Device and method for preparing ecological functional soil by multi-stage processing of high-aluminum coal gangue

Abstract

The application discloses a device for preparing ecological functional soil through multistage treatment of high-aluminum coal gangue, which comprises a feeding hopper, a crusher, a high-temperature calcining furnace, a leaching reaction tank, a mixing stirrer, a granulator and a drying equipment, and a conveying belt is arranged at the bottom of the feeding hopper; the crusher is located at the discharging end of the conveying belt, the feeding inlet of the high-temperature calcining furnace is connected with the outlet of the crusher, the discharging outlet at the bottom of the high-temperature calcining furnace is connected with a cooling tank, the feeding inlet of the leaching reaction tank is connected with the outlet of the cooling tank, the liquid outlet of the leaching reaction tank is connected with the inlet of a filtering device, the liquid outlet of the filtering device is connected with a sedimentation tank, the residue discharging outlet of the filtering device is connected with a residue collecting box, the feeding end of the mixing stirrer is connected with the residue collecting box, the granulator is connected with the outlet of the mixing stirrer, and the drying equipment is connected with the outlet of the granulator. The device for preparing ecological functional soil through multistage treatment of high-aluminum coal gangue has the advantage that aluminum elements in the coal gangue can be fully recovered.

Description

Technical Field

[0001] This invention relates to the technical field of solid waste resource utilization, and in particular to an apparatus and method for preparing ecological functional soil through multi-stage treatment of high-alumina coal gangue. Background Technology

[0002] Current solid waste treatment methods have limitations. In the treatment of high-alumina coal gangue, the extraction and conversion of aluminum and other useful components are not sufficient, making it difficult to meet the needs of ecological functional soil preparation and hindering the resource utilization of high-alumina coal gangue. Summary of the Invention

[0003] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0004] The extraction and recovery of active ingredients were insufficient.

[0005] The present invention aims to at least partially solve one of the technical problems in the related art.

[0006] Therefore, embodiments of the present invention propose an apparatus for preparing ecological functional soil through multi-stage treatment of high-alumina coal gangue, comprising a feeding hopper, a crusher, a high-temperature calcining furnace, a leaching reaction tank, a mixing mixer, a granulator, and a drying device. A conveyor belt is installed at the bottom of the feeding hopper to carry and transport the coal gangue; the crusher is located at the discharge end of the conveyor belt to receive and crush the coal gangue; the inlet of the high-temperature calcining furnace is connected to the outlet of the crusher to receive the crushed material; the discharge port at the bottom of the high-temperature calcining furnace is connected to a cooling tank to cool the high-temperature material; and the leaching reaction tank… The feed inlet of the leaching reaction tank is connected to the outlet of the cooling tank to receive materials. The drain outlet of the leaching reaction tank is connected to the inlet of the filtration device. The reacted mixture undergoes solid-liquid separation through the filtration device. The liquid outlet of the filtration device is connected to the sedimentation tank. The slag outlet of the filtration device is connected to the residue collection box. The feed end of the mixing mixer is connected to the residue collection box to synthesize primary raw materials. The granulator is connected to the outlet of the mixing mixer to receive primary raw materials and extrude them. The drying equipment is connected to the outlet of the granulator to receive granular raw materials and perform hot air dehumidification.

[0007] The present invention has the advantages and technical effects of fully recovering aluminum from coal gangue. This application achieves efficient extraction and conversion of useful components from high-alumina coal gangue through the cooperation of multiple devices, resulting in efficient recovery, environmental friendliness, and a high degree of resource utilization.

[0008] In some embodiments, the crusher is provided with two sets of crushing rollers that rotate relative to each other, the surface of the crushing rollers is provided with a plurality of tooth-like protrusions, and a screen is provided at the bottom of the crusher, and the material falls into the screen through the gap between the two crushing rollers.

[0009] In some embodiments, the high-temperature calcining furnace is provided with multiple heating plates arranged from top to bottom, and the heating plates are separated from any adjacent heating plates by heat insulation plates, and the heating plates are uniformly distributed with heating wires on their surfaces.

[0010] In some embodiments, a spiral cooling water pipe is provided in the cooling tank, and both ends of the cooling water pipe are connected to an external circulating water device.

