Material treatment plant and process for treating mixed materials

Abstract

The invention relates to a material treatment plant with a primary separation unit having an inlet for mixed material, an outlet for a first fraction and an outlet for a second fraction, and a method for treating mixed material in a primary separation unit in which a first fraction is separated from a second fraction. The invention is therefore based on the objective of proposing a material treatment plant and a method to provide particularly pure material products from a mixed material.

Description

[0001] The invention relates to a material treatment plant with a primary separation unit having an inlet for mixed material, an outlet for a first fraction and an outlet for a second fraction, and to a method for treating mixed material in a primary separation unit in which a first fraction is separated from a second fraction.

[0002] Such devices and processes are designed to achieve particularly high separation efficiency of various products with particularly high purity; in particular, non-metallic material, heavy non-ferrous metals, and light non-ferrous metals should be separated.

[0003] The invention is therefore based on the object of proposing a material treatment plant and a method for providing particularly pure material products from a mixed material.

[0004] The object underlying the invention is achieved with a material treatment plant having the features of patent claim 1.

[0005] Advantageous further training is the subject of the subclaims.

[0006] It is advantageous to have a first storage tank upstream of the mixed material inlet. A second storage tank can also be arranged in the primary return line. This allows for precise metering of the mixed material flow and the control of the material flow proportions.

[0007] The two storage tanks aren't absolutely necessary. But without storage, you'd have to calculate how much material there actually is room for in the circuit. If new mixed material is fed into the circuit, it could happen that at some point the processed material has already completed a cycle and is fed back towards the primary separation unit. However, if new material is still being fed from the first storage tank, the amount to be processed increases until the system eventually reaches its limit and the primary separation unit is overloaded. Installing two storage tanks of equal size, if possible, ensures that there is enough space for the material in the circuit. The primary separation unit usually has the lowest throughput of the individual components in the circuit, making it the bottleneck.

[0008] For continuous or discontinuous withdrawal, a material withdrawal outlet for the first fraction can be arranged in the primary return line.

[0009] In order to improve the separation efficiency of the second fraction, another primary separation unit or several additional primary separation units can be arranged between the outlet for the first fraction and the primary return line.

[0010] The primary separation unit and the at least one additional primary separation unit preferably comprise an eddy current separator. There are various types of eddy current separators. The basic variants primarily relate to the position and number of magnets within the magnetic drum. Eddy current separators are available as eccentric and centric, and can be used depending on the material composition.

[0011] The eddy current separator process is based on the repulsion property of the electrical conductivity of individual particles, which is induced by a changing magnetic field of the eddy current separator. The electrical conductivity of the particles is crucial for the strength of the repulsion. However, the successful separation of non-ferrous metals, for example, in the slag industry, depends on a complex interaction between electrical conductivity, material density, particle size, and the geometry of the individual particles.

[0012] For example, aluminum particles, which have a low density and high electrical conductivity, are strongly repelled and have a distinct trajectory, allowing for easy separation. In contrast, lead particles have a high density and low electrical conductivity, which weakens the trajectory and makes separation difficult.

[0013] Other factors also play a role: Flat particles can experience greater air resistance during their trajectory, which weakens the trajectory and makes separation more difficult. Small particles have less repulsion due to their size, which can also lead to a weaker trajectory and thus complicate successful separation. Even the orientation of the particles in space influences separation when they enter the magnetic field.

[0014] Therefore, the adjustment of an eddy current separator is not based on a calculation formula, but rather on empirical values. The selection of the particle size range that is passed through the same eddy current separator also determines the separation efficiency.

[0015] The goal of an eddy current separator is usually to separate all metals from a non-metallic fraction. This results in a compromise: separating more metals leads to an increased presence of non-metallic particles in the metal fraction. On the other hand, separating fewer metals means that fewer non-metallic particles are present in the metal fraction, but more metals remain in the non-metallic fraction. It should be noted that due to the highly heterogeneous properties of the non-ferrous metals to be separated, a single eddy current separator is not sufficient to separate all non-ferrous metal particles with high purity. To achieve high separation efficiency for the non-ferrous metals, it is therefore advantageous to process the material mixture with several eddy current separators.

