no globally unified method capable of processing the mineral slag components and metals to a sufficient quality to meet the recycling regulations of different countries for both materials.

[0004] In typical slag treatment processes, larger particles (>300 mm) and large scrap iron particles are usually separated in the first step. Then, the slag is separated into different components in a separation unit, for example, using a screen. Following this processing to obtain the components, the iron-containing components and magnetic slag particles are separated. Depending on the facility, these process steps can also be carried out using different arrangements. However, regardless of the order, these process steps must be performed before proceeding to the process of separating non-ferrous metals from the mineral slag components. Non-ferrous metal separation is typically carried out using eddy current separators. Non-ferrous metal separation is a decisive factor in the economic benefits for operators of slag treatment facilities and has a significant impact on the profitability of the facility. In separation technologies used for waste incineration slag, the goal is to obtain as much high-purity non-ferrous metal as possible. Each component can typically have 70-90% of all non-ferrous metals separated using one or two eddy current separators in series. A significant drawback of known methods is that, if a certain quality of non-ferrous metals is to be guaranteed, only a certain fraction of the non-ferrous metals present in the slag can be separated in an economically feasible manner. To further improve separation, additional eddy current separation devices or similar methods are required. However, since the absolute amount of non-ferrous metals separated decreases after each additional eddy current separation device, these additional devices have been abandoned until today. The economic viability of adding additional eddy current separation devices cannot be guaranteed.

[0005] However, the presence of unseparated non-ferrous metals limits the recycling of mineral slag components in various industrial applications, such as as a base layer in road construction, cement production, or ceramics production. In particular, heavy metals and aluminum in the remaining mineral slag components continue to pose obstacles to their full integration as secondary materials globally. The leaching of heavy metals or the oxidation of aluminum particles can lead to environmental pollution or a decline in material quality.

[0006] As landfill capacity for non-recyclable materials continues to shrink, and as efforts to recycle secondary resources in response to climate change become increasingly important, the use of mineral slag components after separating ferrous and non-ferrous metal components is becoming increasingly important.

[0007] Eliminating mineral slag components from landfills can also be economically viable for operators, as significant landfill costs can be saved through recycling these components, depending on the country and specific landfill conditions. Therefore, additional economic potential arises for operators through improved and enhanced non-ferrous metal separation. Summary of the Invention

[0008] Therefore, the invention proposes a material processing facility and method that further improves the separation efficiency of non-ferrous metals contained in different slag components from the grate ash of a waste incineration facility. This separation of non-ferrous metals and the remaining mineral slag components ensures the sustainable recycling of both final products as secondary materials.

[0009] The present invention relates to a subsystem of a slag treatment facility having an eddy current separation device having an inlet for slag components, an outlet for mineral slag components and an outlet for non-ferrous metal components, and a method for treating slag from a waste incineration facility using an eddy current separation device integrated into a closed-loop process, wherein the slag is separated into mineral slag components and non-ferrous metal components through multiple cycles.

[0010] The purpose of such apparatus and methods is to produce non-ferrous metal components from mineral slag components with exceptionally high efficiency and purity.

[0011] Therefore, this invention proposes a material processing facility and method to provide a particularly pure material product from slag from which iron particles have been removed; mineral slag components and non-ferrous metals. This is achieved using a closed-loop process, which improves separation efficiency without requiring the integration of additional eddy current separation devices into the process.

[0012] The task on which this invention is based is solved using a material processing facility having the features of claim 1.

[0013] Advantageous improvements are the subject of the dependent claims.

[0014] The method according to the invention can be performed continuously under proper conditioning. Preferably, it is performed as a batch process, wherein the batch is preferably supplied to the eddy current separator at least twice. Here, the material handling facility has two storage containers. A first storage container is used to store the incoming slag and is arranged upstream of the eddy current separator. A second storage container is arranged in the return line for the mineral slag component. The material to be separated is first supplied to the eddy current separator as untreated slag, and a second time as the mineral slag component of the material not separated in the eddy current separator. The loop can be repeated arbitrarily before the material is removed from the loop.

[0015] These two storage containers are necessary to ensure error-free batching. Without storage, the amount of material effectively occupying space in the loop must be calculated. If untreated slag is fed into the loop, a situation may occur where, at some point, the mineral slag component has already been processed for the first time using the eddy current separator and is again fed in the direction of the eddy current separator. If untreated slag continues to be fed into the loop from the first storage container, the amount to be processed will increase until a system like this reaches its maximum separation capacity and the eddy current separator becomes overloaded. Preferably, two storage containers of the same size ensure that material occupies space in the loop. The eddy current separator typically has the lowest throughput of any single component in the loop, thus becoming a bottleneck.

