A phosphogypsum leachate treatment apparatus and method of use thereof

Abstract

This invention discloses a phosphogypsum leachate treatment device and its usage method. The treatment device includes a base with a treatment tank mounted on it, and further includes a separation component, a floating component, and a liquid injection component. By activating the injection pump, the reagent enters the spiral distribution pipe through the injection pipe, and is tangentially sprayed from the first injection hole to drive the spiral pipe to rotate. Simultaneously, the reagent is radially sprayed from the second injection hole. Because the diameter of the second injection hole decreases from bottom to top, the strong shear at the bottom enables rapid dispersion of the reagent, while the weak shear at the top protects the crystals from breakage, thus simultaneously meeting the requirements for rapid mixing and crystal growth within the same reactor. The reaction force generated by the tangential spraying through the first injection hole directly drives the rotation of the spiral distribution pipe, eliminating the need for an additional motor or stirring device. Pure hydraulic drive reduces the risk of dynamic seal corrosion failure, making it particularly suitable for the harsh conditions of phosphogypsum leachate with strong corrosiveness and the presence of solid particles.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, and in particular relates to a phosphogypsum leachate treatment device and its usage method. Background Technology

[0002] Phosphogypsum is a byproduct of wet-process phosphoric acid production. The leachate generated from its stockpiling is characterized by low pH, high phosphorus and fluoride content, coexistence of heavy metals and suspended solids, high calcium and magnesium ion concentrations, and large fluctuations in water volume and quality. In conventional treatment processes, the addition of chemicals and the mixing reaction are crucial to the treatment effect. Currently, chemical mixing in wastewater treatment mainly employs mechanical stirring, pipeline mixers, static mixing tanks, and flow-through reactors. Among these, flow-through reactors are widely used in floc growth and sedimentation processes due to their uniform mixing and high circulation efficiency, but their suitability for the special water quality of phosphogypsum leachate is insufficient.

[0003] Traditional guide tube reactors typically consist of an outer tank and an internally coaxially arranged guide tube. The dosing pipe extends from the bottom or side, and water circulates between the inner and outer tubes driven by an agitator or aeration. However, these reactors suffer from the following drawbacks: a single stirring intensity cannot simultaneously meet the demands of rapid mixing and crystal / flocculation growth; high shear easily breaks up crystals, while low shear results in insufficient mixing; uniform dosing is mismatched with reaction kinetics, preventing controllable nucleation and directional growth; axial circulation and radial mixing are poor, and sedimentation dead zones easily form on the tube walls and bottom. Therefore, a phosphogypsum leachate treatment device is proposed. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a phosphogypsum leachate treatment device and its usage method.

[0005] The present invention is achieved through the following technical solutions.

[0006] The present invention provides a phosphogypsum leachate treatment device, comprising a base, on which a treatment tank is mounted, and further comprising: A partition component is disposed inside the processing tank, dividing the interior of the processing tank into an inner cylinder reaction zone and an outer cylinder reaction zone; A floating assembly is mounted on top of a separator assembly, allowing the separator assembly to float with the liquid level. The liquid injection assembly is disposed inside the partition assembly.

[0007] Preferably, the injection assembly includes a support frame mounted on the floating assembly, and a spiral drug delivery tube movably mounted on the support frame via a docking member, wherein the spiral drug delivery tube has a second injection hole radially formed in its tube wall; The diameter of the second injection hole on the spiral drug delivery tube gradually decreases from bottom to top; The bottom of the treatment tank is equipped with a drug injection pipe, the bottom of which is connected to a drug injection pump. The bottom of the spiral drug distribution pipe is rotatably and sealed to the top of the drug injection pipe through a connecting sleeve. The spiral drug delivery tube can slide up and down along the drug delivery tube with the floating assembly and remain sealed.