[0016] As a rule, valuable metals are the most difficult to separate. To achieve greater separation of valuable metals, a larger amount of non-metallic particles in the separated metal fraction is accepted. If all valuable metals are to be separated, the light metal fraction will have a high degree of purity after the subsequent density separation process, since almost all non-metallic particles end up in the light metal fraction.

[0017] Instead of an eddy current separator, a combination of a crusher and a screen can also be used. Crusher-like substances, such as mineral aggregates in particular, are broken up and reduced in size by the crusher, while less easily crushed substances, such as metals in particular, are deformed at most but are not reduced in size by crushing. The screen can then be used to separate the smaller particles, particularly mineral ones, from the larger, metallic particles.

[0018] To increase the purity of the light particles, a secondary separation unit can be installed downstream of the light particle outlet after the density separation process. With an additional secondary separation unit after the density separation process, it is now possible to more effectively separate the light metal fraction from unwanted non-metallic particles. Since the difficult-to-separate heavy (valuable) metals are now separated during the density separation process, the separation process of light metals and non-metallic particles is greatly simplified using the secondary separation unit.

[0019] A secondary return line can lead from one outlet of the secondary separation unit to the inlet of the primary separation unit. A fraction, such as light metals, then collects at the other outlet of the secondary separation unit. The return line leads either directly or preferably through the second storage tank to the inlet of the primary separation unit.

[0020] In order to improve the total separation efficiency at the secondary separation unit, another secondary separation unit or several additional secondary separation units, such as eddy current separators, can be arranged between the outlet for a third fraction, the non-separated material, and the secondary return line.

[0021] The secondary separation unit preferably comprises an eddy current separator. As with the primary separation unit, a combination of a crusher and a screen can also be used as the secondary separation unit.

[0022] A secondary separation unit, and especially a secondary eddy current separator after the density separation process, is particularly advantageous. For example, with the first eddy current separator, one can focus on separating the valuable metals and disregard the proportion of unwanted non-metallic particles. A larger quantity of non-metallic particles can be accepted, as they are easily separated from the light metals after the density separation process with the secondary eddy current separator. Therefore, the secondary eddy current separator has a significant influence on the separated quantity of heavy metals and the purity of the light metals, and thus also on the non-metallic fraction.

[0023] The density separation unit can, for example, utilize a sink-float process. An air-tight table separator with at least two end products has proven particularly advantageous. An air-tight table separator, in particular, refers to air table separators that can separate particles by varying the following variables, among others: air injection rate, vibration intensity, end tilt, and side tilt. Air is injected from below through a porous ceiling, enabling effective sorting into different density ranges. The ceiling tilt and simultaneous upward flow cause light particles to slide downward, while the vibration moves heavy particles upward, thus enabling sorting by density.

[0024] To prevent a bottleneck in the density separation unit, a screen can be used upstream of the density separation unit to divide the material flow.

[0025] It is also advantageous if several density separation units are arranged in parallel.

[0026] The problem underlying the invention is also solved by a method having the features of patent claim 17.

[0027] This process, for example, leads to a highly selective separation of various non-ferrous metals.

[0028] The heavy particles are usually heavy non-ferrous metals and the light particles are usually lighter non-ferrous metals.

[0029] The second fraction is preferentially fed to another primary separation unit before being treated again in the primary separation unit using the primary return line.

[0030] The light particles separated in the density separation unit can be fed as a light fraction to a secondary separation unit.

[0031] The particles not separated are preferably fed to another secondary separation unit before being treated again in the primary separation unit.

[0032] The unseparated fractions of the secondary separation units can then be fed to the primary separation unit directly or via the second storage tank.

