A high-efficiency, low-consumption aluminum ash and slag recycling equipment and process

Abstract

This invention relates to the field of waste treatment technology, specifically to a high-efficiency, low-consumption aluminum ash and slag recycling device, comprising a transfer furnace, with a discharge pipe and a connecting pipe forming a sleeve; a first conveying structure is provided between the transfer furnace and the slag pressing furnace; a first hydraulic cylinder is installed at the top of the slag pressing furnace, and a pressing plate is also provided at the end of the first hydraulic cylinder; a drain pipe is provided at the bottom of the slag pressing furnace; the slag pressing furnace also has a pushing structure; a rotary kiln is located on the right side of the slag pressing furnace, and a second conveying structure is also installed between the two; an oxygen content detection sensor and a vacuum pump are also provided inside the rotary kiln; a sealed furnace cover is also hinged to one side of the rotary kiln; a flue gas filter is also provided on the sealed furnace cover; a third conveying structure is also provided below the rotary kiln. This invention achieves automated material conveying, low burn-off, and high-efficiency recycling of metallic aluminum, while solving the problems of fugitive dust emissions and high operating costs in existing processes, improving the environmental friendliness, stability, and economy of the process, and adapting to the needs of large-scale production.

Description

Technical Field

[0001] This invention relates to the field of manufacturing technology of special equipment for environmental protection such as solid waste pollution, and specifically to a high-efficiency, low-consumption aluminum ash slag recycling equipment and process. Background Technology

[0002] Aluminum ash is a major byproduct of aluminum smelting, typically containing 40%–60% metallic aluminum, making it a valuable recycled aluminum resource. Currently, the industry commonly employs two processes to treat hot aluminum ash: one uses a vertical stirring paddle ash roaster, utilizing the residual heat of the aluminum ash to mechanically separate the molten aluminum from the ash; the other uses a heatless rotary kiln, relying on the heat of the hot aluminum ash itself, and by adding a combustion aid, burning off a portion of the metallic aluminum to melt and separate the remaining aluminum. Both processes are the most widely used traditional methods in the industry, but their significant technical shortcomings make them difficult to meet current demands for efficient, environmentally friendly, and low-cost production.

[0003] Further analysis reveals that one of the problems with traditional aluminum ash recycling is the high aluminum loss and low recovery rate. During operation, the stirring action of the vertical stirring paddle ash roaster exposes a large area of ​​high-temperature aluminum ash to the air, leading to a violent oxidation reaction in the aluminum. Simultaneously, static accumulation dead zones exist on the walls of the ash roasting pot, where micron-sized aluminum droplets are encapsulated by the ash slag, making complete separation difficult. Ultimately, this results in a secondary aluminum ash with an aluminum content as high as 8%–15%, and a comprehensive aluminum recovery rate of only 75%–82%. Related research data indicates that due to uneven stirring and shearing, and sufficient oxidation exposure, the aluminum loss rate of the vertical ash roaster can reach 10%–18%. The heat-source-free rotary kiln (a ash-frying machine without a combustion system) relies entirely on the sensible heat of the hot aluminum ash for separation, without any supplemental heating methods. This results in a large temperature fluctuation range within the kiln (650–850℃). Simultaneously, the material inside the kiln tumbles violently, and aluminum droplets are easily carried away by the airflow. Furthermore, the exposed area of ​​the high-temperature aluminum ash is much larger than that of a vertical ash-frying machine, further exacerbating aluminum oxidation loss. Its loss rate is 3%–5% higher than that of a vertical ash-frying machine, and the overall aluminum recovery rate is less than 80%. A review of publicly available technical literature, "Optimization Research on Aluminum Ash Rotary Kiln Processing Technology" (Nonferrous Metals Engineering, Vol. 13, No. 7, 2023), clearly confirms that the heat-source-free rotary kiln, due to its inability to achieve precise temperature control, accounts for over 60% of the total metal loss due to aluminum oxidation, which is the core reason for the low recovery rate. In addition, the rotary kiln lacks a supplemental heating system, can only process hot ash above 650℃, and cannot process cold or warm ash, resulting in poor production flexibility and a strong dependence on the production rhythm at the kiln front.

[0004] Secondly, environmental pollution is severe and environmental compliance risks are high. The problem of fugitive dust emissions is prominent: vertical stirring paddle ash roasters generate large amounts of aluminum-containing dust, ammonia, fluorides, and other pollutants during the open-top feeding and discharging process; rotary kilns without heat sources suffer from serious ash leakage and smoke emissions due to the difficulty of dynamically sealing the furnace head and tail. Meanwhile, the pressing and melting conveying processes of aluminum ash and slag materials traditionally rely on forklifts due to high temperatures. However, this method is time-consuming, labor-intensive, and poses significant safety hazards. The workshops have high dust levels, with exposed materials causing dust concentrations to exceed standards by 3-5 times. Long-term exposure can severely harm the respiratory system of operators and fails to meet environmental regulations for fugitive emissions control. Harmful gas emissions are difficult to control: Aluminum nitride (AlN) contained in aluminum ash decomposes to produce ammonia under high temperature or water conditions, while fluorides diffuse with the flue gas. Both pollutants are emitted unorganized, making treatment difficult and easily triggering environmental inspection risks, failing to meet the requirements of the "Emission Standard of Pollutants for Recycled Aluminum Industry" (GB 25465-2010). Secondary hazardous waste disposal faces significant pressure: Existing processes produce secondary aluminum ash containing soluble salts, fluorides, nitrogen oxides, and other harmful substances, classifying it as hazardous waste. The output is substantial, and its harmless disposal cost is as high as 1500 yuan / ton, increasing production costs for enterprises and posing a risk of secondary pollution. Summary of the Invention

[0005] To address the technical bottlenecks of existing aluminum ash slag solid waste treatment equipment, such as low recovery rate, severe pollution, poor equipment reliability, and high operating costs, which fail to meet the needs of the recycled aluminum industry for efficient, environmentally friendly, large-scale, and low-cost production, this invention provides a high-efficiency, low-consumption aluminum ash slag recycling equipment.

[0006] The present invention achieves the above objectives by adopting the following technical solution: A high-efficiency, low-consumption aluminum ash slag recycling device includes a transfer furnace, a slag pressing furnace, a rotary kiln, and a cooling screen. The transfer furnace is vertically arranged with a feed pipe at the top and an inclined discharge pipe at the bottom. An inclined connecting pipe is located on the left side of the slag pressing furnace, and the discharge pipe is connected to the connecting pipe. A first conveying structure is provided between the transfer furnace and the slag pressing furnace to move the transfer furnace to a preset position. A first hydraulic cylinder is installed at the top of the slag pressing furnace, and an extrusion plate adapted to the furnace structure is provided at the end of the first hydraulic cylinder. A high-temperature resistant ultrafine steel filter screen is provided at the bottom of the slag pressing furnace. A drain pipe is provided at the bottom of the slag pressing furnace, and a pressure control valve is installed on the drain pipe. A first collection trough is provided at the lower end of the support frame below the drain pipe. A hinged sealing cover is provided on the right side of the slag pressing furnace, and a hydraulic telescopic rod is provided on the side wall of the slag pressing furnace on one side of the sealing cover. The slag pressing furnace also has a pushing structure. The rotary kiln is located within the slag pressing furnace. On the right side, a second conveying structure is connected between the two to ensure that the pressed ash cake is conveyed in a sealed manner into the rotary kiln. A rotary drive and a tilting drive are also connected to one side of the rotary kiln to complete the kiln's rotation and tilting / tilting operations. The rotary kiln is equipped with a fully automatic combustion system for precise temperature control. An oxygen content detection sensor and a vacuum pump are also installed inside the rotary kiln. The oxygen content detection sensor and the vacuum pump maintain a signal connection to complete the low-temperature smelting operation in a weakly oxidizing atmosphere. A sealed furnace cover is hinged to one side of the rotary kiln, and a liquid outlet pipe is connected to one side of the sealed furnace cover. A high-temperature resistant filter screen is installed at the input end of the liquid outlet pipe. A flue gas filtration device is also installed on the sealed furnace cover. A third conveying structure is located below the rotary kiln. A second collecting tank and a cooling screening machine are installed on the third conveying structure to alternately complete the alternating export of molten aluminum and secondary aluminum ash cooling and screening operations within the rotary kiln.