[0016] The return pipeline typically consists of different transport systems that convey the mineral slag components to a secondary storage container. Here, a combination of vibrating conveyors, conveyor belts, or bucket elevators is commonly used.

[0017] A material removal outlet exists in the loop of the mineral slag component. Through this outlet, material can be conveyed from the system in each cycle. It is advantageous if the material removal outlet is located in the return line of the mineral slag component. Thus, batches of material can be removed from the system after separation by a vortex separator. The material removal outlet can be implemented, for example, using a reversible trough, a reversing valve, or a flap box with two outlets.

[0018] To improve the separation efficiency of non-ferrous metals, one or more additional eddy current separation devices can be arranged between the outlet and return pipeline for the mineral slag components. Here, the non-ferrous metals separated by the respective eddy current separation devices are then collected together.

[0019] Eddy current separation devices and at least one additional eddy current separation device preferably have an eddy current separator. Different types of eddy current separators exist. Basic variations mainly involve eccentric or concentric magnetic drums, the number of magnets within the drum, the working width, and whether the separation apex for separating non-ferrous metals from mineral slag components is adjustable. Furthermore, the adjustment of the eddy current separator also affects the separation efficiency of non-ferrous metals. Here, the throughput of the slag flowing into the eddy current separator, the speed of the conveyor belt in the eddy current separator, the position of the separation apex, and the rotational speed of the magnetic drum can be adjusted. In eddy current separators with eccentric magnetic drums, the position of the magnets within the drum can also be changed.

[0020] The eddy current separator method is based on the repulsive properties caused by the electrical conductivity of individual particles induced by a changing magnetic field through the eddy current separator. The particle conductivity plays a decisive role in the strength of the particle repulsion. However, successful separation of non-ferrous metals in the slag industry depends on the complex interactions between electrical conductivity, material density, particle size, and the geometry of individual particles.

[0021] For example, aluminum particles, with their low density and high electrical conductivity, are strongly repelled and exhibit significant flight paths, making them easy to separate. In contrast, lead, with its high density and low electrical conductivity, exhibits weaker flight paths and makes separation more difficult.

[0022] Other factors also play a role: flat particles may experience greater air resistance during their flight path, thus weakening the trajectory and making separation more difficult. Small particles, due to their size, exhibit less repulsive force, which also leads to a weakened flight path and thus makes successful separation more difficult. Even when particles enter a magnetic field, their orientation in space can affect separation.

[0023] Therefore, the adjustment of the eddy current separator is not based on calculation formulas, but on empirical values. The selection of the particle size range guided by the same eddy current separator also jointly determines the separation efficiency.

[0024] In eddy current separators, the goal is typically to separate all non-ferrous metals from the mineral slag component. This presents a trade-off: separating more non-ferrous metals leads to an increase in the presence of mineral slag particles in the non-ferrous metal component. Conversely, separating less non-ferrous metals means fewer mineral particles in the non-ferrous metal component, but more non-ferrous metals remain in the mineral slag component. It should be noted that due to the strong heterogeneity of the non-ferrous metals to be separated, a single eddy current separator is insufficient to separate all non-ferrous metal particles with high purity. To achieve high separation efficiency for non-ferrous metals, it is therefore advantageous to process the slag using multiple eddy current separators in series. This is because non-ferrous metal particles that are unsuitably arranged and not separated in the first separation unit may have a more suitable arrangement in the second or subsequent separation units and can therefore be successfully separated. By increasing the number of separation units, the possibility of the non-ferrous metals being suitably positioned for separation in one of the separation units is increased.

[0025] The number of loops before material is conveyed from the loop via the material removal outlet can be addressed using two principles: either by a predefined number of loops or by a level sensor in the first storage container. Using a level sensor in the first storage container is advantageous. Therefore, a batch of material can be processed in the loop until the sensor signals that the first storage container has reached its maximum capacity with new slag. The sensor then signals that the batch in the loop must be removed from the system, allowing a new batch of untreated slag to be conveyed into the loop. This leads to optimized utilization of the material handling facility. Similar loop-like methods can be maximized when there are fluctuations in material inflow at the untreated slag conveyed to the first storage container. Therefore, different batches with different numbers of loops can be processed.

[0026] Advantageously, the feed hopper and vibrating feeder are integrated into a closed-loop process upstream of the first eddy current separator. The feed hopper and subsequent vibrating feeder enable a quantitative and constant delivery of material to the eddy current separator. A vibrating feeder is also integrated upstream of each additional eddy current separator in series to ensure constant delivery.

