In-situ leaching simulation device for goaf phosphogypsum filling body

Abstract

The invention relates to an in-situ leaching simulation device for a goaf phosphogypsum filling body, and belongs to the technical field of solid waste disposal and mine filling. The in-situ leaching simulation device for the phosphogypsum filling body in the goaf comprises a shell, a leaching system, a pressure system and a temperature system, the leaching system comprises a water tank, a first sleeve and a liquid storage tank, and a phosphogypsum filling body test piece is arranged in the first sleeve; the leaching system is used for simulating an underground leaching environment in which a phosphogypsum filling body test piece is positioned to realize in-situ leaching simulation; the pressure system comprises a torque motor, a ball screw push rod, a force transmission piston, a pressure-bearing plate and a pressure-bearing cushion block, and is used for applying simulation pressure to the phosphogypsum filling body test piece; the temperature system comprises a temperature sensor, a heating plate supporting column and a heating plate and is used for simulating the underground high-temperature environment of the phosphogypsum filling body test piece. The in-situ leaching process simulated by the device is closer to the real mine environment, and the pollutant concentration measured in the leachate is closer to the pollutant concentration in the underground water environment where the filling body is located.

Description

Technical Field

[0001] The invention relates to an in-situ leaching simulation device for a phosphogypsum filling body in a goaf, belonging to the technical field of solid waste disposal and mine filling. Background Art

[0002] Mixing phosphogypsum with cement and other cementitious materials to make filling materials and backfilling them into the goaf in the mine can not only achieve the backfilling and repair of the goaf and ensure the safety of underground production, but also consume a large amount of phosphogypsum. However, since phosphogypsum itself contains pollutants such as phosphates and fluorides, the phosphogypsum filling body will gradually migrate to the surrounding water bodies with the groundwater under the coupling of groundwater leaching, roof pressure and ambient temperature, causing damage to the ecological environment.

[0003] The evaluation of the leaching characteristics of pollutants in phosphogypsum fillings usually adopts destructive tests, that is, the block filling specimens are broken into powders of a certain fineness, and then an acid solution or deionized water is added as a leaching agent, and the harmful elements are forced to leach out of the filling by mechanical oscillation. However, it is almost impossible for the filling to be destroyed in a short period of time and subjected to violent oscillation in the underground environment. The above results can only reflect the maximum limit leaching concentration of pollutants, not the actual leaching concentration in the in-situ environment. Conducting on-site in-situ experiments is the best choice to determine whether the leaching concentration of pollutants exceeds the relevant standard limits, but there are many uncontrollable factors in on-site in-situ experiments, the experimental conditions are difficult to control, and the safety is poor, which makes the experiment unable to be carried out normally. Therefore, it is necessary to establish a set of in-situ leaching simulation devices suitable for phosphogypsum fillings in goafs. Summary of the invention

[0004] In view of the problems that the leaching characteristics of pollutants in phosphogypsum filling bodies are difficult to evaluate and the evaluation results are inaccurate, the present invention proposes an in-situ leaching simulation device for phosphogypsum filling bodies in goafs. The leaching leaching system simulates the underground leaching environment where the phosphogypsum filling body specimen is located to achieve in-situ leaching simulation; the pressure system applies simulated pressure to the phosphogypsum filling body specimen; and the temperature system simulates the underground high-temperature environment where the phosphogypsum filling body specimen is located. The in-situ leaching process simulated by the device of the present invention is closer to the real mine environment, and the pollutant concentration measured in the leachate is closer to the pollutant concentration in the groundwater environment where the filling body is located; multiple filling body specimens can be used for uniaxial compressive strength determination at different leaching ages.

