Recovery system for metallic aluminum in aluminum ash

Abstract

The utility model discloses a recovery system for metallic aluminum in aluminum ash. The recovery system comprises a feeding mechanism and a stepped crushing and screening mechanism which are sequentially connected in series. The stepped crushing and screening mechanism comprises a plurality of crushing devices which are sequentially arranged from top to bottom, a screening device is arranged below each crushing device, and the apertures of screening holes of the multiple screening devices are gradually reduced from top to bottom. The stepped crushing and screening mechanism is arranged for carrying out stepped separation treatment on primary aluminum ash, the phenomenon that impurities are secondarily coated in the grinding process of large-particle metal aluminum sheets is effectively avoided, the separation efficiency of metal aluminum and the impurities is remarkably improved, meanwhile, the follow-up refining and purifying procedure of secondary aluminum ash is facilitated, and the device has the advantages of being simple in structure, low in cost and the like. The method has the advantages of simple process, easiness in operation, high aluminum recovery efficiency, low equipment investment cost, high practicability and applicability and the like.

Description

Technical Field

[0001] The utility model relates to aluminum ash slag processing equipment, in particular to a recovery system of metal aluminum in the aluminum ash slag, belonging to the technical field of aluminum ash slag resource processing. Background Art

[0002] Primary aluminum slag is an important waste in the aluminum industry, in which the aluminum content can reach 10-80%. Recycling aluminum resources from aluminum slag can reduce costs, protect the environment, save energy and improve resource utilization, which has huge economic and social effects.

[0003] Recovering aluminum from primary aluminum ash not only recovers organic metals, but also facilitates the subsequent harmless treatment of aluminum ash after the recovery of aluminum. At present, there are many studies on the recovery of aluminum from primary aluminum ash, and a series of equipment has been developed on the market. For example, a Chinese patent with the publication number of "CN214636791U" discloses a grinding and screening device for recycling aluminum ash slag, including a device box, a grinding assembly and a screening assembly. The device box is hinged with a sealing cover, a discharge plate is hinged on the side wall, and a collecting box is provided at the bottom; the grinding assembly includes a grinding seat, a grinding roller and a first motor, the grinding seat is arranged at the top of the device box, the grinding seat is provided with a material passing hole, the grinding roller is connected with a rotating shaft, the rotating shaft is connected to the device box through a bearing seat, the first motor provides power for the rotating shaft, the screening assembly includes a movable screen and a second motor, the two side walls of the device box are respectively provided with a through groove and a mounting box, the two ends of the movable screen are respectively engaged with the through groove and extend into the mounting box, one of the mounting boxes is provided with a reset tension spring connected to the end of the movable screen, and the second motor is connected to the movable screen through an intermittent gear; the above device utilizes the good ductility of aluminum particles in aluminum ash slag, and the aluminum particles become larger after grinding, and metallic aluminum can be recovered from the primary aluminum ash slag through screening. However, there is still a problem of low efficiency in recycling aluminum metal, because the aluminum metal ash contains a wide range of particle sizes, including large aluminum metal flakes (particles) and fine aluminum particles. When the large aluminum flakes and small aluminum particles are uniformly ground with a grinding roller, the grinding effect is not good, and there are the following problems: because the large aluminum flakes themselves have a large particle size, they may contain impurities again after re-grinding, which not only increases the workload but also is not conducive to subsequent refining and purification. Utility Model Content

[0004] In view of the problem in the prior art that the separation efficiency of metallic aluminum and impurities is low when roller grinding is performed on primary aluminum ash slag, the utility model provides a system for recovering metallic aluminum in aluminum ash slag, which performs step-by-step separation treatment on the primary aluminum ash slag by arranging a step-by-step crushing and screening mechanism, effectively avoiding the phenomenon of secondary coating of impurities during the grinding process of large-particle metallic aluminum sheets, significantly improving the separation efficiency of metallic aluminum and impurities, and also facilitating the subsequent refining and purification process of the secondary aluminum ash slag.

[0005] In order to achieve the above technical objectives, the technical solutions adopted by the present utility model are specifically described as follows:

[0006] A system for recovering metallic aluminum from aluminum ash slag comprises a feeding mechanism and a step-by-step crushing and screening mechanism which are sequentially arranged in series. The step-by-step crushing and screening mechanism comprises a plurality of crushing devices which are sequentially arranged from top to bottom, a screening device is arranged below each crushing device, and the apertures of the screen holes of the plurality of screening devices gradually decrease from top to bottom.