[0008] Preferably, the outside of the spiral medicine distribution tube is fixed with an agitator blade by a mounting plate. The agitator blade has a hollow structure and its inner cavity is connected to the inside of the spiral medicine distribution tube. The first injection hole is provided on the side of the agitator blade.

[0009] Preferably, the processing tank is provided with a feeding port at the top and a discharge port at the bottom; The separating component includes a separating sleeve with a flared bottom end, and the floating component is mounted on top of the separating sleeve.

[0010] Preferably, the outer wall of the separator sleeve is uniformly provided with a plurality of sliding members along the circumference, and the inner wall of the treatment tank is fixedly provided with a vertical guide rail corresponding to the sliding member, and the sliding member is slidably engaged with the guide rail.

[0011] Preferably, the floating assembly includes a connecting frame installed on the top of the separating sleeve, and the side wall of the connecting frame is uniformly provided with through slots in the circumferential direction.

[0012] Preferably, a floating ring is mounted on the top of the connecting frame via a support ring.

[0013] Preferably, a guide assembly is provided between the inner wall of the processing tank and the outer wall of the partition sleeve; The guiding assembly includes a first guide ring fixed to the outer wall of the partition sleeve and a second guide ring fixed to the inner wall of the processing tank.

[0014] Preferably, the first guide ring and the second guide ring are arranged alternately up and down along the axial direction.

[0015] A method of using a phosphogypsum leachate treatment device includes the following steps: S1: Start the injection pump, and the medicine enters the inner cavity of the spiral distribution tube through the injection pipe and the connecting sleeve; S2: The agent is sprayed tangentially backward from the first injection hole on the side of the agitator blade, generating a reaction force to drive the spiral drug distribution tube and the agitator blade to rotate; S3: The agent is simultaneously sprayed radially from the second injection hole in the spiral drug distribution tube wall; S4: The rotating agitator blades push the leachate upward in the separator sleeve, and it overflows evenly in the circumferential direction through the groove on the side wall of the connecting frame to the outer cylinder reaction zone. The water flow in the outer cylinder reaction zone descends and flows back into the separator sleeve from the bottom, forming a continuous internal and external circulation. S5: When the liquid level in the treatment tank changes, the float ring drives the separator sleeve to rise and fall synchronously along the guide rail. The first guide ring moves synchronously with the separator sleeve and always maintains an interleaved state with the second guide ring. The treated phosphogypsum leachate is discharged through the discharge port of the treatment tank. S5-1: During the treatment process, the turbidity value of the water effluent from the outer reaction zone is monitored in real time by an online turbidity meter installed on the side wall of the outer reaction zone of the treatment tank. At the same time, the controller accumulates and records the running time from the start of the injection pump. The process is considered complete and the material discharge stage begins when any of the following conditions are met: Condition 1: The running time reaches the preset reaction cycle T. The preset reaction cycle T is preset according to the initial concentration of phosphogypsum leachate and the target effluent quality. The value of T ranges from 30 min to 120 min. Condition 2: If the turbidity value detected by the online turbidity meter is lower than the set threshold for 5 consecutive minutes and the fluctuation range does not exceed ±10% of the set threshold, the effluent water quality is deemed to meet the standards. After either condition one or condition two is met, the controller sends a processing completion signal, shuts down the injection pump, stops the drug injection, and executes step S6. If the turbidity value is still higher than the set threshold when the running time exceeds 1.5 times the preset reaction cycle T, the controller will issue an abnormal alarm signal, prompting you to check the dosage of the reagent, the quality of the leachate influent, or the operating status of the equipment. S6: After the treatment is completed, the treated phosphogypsum leachate is discharged through the discharge port of the treatment tank. During discharge, large-diameter crystals and flocs deposited at the bottom are discharged first from the discharge port. After the discharge is completed, the residue at the bottom of the treatment tank is cleaned regularly.