[0007] This invention adopts a preferred technical solution: the inclination angle of the discharge pipe and the connecting pipe is the same, and the outer diameter of the discharge pipe is equal to the inner diameter of the connecting pipe; the right end of the discharge pipe is provided with a horizontal section, and the left end of the connecting pipe is also provided with a horizontal section; so that when the transfer furnace and the slag pressing furnace are conveying materials, the discharge pipe and the connecting pipe are sleeved to form a sealed conveying channel; electromagnetic switching valves are provided on the discharge pipe, the connecting pipe, the drain pipe, and the liquid outlet pipe; the fully automatic combustion system includes a combustion plate, a base, a flame cover, a gas pipe, and an air pipe; the base is fixedly installed at the bottom of the rotary furnace, and the combustion plate is installed... The combustion chamber is mounted on a base and has a mixing chamber inside. A gas passage and an air passage are also provided on one side of the mixing chamber. The gas passage is connected to the gas pipe, and the air passage is connected to the air pipe. Multiple evenly distributed injection holes are provided on the burner cap and are mounted on the combustion chamber. An electric igniter is also connected and installed inside the mixing chamber. A temperature probe is also provided on the inner wall of the rotary kiln. The combustion chamber is a disc-shaped base that supports the burner cap. It has a gas passage and an air inlet inside, allowing the gas to premix with primary air to form a mixture, which is stored in the mixing chamber and then evenly injected through the small holes in the burner cap for combustion.

[0008] The present invention adopts a preferred technical solution: the first conveying structure includes a base, a support frame, support legs, a rotating screw, guide rods, a first motor, and a position sensor; the base is welded to the bottom of the transfer furnace; the support frame is a rectangular frame structure, and the support legs are multiple and can be welded and fixed to the support frame; there are two guide rods symmetrically distributed front and back and disposed within the support frame; the rotating screw is rotatably disposed on the support frame and located between the guide rods, the rotating screw and the guide rods pass through the base and the base and the rotating screw are connected by a threaded rotation, and the base and the guide rods are connected by a sliding connection; the first motor is mounted on the support frame through a bracket and connected to the rotating screw; the position sensor is disposed on one side of the support frame and is connected to the first motor by a signal.

[0009] The present invention adopts a preferred technical solution: the pushing structure includes a telescopic push rod and a push plate; the telescopic push rod is disposed on the left side wall inside the slag pressing furnace, and the push plate is fixedly installed on the end of the telescopic push rod; in the initial state, the push plate is flush with the left side wall of the slag pressing furnace.

[0010] The present invention adopts a preferred technical solution: the second conveying structure includes a conveying frame, guide rails, limiting wheels, and a sealed box; the conveying frame is generally Z-shaped, and its left end is connected to and level with the support frame; the guide rails are arranged on the conveying frame and are two in number, symmetrically distributed front and back; the limiting wheels are arranged at the bottom of the sealed box and are matched and installed with the guide rails; the sealed box is provided with doors on both the left and right sides, and a first electric telescopic rod is also provided between the inner wall of the sealed box and the left door; a second electric telescopic rod is also provided between the sealed box and the right door.

[0011] The present invention adopts a preferred technical solution: the second conveying structure includes a fixed base, a second hydraulic cylinder, a second motor, a reset shaft, a reset wheel, a reset rope, a third motor, a traction shaft, a traction wheel, and a traction rope; the sealed box is disposed above the fixed base, and the right side of the sealed box is hinged to the fixed base; one end of the second hydraulic cylinder is disposed on the fixed base, and the other end is disposed at the bottom of the sealed box; the second motor is mounted on the left side of the conveying frame via a bracket, and the reset shaft is rotatably disposed on the conveying frame and connected to the second motor; the reset wheel is sleeved and mounted on the reset shaft; one end of the reset rope is wound and mounted on the reset wheel, and the other end is connected to the left end of the fixed base. The traction shaft is rotatably disposed on the right end of the conveying frame and connected to the third motor; the traction wheel is sleeved and mounted on the traction shaft, and one end of the traction rope is wound and mounted on the traction wheel, and the other end is fixedly mounted on the right end of the fixed base.

[0012] The present invention adopts a preferred technical solution: the flue gas filtration device includes a filter element, a pressure plate, an exhaust port, and a high-temperature resistant fan; an annular groove is provided on one side of the sealed furnace cover, the filter element is adapted and installed in the groove, the pressure plate is adapted and installed on the outside of the groove by fastening bolts, and an air inlet pipe is provided on the pressure plate; the exhaust port is located on the outside of the sealed furnace cover and communicates with the annular groove; the high-temperature resistant fan is installed at the exhaust port by a bracket; the filter element comprises non-woven filter cotton, activated carbon pack, HEPA air filter cotton, and activated alumina particle pack distributed from the inside to the outside.

[0013] The present invention adopts a preferred technical solution: the third conveying structure includes a fixed frame, a supporting slide rod, a supporting seat, and a third hydraulic cylinder; the fixed frame is fixedly installed on the external ground and is a rectangular frame structure; the supporting slide rods are multiple evenly distributed and are arranged inside the fixed frame, and the two can be fixed by welding; the supporting seat is sleeved and installed on the supporting slide rod; the third hydraulic cylinder is arranged on one side of the fixed frame and its end is connected and fixed to the supporting seat; the second collecting trough is fixedly installed on the rear side of the supporting seat, and the cooling screening machine is arranged on the front side of the supporting seat.

[0014] The present invention adopts a preferred technical solution: the cooling screening machine includes a machine body; the machine body is vertically mounted on a support base and is divided into a cooling chamber and a screening chamber by a partition; a feed hopper is connected to the top of the cooling chamber, and a spirally distributed material pipe is also provided inside the chamber, with the input end of the material pipe connected to the feed hopper and the output end leading to the screening chamber; a temperature sensor and a refrigeration device are also provided on one side of the cooling chamber; a screen is also provided inside the screening chamber, with the left side of the screen hinged to the chamber wall and the right side provided with a shaking screen drive; a slag discharge pipe is also connected to the left side of the machine body at the position corresponding to the screen; the shaking screen drive includes a fourth motor, a rotating shaft, and a cam; the fourth motor is located on one side of the machine body, the rotating shaft is rotatably mounted in the screening chamber, the cam is sleeved and mounted on the rotating shaft and contacts the screen; a vibrator is also installed at the bottom of the screen by screws.

[0015] A high-efficiency, low-consumption aluminum ash slag recycling process is disclosed, which utilizes the aforementioned recycling equipment for the recycling and reuse of aluminum ash slag. The process steps are as follows: Step S1: Sealed transfer of high-temperature hot aluminum ash: Hot aluminum ash at 650-850℃ discharged from the aluminum smelting furnace is discharged to the transfer furnace; the first motor starts and rotates forward, which will drive the transfer furnace to move to the right along the support frame to the preset position, that is, the discharge pipe of the transfer furnace and the connecting pipe of the slag pressing furnace are connected to form a sealed material conveying channel; the 650-850℃ hot aluminum ash is adapted to the temperature of the hot ash discharged from the aluminum smelting furnace to ensure the fluidity of the aluminum liquid; Step S2: Slag Separation: Slag is processed using a closed hydraulic slag pressing furnace. The slag pressing process is relatively sealed, isolating most of the air and reducing oxidation loss. Under high pressure, the liquid aluminum in the hot aluminum ash is squeezed out from the gaps between the ash and slag. The squeezed-out molten aluminum flows out from the molten aluminum outlet at the bottom of the slag press and is collected and directly cast into aluminum ingots, achieving preliminary and efficient separation of metallic aluminum. The maximum pressing pressure is 100MPa, which ensures that the molten aluminum is fully squeezed out of the ash and slag, avoiding residue. The pressing time is 5-25 minutes, and rapid pressing reduces heat loss and avoids oxidation of the molten aluminum. Step S3: Sealed Transfer of Pressed Ash Cake: After pressing, a dense pressed ash cake containing 12%–18% metallic aluminum is formed, and the temperature is maintained at 550–650℃. It is discharged from the sealed cover door of the slag pressing furnace into a sealed box. The third motor is turned on, which pulls the sealed box to move above the rotary kiln. At this time, the rotary kiln opening is tilted upward. The next step is to activate the second hydraulic cylinder to extend, causing the sealed box to tilt and put the pressed ash cake into the rotary kiln. This ensures the economic efficiency of subsequent rotary kiln recycling. Step S4: Low-Temperature Enhanced Recovery: The tilt angle of the tilting rotary furnace is controlled at 40° throughout its entire stroke to ensure smooth aluminum molten material discharge while maximizing ash and slag retention time; the rotation speed is 1–8 r / min; slow tumbling ensures thorough separation of ash and slag from the molten aluminum, preventing splashing; a low-temperature smelting process in a weak oxidizing atmosphere is employed, with real-time heating via a fully automatic combustion system to precisely control the furnace temperature at 680–750℃. This temperature is below the severe oxidation temperature of metallic aluminum, effectively reducing oxidation loss; low-temperature smelting reduces aluminum oxidation loss and ensures the purity of the molten aluminum. Step S5: Weak Oxygen Environment: The oxygen concentration in the rotary kiln cavity is detected in real time by an oxygen content detection sensor, and the air pump is turned on to extract air to complete the low-temperature melting operation in a weak oxidizing atmosphere, while precisely controlling the air-fuel ratio. Step S6: Smelting and separating aluminum liquid: The pressing ash cake is slowly tumbled in the rotary kiln. The remaining metallic aluminum in the ash cake melts into aluminum droplets at low temperature. Under the action of gravity, the droplets gather and flow along the inclined direction of the furnace body. They are discharged from the aluminum liquid outlet pipe at the bottom of the rotary kiln and combined with the aluminum liquid recovered in the slag pressing stage for processing. Step S6: Smelting and Separating Secondary Aluminum Ash: The secondary aluminum ash discharged from the rotary kiln at a high temperature of 450-550℃, containing ≤5% metallic aluminum, is directly fed into a closed cooling and screening machine; maximizing the recovery of metallic aluminum and reducing resource waste; Step S7: Molten Flue Gas Treatment: The flue gas generated during the operation of the rotary kiln is collected through the sealed air inlet pipe of the sealed furnace cover and sent into the filter element. It undergoes four-stage purification treatment through non-woven filter cotton, activated carbon bag, HEPA air filter cotton and activated alumina granule bag to adsorb particulate impurities in the flue gas and adsorb and purify sulfur-containing gases, thus avoiding fugitive emissions of flue gas. Step S8: Secondary aluminum ash cooling, screening, and compliant disposal: After cooling in step S6, the temperature after cooling should not exceed 80℃; the ash is graded using a screen with the assistance of shaking and vibrating screens. Coarse particles on the screen can be returned to the rotary kiln for secondary smelting to further recover the remaining metallic aluminum; the fine powder below the screen is the final secondary aluminum ash, which is entrusted to a third-party organization with hazardous waste disposal qualifications for harmless disposal and resource utilization to complete environmentally compliant disposal.