[0007] Preferably, the step crushing and screening mechanism is a two-stage double-chamber crushing and screening mechanism, including a large bin, a small bin, a first crushing roller, a first screen, a second screen, a second crushing roller and a third screen. The small bin is arranged on one side of the large bin, and the upper feed port and the lower discharge port of the small bin are both connected to the inner cavity of the large bin. The first crushing roller, the first screen and the second screen are arranged in the inner cavity of the large bin from top to bottom, and the upper discharge port of the second screen is connected to the upper feed port of the small bin. The second crushing roller and the third screen are both arranged in the inner cavity of the small bin, and the second crushing roller is located above the third screen. The large bin is also provided with a top feed port and a bottom discharge port connected to its inner cavity.

[0008] Preferably, the first crushing roller is a pair of coarse crushing rollers, and the gap between the two coarse crushing rollers is 20-40 mm, preferably 25-35 mm.

[0009] Preferably, a first driving motor for driving the first crushing roller is also arranged on the outer wall of the large bin body corresponding to the first crushing roller.

[0010] Preferably, the first screen is arranged in an inclined shape in the inner cavity of the large bin. A first vibration cavity is arranged on the outer wall of the large bin corresponding to the higher end of the first screen, and a first vibration motor connected to the first screen is arranged in the first vibration cavity. A first material collection cavity is arranged on the outer wall of the large bin corresponding to the lower end of the first screen, and the feed port of the first material collection cavity is connected to the screen discharge port located at the lower end of the first screen.

[0011] Preferably, the aperture of the first sieve is 20-35 mm, preferably 25-30 mm.

[0012] Preferably, the second screen is arranged in an inclined shape in the inner cavity of the large bin. A second vibration cavity is arranged on the outer wall of the large bin corresponding to the higher end of the second screen, and a second vibration motor connected to the second screen is arranged in the second vibration cavity. The upper discharge port of the second screen is located at its lower end.

[0013] Preferably, the second sieve has a mesh size of 5-15 mm, preferably 8-12 mm.

[0014] Preferably, the second crushing roller is a pair of grinding rollers, and the gap between the two grinding rollers is 5-12 mm, preferably 8-10 mm.

[0015] Preferably, a second driving motor for driving the second crushing roller is also arranged on the outer wall of the small bin body corresponding to the second crushing roller.

[0016] Preferably, the third screen is arranged in an inclined shape in the inner cavity of the small bin body. A third vibration cavity is arranged on the outer wall of the small bin body corresponding to the higher end of the third screen, and a third vibration motor connected to the third screen is arranged in the third vibration cavity. A second material collection cavity is arranged on the outer wall of the small bin body corresponding to the lower end of the third screen, and the feed port of the second material collection cavity is connected to the upper screen discharge port located at the lower end of the third screen. Preferably, the lower screen discharge port of the third screen is connected to the lower discharge port of the small bin body through a material chute inclined plate.

[0017] Preferably, the third sieve has a mesh size of 5-10 mm, preferably 6-8 mm.

[0018] Preferably, the feeding mechanism includes a material grabber, a material bag and a bag breaker. Preferably, the material grabber is one of an electric hoist, a belt feeder, a mechanical arm claw and a bucket elevator arranged on one side of the step crushing and screening mechanism. The bag breaker is a bag breaker cone arranged at the top feed port of the step crushing and screening mechanism.

[0019] Preferably, the recovery system further comprises a ball mill. The bottom discharge port of the large bin body is connected to the feed port of the ball mill via a chute and / or a belt scale.

[0020] Preferably, the recycling system further comprises a fine material screening machine. The discharge port of the ball mill is connected to the feed port of the fine material screening machine through a discharge buffer hopper. The upper discharge port of the fine material screening machine is connected to the feed port of the aggregate box, and the lower discharge port is connected to the feed end of the miscellaneous material transfer belt conveyor. Preferably, the sieve hole diameter of the fine material screening machine is not greater than 5 mm, preferably 1-5 mm.