[0016] The beneficial effects of this invention are as follows: This invention activates the injection pump, allowing the agent to enter the spiral distribution tube through the injection pipe. The agent is tangentially ejected from the first injection hole, driving the spiral tube to rotate, while the agent is radially ejected from the second injection hole. Since the diameter of the second injection hole decreases from bottom to top, the strong shear at the bottom enables rapid dispersion of the agent, while the weak shear at the top protects the crystals from being broken. This simultaneously satisfies the requirements for rapid mixing and crystal growth within the same reactor.

[0017] This invention directly drives the rotation of the spiral dosing pipe through the reaction force generated by tangential spraying from the first injection hole, eliminating the need for an additional motor or stirring device. The pure hydraulic drive reduces the risk of dynamic seal corrosion failure, making it particularly suitable for harsh working conditions such as highly corrosive phosphogypsum leachate containing solid particles. The float ring floats on the liquid surface, driving the separator sleeve to rise and fall synchronously with the liquid level along the guide rail, ensuring that the separator sleeve always maintains the optimal immersion depth under different water volumes, maintaining a stable volume ratio in the reaction zone and preventing the gradient flow field from failing, without the need for manual adjustment or electronically controlled liquid level devices. The cooperation between the sliding component and the guide rail ensures that the separator sleeve remains coaxial during the lifting process, and the first guide ring moves synchronously with the sleeve, maintaining a stable serpentine flow channel shape. The entire device requires no electronic control and can operate stably and unattended for extended periods.

[0018] This invention utilizes a serpentine flow channel formed by the staggered arrangement of the first and second guide rings in the outer cylinder reaction zone. This extends the actual water flow path in the outer cylinder reaction zone by 2-3 times, significantly increasing the residence time of crystals in the growth zone, resulting in more complete crystal growth and larger, more uniform particle size. The serpentine flow channel also gradually reduces the flow velocity and disturbance as the water passes through each baffle, forming a multi-level flow gradient with stronger flow at the bottom and weaker flow at the top, preventing high-speed water flow from breaking up the already formed large crystal particles. At the same time, the staggered structure of the guide rings allows the water flow to repeatedly scour the tank wall and the outer wall of the sleeve, effectively preventing gypsum microcrystals from depositing and caking on the wall surface. This dual technical effect of enhancing reaction and preventing deposition significantly improves the phosphorus recovery efficiency of phosphogypsum leachate. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the structure of the processing tank of the present invention; Figure 3 This is a top view of the structure of the present invention; Figure 4 yes Figure 3 Schematic diagram of the structure of region A; Figure 5 This is a schematic diagram of the structure of the separator component in this invention; Figure 6 This is a schematic diagram of the disassembled structure of the processing tank of the present invention; Figure 7 This is a schematic diagram of the liquid injection assembly of the present invention.

[0020] In the diagram: 1-base, 2-treatment tank, 3-injection assembly, 31-spiral drug distribution tube, 32-stirring blade, 33-first injection hole, 34-support frame, 35-connecting piece, 36-injection tube, 37-connecting sleeve, 38-second injection hole, 39-mounting plate, 4-separation assembly, 41-separation sleeve, 42-sliding piece, 43-guide rail, 5-guide assembly, 51-first guide ring, 52-second guide ring, 6-floating assembly, 61-connecting frame, 62-through groove, 63-support ring, 64-floating ring. Detailed Implementation

[0021] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0022] Example: like Figure 1-7 As shown, a phosphogypsum leachate treatment device includes a base 1, on which a treatment tank 2 is mounted, and further includes: The dividing component 4 is a vertically continuous guide tube structure, coaxially arranged inside the processing tank 2, dividing the interior of the processing tank 2 into an inner cylinder reaction zone and an outer cylinder reaction zone. A linear turbidity meter is installed on the side wall of the outer cylinder reaction zone, and the linear turbidity meter is electrically connected to the controller that controls the operation of the processing equipment. The floating component 6 is installed on top of the separating component 4, so that the separating component 4 floats with the liquid level and always remains submerged in the leachate. The injection component 3 is coaxially disposed at the internal center of the separator 4 and is used to inject the agent into the phosphogypsum permeate.