[0033] The process according to the invention could be carried out continuously if properly adjusted. It is preferably carried out as a batch process, with the first fraction being fed to the primary separation unit at least twice. It is fed to the primary separation unit the first time as part of the mixed material, and the second time as the fraction of material not separated in the primary separation unit. This cycle can be repeated as often as required before the material is removed from the cycle. Particularly with several primary separators connected in series, a single primary cycle may be sufficient.

[0034] The material treatment plant and process can be used anywhere a fraction such as non-ferrous metals is to be recovered or separated using a separation unit, particularly an eddy current separator. For example, when processing shredder scrap, construction rubble, domestic waste, packaging waste, bottom ash from waste incineration, aluminum salt slag, electronic scrap, wood chips, glass, or molding sand. Therefore, the process is designed to first separate non-ferrous metals, such as aluminum, from non-metallic materials, such as stone, in a primary separation unit.

[0035] Considering the overall system using the example of slag, there are essentially three products to be treated: the non-metallic particles, which are mostly located in the primary circuit, the heavy metals, which are separated as heavy non-ferrous metals such as copper, silver, gold, lead, zinc, tin and palladium by the density separation process, and the light metals, which are separated as light non-ferrous metals such as aluminum by the second eddy current separator.

[0036] Advantageous embodiments are illustrated in the figures and are described in more detail below. Identical elements have partly the same reference numerals. Fig. 1 a flow diagram of a simple device, Fig. 2 a flow diagram with an extension by a secondary separation unit, Fig. 3 a flowchart as in the Fig. 2, which is expanded with additional primary and secondary separation units, Fig. 4 an adapted flowchart based on the one in the Fig. 2 shown flow diagram for a material treatment plant, Fig. 5 an extended flowchart based on the one in the Fig. 2 shown flow diagram for a material treatment plant and Fig. 6 an alternative to the Fig. 5 shown flowchart.

[0037] In the Fig. 1, the mixed material 4 is conveyed into the first storage tank 16. As soon as the valve 31 below the first storage tank 16 opens, the first cycle of the mixed material 4 begins. The mixed material 4 is conveyed from the first storage tank 16 to the primary separation unit 2. In the primary separation unit 2, the mixed material 4 is separated for the first time. The separation unit has an outlet 5 for a first fraction 6 and an outlet 7 for a second fraction 8. The first fraction is conveyed into a second storage tank 17 via the primary return line 9. During the separation of the mixed material 4 with the primary separation unit 2, the valve 31 below the second storage tank 17 is closed. As soon as all of the mixed material 4 has been conveyed from the first storage tank 16, the valve 31 below the first storage tank 16 is closed.The two similarly sized storage tanks ensure that new mixed material 4 does not mix with the first fraction 6. As soon as all of the mixed material 4 from the first storage tank 16 has been separated by the primary separation unit 2, the valve 31 below the second storage tank 17 is opened and a new cycle begins. Depending on the mass flow of the incoming mixed material 4 into the first storage tank, a certain number of cycles can be run. As soon as the first storage tank 16 is filled with new mixed material 4, the first fraction 6, which is in the circuit, is removed from the system via the material removal unit 18. As soon as the entire first fraction 6 has been removed from the circuit, the valve 31 below the first storage tank 16 is opened again. A new batch now begins with new mixed material 4, which is separated using the primary separation unit 2.The second fraction 8, which is separated by the primary separation unit 2, is conveyed via a line 10 to a density separation unit 11. The density separation unit 11 has an outlet 12 for a fraction containing heavy particles 13 and an outlet 14 for a fraction containing light particles 15. This system generates three end products: the heavy particles 13, the light particles 15, and the first fraction 6, which is separated from the second fraction 8.

[0038] The Fig. The material treatment plant shown in Figure 2 as a flow diagram shows an expansion by a secondary separation unit 22 after the outlet 14 for light particles 15 separated by the density separation unit 11. After the density separation unit 11, the fraction of light particles 15 is conveyed to the secondary separation unit 22 via line 32 for the light particles. The secondary separation unit 22 separates the fraction of light particles 15 into two fractions. The secondary separation unit has an outlet 24 for the separated particles, mostly light metals, and an outlet 33 for unseparated material 30, which is conveyed to the second storage tank 17 via a secondary return line 23.

