Method for treating wastewater containing calcium chloride tailings

Abstract

The application discloses a kind of calcium chloride tailings wastewater treatment methods containing, comprising the following steps: a. sodium carbonate or sodium phosphate is added to calcium chloride tailings wastewater containing, stirring 6h is mixed uniformly;B. the mixed solution is carried out solid-liquid separation, and calcium-based precipitate and sodium salt wastewater containing are obtained;F. after solid-liquid separation, the calcium-based precipitate is dried, and calcium carbonate or calcium phosphate is obtained;G. after solid-liquid separation, sodium salt wastewater containing is purified in capacitive adsorption desalination device, and regenerated water is obtained.A kind of equipment for realizing the method is also disclosed.The application can realize the effective purification treatment of calcium chloride tailings wastewater containing, so that it reaches regenerated water standard.

Description

Technical Field

[0001] This invention relates to a method for treating tailings wastewater containing calcium chloride, and also to a device for treating tailings wastewater containing calcium chloride. Background Technology

[0002] The fluorite beneficiation process generates tailings wastewater containing calcium chloride. Direct discharge of this tailings wastewater into the environment causes pollution; however, purification treatment to meet reclaimed water standards allows for reuse, improving the environment and saving resources and production costs. Currently, my country's main reclaimed water standards are the "Water Quality Standard for Industrial Water Used in Urban Wastewater Reuse" (GB / T19923-2005) and the "Water Quality Standard for Reclaimed Water Used in Circulating Cooling Water" (HG / T 3923-2007).

[0003] Purification of tailings wastewater containing calcium chloride requires deep removal of calcium chloride to achieve water quality that meets recycling standards while maintaining a high water reuse rate.

[0004] Currently, the main methods for desalination and hardening of tailings wastewater include precipitation, evaporation crystallization, membrane separation, and capacitive adsorption. However, these existing technologies are not ideal for treating tailings wastewater containing calcium chloride and cannot meet the standards for reclaimed water.

[0005] In order to effectively purify and treat tailings wastewater containing calcium chloride to meet the standards for reclaimed water, the applicants conducted joint research and development, and after repeated experiments, obtained a feasible technical solution and applied for this invention patent. Summary of the Invention

[0006] The purpose of this invention is to provide a method for treating calcium chloride-containing tailings wastewater and an apparatus for treating calcium chloride-containing tailings wastewater, so as to achieve effective purification of calcium chloride-containing tailings wastewater and make it meet the standards for reclaimed water.

[0007] To solve this technical problem, the present invention provides a method for treating calcium chloride-containing tailings wastewater, comprising the following steps:

[0008] a. Add sodium carbonate or sodium phosphate to tailings wastewater containing calcium chloride and stir for 6 hours to mix thoroughly;

[0009] b. The mixture is subjected to solid-liquid separation to obtain calcium-based precipitate and sodium-containing wastewater;

[0010] f. Dry the calcium-based precipitate after solid-liquid separation to obtain calcium carbonate or calcium phosphate;

[0011] g. The sodium-containing wastewater after solid-liquid separation is purified in a capacitive adsorption desalination device to obtain reclaimed water.

[0012] During the purification process of the capacitive adsorption desalination device, the flow rate of the electrode solution is 80 mL / min, and the flow rate of the supernatant in the intermediate chamber is 20 mL / min.

[0013] In step a, 9.55-23.87 mg of sodium carbonate or 9.85-19.7 mg of sodium phosphate is added to every 100 ml of tailings wastewater.

[0014] In step a, 9.55 mg of sodium carbonate or 19.7 mg of sodium phosphate is added to every 100 ml of tailings wastewater.

[0015] The present invention provides an apparatus for implementing the above method, comprising a solid-liquid separation device and a capacitive adsorption desalination device; the liquid outlet of the solid-liquid separation device is connected to the liquid inlet of the capacitive adsorption desalination device;

[0016] The solid-liquid separation device includes a workbench with a slot on its top surface. A rotating rod is rotatably connected inside the slot. The rotating rod is fixedly sleeved around the bottom of a barrel. A chamber is formed inside the barrel. A sleeve shaft is rotatably connected to the bottom surface of the chamber. A screen barrel is fixedly connected to the top of the sleeve shaft. The sleeve shaft is rotatably sleeved with a rotating shaft. A screen barrel is fixedly connected to the top of the rotating shaft. The screen barrel is located inside the screen barrel. A crossbar is fixedly connected to the top of the chamber. Multiple threaded rods are rotatably connected to the bottom surface of the crossbar. The multiple threaded rods are threadedly connected to a ring plate and a round plate. A square cavity is formed at the bottom of the barrel. A motor is fixedly connected to one side of the square cavity. A bevel gear is fixedly connected to the shaft of the motor. The bevel gear meshes with bevel gears two and three.