[0023] The injection assembly 3 includes a support frame 34 mounted on the floating assembly 6, and a spiral drug delivery tube 31 movably mounted on the support frame 34 via a docking member 35. The spiral drug delivery tube 31 has a second drug delivery hole 38 radially opened on its tube wall. The diameter of the second injection hole 38 on the spiral drug delivery tube 31 gradually decreases from bottom to top; The bottom of the treatment tank 2 is equipped with a drug injection pipe 36, the bottom of which is connected to a drug injection pump. The bottom of the spiral drug distribution pipe 31 is rotatably and sealed to the top of the drug injection pipe 36 through a connecting sleeve 37. The spiral drug delivery tube 31 can slide up and down along the drug injection tube 36 with the floating component 6 and remain sealed.

[0024] The spiral medicine distribution tube 31 is fixed to the outside by an mounting plate 39 with an agitator blade 32. The agitator blade 32 is a hollow structure and its inner cavity is connected to the inside of the spiral medicine distribution tube 31. The agitator blade 32 has a first injection hole 33 on its side in a tangentially rearward direction.

[0025] The injection pump injects the agent into the spiral drug distribution tube 31 through the injection pipe 36. The agent is sprayed out through the first injection hole 33 and the second injection hole 38 respectively. The tangential spray of the first injection hole 33 generates a reaction force, which pushes the spiral drug distribution tube 31 and the stirring blade 32 to rotate synchronously. The stirring blade 32 pushes the leachate to rise in the separator 4, overflows from the top, enters the outer cylinder reaction zone, and then descends, forming an internal and external circulation.

[0026] The crystal nucleus moves upward with the rising flow in the inner cylinder reaction zone, and gradually mixes with the agent radially sprayed out from the second injection hole 38. The supersaturation gradually decreases along the process, providing a transitional environment for crystal growth. Water carries crystal nuclei out of the channel 62 and into the outer cylinder reaction zone. The inner cylinder reaction zone has a large flow area, low flow velocity, and low reagent concentration, and is in a low supersaturation state. Under this environment, crystals grow directionally and their particle size increases uniformly, avoiding the problems of explosive nucleation and fine crystals under high supersaturation.

[0027] The top of the processing tank 2 is provided with a feeding port, and the bottom of the processing tank 2 is provided with a discharge port; The separating component 4 includes a separating sleeve 41, the bottom end of which is flared in a trumpet shape to increase the inlet flow area and enhance the bottom suction effect. The floating component 6 is installed on the top of the separating sleeve 41.

[0028] The outer wall of the separating sleeve 41 is uniformly provided with a plurality of sliding members 42 along the circumference, and the inner wall of the treatment tank 2 is fixedly provided with a vertical guide rail 43 corresponding to the sliding member 42; the sliding member 42 is slidably engaged on the guide rail 43, so that the separating sleeve 41 is always coaxial with the treatment tank 2 during the process of liquid level rise and fall.

[0029] The floating component 6 includes a connecting frame 61 installed on the top of the separating sleeve 41. The side wall of the connecting frame 61 is uniformly provided with through grooves 62. The rising water flow in the inner cylinder reaction zone overflows into the outer cylinder reaction zone through the through grooves 62 to form a circulation.

[0030] A floating ring 64 is installed on the top of the connecting frame 61 via a support ring 63. The floating ring 64 floats on the surface of the phosphogypsum leachate in the treatment tank 2, providing buoyancy to drive the separator sleeve 41 to rise and fall synchronously with the liquid level, so that the separator sleeve always maintains the preset immersion depth.