[0011] In some embodiments, a stirring paddle is disposed in the center of the leaching reaction tank, a motor is disposed at the top of the leaching reaction tank, the output end of the motor is connected to the stirring paddle for transmission, and through holes are provided on the surface of the stirring paddle blades to form vortices.

[0012] In some embodiments, the filtration device is provided with multiple layers of filter screens arranged at an angle from top to bottom, and the pore size of the filter screens decreases sequentially from top to bottom.

[0013] In some embodiments, the mixer is provided with a double helical stirring shaft that extends horizontally, and a scraper is provided on the outer edge of the helical blades of the double helical stirring shaft, the scraper being attached to the inner wall of the mixer.

[0014] In some embodiments, the granulator is equipped with a rotating drum and a geared motor inside. The axial direction of the rotating drum coincides with the horizontal plane. The output end of the geared motor is connected to the rotating drum for transmission. A vibrating screen is provided at the bottom of the granulator. Several shaping grooves are provided on the surface of the rotating drum.

[0015] In some embodiments, multiple conveyor belts are arranged alternately from top to bottom inside the cavity of the drying equipment, and heating tubes are arranged in parallel between any two adjacent layers of the circulating conveyor belts.

[0016] An embodiment of the present invention provides a method for preparing ecologically functional soil through multi-stage treatment of high-alumina coal gangue, comprising the following steps: Coarsely crushed, high-alumina coal gangue falls into the conveyor belt through the feed hopper and is sent into the crusher where it is crushed by the crushing rollers and screened to obtain material with a particle size of 5mm-10mm; High-temperature activation: The pulverized material is fed into a high-temperature calcining furnace and calcined at 800℃-1000℃ for 2-4 hours to remove organic impurities and activate the internal aluminum elements to obtain high-temperature material.

[0017] Cooling process: High-temperature materials fall into a cooling tank and are rapidly cooled to room temperature by circulating cooling water in the cooling water pipes. Acid leaching: Cooled material enters the leaching reaction tank and mixes with the acid solution. The leaching time is 3-6 hours. After stirring, the aluminum element is dissolved to form an aluminum-containing solution. The leaching mixture is extracted by diversion and then enters a filtration device to separate the aluminum-containing solution from the solid residue. The aluminum-containing solution is sent to a sedimentation tank to refine the by-products, and the solid residue is discharged into a collection box. In the mixed modification process, the solid residue is fed into a mixer and mixed evenly with soil conditioner at a mass ratio of 1:2 to 1:5 to form ecological soil raw material. In the drum granulation process, the raw material of the eco-friendly soil enters the granulator, is extruded and shaped, and unqualified particles are removed by a vibrating screen. The particle size of qualified particles is 3mm-8mm. Low-temperature drying: qualified particles enter the drying equipment and are dried at a low temperature of 60℃-80℃ for 4-6 hours to remove moisture, thus obtaining the finished ecological functional soil product. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the process flow for preparing ecological functional soil from high-alumina coal gangue through multi-stage treatment according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the apparatus for preparing ecological functional soil by multi-stage treatment of high-alumina coal gangue according to an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the structure of the crusher in the apparatus for preparing ecological functional soil by multi-stage treatment of high-alumina coal gangue according to an embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of the high-temperature calcining furnace of the apparatus for preparing ecological functional soil by multi-stage treatment of high-alumina coal gangue according to an embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram of the leaching reaction tank of the apparatus for preparing ecological functional soil by multi-stage treatment of high-alumina coal gangue according to an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of the granulator structure of the apparatus for preparing ecological functional soil from high-alumina coal gangue through multi-stage treatment according to an embodiment of the present invention.