[0021] In the utility model, in view of the problem in the prior art that, due to the wide particle size range of metallic aluminum mixed in primary aluminum ash slag, when grinding rollers are used to uniformly grind large-particle aluminum flakes and small-particle aluminum particles, the large-particle aluminum flakes themselves may be wrapped with impurities again after re-grinding, the utility model relates to a recovery system for metallic aluminum in aluminum ash slag with a stepped crushing and screening mechanism, the stepped crushing and screening mechanism comprises a plurality of crushing devices arranged in sequence from top to bottom, and a screening device is arranged under each crushing device, and the sieve apertures of the plurality of screening devices gradually decrease from top to bottom, that is, the primary aluminum ash slag with a wide particle size range is stepped crushed and separated by the stepped crushing and screening mechanism, which effectively avoids the phenomenon that the large-particle aluminum flakes themselves may be wrapped with impurities again after re-grinding, thereby recovering as much metallic aluminum mixed in the aluminum ash slag as possible, and significantly improving the recovery efficiency of metallic aluminum by avoiding light.

[0022] In the utility model, the stepped crushing and screening mechanism is a two-stage double-chamber crushing and screening mechanism, including a large bin and a small bin, each of which has an inner cavity (both the bins are steel structures), and the upper and lower parts of the inner cavity of the small bin are connected to the inner cavity of the large bin (i.e., the upper feed port and the lower discharge port of the inner cavity of the small bin). A pair of coarse crushing rollers (i.e., the first crushing rollers) are provided at the upper part of the inner cavity of the large bin, and the gap between the two rollers is 20-40mm (the coarse crushing rollers are driven by the first drive motor, and the first drive motor is generally arranged on the floor slab outside the corresponding large bin), and the coarse crushing rollers are mainly used to crush and refine the large particles in the primary aluminum ash slag. A first screen mesh is arranged at an angle below the coarse crushing roller, the aperture of the first screen mesh is 20-35 mm, the lower end of the first screen mesh extends out of the large warehouse body and extends to the first aggregate cavity, the higher end of the first screen mesh extends out of the large warehouse body and extends into the first vibration cavity, and is connected to the first vibration motor in the first vibration cavity. The material on the first screen mesh rolls down along the screen mesh surface into the first aggregate cavity under the vibration action of the first vibration motor. A second screen mesh is arranged at an angle below the first screen mesh (opposite to the tilt direction of the first screen mesh), the aperture of the second screen mesh is 5-15 mm, the lower end of the second screen mesh extends out of the large warehouse body and extends into the inner cavity of the small warehouse body, the higher end of the second screen mesh extends out of the large warehouse body and extends into the second vibration cavity, and is connected to the second vibration motor in the second vibration cavity. The material on the second screen mesh rolls down along the screen mesh surface into the inner cavity of the small warehouse body under the vibration action of the second vibration motor. A pair of grinding rollers (i.e., the second crushing rollers) are provided at the upper part of the inner cavity of the small silo body, and the gap between the pair of grinding rollers is 5-12mm (the grinding rollers are driven by the second drive motor, and the second drive motor is generally arranged on the floor slab outside the corresponding small silo body); a third screen is provided below the grinding roller, and the aperture of the third screen is 5-10mm. The lower end of the third screen extends out of the small silo body and extends into the second aggregate cavity, and the higher end of the third screen extends out of the small silo body and extends into the third vibration cavity, and is connected to the third vibration motor in the third vibration cavity. The material on the third screen rolls down along the surface of the screen into the second aggregate cavity under the vibration of the third vibration motor. A material slitting inclined plate is also provided at the bottom of the inner cavity of the small silo body, and the material under the third screen rolls down into the lower part of the inner cavity of the large silo body through the material slitting inclined plate, and is finally discharged through the bottom of the large silo body (for example, feeding to a belt scale through a chute).

[0023] In the present invention, the feeding mechanism includes a grabber, a bag and a bag breaker. The grabber is one of an electric hoist, a belt feeder, a mechanical arm claw and a bucket elevator arranged on one side of the step crushing and screening mechanism (generally, any existing equipment that can be used to transport the bag containing primary aluminum ash to the top feed port of the large bin body). The bag breaker is a bag breaking cone arranged at the top feed port of the large bin body (preferably, a lower hopper is arranged at the feed port at the top of the large bin body, and the bag breaking cone can be arranged in the lower hopper).