[0005] The technical solution adopted by the present invention to solve the technical problem is: An in-situ leaching simulation device for phosphogypsum filling in goaf includes a shell, a leaching system, a pressure system, and a temperature system. The leaching and leaching system comprises a water tank 5, a first sleeve 18, and a liquid storage tank 28. The liquid storage tank 28 is arranged directly below the shell. The first sleeve 18 is fixedly arranged on the bottom plate 23 of the shell through a sleeve base 21. The first sleeve 18 is located directly above the liquid storage tank 28. A first water-permeable plate is placed at the bottom of the first sleeve 18. A phosphogypsum filling body specimen 20 is filled on the first water-permeable plate. A second water-permeable plate 19 is placed on the top of the phosphogypsum filling body specimen 20. A movable top plate is arranged on the top of the second water-permeable plate 19. The movable top plate is slidably arranged in the first sleeve 18. The water tank 5 is fixedly arranged on the top of the shell. The water tank 5 is located directly above the first sleeve 18. The drain outlet of the water tank 5 is connected to the top of the first sleeve 18 through the leaching pipe 15. The bottom of the first sleeve 18 is connected to the liquid storage tank 28 through the leaching pipe 25. The pressure system includes a torque motor 1, a ball screw push rod 4, a force transmission piston 8, a pressure plate 16 and a pressure pad 17. The torque motor 1 is fixedly arranged at the top of the water tank 5. The output end of the torque motor 1 is connected to the ball screw push rod 4. The ball screw push rod 4 vertically passes through the water tank 5 downward. The force transmission piston 8 is fixedly arranged at the bottom end of the ball screw push rod 4. The pressure pad 17 is arranged on the top surface of the movable top plate. The pressure plate 16 is fixedly arranged on the top of the pressure pad 17. When the pressure system is working, the force transmission piston 8 is pressed on the center of the pressure plate 16. The temperature system comprises a temperature sensor 14, a heating plate support 12 and a heating plate 13. The heating plate 13 is fixedly arranged in the housing through the heating plate support 12, and the temperature sensor 14 is arranged in the housing.

[0006] The movable top plate is provided with a water inlet, the bottom end of the leaching pipe 15 passes through the water inlet and extends into the first sleeve 18 , the sleeve base 21 is provided with a vertical water outlet, the top end of the leaching pipe 25 passes through the water outlet and extends into the first sleeve 18 .

[0007] A first central through hole is provided at the center of the top plate of the water tank 5, a second central through hole is provided at the center of the bottom plate of the water tank 5, a matching second sleeve is vertically fixed between the first central through hole and the second central through hole, sealing rings 30 are provided at the connection between the top plate of the water tank 5 and the second sleeve and at the connection between the bottom plate of the water tank 5 and the second sleeve, and the ball screw push rod 4 passes vertically downward through the second sleeve.

[0008] The pressure plate 16 is provided with a first vertical through hole, the pressure pad 17 is provided with a second vertical through hole, and the leaching pipe 15 passes downward through the first vertical through hole of the pressure plate 16, the second vertical through hole of the pressure pad 17 and the water inlet of the movable top plate in sequence.

[0009] The bottom plate 23 is provided with a third vertical through hole, and the top end of the leaching pipe 25 passes through the third vertical through hole of the bottom plate 23 and the water outlet of the sleeve base 21 in sequence.

[0010] The in-situ leaching simulation device for phosphogypsum filling in the goaf also includes a computer 29, a motor controller 2 is arranged on the torque motor 1, a water injection pipe 6 is arranged at the water injection port of the water tank 5, a third solenoid valve is arranged on the water injection pipe 6, a first solenoid valve is arranged on the leaching tube 15, a pressure box 7 is arranged between the ball screw push rod 4 and the force transmission piston 8, and a second solenoid valve 26 is arranged on the leaching tube 25. The motor controller 2, the third solenoid valve, the first solenoid valve, the pressure box 7, the temperature sensor 14, and the second solenoid valve 26 are all connected to the computer signal to form an intelligent control system.

[0011] The torque motor 1 is fixedly arranged on the top of the water tank 5 through the motor support 3, and the shell is supported by the bottom column 27.

[0012] The sleeve base 21 is fixedly disposed on the bottom plate 23 via a fixing device 22 , and the bottom end of the first sleeve 18 is clamped on the sleeve base 21 .