[0016] The beneficial effects of this invention compared to the prior art are as follows: This invention aims to overcome the technical defects of existing aluminum ash slag recycling processes and provide a high-efficiency and low-consumption aluminum ash slag recycling process route. By optimizing the process flow, improving equipment configuration, and accurately controlling process parameters, it achieves low burning loss and high-efficiency recycling of metallic aluminum. At the same time, it solves the problems of fugitive dust emissions, frequent equipment failures, and high operating costs in existing processes, improves the environmental friendliness, stability, and economy of the process, and adapts to the needs of large-scale production. This invention employs automated, closed-loop material handling, ensuring safety and reliability. The slag pressing process utilizes a closed-loop, air-isolated pressing method, preventing high-temperature molten aluminum from contacting air at the source and effectively reducing oxidation loss. The rotary kiln employs a low-temperature smelting process in a weakly oxidizing atmosphere, precisely controlling furnace temperature and oxygen content to further reduce aluminum oxidation loss, lowering the aluminum burn-off rate to below 3% (compared to 10%–18% in existing processes). Simultaneously, the combination of slag pressing and secondary recycling in the rotary kiln achieves complete separation of molten aluminum and ash, with the secondary aluminum ash containing ≤5% aluminum, far lower than the 8%–15% of existing processes. This increases the overall aluminum recovery rate to 90%–95%, significantly improving the utilization rate of recycled aluminum resources. The low-temperature smelting process in a weakly oxidizing atmosphere, supplemented by a fully automated combustion system in real-time, precisely controls the furnace temperature at 700–750℃ (below the severe oxidation temperature of aluminum, effectively reducing oxidation loss), while simultaneously precisely controlling the air-fuel ratio to create a weakly oxidizing environment. The entire process flow of this invention (slag pressing, rotary kiln smelting, cooling and screening) adopts closed equipment and closed conveying, with no dust and no fugitive emissions. The dust concentration in the workshop is controlled at ≤10mg / m³, which meets the requirements of national standard GB 25465-2010. In addition, after process optimization, the secondary aluminum ash production is reduced by 30%, the hazardous waste disposal cost is reduced by 40%, and the flue gas treatment process is optimized, fundamentally solving the environmental pain points of the existing process and reducing the environmental compliance risks of enterprises. The closed hydraulic ash press (ash furnace) of this invention has a large processing capacity, with a single unit processing capacity of 3 to 7 tons / hour. It can replace multiple vertical ash roasting machines, reducing the floor space by 50%, the number of operators by 60%, and significantly reducing labor costs. The rotary kiln is equipped with a fully automatic combustion system, which can achieve precise temperature control. It can not only process hot ash, but also warm ash above 500°C, with strong production flexibility to adapt to different working conditions. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a perspective view of the overall structure of the present invention; Figure 2 This is a schematic diagram of the first conveying structure of the present invention; Figure 3 This is a schematic diagram of the slag pressing furnace of the present invention; Figure 4 for Figure 3 Enlarged view of section A in the diagram; Figure 5 This is a schematic diagram of the structure of the rotary kiln of the present invention; Figure 6 for Figure 5 Enlarged view of section B in the diagram; Figure 7 for Figure 5 Enlarged view of section C in the diagram; Figure 8 This is a schematic diagram of the structure of the sealed box of the present invention; Figure 9 This is a partial structural diagram of the second conveying structure of the present invention; Figure 10 This is a cross-sectional view of the cooling screening machine of the present invention; Figure 11 This is a three-dimensional structural diagram of the shaking screen drive of the present invention.

[0019] In the diagram: 1. Transfer furnace; 101. Feed pipe; 102. Discharge pipe; 103. Electromagnetic switch valve; 2. Slag pressing furnace; 201. Connecting pipe; 202. First hydraulic cylinder; 203. Extrusion plate; 204. Drain pipe; 205. First collection tank; 206. Sealing cover; 207. Hydraulic telescopic rod; 208. Fine steel ultrafine filter screen; 209. Pressure control valve; 3. Rotary furnace; 301. Oxygen content detection sensor; 302. Vacuum pump; 303. Fully automatic combustion system; 304. Sealed furnace cover; 305. Liquid outlet pipe; 306. High-temperature resistant filter screen; 307. Combustion plate; 308. Base; 309. Burner cap; 310. Gas pipe; 311. Air pipe; 312. Mixing chamber; 313. Gas passage; 314. Air passage; 315. Injection hole; 316. Electric igniter; 317. Temperature probe; 4. Cooling screening machine; 401. Machine body; 402. Partition plate; 403. Cooling chamber; 404. Screening chamber; 405. Feed hopper; 406. Material pipe; 407. Temperature sensor; 408. Refrigeration equipment; 409. Screen; 410. Shaking screen drive; 411. Slag discharge pipe; 412. Fourth motor; 413. Rotating shaft; 414. Cam; 415. Vibrator; 5. First conveying structure; 501. Base; 502. Support frame; 503. Support leg; 504. Rotating screw; 505. Guide rod; 506. First motor; 507. Position sensor; 6. Pushing structure; 601. Telescopic push rod; 602. Push plate; 7. Second conveying structure; 701. Conveying frame; 702. Guide rail; 703. Limiting wheel; 704. Sealed box; 705. Box door; 706. First electric telescopic rod; 707. Second electric telescopic rod; 708. Fixed base; 709. Second hydraulic cylinder; 710. Second motor; 711. Reset shaft; 712. Reset wheel; 713. Reset rope; 714. Third motor; 715. Traction shaft; 716. Traction wheel; 717. Traction rope; 8. Flue gas filtration device; 801. Filter element; 802. Cover plate; 803. Exhaust port; 804. Annular groove; 805. Air inlet pipe; 806. Fan; 807. Non-woven filter cotton; 808. Activated carbon bag; 809. HEPA air filter cotton; 810. Activated alumina granule bag; 9. Third conveying structure; 901. Second collection tank; 902. Fixing frame; 903. Support slide bar; 904. Support base; 905. Third hydraulic cylinder. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1: As Figures 1 to 11 As shown: A high-efficiency, low-consumption aluminum ash slag recycling device includes a transfer furnace 1, a slag pressing furnace 2, a rotary kiln 3, and a cooling screen 4. The transfer furnace 1 is vertically arranged, with a feed pipe 101 at the top and an inclined discharge pipe 102 at the bottom right side. The feed pipe is used to receive hot aluminum ash liquid at 650–850℃. The transfer furnace is integrally die-cast from a high-strength material resistant to high temperature and pressure, ensuring sufficient safety performance. The slag pressing furnace 2 has an inclined connecting pipe 201 on its left side, and the discharge pipe 102 is sleeved with the connecting pipe 201. In a preferred embodiment, the discharge pipe 102 and the connecting pipe 201 have the same inclination angle, and the right end of the discharge pipe has a horizontal section, as does the left end of the connecting pipe. The outer diameter of the discharge pipe 102 is equal to the inner diameter of the connecting pipe 201, so that during material conveying operations between the transfer furnace 1 and the slag pressing furnace 2, the discharge pipe 102 and the connecting pipe 201 are fitted together to form a sealed conveying channel. This arrangement aims to ensure stable material conveying and prevent contact with air. Electromagnetic switching valves 103 are installed on the feed pipe 101, discharge pipe 102, connecting pipe 201, drain pipe 204, and outlet pipe 305. This arrangement facilitates automated material conveying. Hot aluminum ash liquid at 650–850°C discharged from the aluminum smelting furnace is conveyed to the transfer furnace for the next slag pressing process.