[0024] In the utility model, the packaged primary aluminum ash slag raw material is lifted by the grabber to the top of the stepped crushing and screening mechanism, and then falls through the bag breaker set at the top feed port of the large bin body to pierce the packaging bag and enter the inner cavity of the large bin body, and then firstly passes through a pair of coarse crushing rollers to break up the raw material, and then passes through the first screen to screen out the large aluminum flakes mixed in the raw material. The material under the first screen continues to be screened by the second screen, and the medium-sized material on the second screen enters the small bin body and is ground by a pair of grinding rollers. On the one hand, the medium-sized material can be ground finely to facilitate subsequent ball milling, and on the other hand, the aluminum particles in the medium-sized material can be ground larger (aluminum has good ductility, and the volume of aluminum particles increases after grinding, and the particle size of medium-sized aluminum particles itself is not large, and it is not easy to wrap impurities when grinding them); after being ground by the grinding rollers, the third screen is used for screening, and the ground medium-sized aluminum particles in the primary aluminum ash slag can be further sorted out. The third screen The material under the screen is collected again inside the large warehouse through the chute inclined plate and then fed to the belt scale through the chute. The belt scale can measure the amount of raw materials entering the ball mill and transport the raw materials after pre-treatment and aluminum extraction to the feed end of the ball mill. The material enters the ball mill for further grinding. The grinding of the steel balls inside the ball mill can further grind the fine aluminum particles mixed in the material. The ball-milled material is discharged to the discharge buffer hopper and then fed to the vibrating screen (i.e., fine material screening machine) for screening. After screening, the aluminum flakes on the screen enter the aggregate box, and the finely ground material under the screen is transported to the downstream process by the belt conveyor for harmless treatment. The aluminum particles collected in the first aggregate cavity, the second aggregate cavity, and the aggregate box are all sent to the aluminum melting device for melting treatment, and the molten ingot is cooled to obtain aluminum ingots.

[0025] Compared with the prior art, the beneficial technical effects of the utility model are as follows:

[0026] 1: The utility model can recover the large aluminum flakes and medium-sized aluminum particles mixed in the primary aluminum ash slag in advance through the stepped crushing and screening mechanism, and can further recover the fine aluminum particles from the aluminum ash slag after preliminary grinding and ball milling of the primary aluminum ash slag. The stepped crushing and screening mechanism cooperates with the ball mill to form a three-level three-selection system, thereby efficiently recovering the metallic aluminum in the primary aluminum ash slag.

[0027] 2: The system for recovering metallic aluminum from aluminum ash slag of the utility model has a simple overall structure, is easy to operate, has a good effect of screening aluminum particles and impurities in the aluminum ash slag once, has a high aluminum recovery efficiency, has a low equipment investment cost, and has excellent practicality and applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the recycling system of the utility model.

[0029] Figure 2 It is a structural schematic diagram of the step-by-step crushing and screening mechanism of the utility model.

[0030] Figure 3 It is a schematic diagram of the local structure of the feed inlet at the top of the large warehouse body of the utility model.

[0031] Figure numerals: 1: feeding mechanism; 101: grabber; 102: material bag; 103: bag breaker; 2: step crushing and screening mechanism; 201: large bin; 202: small bin; 203: first crushing roller; 204: first screen; 205: second screen; 206: second crushing roller; 207: third screen; 208: first vibration chamber; 209: first vibration motor; 210: first aggregate chamber; 211: second vibration chamber; 212: second vibration motor; 213: third vibration chamber; 214: third vibration motor; 215: second aggregate chamber; 216: material chute; 3: ball mill; 4: chute; 5: belt scale; 6: fine material screening machine; 7: unloading buffer bucket; 8: aggregate box; 9: miscellaneous material transfer belt conveyor. DETAILED DESCRIPTION

[0032] The technical solution of the utility model is illustrated below, and the scope of protection requested for the utility model includes but is not limited to the following embodiments.

[0033] A system for recovering metallic aluminum from aluminum ash slag comprises a feeding mechanism 1 and a step-by-step crushing and screening mechanism 2 which are sequentially arranged in series. The step-by-step crushing and screening mechanism 2 comprises a plurality of crushing devices sequentially arranged from top to bottom, a screening device is arranged below each crushing device, and the apertures of the screen holes of the plurality of screening devices gradually decrease from top to bottom.