[0027] To further optimize the separation of non-ferrous metals, it is advantageous to change the position of the separation apex of the vortex separator that separates non-ferrous metals from the mineral slag component according to the cycle. This is because the non-ferrous metal content in the mineral slag component decreases after each cycle, thus causing the separation process of non-ferrous metals from the mineral slag component to behave differently.

[0028] To ensure the high quality of the two main components, it is advantageous to install a system, such as a reversing valve, downstream of the outlet of the eddy current separator for non-ferrous metals. This system can deliver the separated non-ferrous metals to two different pipelines. Using the reversing valve, the separation apex position can be set in the last cycle, separating as much of the remaining non-ferrous metals as possible from the mineral slag aggregate. To achieve complete separation of the non-ferrous metals in the last cycle, a relatively large amount of mineral slag particles, which act as impurities in the separated non-ferrous metal component, must be accepted in this cycle. To ensure that this separation does not degrade the high quality of the previously separated non-ferrous metals, a third component can be generated by manipulating the reversing valve. This third component contains the separated non-ferrous metals from the last cycle processed by the eddy current separator. In addition to the non-ferrous metal component and the mineral slag component, this third component can subsequently be further separated. In the case of multiple eddy current separators connected in series, only the last eddy current separator in series has a reversing valve for the separated non-ferrous metal component. The reversing valve is integrated into the system before the separated non-ferrous metals from the eddy current separator are collected together.

[0029] It is also advantageous that, if the separation of ferromagnetic particles was not performed in the previous processing system, this separation process is carried out in the closed-loop system. Here, the separation of ferromagnetic materials must be carried out upstream of the eddy current separator. Ferromagnetic materials may negatively affect the separation process of non-ferrous metals and damage the magnetic drum in the eddy current separator. If the ferromagnetic material component has not yet been separated, it is advantageous to install a magnetic separator in the pipeline upstream of the outlet of the first storage container and the inlet of the feed hopper. Here, the ferromagnetic particles are separated upstream of the eddy current separator.

[0030] The pipeline between the two storage containers and the feeding hopper or magnetic separator typically consists of a discharge unit located immediately downstream of the storage containers, and a combination of a vibrating conveyor system, conveyor belt, or pipeline system that transports the slag to the feeding hopper or magnetic separator.

[0031] The system essentially processes two products: the mineral slag component, which is primarily in the loop, and non-ferrous metals, such as aluminum, copper, silver, gold, lead, zinc, tin, and palladium, which are separated from the mineral slag component by a vortex separator. Here, the mineral slag component constitutes the vast majority of the composition relative to its quantity. Attached Figure Description

[0032] Advantageous embodiments are shown in the accompanying drawings and described in more detail below. Identical elements partially have the same reference numerals.

[0033] in: Figure 1 A flowchart of a simple apparatus with a reversing valve for the separated non-ferrous metal components from the last cycle is shown. Figure 2 A flowchart of the extended scheme with a second eddy current separator is shown. Figure 3 It showed the same as Figure 2 The flowchart in the diagram includes an extension with additional eddy current separation devices. Figure 4 Displayed based on Figure 1 The flowchart shown is an extended flowchart for a material handling facility. Figure 5 It showed the same as Figure 1 The flowchart in the document includes an extension of the magnetic separator. Detailed Implementation

[0034] exist Figure 1In the material handling facility 1 shown in the flowchart, slag 2 is fed into a first storage container 3. Once the first storage container 3 reaches its maximum capacity with the slag 2, the first cycle begins. Untreated slag 4 is fed through the outlet 5 of the first storage container via a pipeline 6 leading from the first storage container 3 to the feed hopper 7. After the feed hopper 7, the untreated slag 4 is fed along the inlet 27 of an eddy current separator 9 using a vibrating feeder 8. In the eddy current separator 9, the untreated slag 4 is separated for the first time. The eddy current separator 9 has an outlet 10 for the mineral slag component 11 and an outlet 12 for the non-ferrous metal component 13. The mineral slag component 11 is fed into a second storage container 15 via a primary return pipeline 14. During the separation of the untreated slag 4 using the eddy current separator 9, no mineral slag component 11 is fed from the second storage container 15 along the feed hopper 7 via a pipeline 16. Once the entire batch of untreated slag 4 has been conveyed from the first storage container 3, the conveying of additional untreated slag 4 along the direction of the feed hopper 7 is stopped. Once the entire batch of untreated slag 4 from the first storage container 3 has been separated using the eddy current separator 9, a new cycle begins. Mineral slag components 11 are conveyed from the second storage container 15 via pipeline 16 along the direction of the feed hopper 7 through outlet 29. Depending on the size of the slag 2 flowing into the first storage container 3, a certain number of cycles through the eddy current separator 9 can be run. Once the first storage container 3 reaches its maximum capacity with new slag 2, the mineral slag components 11 in the loop are conveyed out of the system via material removal outlet 17. Once the fully treated mineral slag components 11 are removed from the loop via material removal outlet 17, new untreated slag 4 is conveyed from the first storage container 3 along the direction of the feed hopper 7. A new batch of new untreated slag 4 now begins, which is separated using the eddy current separator 9. The conveying from the two storage containers 3, 15 and the unloading of the mineral slag component 11 from the system are coordinated during operation. Furthermore, the flow diagram shows a reversing valve 18 downstream of the outlet 12 for the non-ferrous metal component 13 of the eddy current separator 9. Before the start of the last cycle of a batch, the reversing valve 18 for the separated non-ferrous metal component 13 of the eddy current separator 9 can be switched to allow these separated non-ferrous metal components 19 from the last cycle to be discharged separately.

