Phosphogypsum slag field leachate treatment system and process

Abstract

The present application relates to wastewater treatment technical field, disclose a kind of phosphogypsum slag field leachate processing system and process, wherein, a kind of phosphogypsum slag field leachate processing system, including tank body, respectively set in the liquid inlet and liquid outlet of tank body top and bottom, and the delivery pipe being set in the inside of tank body, further including the mixing unit being set in the inside of tank body.By means of the forced shunt effect of "A" shaped guide plate, the precise correspondence of drainage groove and drainage hole is combined, so that the leachate and flocculating agent form a closed loop of shunt, injection and forced contact, and eliminate the mixing dead angle of traditional stirring.The guide plate staggered arrangement forms a return flow, extends the water flow path and increases the collision frequency, and the bottom arc structure guides the formation of symmetrical vortex, which can avoid the destruction of floc by shear force, and promote the aggregation of fine suspended solids into dense flocs, to provide good conditions for subsequent sedimentation process.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a leachate treatment system and process for phosphogypsum slag sites. Background Technology

[0002] In the field of leachate treatment from phosphogypsum slag sites, leachate contains high concentrations of suspended solids (such as gypsum microcrystals), colloidal phosphorus or fluoride, and heavy metals. Furthermore, the water volume fluctuates significantly with rainfall (3-5 times higher in the rainy season than in the dry season), placing extremely high demands on the mixing efficiency and stability of the treatment system. Traditional mechanical mixing equipment is prone to problems such as uneven mixing and flocculant waste. The strong shear force generated by high-speed mixing can break up flocs, reducing subsequent sedimentation efficiency. Meanwhile, fixed flow channel designs are difficult to adapt to water volume fluctuations. At low flow rates, suspended solids can easily clog the channels, while at high flow rates, scouring can exacerbate equipment wear, especially in the highly acidic environment of the leachate, leading to high equipment corrosion and maintenance costs. In addition, dead zones easily form at the bottom of the tank, where suspended solids further affect the treatment effect. Existing technologies struggle to simultaneously meet the comprehensive requirements of high-efficiency mixing, shock resistance, low energy consumption, and long service life. Summary of the Invention

[0003] Given the problems of existing technologies, such as uneven mixing and flocculant waste in traditional mechanical mixing equipment, and the strong shear force generated by high-speed mixing that can break up flocs and reduce subsequent sedimentation efficiency, a leachate treatment system for phosphogypsum slag sites is proposed.

[0004] Its purpose is to solve the problems of uneven mixing, easy destruction of flocs, and difficulty in adapting to water volume fluctuations in traditional mixing methods. Through a non-powered mixing unit, adaptive flow channel adjustment, and bottom dynamic rotation design, it can achieve efficient mixing and stable treatment of phosphogypsum leachate, reducing energy consumption and losses.

[0005] The technical solution of the present invention is a leachate treatment system for phosphogypsum slag sites, including a tank, an inlet and an outlet respectively disposed at the top and bottom of the tank, a conveying pipe disposed inside the tank, and a mixing unit disposed inside the tank.

[0006] The mixing unit includes several mixing components arranged vertically and alternately. Each mixing component includes two guide plates arranged in a ring around the periphery of the conveying pipe, a diversion pipe located in the middle of the two guide plates, one end of the diversion pipe penetrating into the interior of the conveying pipe and fixedly connected to the pipe wall, the other end of the diversion pipe being fixedly connected to the side wall of the tank, diversion holes arranged in a linear array penetrating through the diversion pipe, and several diversion grooves opened on the guide plates and corresponding to the positions of the diversion holes.

[0007] Furthermore, the tops of the two guide plates are abutting each other, and their bottoms are curved arcs, forming an "A" shape.

[0008] Furthermore, the depth of one end of the drainage groove is greater than the width of the drainage hole, and the drainage groove is opened along the arc of the guide plate and the depth gradually becomes shallower.