[0034] Preferably, the step crushing and screening mechanism 2 is a two-stage double-chamber crushing and screening mechanism, including a large bin body 201, a small bin body 202, a first crushing roller 203, a first screen 204, a second screen 205, a second crushing roller 206 and a third screen 207. The small bin body 202 is arranged on one side of the large bin body 201, and the upper feed port and the lower discharge port of the small bin body 202 are both connected to the inner cavity of the large bin body 201. The first crushing roller 203, the first screen 204, and the second screen 205 are arranged in the inner cavity of the large bin body 201 from top to bottom, and the upper discharge port of the second screen 205 is connected to the upper feed port of the small bin body 202. The second crushing roller 206 and the third screen 207 are both arranged in the inner cavity of the small bin body 202, and the second crushing roller 206 is located above the third screen 207. The large bin body 201 is also provided with a top feed inlet and a bottom discharge inlet which are connected to the inner cavity thereof.

[0035] Preferably, the first crushing roller 203 is a pair of coarse crushing rollers, and the gap between the two coarse crushing rollers is 20-40 mm, preferably 25-35 mm.

[0036] Preferably, a first driving motor for driving the first crushing roller 203 is also provided on the outer wall of the large bin body 201 corresponding to the first crushing roller 203 .

[0037] Preferably, the first screen 204 is arranged in an inclined shape in the inner cavity of the large bin body 201. A first vibration cavity 208 is arranged on the outer wall of the large bin body 201 corresponding to the higher end of the first screen 204, and a first vibration motor 209 connected to the first screen 204 is arranged in the first vibration cavity 208. A first material collection cavity 210 is arranged on the outer wall of the large bin body 201 corresponding to the lower end of the first screen 204, and the feed port of the first material collection cavity 210 is connected to the screen discharge port located at the lower end of the first screen 204.

[0038] Preferably, the mesh size of the first sieve 204 is 20-35 mm, preferably 25-30 mm.

[0039] Preferably, the second screen 205 is arranged in an inclined shape in the inner cavity of the large bin body 201. A second vibration cavity 211 is arranged on the outer wall of the large bin body 201 corresponding to the higher end of the second screen 205, and a second vibration motor 212 connected to the second screen 205 is arranged in the second vibration cavity 211. The upper screen discharge port of the second screen 205 is located at its lower end.

[0040] Preferably, the mesh size of the second sieve 205 is 5-15 mm, preferably 8-12 mm.

[0041] Preferably, the second crushing roller 206 is a pair of grinding rollers, and the gap between the two grinding rollers is 5-12 mm, preferably 8-10 mm.

[0042] Preferably, a second driving motor for driving the second crushing roller 206 is also provided on the outer wall of the small bin body 202 corresponding to the second crushing roller 206 .

[0043] Preferably, the third screen 207 is arranged in an inclined shape in the inner cavity of the small bin body 202. A third vibration cavity 213 is arranged on the outer wall of the small bin body 202 corresponding to the higher end of the third screen 207, and a third vibration motor 214 connected to the third screen 207 is arranged in the third vibration cavity 213. A second material collection cavity 215 is arranged on the outer wall of the small bin body 202 corresponding to the lower end of the third screen 207, and the feed port of the second material collection cavity 215 is connected to the upper screen discharge port located at the lower end of the third screen 207. Preferably, the lower screen discharge port of the third screen 207 is connected to the lower discharge port of the small bin body 202 through the material slitting inclined plate 216.

[0044] Preferably, the mesh size of the third sieve 207 is 5-10 mm, preferably 6-8 mm.

[0045] Preferably, the feeding mechanism 1 includes a grabber 101, a material bag 102 and a bag breaker 103. Preferably, the grabber 101 is one of an electric hoist, a belt feeder, a mechanical arm claw, and a bucket elevator arranged on one side of the step crushing and screening mechanism 2. The bag breaker 103 is a bag breaker cone arranged at the top feed port of the step crushing and screening mechanism 2.

[0046] Preferably, the recovery system further comprises a ball mill 3. The bottom discharge port of the large bin body 201 is connected to the feed port of the ball mill 3 via a chute 4 and / or a belt scale 5.

[0047] Preferably, the recycling system further includes a fine material screening machine 6. The discharge port of the ball mill 3 is connected to the feed port of the fine material screening machine 6 through the discharge buffer hopper 7. The upper discharge port of the fine material screening machine 6 is connected to the feed port of the aggregate box 8, and the lower discharge port is connected to the feed end of the miscellaneous material transfer belt conveyor 9. Preferably, the sieve hole diameter of the fine material screening machine 6 is not greater than 5 mm, preferably 1-5 mm.