[0031] When the leachate volume increases and the liquid level rises, the floating ring 64 drives the separator sleeve 41 to rise synchronously, always keeping the effective immersion depth of the separator sleeve 41 constant, ensuring that the volume ratio of the reaction zone is stable under high and low liquid levels, and that the gradient flow field does not fail due to fluctuations in water volume; a gradient stirring intensity of strong at the bottom and weak at the top is achieved in the same reactor, which simultaneously meets the requirements of strong shear for rapid mixing and weak shear for crystal growth.

[0032] A guide assembly 5 is provided between the inner wall of the processing tank 2 and the outer wall of the partition sleeve 41; The guide assembly 5 includes two first guide rings 51 fixed to the outer wall of the partition sleeve 41, and two second guide rings 52 fixed to the inner wall of the processing tank 2.

[0033] The two first guide rings 51 and the two second guide rings 52 are arranged alternately up and down along the axial direction, forming a serpentine flow channel in the outer cylinder reaction zone.

[0034] The radial jet formed at the second injection hole 38, the suction at the bottom of the separator sleeve 41, the uniform circumferential overflow at the through groove 62, and the design that the separator sleeve 41 is always coaxial with the treatment tank 2, all work together to improve the defects of traditional guide tube reactors that only have axial circulation, weak radial mixing, and easy deposition, and achieve full tank mixing without dead corners and anti-deposition.

[0035] A method of using a phosphogypsum leachate treatment device includes the following steps: S1: Start the injection pump, and the medicine enters the inner cavity of the spiral distribution tube 31 through the injection tube 36 and the connecting sleeve 37; S2: The agent is sprayed tangentially backward from the first injection hole 33 on the side of the stirring blade 32, generating a reaction force to drive the spiral drug distribution tube 31 and the stirring blade 32 to rotate; S3: The agent is simultaneously sprayed radially from the second injection hole 38 on the wall of the spiral drug distribution tube 31. Since the diameter of the second injection hole 38 gradually decreases from bottom to top, the large hole section at the bottom of the spiral drug distribution tube 31 forms a strong shear flow field for rapid mixing, while the small hole section at the top forms a weak shear flow field to protect the flocs. S4: The rotating agitator blades 32 push the leachate up in the separator sleeve 41 and overflow evenly in the circumferential direction through the through groove 62 on the side wall of the connecting frame 61 to the outer cylinder reaction zone. The water in the outer cylinder reaction zone slowly descends through the serpentine baffle channel and flows back into the separator sleeve 41 from the trumpet-shaped flared opening at the bottom of the separator sleeve 41, forming a continuous internal and external circulation. S5: When the liquid level in the treatment tank 2 changes, the floating ring 64 drives the separator sleeve 41 to rise and fall synchronously along the guide rail 43. The first guide ring 51 moves synchronously with the separator sleeve 41 and always maintains an interlaced state with the second guide ring 52 to ensure the stability of the flow channel shape and reaction zone ratio under different liquid levels. S5-1: During the treatment process, the turbidity value of the water effluent from the outer cylinder reaction zone is monitored in real time by an online turbidity meter installed on the side wall of the outer cylinder reaction zone of treatment tank 2. At the same time, the controller accumulates and records the running time from the start of the injection pump. The process is considered complete and the material discharge stage begins when any of the following conditions are met: Condition 1: The running time reaches the preset reaction cycle T. The preset reaction cycle T is set in advance according to the initial concentration of phosphogypsum leachate and the target effluent quality. The value of T ranges from 30 min to 120 min. Condition 2: If the turbidity value detected by the online turbidity meter is lower than the set threshold for 5 consecutive minutes and the fluctuation range does not exceed ±10% of the set threshold, the effluent water quality is deemed to meet the standards. After either condition one or condition two is met, the controller sends a processing completion signal, shuts down the injection pump, stops the drug injection, and executes step S6. If the turbidity value is still higher than the set threshold when the running time exceeds 1.5 times the preset reaction cycle T, the controller will issue an abnormal alarm signal, prompting you to check the dosage of the reagent, the quality of the leachate influent, or the operating status of the equipment. S6: After the treatment is completed, the treated phosphogypsum leachate is discharged through the discharge port of treatment tank 2. During discharge, large-diameter crystals and flocs deposited at the bottom are discharged first from the discharge port. After the discharge is completed, the residue at the bottom of treatment tank 2 is cleaned regularly.