[0035] exist Figure 2The material handling facility, illustrated as a flow diagram, shows an extended scheme implemented via an additional vibrating feeder 31 and an additional eddy current separator 20 downstream of outlet 10. This eddy current separator 20 further separates the mineral slag component 11 from the additional non-ferrous metal 13 before it is subsequently conveyed to the second storage container 15 via the primary return line 14. The non-ferrous metal components 13 separated by the two eddy current separators 9, 20 are collected together after separation. Furthermore, the flow diagram shows a reversing valve 18 downstream of the outlet 12 of the eddy current separator 20 for the non-ferrous metal component 13. Before the start of the last cycle of a batch, the reversing valve 18 for the separated non-ferrous metal 13 from the eddy current separator 20 can be switched to discharge these separated non-ferrous metal components 19 from the last cycle individually.

[0036] exist Figure 3 In the flowchart shown, Figure 2 The apparatus shown is extended with additional vibratory feeders 32, 33 and eddy current separators 21, 22. For this purpose, the facility has multiple additional vibratory feeders 32, 33 and additional eddy current separators 21, 22 downstream of the outlet 10 for the mineral slag component 11, which further separate the mineral slag component 11 from the non-ferrous metal 13 before it is subsequently conveyed to the second storage container 15 via the primary return line 14. The non-ferrous metal components 13 separated by all the eddy current separators 9, 20, 21, 22 are collected together after separation. Here, in the flow diagram shown, the last eddy current separator 22 in series has a reversing valve 18 downstream of the outlet 12 for the non-ferrous metal component 13.

[0037] If the desired number of circuit cycles for separating non-ferrous metals 13 from untreated slag 4 or mineral slag component 11 cannot be achieved, the material handling facility 1 can be used as follows: Figure 4 The area shown is expanded. By... Figure 1 The facility shown is an extension of the same parallel system, which can double the number of loops for the incoming slag 2. Here, the slag 2 is distributed or halved before reaching the first storage container 3. A portion of the slag 2 is conveyed to the first storage container 3 of the left system 23, and another portion is conveyed to the first storage container 3 of the right system 24. Afterwards, the slag 2... Figure 1 The land was separated as described in the text.

[0038] If the ferromagnetic slag 25 has not yet been separated upstream of the material processing facility 1, the material processing facility 1 can be expanded using a magnetic separator 26. Figure 5 In the flowchart shown, Figure 1The facility shown is extended with a magnetic separator 26. Here, the magnetic separator 26 is integrated into the pipeline 6 between the outlet 5 of the first storage container and the feed hopper 7. This produces untreated slag 4 conveyed along the direction of the feed hopper 7, and ferrous magnetic slag component 25 discharged from the system.

[0039] Typically, material processing facility 1 employs two strategies to improve the separation efficiency of non-ferrous metals. One is as follows: Figure 2 , 3 As shown, the material handling facility is expanded using one or more additional eddy current separation devices 20, 21, 22 in series. Or as in Figure 4 As shown, the amount of slag 2 is halved by an additional parallel system, thereby halving the filling rate of the first storage container 3. This doubles the time for slag batches in the loop and thus doubles the number of cycles. These two strategies can also be combined.