[0013] The shell comprises a bottom plate 23, a first side wall 9, a second side wall 10, a third side wall 11 and a partition plate 24. The first side wall 9, the second side wall 10 and the third side wall 11 connected in sequence are fixedly arranged on the bottom plate 23. The first side end of the first side wall 9 is perpendicularly intersected with the first side end of the second side wall 10, the second side end of the second side wall 10 is perpendicularly intersected with the first side end of the third side wall 11, the second side end of the first side wall is vertically provided with a first slide groove, the second side end of the third side wall is vertically provided with a second slide groove, a horizontal groove is provided on the bottom plate 23, the partition plate 24 is slidably arranged in the first slide groove and the second slide groove to form the fourth side wall of the shell, and when the partition plate 24 slides to the lowest point, the bottom end of the partition plate 24 is inserted into the horizontal groove; The heating plate 13 is fixedly arranged on the first side wall 9 and the third side wall 11 via heating plate supports 12 , and the temperature sensor 14 is fixedly arranged on the second side wall 10 .

[0014] Preferably, a first viewing window is provided on the side wall of the water tank 5 , and a second viewing window is provided on the partition 24 .

[0015] The simulation method based on the in-situ leaching simulation device of phosphogypsum filling in goaf has the following specific steps: 1) The first sleeve is filled with phosphogypsum filling specimens, and the water tank is filled with mine water; 2) The mine water in the water tank is drained into the first sleeve at a predetermined flow rate through the leaching pipe, and the mine water flows downward evenly through the second permeable plate to leach the upper surface of the phosphogypsum filling body specimen. The mine water flows through the phosphogypsum filling body specimen to leach the pollutants in the phosphogypsum filling body specimen in situ at a preset flow rate. The leachate passes through the first permeable plate and is discharged into the liquid storage tank through the leaching pipe at a predetermined flow rate. The predetermined flow rate of mine water drainage and the predetermined flow rate of leachate discharge are set to achieve stable flow of mine water in the first sleeve. The in-situ leaching time of pollutants in the phosphogypsum filling body specimen is adjusted by adjusting the predetermined flow rate of mine water drainage and the predetermined flow rate of leachate discharge to restore the real environmental leaching time of phosphogypsum filling body leaching; 3) The torque output by the torque motor is converted into a preset vertical downward pressure through the ball screw push rod and applied to the force transmission piston. The force transmission piston transmits the pressure to the pressure plate, and the pressure plate evenly applies the pressure to the pressure pad. The pressure pad transmits the force to the phosphogypsum filling body specimen through the movable top plate and the second permeable plate to realize the in-situ leaching experiment under the preset pressure. The pressure of the in-situ leaching of the phosphogypsum filling body specimen is adjusted by changing the torque output by the torque motor to restore the pressure on the phosphogypsum filling body during leaching in the real environment. 4) The heating plate of the temperature system heats the enclosed space inside the shell, and the temperature of the enclosed space inside the shell is monitored in real time through the temperature sensor to restore the temperature of the phosphogypsum filling body during leaching in the real environment; 5) Adjust the predetermined flow rate of mine water drainage and the predetermined flow rate of leachate discharge, adjust the torque output by the torque motor, adjust the temperature of the enclosed space inside the shell, and perform in-situ leaching of the phosphogypsum filling body in a multi-field coupling environment.

[0016] Beneficial effects of the present invention: (1) The present invention can achieve a true restoration of the leaching environment of the phosphogypsum filling body by controlling pressure, temperature and flow, which is closer to the in-situ environment of the phosphogypsum filling body and simulates the leaching of toxic and harmful elements in the phosphogypsum filling body in different in-situ environments; (2) The present invention can perform in-situ leaching of phosphogypsum filling in a multi-field coupling environment, thereby avoiding the problem in the existing toxic leaching standard that the measured leaching concentration is inconsistent with the actual concentration due to first crushing and then leaching, and improving the accuracy of the in-situ leaching simulation experiment; (3) The present invention can realize the simultaneous leaching of multiple phosphogypsum filling bodies, so that the measured leaching concentration of toxic and harmful substances is closer to the concentration in the mine groundwater environment, avoiding the error in the leaching of a single filling body, and at the same time realizing the determination of the uniaxial compressive strength at different leaching ages. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a front cross-sectional view of the in-situ leaching simulation device for phosphogypsum filling in the goaf; Figure 2 It is a side profile of the in-situ leaching simulation device for phosphogypsum filling in the goaf; Figure 3 Assembly drawings for the shell and water tank; Figure 4 Assembly drawings for sleeve base, fixtures and base plate; In the figure, 1-torque motor, 2-motor controller, 3-motor support, 4-ball screw push rod, 5-water tank, 6-water injection pipe, 7-pressure box, 8-force transmission piston, 9-first side wall, 10-second side wall, 11-third side wall, 12-heating plate support, 13-heating plate, 14-temperature sensor, 15-leaching tube, 16-pressure plate, 17-pressure pad, 18-sleeve, 19-second permeable plate, 20-phosphogypsum filling body specimen, 21-sleeve base, 22-fixing device, 23-bottom plate, 24-partition, 25-leaching pipe, 26-second solenoid valve, 27-bottom column, 28-liquid storage tank, 29-computer, 30-sealing ring. DETAILED DESCRIPTION