[0048] Example 1

[0049] like Figure 1-3 As shown, a system for recovering metallic aluminum from aluminum ash slag comprises a feeding mechanism 1 and a step-by-step crushing and screening mechanism 2 which are sequentially arranged in series. The step-by-step crushing and screening mechanism 2 comprises a plurality of crushing devices sequentially arranged from top to bottom, a screening device is arranged below each crushing device, and the apertures of the screen holes of the plurality of screening devices gradually decrease from top to bottom.

[0050] Example 2

[0051] Example 1 is repeated, except that the step crushing and screening mechanism 2 is a two-stage double-chamber crushing and screening mechanism, including a large bin body 201, a small bin body 202, a first crushing roller 203, a first screen 204, a second screen 205, a second crushing roller 206 and a third screen 207. The small bin body 202 is arranged on one side of the large bin body 201, and the upper feed port and the lower discharge port of the small bin body 202 are both connected to the inner cavity of the large bin body 201. The first crushing roller 203, the first screen 204, and the second screen 205 are arranged in the inner cavity of the large bin body 201 from top to bottom, and the upper discharge port of the second screen 205 is connected to the upper feed port of the small bin body 202. The second crushing roller 206 and the third screen 207 are both arranged in the inner cavity of the small bin body 202, and the second crushing roller 206 is located above the third screen 207. The large bin body 201 is also provided with a top feed inlet and a bottom discharge inlet which are connected to the inner cavity thereof.

[0052] Example 3

[0053] Example 2 is repeated, except that the first crushing roller 203 is a pair of coarse crushing rollers, and the gap between the two coarse crushing rollers is 40 mm.

[0054] Example 4

[0055] Example 3 was repeated except that the gap between the two coarse crushing rollers was 30 mm.

[0056] Example 5

[0057] The fourth embodiment is repeated, except that a first driving motor for driving the first crushing roller 203 is further provided on the outer wall of the large bin body 201 corresponding to the first crushing roller 203 .

[0058] Example 6

[0059] Example 5 is repeated, except that the first screen 204 is arranged in an inclined shape in the inner cavity of the large bin body 201. A first vibration cavity 208 is arranged on the outer wall of the large bin body 201 corresponding to the higher end of the first screen 204, and a first vibration motor 209 connected to the first screen 204 is arranged in the first vibration cavity 208. A first material collection cavity 210 is arranged on the outer wall of the large bin body 201 corresponding to the lower end of the first screen 204, and the feed port of the first material collection cavity 210 is connected to the screen discharge port located at the lower end of the first screen 204.

[0060] Example 7

[0061] Example 6 was repeated except that the mesh size of the first mesh 204 was 30 mm.

[0062] Example 8

[0063] Example 7 was repeated except that the mesh size of the first mesh 204 was 25 mm.

[0064] Example 9

[0065] Example 8 is repeated, except that the second screen 205 is arranged in an inclined shape in the inner cavity of the large bin body 201. A second vibration cavity 211 is arranged on the outer wall of the large bin body 201 corresponding to the higher end of the second screen 205, and a second vibration motor 212 connected to the second screen 205 is arranged in the second vibration cavity 211. The upper screen outlet of the second screen 205 is located at its lower end.

[0066] Example 10

[0067] Example 9 was repeated except that the mesh size of the second sieve 205 was 15 mm.

[0068] Embodiment 11

[0069] Example 10 was repeated except that the mesh size of the second mesh 205 was 12 mm.

[0070] Example 12

[0071] Example 11 was repeated, except that the second crushing roller 206 was a pair of grinding rollers, and the gap between the two grinding rollers was 10 mm.

[0072] Embodiment 13

[0073] Example 12 was repeated except that the gap between the two grinding rollers was 8 mm.

[0074] Embodiment 14

[0075] The embodiment 13 is repeated, except that a second driving motor for driving the second crushing roller 206 is further provided on the outer wall of the small bin body 202 corresponding to the second crushing roller 206 .

[0076] Embodiment 15

[0077] Example 14 is repeated, except that the third screen 207 is arranged in an inclined shape in the inner cavity of the small bin body 202. A third vibration cavity 213 is arranged on the outer wall of the small bin body 202 corresponding to the higher end of the third screen 207, and a third vibration motor 214 connected to the third screen 207 is arranged in the third vibration cavity 213. A second material collection cavity 215 is arranged on the outer wall of the small bin body 202 corresponding to the lower end of the third screen 207, and the feed port of the second material collection cavity 215 is connected to the upper screen discharge port located at the lower end of the third screen 207.