[0009] Furthermore, the mixing unit also includes an amplitude adjustment component disposed between the two guide plates. The amplitude adjustment component includes limiting rings disposed at both ends of the drainage tube. The two guide plates are rotatably connected to the limiting rings respectively. A mounting groove is linearly opened on the two guide plates. A torsion spring is disposed in the mounting groove. The torsion spring is sleeved on the drainage tube, and both ends of the torsion spring abut against the two guide plates respectively.

[0010] Furthermore, the bottom of one end of each of the two guide plates is provided with an arc surface to provide rotation space.

[0011] Furthermore, a rotating assembly is provided on several mixing units located at the bottom of the tank. The rotating assembly includes a rotating groove formed on the wall of the conveying pipe, several connecting holes formed on the rotating groove, a rotating ring rotatably set on the rotating groove, a drain pipe passing through the rotating ring and communicating with the connecting holes, the drain pipe being fixedly connected to the rotating ring, and several limiting rods arranged in a ring array on the inner side of the rotating ring, the limiting rods moving within the connecting holes, and a rotating ring set on the inner side of the tank, the rotating ring being fixedly connected to one end of the drain pipe.

[0012] Furthermore, a mounting bracket is provided at the bottom of the tank, and the bottom of the conveying pipe is fixedly connected to the middle of the mounting bracket.

[0013] Another objective of this invention is to provide a process for treating leachate from phosphogypsum slag dumps. The purpose of this process is to address the high phosphorus, fluoride, salt, and heavy metal content of phosphogypsum leachate by using a step-by-step process. First, the pH is adjusted and flocculation and sedimentation are used for preliminary impurity removal. Then, the leachate is further purified to meet the standards, while simultaneously recovering resources. This solves the problems of incomplete removal, resource waste, and high costs associated with traditional processes.

[0014] To achieve the above objectives, the present invention provides the following technical solution:

[0015] Acid adjustment and mixed flocculation: Add lime milk to adjust the pH to 6-7, and transport it into the tank to mix with flocculant, so that fine particles and colloids can be aggregated into large flocs, and phosphorus, fluorine and suspended solids can be initially precipitated.

[0016] Solid-liquid separation: The mixed liquid after flocculation enters the sedimentation tank, and the supernatant is filtered through a quartz sand filter to remove residual flocs, ensuring that subsequent treatment equipment is not clogged;

[0017] Deep removal of phosphorus and fluoride: Magnesium sulfate and ammonium chloride are added to generate magnesium ammonium phosphate precipitate, aluminum sulfate is added to enhance fluoride precipitation, and residual phosphorus and fluoride are deeply purified by an activated alumina adsorption column;

[0018] Heavy metal removal: Sodium sulfide is added to cause heavy metals to precipitate as sulfides, a small amount of flocculant is added to assist precipitation, and trace amounts of heavy metals remaining in the supernatant are captured by chelating agents.

[0019] Desalination: Nanofiltration membranes retain sulfates, and the concentrated water is concentrated by electrodialysis, then evaporated and crystallized to recover industrial gypsum;

[0020] Sludge disposal: Flocculation sedimentation and sludge from each stage are dewatered by pressure filtration, solidified, and then safely landfilled or recycled.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. By utilizing the forced diversion effect of the "A"-shaped guide plates, combined with the precise alignment of the diversion channels and diversion holes, a closed loop of diversion, injection, and forced contact is formed between the leachate and flocculant, eliminating the mixing dead zones of traditional stirring. The staggered guide plates create a zigzag flow, extending the water flow path and increasing the collision frequency. The bottom arc structure guides the formation of symmetrical vortices, which not only prevents the flocs from being destroyed by shear forces but also promotes the coagulation of fine suspended matter into dense, large flocs, providing favorable conditions for subsequent sedimentation processes.

[0023] 2. Through the amplitude adjustment component, the guide plate can dynamically adjust its expansion amplitude according to the water pressure: when the water pressure is high, the flow channel widens to reduce the flow velocity and prevent high concentrations of suspended solids from washing away the equipment; when the water pressure is low, the flow channel narrows to increase the flow velocity and prevent sedimentation and blockage. The entire process requires no additional power, utilizing only the pressure of the leachate itself to achieve powerless mixing, significantly reducing energy consumption. At the same time, mechanical deformation buffers the water pressure impact, extending the service life of the equipment, and can well adapt to water volume fluctuations during rainy and dry seasons.