[0024] Reference numerals: 1. Feed hopper; 2. Crusher; 3. High-temperature calcining furnace; 4. Cooling tank; 5. Leaching reaction tank; 6. Filter device; 7. Residue collection box; 8. Mixing mixer; 9. Granulator; 10. Drying equipment; 11. Crushing roller; 12. Screen; 13. Heating plate; 14. Heat insulation plate; 15. Exhaust port; 16. Agitator; 17. Drainage port; 18. Rotary drum; 19. Vibrating screen. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0026] This invention provides an apparatus for preparing eco-functional soil from high-alumina coal gangue through multi-stage processing, comprising a feed hopper 1, a crusher 2, a high-temperature calcining furnace 3, a leaching reaction tank 5, a mixer 8, a granulator 9, and a drying device 10. A conveyor belt is installed at the bottom of the feed hopper 1 to carry and transport the coal gangue; the crusher 2 is located at the discharge end of the conveyor belt to receive and crush the coal gangue; the feed inlet of the high-temperature calcining furnace 3 is connected to the outlet of the crusher 2 to receive the crushed material; the discharge outlet at the bottom of the high-temperature calcining furnace 3 is connected to a cooling tank 4 to cool the high-temperature material; and the leaching reaction tank... The feed inlet of 5 is connected to the outlet of cooling tank 4 to receive materials. The drain outlet 17 of leaching reaction tank 5 is connected to the inlet of filter device 6. The mixed liquid after reaction is separated into solid and liquid by filter device 6. The liquid outlet of filter device 6 is connected to sedimentation tank. The slag outlet of filter device 6 is connected to residue collection box 7. The feed end of mixer 8 is connected to residue collection box 7 to synthesize primary raw materials. Granulator 9 is connected to the outlet of mixer 8 to receive primary raw materials and extrude them. Drying equipment 10 is connected to the outlet of granulator 9 to receive granular raw materials and perform hot air dehumidification.

[0027] A conveyor belt at the bottom of the feed hopper 1 carries and transports coal gangue, enabling continuous feeding and avoiding uneven feeding caused by manual operation. The crusher 2, located at the discharge end of the conveyor belt, receives and crushes the coal gangue. The crusher 2 controls the particle size after crushing to between 5-10 mm. Materials that do not meet the standard continue to be crushed until they do. Mechanical screening and crushing provide a uniform raw material base for subsequent high-temperature calcination. The feed inlet of the high-temperature calcining furnace 3 is connected to the outlet of the crusher 2. Materials are calcined inside the high-temperature calcining furnace 3. The exhaust port 15 at the top of the high-temperature calcining furnace 3 is connected to a waste gas treatment device to promptly discharge calcination waste gas and prevent pollution. The discharge port at the bottom of the high-temperature calcining furnace 3 is connected to a cooling tank 4. Cooling water pipes are installed inside the cooling tank 4, with both ends connected to a circulating water system. A temperature sensor and controller at the bottom of the cooling tank 4 regulate the cooling water flow to ensure rapid cooling of the material to room temperature and prevent high-temperature damage to the equipment. The inlet of the leaching reaction tank 5 is connected to the outlet of the cooling tank 4. During the stirring process, it promotes full contact between the acidic solution and the material, achieving effective dissolution of aluminum. The drain outlet 17 at the bottom of the leaching reaction tank 5 is connected to the filter device 6 through a pipeline. The filter device 6 is equipped with a filter screen to achieve physical separation. The liquid outlet of the filter device 6 is connected to the sedimentation tank. The aluminum-containing solution enters the sedimentation tank to extract aluminum hydroxide by precipitation and then drys and recovers it as a by-product. The slag outlet is connected to the residue collection box 7, and the separated residue enters the residue collection box 7. The inlet of the mixing mixer 8 is connected to the residue collection box 7. The mixing mixer 8 is equipped with a stirring shaft inside to prevent the material from adhering to the inner wall during the stirring process. The residue and soil conditioner are mixed evenly at a mass ratio of 1:2 to 1:5 to form ecological functional soil raw materials. The granulator 9 is connected to the outlet of the mixing mixer 8, and the granulator 9 achieves uniform particle forming. The drying equipment 10 is connected to the outlet of the granulator 9. The drying equipment 10 has multiple conveyor belts inside, where materials are dried at low temperatures. The top exhaust port of the drying equipment 10 is connected to an exhaust fan to promptly remove moisture. Drying takes 4-6 hours in a low-temperature environment, ultimately yielding the finished eco-functional soil. All devices are connected via transmission pipes to form a multi-stage processing line from crushing, calcination, cooling, leaching, filtration, mixing, granulation to drying. The cooling tank 4 rapidly cools the materials in the high-temperature calcining furnace 3, ensuring the safe operation of the leaching reaction tank 5. The filtration device 6 separates the solid and liquid components of the leaching reaction tank 5, supporting the recovery of aluminum by-products and the preparation of eco-functional soil from the residue. The granulator 9 and the drying equipment 10 ensure the stability of the finished product quality.