[0018] The present invention provides an in-situ leaching simulation device for phosphogypsum filling in a goaf, wherein a leaching leaching system simulates the underground leaching environment in which a phosphogypsum filling specimen is located to realize in-situ leaching simulation; a pressure system applies simulated pressure to the phosphogypsum filling specimen; and a temperature system simulates the underground high temperature environment in which the phosphogypsum filling specimen is located.

[0019] Below, the technical solutions in the present invention are clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments of the present invention. It should be understood that the present invention is not limited to the examples of the embodiments described here. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all of them.

[0020] Example 1: An in-situ leaching simulation device for phosphogypsum filling in goaf (see Figure 1 and 2 ), including shell, leaching system, pressure system, temperature system, The leaching system comprises a water tank 5, a first sleeve 18, and a liquid storage tank 28. The liquid storage tank 28 is arranged directly below the shell. The first sleeve 18 is fixedly arranged on the bottom plate 23 of the shell through a sleeve base 21. The first sleeve 18 is located directly above the liquid storage tank 28. A first water-permeable plate is placed at the bottom of the first sleeve 18. A phosphogypsum filling body specimen 20 is filled on the first water-permeable plate. A second water-permeable plate 19 is placed on the top of the phosphogypsum filling body specimen 20. A movable top plate is arranged on the top of the second water-permeable plate 19. The movable top plate is slidably arranged in the first sleeve 18. The water tank 5 is fixedly arranged on the top of the shell. The water tank 5 is located directly above the first sleeve 18. At the top, the drain port of the water tank 5 is connected to the top of the first sleeve 18 through the leaching pipe 15, and the bottom of the first sleeve 18 is connected to the liquid storage tank 28 through the leaching pipe 25; the water tank 5 is filled with mine water, and the mine water is obtained from the in-situ environment of the mine site, including tap water, acid and alkali; the leaching pipe drains the mine water into the sleeve, and the mine water enters the phosphogypsum filling specimen through the second permeable plate and leaches the top of the phosphogypsum filling specimen. The mine water leaches the harmful substances inside the phosphogypsum filling specimen in situ to form a leachate, and the leachate flows into the leachate pipe through the first permeable plate, and the leachate is discharged into the liquid storage tank; The pressure system includes a torque motor 1, a ball screw push rod 4, a force transmission piston 8, a pressure plate 16 and a pressure pad 17. The torque motor 1 is fixedly arranged at the top of the water tank 5. The output end of the torque motor 1 is connected to the ball screw push rod 4. The ball screw push rod 4 vertically passes through the water tank 5 downward. The force transmission piston 8 is fixedly arranged at the bottom end of the ball screw push rod 4. The pressure pad 17 is arranged on the top surface of the movable top plate. The pressure plate 16 is fixedly arranged on the top of the pressure pad 17. When the pressure system is working, the force transmission piston 8 is pressed on the center of the pressure plate 16; the ball screw push rod can convert the torque output by the torque motor into a vertical downward pressure applied to the force transmission piston, and the force transmission piston can transmit the pressure to the pressure plate, and the pressure plate evenly applies the pressure to the pressure pad, and the pressure pad transmits the force to the movable top plate and the second permeable plate, and finally applies the force to the phosphogypsum filling body specimen under the second permeable plate; The temperature system includes a temperature sensor 14, a heating plate support 12 and a heating plate 13. The heating plate 13 is fixedly arranged in the shell through the heating plate support 12, and the temperature sensor 14 is arranged in the shell. The heating plate of the temperature system can heat the enclosed space in the shell, and the temperature of the enclosed space inside the shell can be monitored in real time through the temperature sensor, so as to facilitate the real-time regulation of the temperature of the enclosed space in the shell. The simulation method based on the in-situ leaching simulation device of phosphogypsum filling in goaf has the following specific steps: 1) The first sleeve is filled with phosphogypsum filling specimens, and the water tank is filled with mine water; 2) The mine water in the water tank is drained into the first sleeve at a predetermined flow rate through the leaching pipe, and the mine water flows downward evenly through the second permeable plate to leach the upper surface of the phosphogypsum filling body specimen. The mine water flows through the phosphogypsum filling body specimen to leach the pollutants in the phosphogypsum filling body specimen in situ at a preset flow rate. The leachate passes through the first permeable plate and is discharged into the liquid storage tank through the leaching pipe at a predetermined flow rate. The predetermined flow rate of mine water drainage and the predetermined flow rate of leachate discharge are set to achieve stable flow of mine water in the first sleeve. The in-situ leaching time of pollutants in the phosphogypsum filling body specimen is adjusted by adjusting the predetermined flow rate of mine water drainage and the predetermined flow rate of leachate discharge to restore the real environmental leaching time of phosphogypsum filling body leaching; 3) The torque output by the torque motor is converted into a preset vertical downward pressure through the ball screw push rod and applied to the force transmission piston. The force transmission piston transmits the pressure to the pressure plate, and the pressure plate evenly applies the pressure to the pressure pad. The pressure pad transmits the force to the phosphogypsum filling body specimen through the movable top plate and the second permeable plate to realize the in-situ leaching experiment under the preset pressure. The pressure of the in-situ leaching of the phosphogypsum filling body specimen is adjusted by changing the torque output by the torque motor to restore the pressure on the phosphogypsum filling body during leaching in the real environment. 4) The heating plate of the temperature system heats the enclosed space inside the shell, and the temperature of the enclosed space inside the shell is monitored in real time through the temperature sensor to restore the temperature of the phosphogypsum filling body during leaching in the real environment; 5) Adjust the predetermined flow rate of mine water drainage and the predetermined flow rate of leachate discharge, adjust the torque output by the torque motor, adjust the temperature of the enclosed space inside the shell, and perform in-situ leaching of the phosphogypsum filling body in a multi-field coupling environment.