[0024] 3. The mixing unit at the bottom of the tank achieves limited-angle oscillation through a rotating component, dynamically changing the direction of water flow division under the influence of turbulence, thus avoiding uneven mixing caused by multiple units arranged in the same direction. The local eddies generated by the oscillation can flush away suspended solids deposited at the bottom, re-entraining them into the water flow to participate in the reaction, solving the problem of the "dead zone" at the bottom of traditional tanks. Combined with the stable support of the delivery pipe by the mounting frame, this ensures that the leachate throughout the entire tank can fully react with the flocculant, improving treatment stability. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall internal structure of the tank body after half-section.

[0026] Figure 2 This is a schematic diagram of the overall three-dimensional structure of the hybrid unit of the present invention;

[0027] Figure 3 This is a top view of the hybrid unit of the present invention;

[0028] Figure 4 This is a schematic diagram of the overall structure of the two guide plates of the present invention;

[0029] Figure 5 This is an exploded structural diagram of the amplitude adjustment component of the present invention;

[0030] Figure 6 This is a schematic diagram of the mating structure of the drainage groove, drainage hole, and drainage pipe of the present invention;

[0031] Figure 7 This is a three-dimensional structural diagram of the delivery pipe of the present invention;

[0032] Figure 8 This is a schematic diagram of a half-sectional view of the delivery pipe of the present invention;

[0033] Figure 9 For the present invention Figure 8 Enlarged structural diagram at point A in the middle.

[0034] In the picture:

[0035] 1. Tank body; 11. Inlet; 12. Outlet; 13. Delivery pipe; 2. Mixing assembly; 21. Guide plate; 22. Drain pipe; 23. Drain hole; 24. Drain groove; 3. Amplitude adjustment assembly; 31. Limiting ring; 32. Mounting groove; 33. Arc surface; 4. Rotating assembly; 41. Rotating groove; 42. Connecting hole; 43. Rotating ring; 44. Limiting rod; 45. Rotating ring; 5. Mounting bracket. Detailed Implementation

[0036] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0037] Example 1, referring to Figures 1-6This is the first embodiment of the present invention, which provides a leachate treatment system for phosphogypsum slag sites, including a tank 1, an inlet 11 and an outlet 12 respectively disposed at the top and bottom of the tank 1, and a conveying pipe 13 installed inside the tank 1, and also includes a mixing unit disposed inside the tank 1; the mixing unit includes a plurality of mixing components 2 arranged vertically and alternately, the mixing components 2 including two guide plates 21 arranged in a ring around the periphery of the conveying pipe 13, a diversion pipe 22 rotatably connected to the middle of the two guide plates 21, one end of the diversion pipe 22 penetrating into the interior of the conveying pipe 13 and fixedly connected to the pipe wall of the conveying pipe 13, the other end of the diversion pipe 22 being fixedly connected to the side wall of the tank 1, diversion holes 23 opened through the diversion pipe 22 in a linear array, and a plurality of diversion grooves 24 opened on the guide plates 21 and corresponding to the positions of the diversion holes 23.

[0038] Specifically, during leachate treatment, leachate is supplied through inlet 11, and flocculant is simultaneously supplied through delivery pipe 13. The leachate continuously enters the tank 1, while the flocculant flows from the drainage pipe 22 to the drainage channels 24 on the guide plate 21. When the leachate enters the tank 1, it is bisected by the two guide plates 21. The linear array of staggered guide plates 21 ensures that the leachate is thoroughly mixed with the flocculant after passing through the tank 1. The mixing effect is improved by mixing the flocculant with the leachate through the drainage channels 24. The vertically staggered guide plates 21 forcibly divide the leachate flow path, and the precise correspondence between the drainage channels 24 and the drainage holes 23 allows the flocculant to flow directionally from the drainage channels 24 into the leachate diversion path, achieving a closed loop of "leachate diversion - precise flocculant injection - forced contact within the flow channel," improving mixing uniformity and avoiding local concentration imbalance. Suspended solids (such as gypsum microcrystals) in phosphogypsum leachate have small particle sizes and strong dispersibility, requiring sufficient collision to coagulate into large, settleable flocs. The staggered guide plates 21 create a "reverse flow" of the leachate within the tank 1, extending the water flow path and increasing the collision frequency with the flocculant. The linear array design of the diversion channels 24 allows the flocculant to enter the water flow in a "multi-point dispersion" manner, expanding the contact area with the leachate.