[0028] In some embodiments, the crusher 2 is provided with two sets of relatively rotating crushing rollers 11 inside, the surface of the crushing rollers 11 is provided with a number of tooth-shaped protrusions, and a screen 12 is provided at the bottom of the crusher 2, so that the material falls into the screen 12 through the gap between the two crushing rollers 11.

[0029] Specifically, the crusher 2 is equipped with two sets of relatively rotating crushing rollers 11. Each crushing roller 11 has several toothed protrusions on its surface, with a spacing of 5 to 10 millimeters between them. This causes the material to be subjected to compression and shearing during the relative rotation of the two rollers, initially crushing it to near the target particle size. The screen 12 has an aperture of 5 to 10 millimeters. The material falls into the screen 12 through the gap between the two crushing rollers 11. The screen 12 screens the crushed material; particles that meet the aperture requirements pass through the screen 12 and enter the next process, while materials that do not meet the requirements continue to remain in the crusher 2 for further crushing until they meet the particle size requirements and are discharged. The spacing of the toothed protrusions and the aperture of the screen 12 are matched to form a process from coarse crushing to fine screening. The gap between the crushing rollers 11 determines the upper limit of the initial crushed size of the material, while the screen 12 acts as a quality control point to ensure that the output particle size is controlled within the range of 5-10 millimeters. Through mechanical screening and crushing, the particle size of the material is controlled, providing uniform raw materials for the subsequent high-temperature calcination process.

[0030] Furthermore, the crushing rollers 11 are fixed to the crusher housing 2 via bearings, resulting in smoother rotation. The toothed protrusions increase the gripping ability of the material, preventing slippage. The two sets of crushing rollers 11, together with the bottom screen 12, complete the crushing and screening operations within a single unit without relying on external grading equipment, improving crushing efficiency and reducing energy consumption.

[0031] In some embodiments, multiple heating plates 13 are arranged from top to bottom inside the high-temperature calcining furnace 3, and the heating plates 13 are separated from any adjacent heating plates 13 by heat insulation plates 14, and heating wires are evenly distributed on the surface of the heating plates 13.

[0032] Specifically, the high-temperature calcining furnace 3 is equipped with multiple layers of heating plates 13 arranged from top to bottom. The original document describes that the heating plates 13 are heated by heating wires, which are evenly distributed on the surface of each heating plate 13, ensuring a uniform temperature distribution across all layers. Each heating plate 13 is separated from any adjacent heating plate 13 by a heat insulation plate 14 made of high-temperature resistant ceramic material, reducing heat loss and improving energy efficiency. As the material passes through the multiple layers of heating plates 13 from top to bottom, it receives uniform heating from each layer, preventing localized overheating or underheating. Calcination at 800-1000 degrees Celsius for 2-4 hours removes organic impurities and activates aluminum. The alternating arrangement of the multiple heating plates 13 and heat insulation plates 14 forms independent temperature zones, allowing each heating plate 13 to be independently controlled. Even if one layer malfunctions, it does not affect the heating function of other layers. The heat insulation plates 14 block heat convection and conduction between adjacent layers, preventing heat from directly transferring from the high-temperature layer to the low-temperature layer and maintaining the stability of the set temperature for each layer. The uniform distribution of heating wires, in conjunction with the heat insulation plate 14, ensures the uniformity of the surface temperature of the heating plate 13, while the heat insulation plate 14 maintains the temperature gradient between layers, allowing the material to achieve a consistent heat treatment effect in each layer. The exhaust port 15 at the top of the high-temperature calcining furnace 3 is connected to a waste gas treatment device to promptly discharge calcination waste gas and prevent pollution. The multi-layered heating plate 13 structure from top to bottom, combined with the heat insulation plate 14 and uniformly distributed heating wires, achieves uniform heating of the material during continuous operation, reduces energy consumption, and improves the activation efficiency of aluminum elements, creating favorable conditions for subsequent leaching reactions.

[0033] In some embodiments, a spiral cooling water pipe is provided in the cooling tank 4, and both ends of the cooling water pipe are connected to an external circulating water device.