[0022] like Figure 2As shown: In this embodiment, a first conveying structure 5 is provided between the transfer furnace 1 and the slag pressing furnace 2 to move the transfer furnace 1 to a preset position. Preferably, the first conveying structure 5 includes a base 501, a support frame 502, support legs 503, a rotating screw 504, guide rods 505, a first motor 506, and a position sensor 507. The base 501 is welded to the bottom of the transfer furnace 1; the two are fixedly connected to form a whole. The support frame 502 is a rectangular frame structure, and there are multiple support legs 503, which can be welded and fixed to the support frame 502; this arrangement ensures sufficient stability and support strength. There are two guide rods 505 symmetrically distributed front and back, and they are set inside the support frame 502; preferably, four or six guide rods can also be symmetrically distributed, etc., depending on the on-site process requirements. A rotating screw 504 is rotatably mounted on the support frame 502 and located between guide rods 505. The rotating screw 504 and guide rods 505 pass through the base 501, and the base 501 and rotating screw 504 are connected by a thread, while the base 501 and guide rods 505 are connected by a sliding connection. The first motor 506 is mounted on the support frame 502 via a bracket and is connected to the rotating screw 504. The first motor is preferably a servo-controlled motor. The position sensor 507 is located on one side of the support frame 502 and is connected to the first motor 506 by a signal. Specifically, an industrial control computer with a built-in PLC controller can be installed on one side of the support frame to realize the automated control of sensors, electromagnetic valves, motors, etc. The technical principle of this industrial control computer is common knowledge to those skilled in the art and will not be described in detail here.

[0023] When a certain amount of hot aluminum ash liquid is loaded into the transfer furnace, the electromagnetic valves on the feed pipe and discharge pipe are closed, thus forming a sealed structure. At this time, the first motor is turned on and rotates clockwise, driving the rotating screw. With the assistance of the guide rod, the base and the entire transfer furnace move to the right along the rotating screw to a preset position, where the horizontal section of the discharge pipe and the horizontal section of the connecting pipe are engaged. Here, the position sensor and the first motor work together for precise position control. Simultaneously, the first motor has a locking function, ensuring that the discharge pipe 102 and the connecting pipe 201 form a sealed conveying channel. The electromagnetic valves on the discharge pipe and the connecting pipe are opened simultaneously, facilitating the automatic delivery of the 650–850℃ hot aluminum ash liquid to the slag pressing furnace. Next, the first motor reverses, causing the base and the entire transfer furnace to move to the left and reset, thus repeating the cycle.

[0024] In this embodiment, as Figure 3As shown: A first hydraulic cylinder 202 is installed at the top of the slag pressing furnace 2, and the pressure of the first hydraulic cylinder is set not to exceed 100 MPa. The slag pressing furnace 2 is preferably a closed hydraulic slag pressing machine. An extrusion plate 203 adapted to the furnace structure is also provided at the end of the first hydraulic cylinder 202. A drain pipe 204 is provided at the bottom of the extrusion plate slag pressing furnace 2. Under normal conditions, the electromagnetic switch valve on the drain pipe is in a normally closed state. And it is set to be strong enough to ensure the sealing conditions of the slag pressing furnace. An ultra-fine high-temperature resistant steel filter screen 208 is also provided at the bottom of the slag pressing furnace 2. This setting ensures effective separation of slag and aluminum liquid. A pressure control valve 209 is also provided on the drain pipe 204. The purpose of this setting is that when the closed hydraulic slag pressing machine completes the extrusion of hot aluminum ash liquid and the aluminum liquid is precipitated, when the pressure reaches the preset threshold, the pressure control valve opens to discharge the aluminum liquid from the drain pipe. A first collection trough 205 is provided at the lower end of the support frame 502 and below the drain pipe 204. Preferably, the first collection trough is a rectangular concave box structure, and one side of the first collection trough can be fixedly connected to the support frame by a snap fastener to ensure a fixed position. At the same time, a movable wheel can be installed below the first collection trough to ensure good mobility. A hinged sealing cover 206 is also provided on the right side of the slag pressing furnace 2, and the two ensure sufficient sealing effect when connected and closed. A hydraulic telescopic rod 207 is also provided on the side wall of the slag pressing furnace 2 and on the side of the sealing cover 206. One end of the hydraulic telescopic rod is hinged to the outer side wall of the slag pressing furnace, and the other end is hinged to the sealing cover. With this configuration, after the slag pressing furnace has finished pressing the hot aluminum ash, the sealing cover can be opened to push the pressed ash cake out through the cooperation of the telescopic push rod and the push plate.

[0025] like Figure 3 and Figure 4 As shown: In this preferred embodiment, the slag pressing furnace 2 is further provided with a pushing structure 6. The pushing structure 6 includes a telescopic push rod 601 and a push plate 602. The telescopic push rod 601 is disposed on the inner left side wall of the slag pressing furnace 2, and the push plate 602 is fixedly installed on the end of the telescopic push rod 601. The push plate has a rectangular structure. In the initial state, the push plate 602 is flush with the left side wall of the slag pressing furnace 2. Specifically, a connecting body can be provided on the outside of the slag pressing furnace. The connecting body has a groove structure that communicates with the inner cavity of the furnace body to facilitate the installation of the telescopic push rod and the push plate. When the push plate is flush with the side wall of the furnace body, a sealing rubber ring is provided at the connection between the two. The purpose of this design is to ensure a sealed environment inside the slag pressing furnace. The closed hydraulic slag pressing machine (slag pressing furnace) of the present invention has a large processing capacity, with a single unit processing capacity of 3 to 7 tons / hour. It can replace multiple vertical ash roasting machines, reducing the floor space by 50%, the number of operators by 60%, and significantly reducing labor costs.

[0026] like Figure 1As shown: In this embodiment, the rotary kiln 3 is located on the right side of the slag pressing furnace 2, and a second conveying structure 7 is connected and installed between the two to ensure that the pressed ash cake is conveyed into the rotary kiln 3 in a sealed manner. Preferably, combined with Figure 8 and Figure 9 As shown: The second conveying structure 7 includes a conveying frame 701, a guide rail 702, a limiting wheel 703, and a sealed box 704. The conveying frame 701 has a Z-shaped structure, and its left end is connected to and level with the support frame 502; the connection can be fixed by welding. Two guide rails 702 are symmetrically distributed on the conveying frame 701; the corners of both the conveying frame and the guide rails are arc-shaped to ensure smooth movement of the sealed box. Support columns are also provided below the conveying frame to ensure the stability of the foundation. The limiting wheel 703 is located at the bottom of the sealed box 704 and is matched and installed with the guide rail 702; specifically, the limiting wheel is mounted on a fixed base, and the limiting wheel is a single-groove wheel structure, while the guide rail is a single-rail structure. This design fully considers the requirements of the factory process, serving not only a moving function but also a limiting and guiding function. Figure 8 As shown: The sealed box 704 is equipped with doors 705 on both the left and right sides. A first electric telescopic rod 706 is also provided between the inner wall of the sealed box 704 and the left door 705. This door is equipped with an electric telescopic rod and designed as an automated inward-opening structure. A second electric telescopic rod 707 is also provided between the sealed box 704 and the right door 705. This arrangement is mainly to ensure that the pressed ash cake can smoothly enter through the left door when the telescopic pusher pushes it into the sealed box. The right door is designed with a main drive opening structure, mainly to ensure that the pressed ash cake is transported to the rotary kiln in a time-saving and labor-saving manner. Thus, while further ensuring the sealed environment of the sealed box, the automated transport of the pressed ash cake to the rotary kiln can be effectively guaranteed. This invention adopts automated, sealed material transfer, which is safe and reliable. The slag pressing process uses a sealed, air-isolated pressing method to prevent high-temperature molten aluminum from contacting air at the source, effectively reducing oxidation and burn-off.