[0039] The mixing unit achieves "powerless mixing" through the flow channel structure design, and completes the mixing only by the inlet pressure of the leachate itself and the flow field constraint of the guide plate 21, without the need for an additional stirring motor, thus reducing energy consumption. The amount of leachate in the phosphogypsum slag yard is greatly affected by rainfall (the amount of water in the rainy season can increase to 3-5 times that in the dry season). Traditional stirring systems are prone to uneven mixing due to "overload" when the amount of water increases suddenly.

[0040] Reference Figure 4 and Figure 6 The tops of the two guide plates 21 are set in abutting position, and their bottoms are curved arcs, forming an "A" shape.

[0041] Specifically, the A-shaped structure at the top can force the leachate entering the tank 1 into two streams in a "one-cut" manner, which flow downwards along the guide plates 21 on both sides, preventing the water from "short-circuiting" around the mixing area above the guide plates 21. The curved arc design at the bottom allows the diverted water to naturally form symmetrical vortices as it flows along the arc surface. Guided by the curvature of the arc bottom, the velocity direction of the water flow is deflected, forming a local circulation, which increases the collision frequency and contact time between the flocculant (flowing out from the diversion channel 24) and suspended matter (such as gypsum microcrystals) and colloids (such as phosphate colloids) in the leachate. Compared with a right angle or flat bottom, the arc design can reduce the "turbulent shear force" caused by the water flow impact, avoiding breaking the newly formed small flocs, allowing the flocs to gradually grow and become dense in the vortex, improving the subsequent sedimentation efficiency. For phosphogypsum leachate containing a large amount of gypsum particles and colloids, this design ensures that the leachate must pass through the flow channels on both sides of the guide plate 21 and be forced to contact the flocculant flowing out of the diversion channel 24, completely eliminating the "mixing dead zone" and solving the problem of "insufficient mixing of edge water flow" in traditional stirring.

[0042] Reference Figure 6 The depth of one end of the drainage groove 24 is greater than the width of the drainage hole 23. The drainage groove 24 is opened along the arc of the guide plate 21 and the depth gradually becomes shallower.

[0043] Specifically, when the guide plate 21 rotates, it facilitates the continuous output of flocculant from the drainage hole 23 into the drainage channel 24. The gradual depth design of the drainage channel 24 facilitates the mixing of the flocculant with the leachate after it flows out, and can reduce the mixing of water flow and flow resistance.

[0044] Example 2, refer to Figures 4-6 This is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the mixing unit further includes an amplitude adjustment component 3 disposed between the two guide plates 21. The amplitude adjustment component 3 includes a limiting ring 31 fixedly connected to both ends of the drainage tube 22. The limiting ring 31 has a T-shaped cross section. The two guide plates 21 are rotatably connected to the limiting ring 31 respectively. The mounting groove 32 is linearly opened on the two guide plates 21. A torsion spring (not shown in the figure) is installed in the mounting groove 32. The torsion spring is sleeved on the drainage tube 22, and both ends of the torsion spring abut against the two guide plates 21 respectively.