[0034] Specifically, a spiral cooling water pipe is installed inside the cooling tank 4. The original document describes the cooling water pipe as spirally distributed, with inlet and outlet connected at both ends, respectively. The inlet and outlet are connected to a circulating water system via pipes, i.e., connected to an external circulating water device. The spiral pipe design extends the flow path of the cooling water within the tank, increasing the heat exchange area and contact time between the cooling water and the high-temperature material, thus improving cooling efficiency. A temperature sensor is installed at the bottom of the cooling tank 4. The temperature sensor is connected to a controller via a signal line to monitor the material temperature and adjust the cooling water flow rate, ensuring that the material is rapidly cooled to room temperature. This avoids the possibility of damage to subsequent equipment due to excessively high temperatures.

[0035] The circulating water system drains the water after heat absorption, cools it, and then returns it to the water pipes, achieving the reuse of cooling water and reducing water consumption. Feedback regulation from temperature sensors and controllers, combined with continuous heat exchange through the spiral water pipes, dynamically adjusts the water flow rate based on the actual material temperature to prevent over-cooling or under-cooling. The calcined material enters the cooling tank 4 from the bottom of the high-temperature calcining furnace 3, where it undergoes counter-current or cross-current heat exchange with the spiral cooling water pipes. The material temperature rapidly drops to room temperature, ensuring the safe operation of the subsequent leaching reaction tank 5. This achieves an efficient, water-saving, and controllable cooling process, ensuring a uniform decrease in material temperature and protecting downstream equipment.

[0036] In some embodiments, a stirring paddle 16 is provided in the center of the leaching reaction tank 5, and a motor is provided at the top of the leaching reaction tank 5. The output end of the motor is connected to the stirring paddle 16 for transmission. Through holes are provided on the surface of the blades of the stirring paddle 16 to form vortices.

[0037] Specifically, the agitator 16 is driven by a motor, which is fixed to the top of the leaching reaction tank 5. The blades of the agitator 16 are arc-shaped, with through-holes distributed on the surface of the arc-shaped blades. The diameter of the through-holes is 2 mm to 5 mm, which are used to form vortices. When the arc-shaped blades rotate, they push the liquid to generate radial and axial flow. The through-holes on the blade surface allow some fluid to pass through, forming local high-speed jets and micro-vortices at the edge of the holes, enhancing the turbulence inside the liquid. During the stirring process, the agitator 16 promotes full contact between the acidic solution and the material, thereby allowing aluminum to gradually dissolve into the acidic solution within the leaching reaction time of 3-6 hours, forming an aluminum-containing solution. The transmission between the agitator 16 and the motor provides a stable rotation speed, ensuring continuous generation of vortices. The geometry of the arc-shaped blades and the distribution density of the through-holes work together to prevent material from settling to the bottom or being coated on the blade surface, improving the mixing uniformity of the solid and liquid phases. A drain port 17 is provided at the bottom of the leaching reaction tank 5, which is connected to the filter device 6 through a pipe. The uniform suspension formed by stirring results in a consistent solid content distribution in the discharged leachate, which is beneficial for subsequent filtration and separation.

[0038] In some embodiments, the filter device 6 is provided with multiple layers of filter screens at an angle from top to bottom, and the pore size of the filter screens decreases sequentially from top to bottom.

[0039] Specifically, the mesh size of the multi-layer filter screen decreases progressively from top to bottom, and the screens are secured within the housing of the filter device 6 using clips. The inclined arrangement of the screens creates a slope on the surface of each layer, allowing the leachate to flow downwards along the screen under gravity. Filter residue accumulates and slides off towards the lower end, preventing solid particles from accumulating evenly on the screen surface and causing blockage. The progressively decreasing mesh size enables stepwise filtration. The upper layer with larger pores intercepts larger particles, the middle layer captures medium-sized suspended solids, and the lower layer with smaller pores blocks fine particles, ensuring a clear division of labor and preventing any single layer from becoming overloaded. A discharge port is located at the bottom of the filter device 6 housing, connected to a residue collection box 7 via a pipe. The screens are inclined towards the discharge port, allowing residue trapped by each layer to slide off under the combined effect of gravity and the inclination angle, reducing the frequency of manual cleaning. The clips secure the screens for easy replacement and cleaning. After the leachate is separated by the filtration device 6, an aluminum-containing solution and residue are obtained. The aluminum-containing solution is transported to the sedimentation tank through a pipeline, while the residue enters the residue collection box 7. The inclined multi-layer filter screen and the decreasing pore size work together to achieve efficient graded filtration, self-cleaning slag discharge, and continuous operation.