[0027] like Figure 8 and Figure 9As shown: In this embodiment, the second conveying structure 7 further includes a fixed base 708, a second hydraulic cylinder 709, a second motor 710, a reset shaft 711, a reset wheel 712, a reset rope 713, a third motor 714, a traction shaft 715, a traction wheel 716, and a traction rope 717. The sealed box 704 is disposed above the fixed base 708, and the two can be fixed by welding. The right side of the sealed box 704 is hinged to the fixed base 708. One end of the second hydraulic cylinder 709 is disposed on the fixed base 708, and the other end is disposed on the bottom end of the sealed box 704; the purpose of this arrangement is to enable the sealed box to tilt by opening the second hydraulic cylinder when conveying the pressed ash cake to the rotary kiln, specifically a tilting structure with the left side higher than the right side. The second motor 710 is mounted on the left side of the conveying frame 701 by a bracket, wherein both the second motor and the third motor are preferably servo-controlled motors. The reset shaft 711 is rotatably mounted on the conveyor frame 701 and connected to the second motor 710; the reset wheel 712 is sleeved and installed on the reset shaft 711; one end of the reset rope 713 is wound and installed on the reset wheel 712, and the other end is connected to the left end of the fixed seat 708. With this configuration, multiple sets of reset wheels and reset ropes can be matched and evenly distributed. The traction shaft 715 is rotatably mounted on the right end of the conveyor frame 701 and connected to the third motor 714; the traction wheel 716 is sleeved and installed on the traction shaft 715, and one end of the traction rope 717 is wound and installed on the traction wheel 716, and the other end is fixedly installed on the right end of the fixed seat 708. Multiple sets of traction ropes and traction wheels can also be matched and evenly distributed.

[0028] Once the pressed ash cake is fully inside the sealed chamber, the telescopic push rod drives the push plate to reset. The left chamber door, under the release of the pressure spring, will first rest on the telescopic push rod. Due to the unique design of the push plate and the telescopic push rod, this does not prevent the telescopic push rod from continuing to drive the push plate to reset. When the push plate has completely moved outside the sealed chamber, the left chamber door closes again. The next step is to activate the second and third motors. At this time, the third motor rotates forward, and the second motor rotates in reverse. Specifically, the third motor's forward rotation drives the traction shaft to rotate clockwise, which in turn drives the traction wheel to wind and collect the traction rope. The second motor's reverse rotation drives the reset shaft to rotate counterclockwise, releasing the reset rope wound on the reset wheel. Thus, the third motor acts as the active traction force, and the second motor as an auxiliary force, thereby moving the sealed chamber on the conveyor frame until it reaches the right end of the conveyor frame, above the rotary kiln opening. The next step is to activate the extension of the second hydraulic cylinder and the opening of the right chamber door to pour the pressed ash cake into the rotary kiln while the sealed chamber is tilted. Conversely, when the third motor starts and reverses, and the second motor starts and rotates forward, the sealed box will return to its initial state, that is, the position near the slag pressing furnace. This cycle repeats.

[0029] like Figure 5As shown: In this embodiment, a rotary drive and a tilting drive are also connected to one side of the rotary furnace 3 to complete the rotary and tilting drive operations of the furnace body. The rotary drive and tilting drive are existing technologies, as can be found from publicly available information. Specifically, the tilting drive includes a structure consisting of a base plate, a mounting plate, and a hydraulic cylinder. The base plate is fixedly installed on the ground; the mounting plate has an overall L-shaped structure, with one vertical end hinged to the base plate; one end of the hydraulic cylinder is hinged to the horizontal section of the mounting plate, and the other end is hinged to the base plate. The rotary furnace is mounted on the mounting plate; thus, the tilting of the rotary furnace at different angles can be achieved by the extension and retraction of the hydraulic cylinder. Initially, the rotary furnace is horizontal. The rotary drive includes a rotary motor, an output shaft, and a limiting roller. The rotary motor is mounted on one side of the mounting plate via a bracket. The output shaft is connected to the rotary motor, and the other end is connected to the rotary furnace. The limiting roller adopts a grooved wheel structure, which is adapted to the ring body set on the rotary kiln. The limiting roller is installed on the mounting plate, forming support for the rotary kiln and providing the conditions for rotation. In this way, the start of the rotary motor will drive the rotary kiln to rotate. Rotary kiln 3 is equipped with a fully automatic combustion system, which can achieve precise temperature control. It can not only handle hot ash, but also warm ash above 500℃. It has strong production flexibility and can adapt to different working conditions. The rotary kiln adopts a low-temperature melting in a weak oxidizing atmosphere, and precisely controls the furnace temperature and oxygen content to further reduce aluminum oxidation loss, reducing the aluminum burning loss rate to below 3% (the existing process has a burning loss rate of 10% to 18%). At the same time, the combination of slag pressing and secondary recycling in the rotary kiln achieves complete separation of aluminum liquid and ash slag. The aluminum content of secondary aluminum ash is ≤5%, which is far lower than the 8% to 15% of the existing process. The comprehensive aluminum recovery rate is increased to 90% to 95%, which greatly improves the utilization rate of recycled aluminum resources.

[0030] like Figure 5 and Figure 6As shown: In this embodiment, the rotary kiln 3 is also equipped with an oxygen content detection sensor 301 and an air extraction pump 302. The oxygen content detection sensor 301 and the air extraction pump 302 maintain a signal connection to complete the low-temperature melting operation in a weakly oxidizing atmosphere. With this configuration, the oxygen content sensor is used to monitor the oxygen content in the rotary kiln in real time, with an oxygen concentration set within the range of 2-4%; and the low-oxygen environment in the rotary kiln is controlled through the auxiliary cooperation of the air extraction pump. In this embodiment, the rotary kiln 3 is equipped with a fully automatic combustion system 303. Preferably, the fully automatic combustion system 303 includes a combustion plate 307, a base 308, a flame cap 309, a gas pipe 310, and an air pipe 311. The base 308 is fixedly installed at the bottom of the rotary kiln 3, specifically by welding. The combustion plate 307 is installed on the base 308, specifically by bolts. The combustion plate 307 has a mixing chamber 312, and the top of the combustion plate also has a combustion hole communicating with the mixing chamber for combustion output. A gas passage 313 and an air passage 314 are also provided on one side of the mixing chamber 312. The gas passage 313 is connected to the gas pipe 310, and the air passage 314 is connected to the air pipe 311.

[0031] Specifically, both the gas pipe and the air passage are installed through the base and secured with clamps to prevent loosening. The gas pipe and gas passage, and the air passage and air pipe are connected via valve connectors. Both the gas pipe and air pipe are equipped with electromagnetic valves. The burner cap 309 has multiple evenly distributed injection holes 315 and is mounted on the combustion plate 307; these can be fixed with screws. An electric igniter 316 is also installed inside the mixing chamber 312; the purpose of the electric igniter is to facilitate the initiation of gas combustion; preferably, the electric igniter is connected to an external switch. A temperature probe 317 is also installed on the inner wall of the rotary kiln 3, and the temperature probe maintains a signal connection with the electromagnetic valves on the gas pipe and air pipe. This arrangement is intended so that when the temperature probe detects that the temperature inside the rotary kiln has reached a preset threshold, it triggers a signal to the industrial control computer, which then controls the corresponding electromagnetic valve to close, thus shutting off gas combustion. When the temperature probe detects that the temperature inside the rotary kiln is lower than the preset threshold, it controls the corresponding electromagnetic switch valve to open, simultaneously triggering the electric igniter, which in turn starts the gas combustion. Thus, the combustion plate is a disc-shaped base that supports the burner cap, with gas passages and air inlets inside, allowing the gas to be premixed with primary air to form a mixture, which is stored in the mixing chamber and then evenly sprayed out for combustion through the small holes of the burner cap.

[0032] like Figure 5 and Figure 7As shown: In this embodiment, a sealing furnace cover 304 is hinged to one side of the rotary furnace 3, and a sealing ring is provided on the outer side of the sealing furnace cover. The other side of the sealing furnace cover can be connected, fixed, and sealed by a knob. A connecting screw is connected to one side of the knob, and the connecting screw passes through the sealing furnace cover. An installation hole is provided on one side of the furnace body, and the connecting screw is threadedly connected to the installation hole; this ensures a good tightening and sealing effect. A liquid outlet pipe 305 is also connected to one side of the sealing furnace cover 304, and an electromagnetic switch valve is also installed on the liquid outlet pipe to realize the discharge of molten aluminum. A high-temperature resistant filter screen 306 is also provided at the input end of the liquid outlet pipe 305; the purpose is to filter aluminum dross, ensure the orderly output of molten aluminum, and thus achieve effective separation of aluminum liquid and aluminum dross. A flue gas filter device 8 is also provided on the sealing furnace cover 304; this setting is to ensure the filtration and purification effect of flue gas. The entire process flow of this invention (slag pressing, rotary kiln smelting, cooling and screening) adopts closed equipment and closed conveying, resulting in zero dust and fugitive emissions. The dust concentration in the workshop is controlled at ≤10mg / m³, meeting the requirements of national standard GB 25465-2010. Furthermore, the optimized process reduces secondary aluminum ash production by 30%, hazardous waste disposal costs by 40%, and optimizes flue gas treatment, fundamentally addressing the environmental pain points of existing processes and reducing environmental compliance risks for enterprises.