[0045] Specifically, when the leachate flow is fast and the water pressure is high, the water pressure will push the two guide plates 21 to rotate towards each other in the middle, thus reducing the expansion range of the guide plates 21. The leachate volume of phosphogypsum is affected by rainfall, with fluctuations reaching 3-5 times (a sudden increase in instantaneous flow during the rainy season). Water pressure impact may cause deformation or breakage of the fixed guide plates 21 (especially under high suspended solids scouring). When the water flow is fast and the water pressure is high, the guide plates 21 rotate towards each other in the middle under the pressure of the water pressure, absorbing the impact energy through mechanical deformation and converting the instantaneous impact force into the elastic potential energy of the torsion spring. This prevents damage to the connection between the guide plates 21 and the tank body 1 due to rigid stress, thus achieving an adaptive buffering effect against water pressure impact and protecting the equipment structure. When the water... When the pressure is high (the water flow is fast), the guide plate 21 expands to a smaller extent, making the flow channel wider. By increasing the cross-section of the water passage, the actual flow velocity is reduced, avoiding the severe scouring of the guide plate 21 and the diversion channel 24 by gypsum particles at high flow velocities (reducing surface scratches and the adhesion of corrosive media). At the same time, it prevents the turbulence from being too strong and breaking up the newly formed flocs. When the water pressure is low (the water flow is slow), the torsion spring pushes the guide plate 21 to expand to a larger extent, making the flow channel narrower. By reducing the cross-section of the water passage, the actual flow velocity is increased, preventing gypsum particles from settling on the surface of the guide plate 21 or in the diversion hole 23 due to the slow flow velocity.

[0046] Reference Figures 5-6 The bottom of one end of each of the two guide plates 21 is provided with an arc surface 33 to provide rotation space.

[0047] Specifically, it is used to provide rotational space for the two guide plates 21 to face each other.

[0048] Reference Figures 8-9 A rotating assembly 4 is provided on several mixing units located at the bottom of the tank body 1. The rotating assembly 4 includes a rotating groove 41 opened on the wall of the conveying pipe 13, several connecting holes 42 opened on the rotating groove 41, a rotating ring 43 rotatably set on the rotating groove 41, a diversion pipe 22 passing through the rotating ring 43 and communicating with the connecting holes 42, the diversion pipe 22 being fixedly connected to the rotating ring 43, and several limiting rods 44 fixedly connected in a ring array to the inner side of the rotating ring 43, and the limiting rods 44 moving within the connecting holes 42, and a rotating ring 45 rotatably connected to the inner side of the tank body 1, and the rotating ring 45 being fixedly connected to one end of the diversion pipe 22.

[0049] Specifically, the flocculant enters the drainage pipe 22 through the connecting hole 42. Unlike the mixing units at the top, the mixing units at the bottom can rotate. However, due to the limiting rod 44 confining them within the connecting hole 42, their rotation angle is limited. This ensures that the guide plate 21 can be continuously oscillated by the turbulent flow, preventing the mixing units from maintaining the same vertical direction and guaranteeing sufficient separation of the water flow by the mixing units. The rotating component 4 allows the bottom mixing units to oscillate with the turbulent flow (the rotation angle is limited by the limiting rod 44 to avoid excessive rotation), causing the separation direction of the guide plate 21 to dynamically change with the flow field, no longer a fixed "A"-shaped channel. This "dynamic separation" forces the bottom water flow to continuously change direction, forming a "multi-directional collision" with the flocculant flowing out of the drainage pipe 22. Especially for the bottom area with high deposition risk, this effectively improves mixing uniformity and avoids the formation of "dead zones" due to localized accumulation of suspended matter. Furthermore, the rotating component 4 causes the guide plate 21 to swing naturally with the turbulent flow. During the swing, it will generate "local agitation" on the bottom water flow, forming a small vortex that washes away the sediment and suspended matter on the surface of the guide plate 21 and the bottom of the tank 1, and re-injects it into the water flow to participate in the mixing.

[0050] Reference Figure 1 The bottom of the tank 1 is fixedly connected to the mounting bracket 5, and the bottom of the conveying pipe 13 is fixedly connected to the middle of the mounting bracket 5.

[0051] Specifically, it is used to support the delivery pipe 13. The rest of the structure is the same as that in Embodiment 1.