[0040] In some embodiments, a double helical stirring shaft is provided inside the mixer 8. The double helical stirring shaft extends in a horizontal direction, and a scraper is provided on the outer edge of the helical blades of the double helical stirring shaft. The scraper is attached to the inner wall of the mixer 8.

[0041] Specifically, the double-helix stirring shaft is connected to the drive motor via a gear transmission mechanism. The drive motor is fixed to the top of the mixing mixer 8. The horizontally arranged double shafts generate convection and shear during rotation, allowing the residue and soil conditioner to fully exchange positions axially and radially. The gap between the scraper and the inner wall of the mixing mixer 8 is 1-3 mm, preventing material from adhering to the inner wall and avoiding severe wear caused by intense friction between the scraper and the wall surface. The scraper prevents material from adhering to the inner wall during mixing. The double-helix stirring shaft extends horizontally, allowing the scraper to cover a longer area of ​​the inner wall, cleaning the entire cylinder wall with each rotation. The helical blades of the two stirring shafts rotate in opposite or the same direction, working with the scraper to clean the left and right side walls. The residue and soil conditioner are added to the mixing mixer 8 at a mass ratio of 1:2 to 1:5. After being mixed evenly, they form ecological functional soil raw materials. The continuous scraping of the wall by the scraper prevents the material from accumulating, carbonizing, or clumping on the inner wall, ensuring uniform mixing and smooth discharge. Through continuous wall scraping and forced convection, uniform mixing of highly viscous materials is achieved, and residue is reduced.

[0042] In some embodiments, the granulator 9 is provided with a rotating drum 18 and a geared motor inside. The axial direction of the rotating drum 18 coincides with the horizontal plane. The output end of the geared motor is connected to the rotating drum 18 for transmission. A vibrating screen is provided at the bottom of the granulator 9. Several shaping grooves are provided on the surface of the rotating drum 18.

[0043] Specifically, the rotating drum 18 is connected to a geared motor via a chain drive mechanism. The geared motor is fixed to the bottom of the granulator 9 and is arranged horizontally so that the material falls naturally under gravity inside the drum and is evenly distributed on the drum surface, preventing the material from tilting to one side. The output end of the geared motor is connected to the rotating drum 18 via a chain drive mechanism, driving the rotating drum 18 to rotate at a set speed. The chain drive allows for a certain center distance deviation and is impact-resistant, suitable for uneven loads during granulation. The shaping groove has a depth of 3 mm to 8 mm and is used to form granules. The shape and depth of the groove determine the diameter and shape of the finished granules. After the material is pressed into the groove, it is ejected as the drum rotates to form granules.

[0044] The vibrating screen, fixed to the granulator 9 housing by springs, is used to screen granules that meet the required particle size, with the particle diameter controlled between 3 mm and 8 mm. During the interaction between the rotating drum 18 and the vibrating screen, the granules formed by the drum fall directly into the vibrating screen. The vibrating screen generates high-frequency vibrations through the springs, causing qualified granules to pass through the screen 12, while excessively large or small granules are separated and can be returned for re-granulation. The horizontally axially rotating drum 18, combined with the smooth drive of the geared motor, ensures that the grooves are evenly filled with material. The springs absorb vibration impacts, preventing damage to the housing caused by rigid connections.

[0045] In some embodiments, multiple conveyor belts are arranged alternately from top to bottom inside the cavity of the drying equipment 10, and heating tubes are arranged in parallel between any two adjacent layers of circulating conveyor belts.

[0046] Specifically, the conveyor belts are supported by rollers, with both ends of the rollers fixed inside the drying equipment 10 housing by bearings. The staggered arrangement of the conveyor belts ensures that the material falls sequentially at the starting end of the next conveyor belt during the downward transport process, extending the travel time of the material within a limited height and preventing breakage caused by vertical falls. Heating tubes are installed inside the drying equipment 10 housing, connected to a power source via wires. These heating tubes, arranged parallel between the two conveyor belts, can simultaneously radiate heat to the lower surface of the upper conveyor belt and the upper surface of the lower conveyor belt, improving heat utilization. The granulated material enters from the input end of the top conveyor belt, moves to the end, and falls onto the next conveyor belt, repeatedly passing through multiple heating zones. A dehumidification fan connected to the top exhaust port promptly removes moisture. The combination of the staggered conveyor belts and the interlayer heating tubes ensures material tumbling and uniform heating, preventing material stacking that would prevent internal moisture from dissipating. The parallel arrangement of the heating tubes ensures a uniform heat distribution and consistent temperature across all layers. Low-temperature drying achieves final solidification of the material, ensuring the quality and stability of the finished product. The conveyor belt is supported by rollers and the bearings are fixed inside the housing for reliable operation. The dehumidifying fan promptly extracts water vapor to prevent moisture from condensing and flowing back at the top of the equipment. This allows for continuous drying of materials within a compact space, ensuring long-path, low-drop, and uniform heating, improving energy efficiency and guaranteeing low product moisture content.