[0017] The second bevel gear is fixedly sleeved on the rotating shaft, and the third bevel gear is fixedly connected to the bottom end of the sleeve shaft. The third bevel gear is rotatably sleeved on the rotating shaft. The first bevel gear, the second bevel gear, and the third bevel gear are located inside the first square cavity. The top of one side of the workbench is fixedly connected to the second motor. The first rotating rod is fixedly connected to the rotating shaft. The worm gear is fixedly sleeved on one side of the rotating rod. The worm gear meshes with the worm wheel. The worm wheel is fixedly sleeved on the second rotating rod. The bottom of the barrel has a second square cavity, and the worm gear and the worm wheel are located inside the second square cavity.

[0018] The top periphery of the rotating rod 2 is fixedly sleeved with a sprocket 1. The sprocket 1 is connected to a chain for transmission. The chain is connected to multiple sprocket 2s for transmission. Multiple sprocket 2s are fixedly sleeved with multiple threaded rods. A chain groove is opened inside the crossbar. The sprocket 1, the chain, and the sprocket 2 are located inside the chain groove. The top of the barrel is rotatably connected to a cover. The top surface of the cover is fixed and connected to a water inlet pipe. The bottom of the barrel is fixed and connected to a drain pipe.

[0019] The capacitive adsorption desalination device includes a housing, with connecting pipes fixedly connected to both ends of the housing. A desalination chamber is fixedly installed in the middle of the housing. Ion membranes are provided on both sides of the desalination chamber. Graphite electrode plates are fixedly connected to the opposite sides of the ion membranes. Mounting components are movably provided at the four corners of one end face of each graphite electrode plate. An end plate is snapped into the mounting component and is located on the opposite side of the graphite electrode plate. The desalination chamber has a U-shaped structure, with connecting holes opened in the middle of both ends of the desalination chamber, and these connecting holes are interconnected with the connecting pipes.

[0020] A sealed door is hinged to one side of the housing; limit strips are fixedly connected to both sides inside the housing, and sealing strips are fixedly connected to opposite sides of the limit strips, with the limit strips abutting against the end plate.

[0021] The end plate has mounting holes at its four corners, and mounting components are slidably fitted into the mounting holes. The graphite electrode plate has movable grooves at its four corners. The mounting components include a movable rod, a base, a toggle part, a strong spring, and a limiting plate. The limiting plate is slidably fitted into the movable groove. One end of the limiting plate is fixedly connected to the movable rod. A strong spring is movably fitted outside the movable rod. One end of the strong spring is fixedly connected to the limiting plate. The other end of the strong spring is fixedly connected to the inner wall of one end of the movable groove. The end of the movable rod away from the limiting plate is fixedly connected to the base. The base is hinged to the toggle part after moving through the mounting hole. The toggle part abuts against the outside of the end plate.

[0022] This method and apparatus have the following advantages:

[0023] 1. The method of the present invention adopts a combined process of calcium precipitation and capacitive adsorption for sodium chloride removal (i.e., FCDI) to achieve efficient decalcification and reuse of tailings wastewater. First, by introducing a sodium salt precipitant, calcium ions are precipitated, realizing the conversion of calcium into calcium-based precipitate. Second, the resulting saline wastewater, which is mainly composed of sodium chloride, undergoes capacitive adsorption to remove sodium chloride, further desalination, and meets the water regeneration and reuse standards. The method is simple, reliable, easy to implement, and has a high salt removal rate, which can reach more than 97%.

[0024] 2. The solid-liquid separation device of the present invention, through the cooperation of various components, uses centrifugal force to separate sodium salts in wastewater through mesh bucket one and mesh bucket two. The separation effect is good and thorough, avoiding resource waste. After the separation is completed, the circular plate and the circular ring plate can push out the solids, which is convenient for workers to collect.

[0025] 3. The capacitive adsorption desalination (FCDI) device of the present invention facilitates the disassembly and separation of the end plate and graphite electrode plate through the installation components, thereby facilitating the quick disassembly and assembly of the graphite electrode plate, and making it easy to clean the scale on the graphite electrode plate or replace the graphite electrode plate, saving time and manpower and improving efficiency. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0027] Figure 2 This is a schematic diagram of the solid-liquid separation device of the present invention;

[0028] Figure 3 This is a schematic cross-sectional view of the solid-liquid separation device of the present invention;

[0029] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0030] Figure 5 for Figure 3 Enlarged view of point B in the middle;

[0031] Figure 6 This is a schematic diagram of the capacitive adsorption desalination device FCDI of the present invention;