[0052] Based on embodiments 1-2, the working principle of this invention is as follows: After the leachate enters through the inlet 11 at the top of the tank 1, it flows downwards along the internal space of the tank. At the same time, the flocculant is transported through the internal delivery pipe 13 to the guide pipes 22 of each mixing unit. Through the linear array of guide holes 23 on the guide pipes 22, it flows precisely into the corresponding guide grooves 24 on the guide plate 21. In the mixing unit, the two "A"-shaped guide plates 21 force the leachate to split into two streams. With the help of multiple vertically intersecting mixing components 2, the water flow forms a zigzag flow and symmetrical vortex within the tank. This extends the water flow path and significantly increases the collision frequency and contact area between the flocculant and suspended solids such as gypsum particles and colloids in the leachate, achieving efficient mixing without power and avoiding the mixing dead zones of traditional stirring. When the leachate volume fluctuates due to factors such as rainfall, causing changes in water pressure, the torsion spring and limiting ring 31 of the amplitude adjustment component 3 drive the guide plate 21 to adaptively adjust: when the water pressure is high, the guide plate 21 is pushed by the water flow to rotate towards the center, reducing the expansion amplitude to widen the flow channel and reduce the actual flow velocity to avoid high flow velocity scouring the equipment or breaking up the flocs; when the water pressure is low, the torsion spring force pushes the guide plate 21 to expand the expansion amplitude, narrowing the flow channel and increasing the flow velocity to prevent suspended matter from settling and clogging due to excessively slow flow velocity. The mixing unit at the bottom of the tank 1 achieves limited angle rotation through the rotating component 4, and under the constraint of the limiting rod 44, it oscillates slightly with the turbulence, dynamically changing the direction of water flow division. This avoids uneven mixing caused by multiple units arranged in the same direction, and the oscillation creates local vortices to flush away suspended matter deposited at the bottom, ensuring that the leachate throughout the entire tank can fully react with the flocculant. Finally, the leachate that has completed flocculation and mixing is discharged from the outlet 12 at the bottom of the tank 1, laying the foundation for subsequent treatment processes.

[0053] Example 3, the third embodiment of the present invention, provides a process for treating leachate from phosphogypsum slag disposal sites:

[0054] S1. Acid adjustment and mixed flocculation: Add lime milk to adjust the pH to 6-7, and transport it to tank 1 to mix with flocculant, so that fine particles and colloids can be aggregated into large flocs, and phosphorus, fluorine and suspended solids can be initially precipitated.

[0055] S2, Solid-liquid separation: The mixed liquid after flocculation enters the sedimentation tank, and the supernatant is filtered by a quartz sand filter to remove residual flocs, ensuring that the subsequent treatment equipment is not blocked;

[0056] S3. Deep removal of phosphorus and fluorine: Magnesium sulfate and ammonium chloride are added to generate magnesium ammonium phosphate precipitate, and aluminum sulfate is added to enhance fluorine precipitation. Residual phosphorus and fluorine are deeply purified by an activated alumina adsorption column.

[0057] S4. Heavy metal removal: Sodium sulfide is added to cause heavy metals to form sulfide precipitates. A small amount of flocculant is added to assist precipitation. Trace heavy metals remaining in the supernatant are captured by chelating agents.

[0058] S5. Desalination treatment: Nanofiltration membrane retains sulfate, and the concentrated water is concentrated by electrodialysis and then evaporated and crystallized to recover industrial gypsum.

[0059] S6. Sludge disposal: Flocculation sedimentation and sludge from each stage are dewatered by pressure filtration, solidified, and then safely landfilled or recycled.

[0060] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A phosphogypsum residue field leachate treatment system, comprising a tank body (1), an inlet (11) and an outlet (12) arranged at the top and the bottom of the tank body (1) respectively, and a conveying pipe (13) arranged in the tank body (1), characterized in that, Further comprising a mixing unit arranged inside the tank body (1); The mixing unit comprises a plurality of mixing assemblies (2) arranged vertically staggered, the mixing assembly (2) comprises two guide plates (21) arranged annularly on the side of the conveying pipe (13), a flow guide pipe (22) arranged at the middle of the two guide plates (21), one end of the flow guide pipe (22) penetrates into the inside of the conveying pipe (13) and is fixedly connected with the pipe wall of the conveying pipe (13), the other end of the flow guide pipe (22) is fixedly connected with the side wall of the tank body (1), a plurality of flow guide holes (23) arranged in linear array penetrate on the flow guide pipe (22), and a plurality of flow guide grooves (24) arranged on the guide plate (21) correspond to the positions of the flow guide holes (23).