[0047] An embodiment of the present invention provides a method for preparing ecologically functional soil through multi-stage treatment of high-alumina coal gangue, comprising the following steps: Coarsely crushed, high-alumina coal gangue falls into the conveyor belt through the feed hopper 1 and is fed into the crusher 2, where it is crushed by the crushing roller 11 and screened to obtain material with a particle size of 5mm-10mm; the toothed protrusions on the surface of the crushing roller 11 and the aperture of the bottom screen 12 cooperate with each other to achieve particle size control.

[0048] After high-temperature activation, the pulverized material enters the high-temperature calcining furnace 3 and is calcined at 800℃-1000℃ for 2-4 hours to remove organic impurities and activate the internal aluminum elements to obtain high-temperature material.

[0049] Cooling is achieved by allowing high-temperature materials to fall into the cooling tank 4 and be rapidly cooled to room temperature by circulating cooling water in the cooling water pipes. The spiral cooling water pipes and the circulating water system work together to achieve efficient water-saving cooling. Temperature sensors and controllers regulate the water flow to prevent excessive temperature from damaging subsequent equipment.

[0050] Acid leaching: Cooled material enters leaching reaction tank 5 and mixes with acidic solution. Leaching time is 3-6 hours. After stirring, aluminum elements are dissolved to form an aluminum-containing solution. The leaching mixture is extracted by diversion and then enters the filtration device 6 to separate the aluminum-containing solution from the solid residue. The aluminum-containing solution is sent to the sedimentation tank to refine the by-product, and the solid residue is discharged into the collection box. The aluminum-containing solution is sent to the sedimentation tank to extract aluminum hydroxide by precipitation and then dried and recovered as a by-product.

[0051] The solid residue is fed into a mixing mixer 8 and mixed evenly with soil conditioner at a mass ratio of 1:2 to 1:5 to form ecological soil raw material. In the drum granulation process, the raw material of the ecological soil enters the granulator 9, is extruded and shaped, and unqualified particles are removed by a vibrating screen. The particle size of qualified particles is 3mm-8mm. Low-temperature drying: qualified particles enter the drying equipment 10 and are dried at a low temperature of 60℃-80℃ for 4-6 hours to remove moisture, thus obtaining the finished ecological functional soil product.

[0052] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0054] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0055] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0056] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A device for preparing ecologically functional soil through multi-stage treatment of high-alumina coal gangue, characterized in that, include: The system includes a feed hopper, a crusher, a high-temperature calcining furnace, a leaching reaction tank, a mixing mixer, a granulator, and a drying device. A conveyor belt is installed at the bottom of the feed hopper to carry and transport coal gangue. The crusher is located at the discharge end of the conveyor belt to receive and crush the coal gangue. The feed inlet of the high-temperature calcining furnace is connected to the outlet of the crusher to receive the crushed material. The discharge outlet at the bottom of the high-temperature calcining furnace is connected to a cooling tank to cool the high-temperature material. The feed inlet of the leaching reaction tank is connected to the outlet of the cooling tank to carry and transport coal gangue. The leaching reaction tank's drain outlet is connected to the inlet of the filtration device. The reacted mixture undergoes solid-liquid separation via the filtration device. The filtration device's liquid outlet is connected to a sedimentation tank, and its slag outlet is connected to a residue collection box. The mixing mixer's feed end is connected to the residue collection box for synthesizing primary raw materials. The granulator is connected to the mixing mixer's outlet for receiving and extruding the primary raw materials. The drying equipment is connected to the granulator's outlet for receiving granular raw materials and performing hot air dehumidification.