[0078] Example 16

[0079] Example 15 is repeated, except that the under-screen discharge port of the third screen 207 is connected to the lower discharge port of the small bin body 202 through the material sliding inclined plate 216.

[0080] Embodiment 17

[0081] Example 16 was repeated except that the mesh size of the third mesh 207 was 8 mm.

[0082] Embodiment 18

[0083] Example 17 was repeated except that the mesh size of the third mesh 207 was 6 mm.

[0084] Embodiment 19

[0085] Example 18 is repeated, except that the feeding mechanism 1 includes a material grabber 101, a material bag 102, and a bag breaker 103. The material grabber 101 is an electric hoist arranged on one side of the step crushing and screening mechanism 2. The bag breaker 103 is a bag breaker cone arranged at the top feeding port of the step crushing and screening mechanism 2.

[0086] Embodiment 20

[0087] Example 19 is repeated, except that the recovery system further includes a ball mill 3. The bottom discharge port of the large bin body 201 is connected to the feed port of the ball mill 3 through a chute 4 and a belt scale 5.

[0088] Embodiment 21

[0089] Example 20 is repeated, except that the recovery system further includes a fine material screener 6. The discharge port of the ball mill 3 is connected to the feed port of the fine material screener 6 through the discharge buffer hopper 7. The above-screen discharge port of the fine material screener 6 is connected to the feed port of the aggregate box 8, and the below-screen discharge port is connected to the feed end of the miscellaneous material transfer belt conveyor 9.

[0090] Embodiment 22

[0091] Example 21 was repeated except that the mesh size of the fine material screener 6 was 5 mm.

[0092] Embodiment 23

[0093] Example 22 was repeated except that the mesh size of the fine material screener 6 was 4 mm.

Claims

1. A system for recovering metallic aluminum from aluminum ash slag, characterized by: The recovery system comprises a feeding mechanism (1) and a stepped crushing and screening mechanism (2) which are arranged in series; the stepped crushing and screening mechanism (2) comprises a plurality of crushing devices which are arranged in series from top to bottom, a screening device is arranged below each crushing device, and the apertures of the screen holes of the plurality of screening devices gradually decrease from top to bottom.

2. The recycling system according to claim 1, characterized in that: The step crushing and screening mechanism (2) is a two-stage double-chamber crushing and screening mechanism, comprising a large bin body (201), a small bin body (202), a first crushing roller (203), a first screen (204), a second screen (205), a second crushing roller (206) and a third screen (207); the small bin body (202) is arranged on one side of the large bin body (201), and the upper feed port and the lower discharge port of the small bin body (202) are both connected to the inner cavity of the large bin body (201); the first crushing roller (203), the first screen (204), the second screen (205), the second crushing roller (206) and the third screen (207); A first screen (204) and a second screen (205) are arranged in sequence from top to bottom in the inner cavity of the large bin body (201), and the upper discharge port of the second screen (205) is connected to the upper feed port of the small bin body (202); the second crushing roller (206) and the third screen (207) are both arranged in the inner cavity of the small bin body (202), and the second crushing roller (206) is located above the third screen (207); and the large bin body (201) is also provided with a top feed port and a bottom discharge port connected to its inner cavity.

3. The recycling system according to claim 2, characterized in that: The first crushing roller (203) is a pair of coarse crushing rollers, and the gap between the two coarse crushing rollers is 20-40 mm.

4. The recovery system according to claim 3, characterized in that: The gap between the two coarse crushing rollers is 25-35 mm.

5. The recovery system according to claim 2, characterized in that: A first driving motor for driving the first crushing roller (203) is also arranged on the outer wall of the large bin body (201) corresponding to the first crushing roller (203).

6. The recycling system according to claim 2, characterized in that: The first screen (204) is arranged in an inclined shape in the inner cavity of the large bin body (201); wherein a first vibration cavity (208) is arranged on the outer wall of the large bin body (201) corresponding to the higher end of the first screen (204), and a first vibration motor (209) connected to the first screen (204) is arranged in the first vibration cavity (208); and a first material collection cavity (210) is arranged on the outer wall of the large bin body (201) corresponding to the lower end of the first screen (204), and the feed port of the first material collection cavity (210) is connected to the screen discharge port located at the lower end of the first screen (204).