[0039] In the Fig. The flowchart shown in Figure 3 is the Fig. 2 is expanded with additional primary and secondary separation units. For this purpose, the system has several additional primary separation units 19, 20, 21 after the outlet 5 for the first fraction 6, which separate the first fraction again before the first fraction 6 is then conveyed into the second storage tank 17 via the primary return line 9. Between the outlet 33 of the secondary separation unit 22 for unseparated material 30 and the secondary return line 23, as shown in the Fig. 3, one or more further secondary separation units 25, 26, 27 may be integrated.

[0040] In case of an excessive material flow of the second fraction 8, the density separation unit can be switched off as in the Fig. 4 shown. The second fraction 8 is conveyed after the outlet 7 from the primary separation unit 2 via a screen 28, which separates the second fraction 8 with the screen 28 into a fraction with smaller particles 34 and a fraction with larger particles 35. Both fractions are then conveyed to two separate density separation units 11, 29. After separation into a fraction with heavy particles 13 and a fraction with light particles 15 by the density separation units, the light particles 15 from the two density separation units are combined and conveyed to the secondary separation unit 22. The rest of the system is identical to that shown in the Fig. 2 shown system.

[0041] In a case where the desired number of circuits for the separation of the second fraction from the mixed material or the first fraction is not achieved, the material treatment plant can be operated as described in the Fig. 5. By extending the Fig. 2 with an identical system, the number of circuits for the incoming mixed material 4 or the first fraction 6 can be doubled. The mixed material 4 is divided or halved before it reaches the first storage container 16. One part of the mixed material is conveyed to the first storage container 16 of the left system, the other part is conveyed to the first storage container 16 of the right system. The mixed material 4 is then, as shown in Fig. 2 explained, separated.

[0042] The Fig. 6 shows a flow chart, which is again based on the Fig. The flow diagram shown in Figure 2 is based on an alternative system in case the desired number of circuits for the separation of the second fraction from the mixed material or the first fraction is not achieved. After opening the valve 31 below the first storage tank 16, the mixed material 4 is fed into two identical circuits as shown in Figure 2. Fig. 2 described systems. After both fractions of the separated mixed material 4 have been separated by the primary separation unit 2, the first fractions 6 of the two systems are combined after the outlet 5 and conveyed into the second storage tank 17. In addition, the non-separated material 30 is also combined after the outlet 33 of the secondary separation units 22 and conveyed into the same second storage tank 17 via a common secondary return line 23. The rest of the flow diagram is identical, as in the Fig.2 described.

[0043] Generally, the first circuit always shows a division of two material streams: In the particularly relevant example of metal separation, the separated metals are conveyed toward the density separation process, and the non-metallic particles are usually conveyed back via a second storage container. The material (the separated metals from the first eddy current separator), which is processed using the density separation process, is divided into two products. Nothing further is done with the heavier particles (higher density) after the density separation process. The lighter particles (low density) are then separated again using the subsequent eddy current separator, with the separated product being the end product, and the non-separated material being returned to the primary circuit. 1 1 material treatment plant 2 primary separation unit 3 Input for mixed material 4 Mixed material 5 Exit for the first group 6 first faction 7 Exit for the second group 8 second faction 9 primary return line 10 Leadership for the second faction 11 Density separation unit 12 Outlet for heavy particles 13 heavy particles 14 Exit for light particles 15 light particles 16 first storage tank 17 second storage tank 18 Material withdrawal exit 19 additional primary separation unit 20 additional primary separation units 21 additional primary separation units 22 secondary separation unit 23 secondary return line 24 Output of the secondary separation unit 25 additional secondary separation unit 26 additional secondary separation units 27 additional secondary separation units 28 sieve 29 additional density separation unit 30 unseparated fraction of the secondary separation unit 31 Valve 32 Line for light particles 33 Output for non-separated material 34 smaller particles 35 larger particles