[0021] Example 2: The structure of the in-situ leaching simulation device for phosphogypsum filling in the goaf of this example is basically the same as that of the in-situ leaching simulation device for phosphogypsum filling in the goaf of Example 1, except that: The movable top plate is provided with a water inlet, the bottom end of the leaching pipe 15 passes through the water inlet and extends into the first sleeve 18, a vertical water outlet is provided on the sleeve base 21, the top end of the leaching pipe 25 passes through the water outlet and extends into the first sleeve 18; A first central through hole is provided at the center of the top plate of the water tank 5, a second central through hole is provided at the center of the bottom plate of the water tank 5, a matching second sleeve is vertically fixedly provided between the first central through hole and the second central through hole, a sealing ring 30 is provided at the connection between the top plate of the water tank 5 and the second sleeve and at the connection between the bottom plate of the water tank 5 and the second sleeve, and the ball screw push rod 4 passes vertically downward through the second sleeve; by providing the second sleeve, it is convenient for the ball screw push rod to pass through the water tank without being subject to resistance and erosion by the mine water in the water tank; The pressure plate 16 is provided with a first vertical through hole, the pressure pad 17 is provided with a second vertical through hole, and the leaching pipe 15 passes downward through the first vertical through hole of the pressure plate 16, the second vertical through hole of the pressure pad 17 and the water inlet of the movable top plate in sequence; The bottom plate 23 is provided with a third vertical through hole, and the top end of the leaching pipe 25 passes through the third vertical through hole of the bottom plate 23 and the water outlet of the sleeve base 21 in sequence.