[0033] like Figure 1As shown: In this embodiment, a third conveying structure 9 is also provided below the rotary kiln 3. The third conveying structure 9 is equipped with a second collecting trough 901 and the cooling screening machine 4 to alternately complete the alternating discharge operations of aluminum liquid precipitation storage and secondary aluminum ash slag cooling screening within the rotary kiln 3. The second collecting trough is a rectangular hollow trough structure, fixedly welded to a support base. In a preferred embodiment, the third conveying structure 9 includes a fixed frame 902, a support slide rod 903, a support base 904, and a third hydraulic cylinder 905. The fixed frame 902 can be fixed to the external ground by pre-embedded anchor bolts and is a rectangular frame structure. Multiple evenly distributed support slide rods 903 are arranged within the fixed frame 902, and the two can be fixed by welding. The support base 904 is sleeved and installed on the support slide rod 903; this arrangement provides a supporting carrier. The third hydraulic cylinder 905 is located on one side of the fixed frame 902 and its end is connected and fixed to the support base 904; the second collecting trough 901 is fixedly installed on the rear side of the support base 904, and the cooling screening machine 4 is located on the front side of the support base 904. The purpose of setting the third hydraulic cylinder is to realize the automated recovery of molten aluminum liquid and the collection of aluminum dross to facilitate the subsequent cooling and screening process. In the initial state, the third hydraulic cylinder is in the retracted state, and at this time the second collecting trough is located below the rotary kiln opening. After the molten aluminum liquid is collected, the electromagnetic switch valve on the drain pipe is closed, and the aluminum dross is intercepted by the high-temperature resistant filter screen. In the next step, the third hydraulic cylinder extends, which will drive the support base to move backward to the preset position, that is, the feeding hopper is located below the rotary kiln opening. Specifically, a position sensor can be set to assist the third hydraulic cylinder and connected to an industrial control computer to achieve precise position movement. In the next step, the sealing aluminum cover is opened, and the aluminum dross remaining in the rotary kiln will fall to the feeding hopper, where the diameter of the feeding hopper is large enough.

[0034] Example 2: Based on Example 1, as follows Figure 1 , Figure 5 and Figure 7 As shown: A high-efficiency, low-consumption aluminum ash slag recycling device further includes: the flue gas filtration device 8 comprising a filter element 801, a pressure plate 802, an exhaust port 803, and a high-temperature resistant fan 806. An annular groove 804 is provided on one side of the sealed furnace cover 304, and the filter element 801 is fitted into the groove. The pressure plate 802 can be fitted onto the outside of the annular groove 804 using fastening bolts, for the purpose of installing and covering the filter element, and connecting it to the sealed furnace cover for easy maintenance and replacement. An air inlet pipe 805 is provided on the pressure plate 802; a filter screen can also be installed at the outer end of the air inlet pipe to prevent impurities from entering during flue gas filtration. Furthermore, during actual rotary kiln melting operations, the rotary kiln is set with the furnace opening facing upwards or horizontally, meaning that molten aluminum will not flow towards the sealed furnace cover during the melting stage. Only when the molten aluminum is poured will the furnace opening of the rotary kiln, i.e., the location of the sealed furnace cover, tilt downwards. The exhaust port 803 is located on the outside of the sealed furnace cover 304 and communicates with the annular groove 804; this arrangement facilitates exhaust operations. The high-temperature resistant fan 806 is mounted on the exhaust port 803 via a bracket. The filter element 801 comprises, from the inside out, non-woven fabric filter cotton 807, activated carbon pack 808, HEPA air filter cotton 809, and activated alumina granule pack 810. This arrangement allows the high-temperature resistant fan to be activated to absorb flue gas when the pressed ash cake enters the rotary kiln for melting. The four-stage deep filtration through the non-woven fabric filter cotton, activated carbon pack, HEPA air filter cotton, and activated alumina granule pack ensures harmless and environmentally friendly emission of the flue gas, avoids significant dust in the workshop, and solves the problem of long-term exposure causing serious respiratory harm to operators. Through four-stage filtration and adsorption, residual ammonia and fluorides can be effectively adsorbed and purified, solving the problem that aluminum nitride (AlN) contained in aluminum ash decomposes to produce ammonia under high temperature or water conditions, and fluorides diffuse with the flue gas, endangering the health of workers. The emission of harmful gases can be controlled.

[0035] Example 3: Based on Example 2, such as Figure 1 , Figure 10 and Figure 11 As shown: A high-efficiency, low-consumption aluminum ash slag recycling device further includes: the cooling screening machine 4, comprising a body 401. The body 401 is vertically mounted on a support base 904, and the two can be fixed by welding. The body 401 is divided into a cooling chamber 403 and a screening chamber 404, which are distributed vertically, by a partition 402. A feed hopper 405 is connected to the top of the cooling chamber 403, and a spirally distributed material pipe 406 is also provided inside the chamber. This arrangement facilitates the release and transportation of aluminum slag from the rotary kiln to the feed hopper. The current transportation method is direct pouring. Specifically, when the molten aluminum liquid is first transported to the second collection tank through the drain pipe, the sealed furnace cover of the rotary kiln is opened to discharge the aluminum slag into the feed hopper. The input end of the material pipe 406 is connected to the feed hopper 405, and the output end leads to the screening chamber 404. An electromagnetic switch valve can also be installed on the material pipe. This arrangement is for the purpose of facilitating the control of cooling time. A temperature sensor 407 and a refrigeration device 408 are also provided on one side of the cooling chamber 403. The purpose of the temperature sensor is to monitor the temperature environment of the cooling chamber in real time. The purpose of the refrigeration device is to achieve a refrigeration environment. The refrigeration device is existing technology and includes a combined refrigeration structure such as a compressor, condenser tube, and heat exchange tube, similar to the refrigeration principle of a refrigerator. Its refrigeration working principle will not be described in detail here. A cover door is also provided on one side of the machine body, located at the bottom of the screening chamber, to facilitate the handling of aluminum ash. Automated discharge can also be achieved through connecting pipelines and suction equipment.

[0036] like Figure 11As shown: The screening chamber 404 is further equipped with an inclined screen 409. The screen mesh diameter is sufficiently small, and specifically, it has a left-low, right-high structure. The left side of the screen 409 is hinged to the chamber wall, and the right side is equipped with a shaking screen drive 410. A slag discharge pipe 411 is also connected to the left side of the machine body 401, corresponding to the position of the screen 409. Preferably, the connection between the slag discharge pipe and the machine body is a concave-center contraction structure, which forms a gathering effect on large aluminum slag particles, facilitating their discharge through the slag discharge pipe. In a preferred embodiment, the shaking screen drive 410 includes a fourth motor 412, a rotating shaft 413, and a cam 414. The cam is an irregular mechanism designed to drive the screen to perform reciprocating shaking screening operations. The fourth motor 412 is located on one side of the machine body 401, the rotating shaft 413 is rotatably mounted in the screening chamber 404, and the cam 414 is sleeved and installed on the rotating shaft 413, contacting the screen 409. A vibrator 415 is also screwed to the bottom of the screen 409. With this configuration, when the fourth motor is turned on, it drives the rotating shaft to rotate synchronously. Simultaneously, the shaft drives the cam to rotate. Due to the irregular structure of the cam, the screen is supported by the left hinge point, and the right side reciprocates and oscillates during the screening process. The vibrator can be activated during this process to vibrate the screen. This configuration ensures that large aluminum slag particles can smoothly enter the slag discharge pipe for recycling while ensuring proper screening of aluminum ash. The coarse aluminum slag particles on the screen can be returned to the rotary kiln for secondary smelting to further recover the remaining metallic aluminum. The fine powder below the screen is the final secondary aluminum ash, which is then centrally recycled and processed.

[0037] A high-efficiency, low-consumption aluminum ash slag recycling process is disclosed, which utilizes the aforementioned recycling equipment for the recycling and reuse of aluminum ash slag. The process steps are as follows: Step S1: Sealed Transfer of High-Temperature Hot Aluminum Ash: Hot aluminum ash at 650-850℃ discharged from the aluminum smelting furnace is transferred to a transfer furnace. The first motor, starting and rotating forward, moves the transfer furnace to the right along the support frame to a preset position. This means the transfer furnace's discharge pipe and the connecting pipe of the slag pressing furnace are connected to form a sealed conveying channel. The 650-850℃ hot aluminum ash is adapted to the temperature of the hot ash discharged from the aluminum smelting furnace, ensuring the fluidity of the molten aluminum. In this embodiment, hot aluminum ash at 750℃ and containing 50% metallic aluminum is preferred.

[0038] Step S2: Slag Separation: Slag is processed using a closed hydraulic slag pressing furnace. The slag pressing process is relatively sealed, isolating most of the air and reducing oxidation loss. Under high pressure, liquid aluminum in the hot aluminum ash is squeezed out from the gaps between the ash and slag. The squeezed-out molten aluminum flows out from the molten aluminum outlet at the bottom of the slag press and is collected and directly cast into aluminum ingots, achieving preliminary and efficient separation of metallic aluminum. The maximum pressing pressure is 100 MPa, ensuring that the molten aluminum is fully squeezed out of the ash and slag, avoiding residue. The pressing time is 5-25 minutes, and rapid pressing reduces heat loss and avoids oxidation of the molten aluminum. In this embodiment, the preferred pressing pressure is 50 MPa and the pressing time is 5 minutes.