2. The phosphogypsum pile leachate treatment system of claim 1, wherein, The top of the two guide plates (21) is arranged in abutment, and the bottom is curved in arc shape, and the two guide plates (21) as a whole form an "A" shape.

3. The phosphogypsum pile leachate treatment system of claim 1, wherein, The depth of one end of the flow guide groove (24) is greater than the width of the flow guide hole (23), the flow guide groove (24) is arranged along the arc of the guide plate (21) and the depth gradually decreases.

4. The phosphogypsum pile leachate treatment system of claim 1, wherein, The mixing unit further comprises an amplitude adjusting assembly (3) arranged between the two guide plates (21), the amplitude adjusting assembly (3) comprises a limiting ring (31) arranged at both ends of the flow guide pipe (22) respectively, the two guide plates (21) are rotatably connected with the limiting rings (31) respectively, an installation groove (32) linearly arranged on the two guide plates (21), a torsion spring arranged in the installation groove (32), the torsion spring is sleeved on the flow guide pipe (22), and the two ends of the torsion spring are respectively in abutment with the two guide plates (21).

5. The phosphogypsum pile leachate treatment system of claim 4, wherein, The bottom of one end of the two guide plates (21) is provided with an arc surface (33) for providing a rotating space.

6. The phosphogypsum pile leachate treatment system of claim 1, wherein, A rotating assembly (4) is arranged on the plurality of mixing units at the bottom of the tank body (1), the rotating assembly (4) comprises a rotating groove (41) arranged on the pipe wall of the conveying pipe (13), a plurality of communication holes (42) arranged on the rotating groove (41), a rotating ring (43) rotatably arranged on the rotating groove (41), the flow guide pipe (22) penetrates through the rotating ring (43) and is connected with the communication holes (42), the flow guide pipe (22) is fixedly connected with the rotating ring (43), and a plurality of limiting rods (44) are annularly arranged on the inner side of the rotating ring (43), and the limiting rods (44) are movable in the communication holes (42), a rotating ring (45) arranged on the inner side of the tank body (1), and the rotating ring (45) is fixedly connected with one end of the flow guide pipe (22).

7. The phosphogypsum pile leachate treatment system of claim 1, wherein, The bottom of the tank body (1) is provided with a mounting frame (5), and the bottom of the conveying pipe (13) is fixedly connected with the middle of the mounting frame (5).

8. A process for treating phosphogypsum waste field leachate using the phosphogypsum waste field leachate treatment system according to claim 1, characterized in that, The method comprises the following steps: Acid adjustment and mixed flocculation: lime milk is added to adjust the pH to 6-7, and then the mixed liquid is conveyed into the tank body (1) to mix with the flocculant, so that the fine particles and colloids are coagulated into large flocs, and the phosphorus, fluorine and suspended solids are preliminarily precipitated; Solid-liquid separation: the mixed liquid after mixed flocculation enters the sedimentation tank, and the supernatant passes through the quartz sand filter to remove the residual flocs, so as to ensure that the subsequent treatment equipment is not blocked; Phosphorus and fluorine removal: adding magnesium sulfate and ammonium chloride to generate magnesium ammonium phosphate precipitation, adding aluminum sulfate to strengthen fluorine precipitation, and using activated alumina adsorption column to deeply purify residual phosphorus and fluorine; Heavy metal removal: adding sodium sulfide to make heavy metals into sulfide precipitate, adding a small amount of flocculant to assist precipitation, and using chelating agent to capture trace heavy metals in supernatant; Desalination treatment: nanofiltration membrane intercepts sulfate, concentrated water is concentrated by electrodialysis and then evaporated and crystallized to recover industrial gypsum; Sludge disposal: flocculation and sedimentation and sludge at each link are dewatered by pressure filtration, and then safely landfilled or recycled as resources.

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