[0022] Example 3: The structure of the in-situ leaching simulation device for phosphogypsum filling body in the goaf of this embodiment is basically the same as that of the in-situ leaching simulation device for phosphogypsum filling body in the goaf of Example 1 or 2, except that: The goaf phosphogypsum filling body in-situ leaching simulation device also includes a computer 29, a motor controller 2 is provided on the torque motor 1, a water injection pipe 6 is provided at the water injection port of the water tank 5, a third solenoid valve is provided on the water injection pipe 6, a first solenoid valve is provided on the leaching pipe 15, a pressure box 7 is provided between the ball screw push rod 4 and the force transmission piston 8, and a second solenoid valve 26 is provided on the leaching pipe 25. The motor controller 2, the third solenoid valve, the first solenoid valve, the pressure box 7, the temperature sensor 14, and the second solenoid valve 26 are all connected to the computer signal to form an intelligent control system; The computer controls the torque output by the torque motor through the motor controller; the computer controls the injection flow of mine water in the water tank through the third solenoid valve; the computer controls the flow rate of mine water in the leaching pipe through the first solenoid valve to match the preset flow rate; the computer monitors the pressure borne by the force transmission piston in real time through the pressure box, and according to the monitored implementation pressure, the computer controls the torque output by the torque motor through the motor controller to match the preset pressure; the computer controls the flow rate of the leachate in the leaching pipe through the second solenoid valve to match the preset flow rate; the temperature of the enclosed space in the shell is monitored in real time through the temperature sensor so that the heating plate of the computer-controlled temperature system can heat and regulate the enclosed space in the shell, thereby realizing pressure control, temperature control, and flow control, and truly restoring the leaching environment of the phosphogypsum filling body.

[0023] Example 4: The structure of the in-situ leaching simulation device for phosphogypsum filling in the goaf of this example is basically the same as that of the in-situ leaching simulation device for phosphogypsum filling in the goaf of Example 3, except that: The torque motor 1 is fixedly mounted on the top of the water tank 5 via a motor support 3, and the housing is supported by a bottom column 27; like Figure 4 As shown, the sleeve base 21 is fixedly arranged on the bottom plate 23 by a fixing device 22, and the bottom end of the first sleeve 18 is clamped on the sleeve base 21 to fix the first sleeve 18, thereby preventing the first sleeve 18 from slipping and affecting the experimental accuracy when the pressure system applies pressure to the phosphogypsum filling body specimen; The shell comprises a bottom plate 23, a first side wall 9, a second side wall 10, a third side wall 11 and a partition plate 24. The first side wall 9, the second side wall 10 and the third side wall 11 connected in sequence are fixedly arranged on the bottom plate 23. The first side end of the first side wall 9 is perpendicularly intersected with the first side end of the second side wall 10, the second side end of the second side wall 10 is perpendicularly intersected with the first side end of the third side wall 11, the second side end of the first side wall is vertically provided with a first slide groove, the second side end of the third side wall is vertically provided with a second slide groove, a horizontal groove is provided on the bottom plate 23, the partition plate 24 is slidably arranged in the first slide groove and the second slide groove to form the fourth side wall of the shell, when the partition plate 24 slides to the lowest point, the bottom end of the partition plate 24 is inserted into the horizontal groove; the partition plate 24 can slide out from the first slide groove and the second slide groove, which is convenient for the installation and replacement of the phosphogypsum filling body specimen inside the shell, and improves the convenience of the experiment; The heating plate 13 is fixedly arranged on the first side wall 9 and the third side wall 11 via heating plate supports 12 , and the temperature sensor 14 is fixedly arranged on the second side wall 10 .

[0024] Example 5: The structure of the in-situ leaching simulation device for phosphogypsum filling in the goaf of this example is basically the same as that of the in-situ leaching simulation device for phosphogypsum filling in the goaf of Example 4, except that: The side wall of the water tank 5 is provided with a first viewing window, and the partition 24 is provided with a second viewing window; the first viewing window is convenient for real-time observation of the water level of the mine water in the water tank; the second viewing window is convenient for real-time observation of the in-situ leaching of the phosphogypsum filling specimen by the mine water in the shell.