[0039] Step S3: Sealed Transfer of Pressed Ash Cake: After pressing, a dense pressed ash cake containing 12%–18% metallic aluminum is formed, and the temperature is maintained at 550–650℃. In this embodiment, preferably, after pressing, a pressed ash cake with a temperature of 600℃ and a metallic aluminum content of 15% is obtained. It is discharged from the sealed cover of the slag press furnace into a sealed box. The third motor is activated, which pulls the sealed box to move above the rotary kiln, at which point the rotary kiln opening tilts upwards. The next step is to activate the second hydraulic cylinder to extend, causing the sealed box to tilt and feed the pressed ash cake into the rotary kiln, ensuring the economic efficiency of subsequent rotary kiln recycling. Step S4: Low-Temperature Enhanced Recovery: The tilt angle of the tilting rotary furnace is controlled at 40° throughout its entire stroke to ensure smooth aluminum molten material discharge while maximizing ash and slag retention time; the rotation speed is 1–8 r / min; slow tumbling ensures thorough separation of ash and slag from the molten aluminum, preventing splashing; a low-temperature smelting process in a weakly oxidizing atmosphere is employed, with real-time heating via a fully automatic combustion system to precisely control the furnace temperature at 680–750°C. This temperature is below the severe oxidation temperature of metallic aluminum, effectively reducing oxidation loss; low-temperature smelting reduces aluminum oxidation loss and ensures the purity of the molten aluminum; in this embodiment, the preferred setting is a rotary furnace temperature of 720°C, with automatic air-fuel ratio control. The rotary furnace rotation speed is automatically stepless, adjusted from 1 to 8 r / min; the smelting tilt angle is -17° (horizontal reference plane); and the smelting time is 1.5–2.5 hours.

[0040] Step S5: Weak Oxygen Environment: The oxygen concentration in the rotary kiln cavity is detected in real time by an oxygen content detection sensor, and the air pump is turned on to extract air to complete the low-temperature melting operation in a weak oxidizing atmosphere, while precisely controlling the air-fuel ratio. Step S6: Smelting and separating aluminum liquid: The pressing ash cake is slowly tumbled in the rotary kiln. The remaining metallic aluminum in the ash cake melts into aluminum droplets at low temperature. Under the action of gravity, the droplets gather and flow along the inclined direction of the furnace body. They are discharged from the aluminum liquid outlet pipe at the bottom of the rotary kiln and combined with the aluminum liquid recovered in the slag pressing stage for processing. Step S6: Smelting and Separating Secondary Aluminum Ash: Secondary aluminum ash discharged from the rotary kiln at a high temperature of 450-550℃, containing ≤5% metallic aluminum, is directly fed into a closed-loop cooling and screening machine; this maximizes the recovery of metallic aluminum and reduces resource waste. In this embodiment, secondary aluminum ash discharged from the rotary kiln at a temperature of 500℃, containing ≤5% metallic aluminum, is fed into the closed-loop cooling and screening machine. Water cooling is preferably used to cool it to ≤80℃.

[0041] Step S7: Molten Flue Gas Treatment: The flue gas generated during the operation of the rotary kiln is collected through the sealed air inlet pipe of the sealed furnace cover and sent into the filter element. It undergoes four-stage purification treatment through non-woven filter cotton, activated carbon bag, HEPA air filter cotton and activated alumina granule bag to adsorb particulate impurities in the flue gas and adsorb and purify sulfur-containing gases, thus avoiding fugitive emissions of flue gas. Step S8: Secondary Aluminum Ash Cooling, Screening, and Compliant Disposal: After cooling in step S6, the temperature should not exceed 80℃. The ash is graded using a screen with auxiliary shaking and vibrating methods. Coarse particles on the screen can be returned to the rotary kiln for secondary smelting to further recover the remaining metallic aluminum. The fine powder below the screen is the final secondary aluminum ash, which is entrusted to a qualified third-party organization for harmless disposal and resource utilization to achieve environmentally compliant disposal. In this embodiment, the metallic aluminum burn-off rate is 2%, the comprehensive recovery rate is 93%, the workshop dust concentration is ≤10mg / m³, and the emission concentrations of ammonia and fluorides in the flue gas meet the GB 25465-2010 standard.

[0042] This process is simple, consisting of only three core steps: "slag pressing → rotary smelting → cooling and screening". Each step is closely connected, resulting in minimal heat loss and no need for additional heating (only the rotary furnace requires a small amount of supplemental heating), thus reducing energy consumption by 30%. The process can be directly connected to existing aluminum smelting furnaces without large-scale equipment modifications, and is suitable for recycled aluminum production lines ranging from 50,000 to 200,000 tons / year. It has strong scalability and can meet the needs of enterprises for large-scale and efficient production.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0044] It should be noted that, in specific embodiments of the present invention, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, terms such as "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the use of phrases such as "comprising one" to define an element does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0045] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," and "equipped" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; or they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A high-efficiency, low-consumption aluminum ash and slag recycling device, characterized in that: The recycling equipment includes a transfer furnace, a slag pressing furnace, a rotary kiln, and a cooling screening machine. The transfer furnace is vertically arranged with a feed pipe at the top and an inclined discharge pipe at the bottom. An inclined connecting pipe is located on the left side of the slag pressing furnace, and the discharge pipe and the connecting pipe are connected in a sleeve. A first conveying structure is provided between the transfer furnace and the slag pressing furnace to move the transfer furnace to a preset position. A first hydraulic cylinder is installed at the top of the slag pressing furnace, and an extrusion plate adapted to the furnace structure is provided at the end of the first hydraulic cylinder. A high-temperature resistant ultrafine steel filter screen is also provided at the bottom of the slag pressing furnace. A drain pipe is located at the bottom of the slag pressing furnace, and a pressure control valve is installed on the drain pipe. A first collection trough is located at the lower end of the support frame below the drain pipe. A hinged sealing cover is located on the right side of the slag pressing furnace, and a hydraulic telescopic rod is located on the side wall of the slag pressing furnace, next to the sealing cover. The slag pressing furnace also has a pushing structure. The rotary kiln is located to the right of the slag pressing furnace. Furthermore, a second conveying structure is connected between the two to ensure that the pressed ash cake is conveyed in a sealed manner into the rotary kiln. A rotary drive and a tilting drive are also connected to one side of the rotary kiln to complete the kiln's rotation and tilting / tilting operations. An oxygen content detection sensor and a vacuum pump are installed inside the rotary kiln, with the oxygen content detection sensor and vacuum pump maintaining a signal connection to complete the low-temperature smelting operation in a weakly oxidizing atmosphere. The rotary kiln is equipped with a fully automatic combustion system. A sealed furnace cover is hinged to one side of the rotary kiln, and a liquid outlet pipe is connected to one side of the sealed furnace cover. A high-temperature resistant filter screen is installed at the input end of the liquid outlet pipe. A flue gas filtration device is also installed on the sealed furnace cover. A third conveying structure is located below the rotary kiln, on which a second collecting tank and a cooling screening machine are installed to alternately complete the alternating export operations of aluminum liquid precipitation storage and secondary aluminum ash slag cooling screening within the rotary kiln.

2. The high-efficiency, low-consumption aluminum ash slag recycling equipment as described in claim 1, characterized in that: The discharge pipe and the connecting pipe have the same inclination angle, and the outer diameter of the discharge pipe is equal to the inner diameter of the connecting pipe. The right end of the discharge pipe has a horizontal section, and the left end of the connecting pipe also has a horizontal section, so that during material conveying operations between the transfer furnace and the slag pressing furnace, the discharge pipe and the connecting pipe are fitted together to form a sealed conveying channel. Electromagnetic valves are installed on the discharge pipe, connecting pipe, drain pipe, and liquid outlet pipe. The fully automatic combustion system includes a combustion plate, a base, a flame cap, a gas pipe, and an air pipe. The base is fixedly installed at the bottom of the rotary kiln, and the combustion plate is installed on the base. A mixing chamber is provided inside the combustion plate, and a gas passage and an air passage are provided on one side of the mixing chamber. The gas passage is connected to the gas pipe, and the air passage is connected to the air pipe. Multiple evenly distributed injection holes are provided on the flame cap, which is installed on the combustion plate. An electric igniter is also connected and installed inside the mixing chamber. A temperature probe is also provided on the inner wall of the rotary kiln.