[0036] In this application, the reagent is sprayed from the second injection hole 38. Since the diameter of the second injection hole 38 gradually decreases from bottom to top, the lower hole has a large diameter and a large flow rate, forming a strong shear flow field, which realizes the rapid mixing of the reagent and the leachate and avoids local supersaturation; the upper hole has a small diameter and a small flow rate, forming a weak shear flow field, which provides stable hydraulic conditions for crystal and floc growth. The lower high-shear zone ensures rapid dispersion of the reagent, while the upper low-shear zone protects the formed crystals and flocs from being broken, thus simultaneously meeting the needs of rapid mixing and crystal growth within the same reactor.

[0037] The first injection hole 33 on the side of the stirring blade 32 sprays the agent tangentially, forming a local high-concentration micro-region on the back of the stirring blade. Under high supersaturation, a large number of crystal nuclei are rapidly generated, achieving controllable nucleation. The crystal nuclei overflow from the top of the separator component 4 with the water flow and enter the outer cylinder reaction zone. The outer cylinder reaction zone has a large flow area and low flow rate, which dilutes the reagent and reduces the supersaturation. The crystals grow directionally in a low supersaturation environment, and the particle size increases uniformly. The inner cylinder reaction zone provides a stable source of crystal nuclei as the nucleation zone, while the outer cylinder reaction zone provides a suitable growth environment as the growth zone. This solves the technical problem of mutual interference between nucleation and growth in traditional uniform drug distribution, and achieves controllable nucleation and directional growth.

Claims

1. A phosphogypsum leachate treatment device, characterized in that: The system includes a base (1) on which a processing tank (2) is mounted, and further includes: The partition component (4) is disposed inside the processing tank (2) and divides the interior of the processing tank (2) into an inner cylinder reaction zone and an outer cylinder reaction zone; A floating assembly (6) is installed on top of the separator assembly (4) so ​​that the separator assembly (4) floats with the liquid level; The injection assembly (3) is disposed inside the partition assembly (4).

2. The phosphogypsum leachate treatment equipment as described in claim 1, characterized in that: The injection assembly (3) includes a support frame (34) mounted on the floating assembly (6) and a spiral drug delivery tube (31) movably mounted on the support frame (34) via a docking part (35). The spiral drug delivery tube (31) has a second injection hole (38) radially opened on its wall. The diameter of the second injection hole (38) on the spiral drug delivery tube (31) gradually decreases from bottom to top; The bottom of the treatment tank (2) is equipped with a drug injection pipe (36), the bottom of the drug injection pipe (36) is connected to the drug injection pump, and the bottom of the spiral drug distribution pipe (31) is rotated and sealed to the top of the drug injection pipe (36) through the docking sleeve (37). The spiral drug delivery tube (31) can slide up and down along the drug delivery tube (36) with the floating assembly (6) and remain sealed.

3. The phosphogypsum leachate treatment equipment as described in claim 2, characterized in that: The spiral drug delivery tube (31) is fixed with an agitator (32) by a mounting plate (39). The agitator (32) is a hollow structure and its inner cavity is connected to the inside of the spiral drug delivery tube (31). The agitator blade (32) has a first injection hole (33) on its side.

4. The phosphogypsum leachate treatment equipment as described in claim 1, characterized in that: The processing tank (2) is provided with a feeding port at the top and a discharge port at the bottom. The separating component (4) includes a separating sleeve (41) with a flared bottom end, and the floating component (6) is installed on the top of the separating sleeve (41).