[0025] The specific embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. An in-situ leaching simulation device for phosphogypsum filling in goaf, characterized in that: Including shell, leaching system, pressure system, temperature system, The leaching and leaching system comprises a water tank (5), a first sleeve (18), and a liquid storage tank (28). The liquid storage tank (28) is arranged directly below the shell. The first sleeve (18) is fixedly arranged on the bottom plate (23) of the shell through a sleeve base (21). The first sleeve (18) is located directly above the liquid storage tank (28). A first water-permeable plate is placed at the bottom of the first sleeve (18). A phosphogypsum filling body specimen (20) is loaded on the first water-permeable plate. The phosphogypsum filling body specimen (20) is loaded on the first water-permeable plate. A second water-permeable plate (19) is placed on the top of the body specimen (20), a movable top plate is arranged on the top of the second water-permeable plate (19), the movable top plate is slidably arranged in the first sleeve (18), a water tank (5) is fixedly arranged on the top of the shell body, the water tank (5) is located directly above the first sleeve (18), a drainage port of the water tank (5) is connected to the top of the first sleeve (18) through a leaching pipe (15), and the bottom of the first sleeve (18) is connected to the liquid storage tank (28) through a leaching pipe (25); The pressure system comprises a torque motor (1), a ball screw push rod (4), a force transmission piston (8), a pressure plate (16) and a pressure pad (17); the torque motor (1) is fixedly arranged at the top of the water tank (5); the output end of the torque motor (1) is connected to the ball screw push rod (4); the ball screw push rod (4) vertically passes through the water tank (5); the bottom end of the ball screw push rod (4) is fixedly arranged with a force transmission piston (8); the pressure pad (17) is arranged on the top surface of the movable top plate; the pressure plate (16) is fixedly arranged on the top of the pressure pad (17); when the pressure system is working, the force transmission piston (8) is pressed on the center of the pressure plate (16); The temperature system comprises a temperature sensor (14), a heating plate support (12) and a heating plate (13); the heating plate (13) is fixedly arranged in a housing via the heating plate support (12); and the temperature sensor (14) is arranged in the housing.

2. The in-situ leaching simulation device for phosphogypsum filling in goaf according to claim 1, characterized in that: The movable top plate is provided with a water inlet, the bottom end of the leaching pipe (15) passes through the water inlet and extends into the first sleeve (18), the sleeve base (21) is provided with a vertical water outlet, the top end of the leaching pipe (25) passes through the water outlet and extends into the first sleeve (18).

3. The in-situ leaching simulation device for phosphogypsum filling in goaf according to claim 1, characterized in that: A first central through hole is provided at the center of the top plate of the water tank (5), a second central through hole is provided at the center of the bottom plate of the water tank (5), a matching second sleeve is vertically fixedly arranged between the first central through hole and the second central through hole, a sealing ring (30) is provided at the connection between the top plate of the water tank (5) and the second sleeve and at the connection between the bottom plate of the water tank (5) and the second sleeve, and the ball screw push rod (4) vertically passes through the second sleeve downward.

4. The in-situ leaching simulation device for phosphogypsum filling in goaf according to claim 2, characterized in that: The pressure plate (16) is provided with a first vertical through hole, the pressure pad (17) is provided with a second vertical through hole, and the leaching pipe (15) passes downwardly through the first vertical through hole of the pressure plate (16), the second vertical through hole of the pressure pad (17) and the water inlet of the movable top plate in sequence.

5. The in-situ leaching simulation device for phosphogypsum filling in goaf according to claim 2, characterized in that: A third vertical through hole is formed on the bottom plate (23), and the top end of the leaching pipe (25) passes upward through the third vertical through hole of the bottom plate (23) and the water outlet of the sleeve base (21) in sequence.

6. The in-situ leaching simulation device for phosphogypsum filling in goaf according to claim 1, characterized in that: The invention also comprises a computer (29), a motor controller (2) is arranged on the torque motor (1), a water injection pipe (6) is arranged at the water injection port of the water tank (5), a third electromagnetic valve is arranged on the water injection pipe (6), a first electromagnetic valve is arranged on the leaching pipe (15), a pressure box (7) is arranged between the ball screw push rod (4) and the force transmission piston (8), and a second electromagnetic valve (26) is arranged on the leaching pipe (25), and the motor controller (2), the third electromagnetic valve, the first electromagnetic valve, the pressure box (7), the temperature sensor (14), and the second electromagnetic valve (26) are all connected to the computer signal to form an intelligent control system.