3. The high-efficiency, low-consumption aluminum ash slag recycling equipment as described in claim 2, characterized in that: The first conveying structure includes a base, a support frame, support legs, a rotating screw, guide rods, a first motor, and a position sensor. The base is welded to the bottom of the transfer furnace. The support frame is a rectangular frame structure with multiple support legs that can be welded to and fixed to the support frame. Two guide rods are symmetrically distributed front and back and are located inside the support frame. The rotating screw is rotatably mounted on the support frame and located between the guide rods. The rotating screw and guide rods pass through the base, and the base and rotating screw are connected by a threaded rotation, while the base and guide rods are connected by a sliding connection. The first motor is mounted on the support frame via a bracket and connected to the rotating screw. The position sensor is located on one side of the support frame and is connected to the first motor via a signal connection.

4. The high-efficiency, low-consumption aluminum ash slag recycling equipment as described in claim 3, characterized in that: The pushing structure includes a telescopic push rod and a push plate; the telescopic push rod is set on the left side wall inside the slag pressing furnace, and the push plate is fixedly installed on the end of the telescopic push rod; in the initial state, the push plate is flush with the left side wall of the slag pressing furnace.

5. The high-efficiency, low-consumption aluminum ash slag recycling equipment as described in claim 4, characterized in that: The second conveying structure includes a conveying frame, guide rails, limiting wheels, and a sealed box; the conveying frame has an overall Z-shaped structure, and its left end is connected to and level with the support frame; the guide rails are arranged on the conveying frame and are two in number, symmetrically distributed front and back; the limiting wheels are arranged at the bottom of the sealed box and are matched and installed with the guide rails; the sealed box has doors on both the left and right sides, and a first electric telescopic rod is also provided between the inner wall of the sealed box and the left door; a second electric telescopic rod is also provided between the sealed box and the right door.

6. The high-efficiency, low-consumption aluminum ash slag recycling equipment as described in claim 5, characterized in that: The second conveying structure further includes a fixed base, a second hydraulic cylinder, a second motor, a reset shaft, a reset wheel, a reset rope, a third motor, a traction shaft, a traction wheel, and a traction rope; the sealed box is positioned above the fixed base, and the right side of the sealed box is hinged to the fixed base; one end of the second hydraulic cylinder is positioned on the fixed base, and the other end is positioned at the bottom of the sealed box; the second motor is mounted on the left side of the conveying frame via a bracket, and the reset shaft is rotatably mounted on the conveying frame and connected to the second motor; the reset wheel is sleeved and mounted on the reset shaft; one end of the reset rope is wound and mounted on the reset wheel, and the other end is connected to the left end of the fixed base; the traction shaft is rotatably mounted on the right end of the conveying frame and connected to the third motor; the traction wheel is sleeved and mounted on the traction shaft, and one end of the traction rope is wound and mounted on the traction wheel, and the other end is fixedly mounted on the right end of the fixed base.

7. The high-efficiency, low-consumption aluminum ash slag recycling equipment as described in claim 6, characterized in that: The flue gas filtration device includes a filter element, a pressure plate, an exhaust port, and a high-temperature resistant fan. An annular groove is provided on one side of the sealed furnace cover, and the filter element is fitted into the groove. The pressure plate is fitted onto the outside of the groove by fastening bolts, and an air inlet pipe is provided on the pressure plate. The exhaust port is located on the outside of the sealed furnace cover and communicates with the annular groove. The high-temperature resistant fan is mounted at the exhaust port via a bracket. The filter element comprises, from the inside out, non-woven filter cotton, activated carbon packs, HEPA air filter cotton, and activated alumina granule packs.

8. The high-efficiency, low-consumption aluminum ash slag recycling equipment as described in claim 7, characterized in that: The third conveying structure includes a fixed frame, supporting slide rods, a support base, and a third hydraulic cylinder; the fixed frame is fixedly installed on the external ground and is a rectangular frame structure; multiple supporting slide rods are evenly distributed and are set inside the fixed frame, and the two can be fixed by welding; the support base is sleeved and installed on the supporting slide rods; the third hydraulic cylinder is set on one side of the fixed frame and its end is connected and fixed to the support base; the second collecting trough is fixedly installed on the rear side of the support base, and the cooling screening machine is set on the front side of the support base.

9. The high-efficiency, low-consumption aluminum ash slag recycling equipment as described in claim 8, characterized in that: The cooling screening machine includes a machine body; the machine body is vertically mounted on a support base and is divided into a cooling chamber and a screening chamber by a partition; a feed hopper is connected to the top of the cooling chamber, and a spirally distributed material pipe is also provided inside the chamber. The input end of the material pipe is connected to the feed hopper, and the output end leads to the screening chamber. A temperature sensor and a refrigeration device are also provided on one side of the cooling chamber; a screen is also provided inside the screening chamber, with the left side of the screen hinged to the chamber wall and the right side equipped with a shaking screen drive; a slag discharge pipe is also connected to the left side of the machine body at the position corresponding to the screen; the shaking screen drive includes a fourth motor, a rotating shaft, and a cam; the fourth motor is located on one side of the machine body, the rotating shaft is rotatably mounted in the screening chamber, the cam is sleeved on the rotating shaft and contacts the screen; a vibrator is also installed at the bottom of the screen by screws.

10. A high-efficiency, low-consumption aluminum ash slag recycling process, characterized in that: The process steps for recycling and reusing aluminum ash using the above-mentioned recycling equipment are as follows: Step S1: High-temperature hot aluminum ash closed transfer: Hot aluminum ash of 650-850℃ discharged from the aluminum smelting furnace is discharged to the transfer furnace; the first motor starts and rotates forward, which will drive the transfer furnace to move to the right along the support frame to the preset position, that is, the discharge pipe of the transfer furnace and the connecting pipe of the slag pressing furnace are connected to form a sealed material conveying channel. Step S2: Slag Separation: Slag is processed using a closed hydraulic slag pressing furnace. The slag pressing process is relatively sealed, isolating most of the air and reducing oxidation loss. Under high pressure, the liquid aluminum in the hot aluminum ash is squeezed out from the gaps between the ash and slag. The squeezed-out molten aluminum flows out from the molten aluminum outlet at the bottom of the slag press and is collected and directly cast into aluminum ingots, achieving preliminary and efficient separation of metallic aluminum. The maximum pressing pressure is 100 MPa, and the pressing time is 5-25 minutes. Step S3: Sealed Transfer of Pressed Ash Cake: After pressing, a dense pressed ash cake containing 12% to 18% metallic aluminum is formed, and the temperature is maintained at 550 to 650℃; it is discharged from the sealed cover door of the slag pressing furnace into the sealed box; the third motor is turned on, which pulls the sealed box to move above the rotary kiln, at which time the kiln opening tilts upward; the next step is to turn on the second hydraulic cylinder to extend it, causing the sealed box to tilt and put the pressed ash cake into the rotary kiln; Step S4: Low-temperature enhanced recovery: The tilt angle of the tilting rotary furnace is controlled at 40° throughout its entire stroke, and the rotation speed is 1-8 r / min; a low-temperature smelting process with a weak oxidizing atmosphere is adopted, and the furnace temperature is precisely controlled at 680-750℃ through real-time heat replenishment by a fully automatic combustion system. This temperature is lower than the severe oxidation temperature of metallic aluminum, which can effectively reduce oxidation loss. Step S5: Weak Oxygen Environment: The oxygen concentration in the rotary kiln cavity is detected in real time by an oxygen content detection sensor, and the air pump is turned on to extract air to complete the low-temperature melting operation in a weak oxidizing atmosphere, while precisely controlling the air-fuel ratio. Step S6: Smelting and separating aluminum liquid: The pressing ash cake is slowly tumbled in the rotary kiln. The remaining metallic aluminum in the ash cake melts into aluminum droplets at low temperature. Under the action of gravity, the droplets gather and flow along the inclined direction of the furnace body. They are discharged from the aluminum liquid outlet pipe at the bottom of the rotary kiln and combined with the aluminum liquid recovered in the slag pressing stage for processing. Step S6: Smelting and separating secondary aluminum ash: The secondary aluminum ash discharged from the rotary kiln at a high temperature of 450-550℃, containing ≤5% metallic aluminum, is directly fed into a closed cooling and screening machine. Step S7: Molten Flue Gas Treatment: The flue gas generated during the operation of the rotary kiln is collected through the sealed air inlet pipe of the sealed furnace cover and sent into the filter element. It undergoes four-stage purification treatment through non-woven filter cotton, activated carbon bag, HEPA air filter cotton and activated alumina granule bag to adsorb particulate impurities in the flue gas and adsorb and purify sulfur-containing gases, thus avoiding fugitive emissions of flue gas. Step S8: Secondary aluminum ash cooling, screening, and compliant disposal: After cooling in step S6, the temperature after cooling should not exceed 80℃; the ash is graded using a screen with the assistance of shaking and vibrating screens. Coarse particles on the screen can be returned to the rotary kiln for secondary smelting to further recover the remaining metallic aluminum; the fine powder below the screen is the final secondary aluminum ash, which is entrusted to a third-party organization with hazardous waste disposal qualifications for harmless disposal and resource utilization to complete environmentally compliant disposal.

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