5. The phosphogypsum leachate treatment equipment as described in claim 4, characterized in that: The outer wall of the separator sleeve (41) is uniformly provided with a number of sliding parts (42) along the circumference, and the inner wall of the processing tank (2) is fixedly provided with a vertical guide rail (43) corresponding to the sliding part (42); the sliding part (42) is slidably engaged on the guide rail (43).

6. The phosphogypsum leachate treatment equipment as described in claim 4, characterized in that: The floating assembly (6) includes a connecting frame (61) installed on the top of the dividing sleeve (41), and the side wall of the connecting frame (61) is uniformly provided with through grooves (62).

7. The phosphogypsum leachate treatment equipment as described in claim 6, characterized in that: The top of the connecting frame (61) is fitted with a floating ring (64) via a support ring (63).

8. The phosphogypsum leachate treatment equipment as described in claim 5, characterized in that: A guide assembly (5) is provided between the inner wall of the processing tank (2) and the outer wall of the partition sleeve (41). The guide assembly (5) includes a first guide ring (51) fixed to the outer wall of the partition sleeve (41) and a second guide ring (52) fixed to the inner wall of the processing tank (2).

9. The phosphogypsum leachate treatment equipment as described in claim 8, characterized in that: The first guide ring (51) and the second guide ring (52) are arranged alternately up and down along the axial direction.

10. A method of using the phosphogypsum leachate treatment equipment as described in claims 1-9, characterized in that, Includes the following steps: S1: Start the injection pump, and the medicine enters the inner cavity of the spiral distribution tube (31) through the injection tube (36) and the connecting sleeve (37); S2: The agent is sprayed tangentially backward from the first injection hole (33) on the side of the stirring blade (32), generating a reaction force to drive the spiral drug distribution tube (31) and the stirring blade (32) to rotate; S3: The agent is simultaneously sprayed radially from the second injection hole (38) on the wall of the spiral drug distribution tube (31); S4: The rotating agitator blades (32) push the leachate up in the separator sleeve (41), and it overflows evenly in the outer cylinder reaction zone through the through groove (62) on the side wall of the connecting frame (61). The water flow in the outer cylinder reaction zone drops down and flows back into the separator sleeve (41) from the bottom, forming a continuous internal and external circulation. S5: When the liquid level in the treatment tank (2) changes, the float ring (64) drives the separator sleeve (41) to rise and fall synchronously along the guide rail (43). The first guide ring (51) moves synchronously with the separator sleeve (41) and always maintains an interleaved state with the second guide ring (52). The treated phosphogypsum leachate is discharged through the discharge port of the treatment tank (2). S5-1: During the treatment process, the turbidity value of the water effluent from the outer cylinder reaction zone is monitored in real time by an online turbidity meter installed on the side wall of the outer cylinder reaction zone of the treatment tank (2), and the running time from the start of the injection pump is recorded by the controller. The process is considered complete and the material discharge stage begins when any of the following conditions are met: Condition 1: The running time reaches the preset reaction cycle T. The preset reaction cycle T is preset according to the initial concentration of phosphogypsum leachate and the target effluent quality. The value of T ranges from 30 min to 120 min. Condition 2: If the turbidity value detected by the online turbidity meter is lower than the set threshold for 5 consecutive minutes and the fluctuation range does not exceed ±10% of the set threshold, the effluent water quality is deemed to meet the standards. After either condition one or condition two is met, the controller sends a processing completion signal, shuts down the injection pump, stops the drug injection, and executes step S6. If the turbidity value is still higher than the set threshold when the running time exceeds 1.5 times the preset reaction cycle T, the controller will issue an abnormal alarm signal, prompting you to check the dosage of the reagent, the quality of the leachate influent, or the operating status of the equipment. S6: After the treatment is completed, the treated phosphogypsum leachate is discharged through the discharge port of the treatment tank (2); during discharge, large-diameter crystals and flocs deposited at the bottom are discharged first from the discharge port, and the residue at the bottom of the treatment tank (2) is cleaned regularly after the discharge is completed.

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