7. The recovery system according to claim 6, characterized in that: The first sieve (204) has a mesh size of 20-35 mm.

8. The recovery system according to claim 7, characterized in that: The first sieve (204) has a sieve hole diameter of 25-30 mm.

9. The recycling system according to claim 2, characterized in that: The second screen (205) is arranged in an inclined manner in the inner cavity of the large bin body (201); wherein a second vibration cavity (211) is arranged on the outer wall of the large bin body (201) corresponding to the higher end of the second screen (205), and a second vibration motor (212) connected to the second screen (205) is arranged in the second vibration cavity (211); and the upper screen discharge port of the second screen (205) is located at its lower end.

10. The recycling system according to claim 9, characterized in that: The second sieve (205) has a mesh size of 5-15 mm.

11. The recycling system according to claim 10, characterized in that: The second sieve (205) has a mesh size of 8-12 mm.

12. The recycling system according to claim 2, characterized in that: The second crushing roller (206) is a pair of grinding rollers, and the gap between the two grinding rollers is 5-12 mm.

13. The recycling system according to claim 12, characterized in that: The gap between the two grinding rollers is.

14. The recycling system according to claim 2, characterized in that: A second driving motor for driving the second crushing roller (206) is also arranged on the outer wall of the small bin body (202) corresponding to the second crushing roller (206).

15. The recycling system according to claim 2, characterized in that: The third screen (207) is arranged in an inclined shape in the inner cavity of the small bin body (202); wherein a third vibration cavity (213) is arranged on the outer wall of the small bin body (202) corresponding to the higher end of the third screen (207), and a third vibration motor (214) connected to the third screen (207) is arranged in the third vibration cavity (213); and a second material collection cavity (215) is arranged on the outer wall of the small bin body (202) corresponding to the lower end of the third screen (207), and the feed port of the second material collection cavity (215) is connected to the upper screen discharge port located at the lower end of the third screen (207).

16. The recycling system according to claim 15, characterized in that: The under-screen discharge port of the third screen (207) is connected to the lower discharge port of the small bin body (202) through the material sliding inclined plate (216).

17. The recycling system according to claim 15, characterized in that: The third sieve (207) has a mesh size of 5-10 mm.

18. The recycling system according to claim 17, characterized in that: The third sieve (207) has a mesh size of 6-8 mm.

19. The recovery system according to any one of claims 1 to 18, characterized in that: The feeding mechanism (1) comprises a material grabber (101), a material bag (102) and a bag breaker (103).

20. The recovery system according to claim 19, characterized in that: The grabber (101) is one of an electric hoist, a belt feeder, a mechanical arm claw, and a bucket elevator arranged on one side of the stepped crushing and screening mechanism (2); and the bag breaker (103) is a bag breaker cone arranged at the top feed port of the stepped crushing and screening mechanism (2).

21. The recovery system according to any one of claims 1 to 18 and 20, characterized in that: The recovery system also includes a ball mill (3); the bottom discharge port of the large bin body (201) is connected to the feed port of the ball mill (3) via a chute (4) and / or a belt scale (5).

22. The recovery system according to claim 19, characterized in that: The recovery system also includes a ball mill (3); the bottom discharge port of the large bin body (201) is connected to the feed port of the ball mill (3) via a chute (4) and / or a belt scale (5).

23. The recycling system according to claim 21, characterized in that: The recovery system also includes a fine material screening machine (6); the discharge port of the ball mill (3) is connected to the feed port of the fine material screening machine (6) through a discharge buffer hopper (7); the above-screen discharge port of the fine material screening machine (6) is connected to the feed port of a collection box (8), and the below-screen discharge port is connected to the feed end of a miscellaneous material transfer belt conveyor (9).

24. The recovery system according to claim 22, characterized in that: The recovery system also includes a fine material screening machine (6); the discharge port of the ball mill (3) is connected to the feed port of the fine material screening machine (6) through a discharge buffer hopper (7); the above-screen discharge port of the fine material screening machine (6) is connected to the feed port of a collection box (8), and the below-screen discharge port is connected to the feed end of a miscellaneous material transfer belt conveyor (9).

25. The recovery system according to claim 23 or 24, characterized in that: The sieve hole diameter of the fine material screening machine (6) is not greater than 5 mm.

26. The recovery system according to claim 25, characterized in that: The sieve hole diameter of the fine material screening machine (6) is 1-5 mm.

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