7. The in-situ leaching simulation device for phosphogypsum filling in goaf according to claim 1, characterized in that: The torque motor (1) is fixedly arranged on the top end of the water tank (5) via a motor support (3), and the housing is supported by a bottom column (27).

8. The in-situ leaching simulation device for phosphogypsum filling in goaf according to claim 1, characterized in that: The sleeve base (21) is fixedly arranged on the bottom plate (23) via a fixing device (22), and the bottom end of the first sleeve (18) is clamped on the sleeve base (21).

9. The in-situ leaching simulation device for phosphogypsum filling in goaf according to claim 1, characterized in that: The shell comprises a bottom plate (23), a first side wall (9), a second side wall (10), a third side wall (11) and a partition plate (24); the bottom plate (23) is fixedly provided with the first side wall (9), the second side wall (10) and the third side wall (11) which are connected in sequence; the first side end of the first side wall (9) is perpendicularly intersected with the first side end of the second side wall (10); the second side end of the second side wall (10) is perpendicularly intersected with the first side end of the third side wall (11); the second side end of the first side wall is vertically provided with a first slide groove; the second side end of the third side wall is vertically provided with a second slide groove; the bottom plate (23) is provided with a horizontal groove; the partition plate (24) is slidably arranged in the first slide groove and the second slide groove to form a fourth side wall of the shell; when the partition plate (24) slides to the lowest point, the bottom end of the partition plate (24) is inserted into the horizontal groove; The heating plate (13) is fixedly arranged on the first side wall (9) and the third side wall (11) via a heating plate support (12), and the temperature sensor (14) is fixedly arranged on the second side wall (10); The side wall of the water tank (5) is provided with a first viewing window, and the partition (24) is provided with a second viewing window.

10. A simulation method for the in-situ leaching simulation device for phosphogypsum filling in goaf according to any one of claims 1 to 9, wherein the specific steps are as follows: 1) The first sleeve is filled with phosphogypsum filling specimens, and the water tank is filled with mine water; 2) The mine water in the water tank is drained into the first sleeve at a predetermined flow rate through the leaching pipe, and the mine water flows downward evenly through the second permeable plate to leach the upper surface of the phosphogypsum filling body specimen. The mine water flows through the phosphogypsum filling body specimen to leach the pollutants in the phosphogypsum filling body specimen in situ at a preset flow rate. The leachate passes through the first permeable plate and is discharged into the liquid storage tank through the leaching pipe at a predetermined flow rate. The predetermined flow rate of mine water drainage and the predetermined flow rate of leachate discharge are set to achieve stable flow of mine water in the first sleeve. The in-situ leaching time of pollutants in the phosphogypsum filling body specimen is adjusted by adjusting the predetermined flow rate of mine water drainage and the predetermined flow rate of leachate discharge to restore the real environmental leaching time of phosphogypsum filling body leaching; 3) The torque output by the torque motor is converted into a preset vertical downward pressure through the ball screw push rod and applied to the force transmission piston. The force transmission piston transmits the pressure to the pressure plate, and the pressure plate evenly applies the pressure to the pressure pad. The pressure pad transmits the force to the phosphogypsum filling body specimen through the movable top plate and the second permeable plate to realize the in-situ leaching experiment under the preset pressure. The pressure of the in-situ leaching of the phosphogypsum filling body specimen is adjusted by changing the torque output by the torque motor to restore the pressure on the phosphogypsum filling body during leaching in the real environment. 4) The heating plate of the temperature system heats the enclosed space inside the shell, and the temperature of the enclosed space inside the shell is monitored in real time through the temperature sensor to restore the temperature of the phosphogypsum filling body during leaching in the real environment; 5) Adjust the predetermined flow rate of mine water drainage and the predetermined flow rate of leachate discharge, adjust the torque output by the torque motor, adjust the temperature of the enclosed space inside the shell, and perform in-situ leaching of the phosphogypsum filling body in a multi-field coupling environment.

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