Claims

[1] Material treatment plant (1) with a primary separation unit (2) having an inlet (3) for mixed material (4), an outlet (5) for a first fraction (6) and an outlet (7) for a second fraction (8), characterized by that a primary return line (9) leads from the outlet (5) for the first fraction (6) to the inlet (3) for mixed material (4) and a line (10) for the second fraction (8) leads to a density separation unit (11) which has an outlet (12) for heavy particles (13) and an outlet (14) for light particles (15). [2] Material treatment plant according to claim 1, characterized by that a first storage container (16) is arranged in front of the inlet (3) for mixed material (4). [3] Material treatment plant according to one of the preceding claims, characterized by that a second storage tank (17) is arranged in the primary return line (9). [4] Material treatment plant according to one of the preceding claims, characterized by that a material removal outlet (18) for the first fraction (6) is arranged in the primary return line (9). [5] Material treatment plant according to one of the preceding claims, characterized by that a further primary separation unit (19) is arranged between the outlet (5) for the first fraction (6) and the primary return line (9). [6] Material treatment plant according to claim 5, characterized by that several further primary separation units (20, 21) are arranged between the outlet (5) for the first fraction (6) and the primary return line (9). [7] Material treatment plant according to one of the preceding claims, characterized by that the primary separation unit (2 & 19 to 21) has an eddy current separator. [8] Material treatment plant according to one of the preceding claims, characterized bythat a secondary separation unit (22) is connected downstream of the outlet (14) for light particles (15). [9] Material treatment plant according to claim 8, characterized by that a secondary return line (23) leads from an outlet (33) of the secondary separation unit (22) to the inlet of the primary separation unit (2). [10] Material treatment plant according to claim 8 or 9, characterized by that the secondary separation unit has an eddy current separator. [11] Material treatment plant according to one of the preceding claims, characterized by that a further secondary separation unit (25) is arranged between the outlet (33) of the secondary separation unit (22) and the secondary return line (23). [12] Material treatment plant according to claim 11, characterized bythat several further primary separation units (26, 27) are arranged between the outlet (33) of the secondary separation unit (22) and the secondary return line (9). [13] Material treatment plant according to one of the preceding claims, characterized by that the secondary separation unit (22, 25 to 27) has an eddy current separator. [14] Material treatment plant according to one of the preceding claims, characterized by that the density separation unit (11) has an air density table separator. [15] Material treatment plant according to one of the preceding claims, characterized by that a sieve (28) is used upstream of the density separation unit (11) to divide the material flow in order to prevent a bottleneck in the density separation unit (11). [16] Material treatment plant according to one of the preceding claims, characterized by that several density separation units (11, 29) are arranged in parallel. [17] Method for treating mixed material (4) in a primary separation unit (2) in which a first fraction (6) is separated from a second fraction (8), characterized by that the first fraction (6) is treated again in the primary separation unit (2) and the second fraction (8) is fed to a density separation unit (11) in order to separate heavy particles (13) from light particles (15). [18] Method according to claim 17, characterized by that the first fraction (6) is fed to a further primary separation unit (19) before being treated again in the primary separation unit (2). [19] Method according to claim 17 or 18, characterized by that the light particles are fed to a secondary separation unit (22). [20] Method according to claim 19, characterized by that a non-separated fraction (30) of the secondary separation unit is fed to the primary separation unit (2). [21] Method according to one of claims 17 to 20, characterized by that the process is carried out as a batch process and the first fraction (6) is fed to the primary separation unit (2) at least twice. [22] Method according to one of claims 17 to 21, characterized by that the first fraction (6) is non-metallic materials and the second fraction (8) is non-ferrous metals. [23] Use of the material treatment plant according to one of claims 1 to 16 for treating shredder scrap, construction rubble, domestic waste, packaging waste, bottom ash from waste incineration, aluminium-salt slag, electronic scrap, wood chip mixtures or mixtures with glass or moulding sand.

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