[0040] List of reference numerals in the attached diagram: 1. Material handling facilities 2. Slag 3 First storage container 4. Untreated slag 5. Outlet of the first storage container 6. Piping from the first storage container to the feeding hopper 7 Feeding bin 8 Vibrating feeder 9. Eddy current separation device 10. For the export of mineral slag components 11. Mineral Slag Components 12. Outlet for separated non-ferrous metal components 13 Non-ferrous metal components 14 Primary return pipeline 15 Second storage container 16 Piping from the second storage container to the feeding hopper 17. Material Removal Exit 18. Reversing valve 19 Non-ferrous metal components from the last cycle 20. Additional eddy current separation devices 21. Other eddy current separation devices 22. Other eddy current separation devices 23 Left-side system 24 Right-side system 25. Ferrous magnetic slag 26 Magnetic Separator 27. Inlet of the eddy current separator 28. Inlet of the vibrating feeder 29. The outlet of the second storage container 30. Mineral slag discharged from the system 31. Other vibrating feeders 32. Other vibrating feeders 33 Other vibrating feeders

Claims

1. A material processing facility (1) for separating non-ferrous metals (13) from slag (2), said material processing facility (1) having an eddy current separation device (9). - The eddy current separator (9) has an inlet (27) for untreated slag (4) or mineral slag components (11). - For the outlet (10) of the mineral slag component (11), and - Outlet (12) for the separated non-ferrous metal components (13). Its features are, - A first storage container (3) is arranged upstream of the inlet (27) for untreated slag (4). - The first storage container (3) has an outlet (5) for untreated slag (4) of the first storage container (3). - The pipeline (6) leading from the outlet (5) to the inlet (27) of the eddy current separator (9), and - A primary return line (14) from the outlet (10) for the mineral slag component (11) to the second storage container (15). - The second storage container (15) has an outlet (29) and a pipeline (16) leading from the outlet (29) to the inlet (27) of the eddy current separator (9).

2. The material handling facility according to any one of the preceding claims, characterized in that, In the primary return line (14), upstream of the second storage container (15), there is a material removal outlet (17) for the mineral slag component (11).

3. The material handling facility according to any one of the preceding claims, characterized in that, A vibrating feeder (8) is arranged upstream of the inlet (27) of the eddy current separator (9).

4. The material handling facility according to any one of the preceding claims, characterized in that, A feeding bin (7) is arranged upstream of the inlet (28) of the vibrating feeder (8).

5. The material handling facility according to any one of claims 2 to 4, characterized in that, Another vibrating feeder (31) and a subsequent eddy current separator (20) are arranged between the outlet (10) for the mineral slag component (11) and the material removal outlet (17).

6. The material handling facility according to any one of claims 2 to 4, characterized in that, A plurality of additional vibrating feeders (32, 33) and additional eddy current separators (21, 22) are arranged between the outlet (10) for the mineral slag component (11) and the material removal outlet (17).

7. The material handling facility according to any one of claims 4 to 6, characterized in that, A magnetic separator (26) is arranged between the outlet (5) for untreated slag (4) and the inlet of the feeding bin (7).

8. The material handling facility according to any one of the preceding claims, characterized in that, A reversing valve (18) is arranged downstream of the outlet (12) for the separated non-ferrous metal component (13).

9. A method for using the material handling facility (1) according to any one of the preceding claims, characterized in that, The material is processed in batches, and the slag (2) is supplied to the eddy current separator (9) at least twice.

10. The method according to claim 9, characterized in that, During the processing of untreated slag (4), slag (2) from which non-ferrous metals (13) have not yet been separated is stored in the first storage container (3).

11. The method according to claim 9 or 10, characterized in that, A batch of untreated slag (4) is discharged from the loop after a certain number of cycles in the material handling facility (1), and then a new batch of slag (2) from the first storage container (3) is supplied to the feed hopper (7) via the outlet (5).

12. The method according to any one of claims 9 to 11, characterized in that, Material batches are conveyed in the loop system until the incoming slag (2) reaches the predefined filling height of the first storage container (3).

13. The method according to any one of claims 9 to 11, characterized in that, The amount of slag (2) flowing into the first storage container (3) per unit time can be adjusted to change the number of slag batches circulated in the material processing facility (1).

14. The method according to any one of claims 9 to 13, characterized in that, The apex position of the eddy current separation device (9) used to separate the non-ferrous metal component (13) is changed after at least one cycle, and preferably after each cycle.

15. The method according to any one of claims 9 to 14, characterized in that, The slag is derived from a waste incineration facility and has a moisture content of less than 5 wt%.

16. The method according to any one of claims 9 to 18, characterized in that, The slag components to be treated have a particle size of less than 100 mm.

17. The use of a material processing facility (1) according to any one of claims 1 to 8 for processing bottom ash from waste incineration.

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