2. The apparatus for preparing ecological functional soil through multi-stage treatment of high-alumina coal gangue according to claim 1, characterized in that, The crusher is equipped with two sets of crushing rollers that rotate in opposite directions. The surface of the crushing rollers is provided with several tooth-like protrusions. A screen is provided at the bottom of the crusher. The material falls into the screen through the gap between the two crushing rollers.

3. The apparatus for preparing ecological functional soil through multi-stage treatment of high-alumina coal gangue according to claim 1, characterized in that, The high-temperature calcining furnace is equipped with multiple heating plates arranged from top to bottom. Each heating plate is separated from any adjacent heating plate by a heat insulation plate, and heating wires are evenly distributed on the surface of the heating plate.

4. The apparatus for preparing ecological functional soil through multi-stage treatment of high-alumina coal gangue according to claim 1, characterized in that, The cooling tank is equipped with a spiral cooling water pipe, and both ends of the cooling water pipe are connected to an external circulating water device.

5. The apparatus for preparing ecological functional soil through multi-stage treatment of high-alumina coal gangue according to claim 1, characterized in that, A stirring paddle is installed in the center of the leaching reaction tank, and a motor is installed at the top of the leaching reaction tank. The output end of the motor is connected to the stirring paddle for transmission. Through holes are provided on the surface of the stirring paddle blades to form vortices.

6. The apparatus for preparing ecological functional soil through multi-stage treatment of high-alumina coal gangue according to claim 1, characterized in that, The filtration device is equipped with multiple layers of filter screens arranged at an angle from top to bottom, and the pore size of the filter screens decreases sequentially from top to bottom.

7. The apparatus for preparing ecological functional soil through multi-stage treatment of high-alumina coal gangue according to claim 1, characterized in that, The mixer is equipped with a double helical stirring shaft that extends horizontally. Scrapers are provided on the outer edges of the helical blades of the double helical stirring shaft and are attached to the inner wall of the mixer.

8. The apparatus for preparing ecological functional soil through multi-stage treatment of high-alumina coal gangue according to claim 1, characterized in that, The granulator is equipped with a rotating drum and a geared motor. The axial direction of the rotating drum coincides with the horizontal plane. The output end of the geared motor is connected to the rotating drum for transmission. A vibrating screen is installed at the bottom of the granulator. Several shaping grooves are provided on the surface of the rotating drum.

9. The apparatus for preparing ecological functional soil through multi-stage treatment of high-alumina coal gangue according to claim 1, characterized in that, The drying equipment has multiple conveyor belts arranged alternately from top to bottom inside the cavity, and heating tubes are arranged in parallel between any two adjacent layers of the circulating conveyor belts.

10. A method for preparing ecological functional soil through multi-stage treatment of high-alumina coal gangue, using the apparatus according to any one of claims 1-9, characterized in that, Includes the following steps: Coarsely crushed, high-alumina coal gangue falls into the conveyor belt through the feed hopper and is sent into the crusher where it is crushed by the crushing rollers and screened to obtain material with a particle size of 5mm-10mm; High-temperature activation: The pulverized material is fed into a high-temperature calcining furnace and calcined at 800℃-1000℃ for 2-4 hours to remove organic impurities and activate the internal aluminum elements to obtain high-temperature material. Cooling process: High-temperature materials fall into a cooling tank and are rapidly cooled to room temperature by circulating cooling water in the cooling water pipes. Acid leaching: Cooled material enters the leaching reaction tank and mixes with the acid solution. The leaching time is 3-6 hours. After stirring, the aluminum element is dissolved to form an aluminum-containing solution. The leaching mixture is extracted by diversion and then enters a filtration device to separate the aluminum-containing solution from the solid residue. The aluminum-containing solution is sent to a sedimentation tank to refine the by-products, and the solid residue is discharged into a collection box. In the mixed modification process, the solid residue is fed into a mixer and mixed evenly with soil conditioner at a mass ratio of 1:2 to 1:5 to form ecological soil raw material. In the drum granulation process, the raw material of the eco-friendly soil enters the granulator, is extruded and shaped, and unqualified particles are removed by a vibrating screen. The particle size of qualified particles is 3mm-8mm. Low-temperature drying: qualified particles enter the drying equipment and are dried at a low temperature of 60℃-80℃ for 4-6 hours to remove moisture, thus obtaining the finished ecological functional soil product.

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