[0032] Figure 7 This is a schematic cross-sectional view of the capacitive adsorption desalination device FCDI of the present invention;

[0033] Figure 8 for Figure 7 Enlarged schematic diagram of the structure at point C. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0035] like Figure 1 As shown, the method for treating calcium chloride-containing tailings wastewater of the present invention includes the following steps:

[0036] a. Add sodium carbonate or sodium phosphate to tailings wastewater containing calcium chloride and stir for 6 hours to mix thoroughly;

[0037] b. The mixture is subjected to solid-liquid separation to obtain calcium-based precipitate and sodium-containing wastewater;

[0038] f. Dry the calcium-based precipitate after solid-liquid separation to obtain calcium carbonate or calcium phosphate;

[0039] g. The sodium-containing wastewater after solid-liquid separation is purified in a capacitive adsorption desalination device to obtain reclaimed water.

[0040] During the purification process of the capacitive adsorption desalination device, the preferred flow rate of the electrode solution is 80 mL / min, and the preferred flow rate of the supernatant in the intermediate chamber is 20 mL / min.

[0041] Preferably, in step a, 9.55-23.87 mg of sodium carbonate or 9.85-19.7 mg of sodium phosphate is added per 100 ml of tailings wastewater. More preferably, 9.55 mg of sodium carbonate or 19.7 mg of sodium phosphate is added per 100 ml of tailings wastewater.

[0042] This invention, through repeated comparative experiments, selected sodium carbonate or sodium phosphate as the calcium precipitant. The solubility of a precipitate in water is closely related to its solubility product; the lower the solubility, the less soluble it is in water. Both calcium phosphate and calcium carbonate are sparingly soluble, with solubility products of 2.07 × 10⁻³³ and 3.36 × 10⁻⁹, respectively, indicating extremely low solubility. This demonstrates that phosphate and carbonate ions can precipitate the very low concentration of calcium ions in water. The precipitation principle equation is as follows:

[0043] CaCl₂ + Na₂CO₃ = CaCO₃ + 2NaCl;

[0044] 3CaCl2+2Na3PO4=𝐶𝑎3(PO4)2+6NaCl.

[0045] In the purification process of the capacitive adsorption desalination device, comparative experiments were conducted on the addition of different amounts of sodium carbonate or sodium phosphate, and a relatively small optimal range was obtained.

[0046] The key parameters for capacitive adsorption desalination performance are calculated using the average salt removal rate (ASRR), salt removal efficiency (SRE), and charge efficiency (CE) to evaluate the system's desalination performance. The formulas are as follows:

[0047] 𝐴𝑆𝑅𝑅=(𝐶0−𝐶𝑡)·𝑉 / 𝑆·𝑡;

[0048] 𝑆𝑅𝐸=(𝐶0−𝐶𝑡) / 𝐶0×100%;

[0049] 𝐶𝐸=𝐹·(𝐶0−𝐶𝑡)·𝑉 / 𝑀·∫𝐼(𝑡)·d𝑡.

[0050] In the formula, ASRR This represents the average salt removal rate; SRE Salt removal rate; CE This represents the charge efficiency. Wherein, C0 This represents the initial concentration of the salt solution in the desalination chamber. Ct Let be the concentration of the salt solution in the desalination chamber at time 't'; V This represents the volume of the desalting solution; S The effective contact area between the ion exchange membrane and the flow electrode; t This refers to system uptime. F It is Faraday's constant; M It is the molar mass of NaCl / CaCl2; I(t)Let t be the current of the system at time 't'; the integral of the current over time is calculated using Origin software.

[0051] The following are the experimental results without the addition of calcium precipitant, and with the addition of sodium carbonate or sodium phosphate within a smaller preferred range (after purification and desalination reaction in a capacitive adsorption desalination device for 90 minutes at 2.5V):

[0052] Without adding calcium precipitant, the conductivity of the tailings water decreased from 3.68 to 0.219 mS / cm, and the sodium removal rate reached 94.29%.

[0053] Adding sodium carbonate to 100 ml of tailings wastewater at concentrations of 9.55 mg, 14.32 mg, 19.1 mg, 23.87 mg, and 28.65 mg resulted in a decrease in conductivity of the tailings wastewater after sodium carbonate precipitation treatment. This decreased from 3.83, 3.75, 3.9, 3.91, and 4.03 to 0.0809, 0.117, 0.1944, 0.0919, and 0.275 mS / cm, respectively, achieving sodium removal rates of 97.96%, 96.75%, 94.91%, 97.75%, and 93.17%, respectively.

[0054] Adding sodium phosphate to 100 ml of tailings wastewater at concentrations of 9.85 mg, 14.77 mg, 19.7 mg, 24.63 mg, and 29.55 mg resulted in the following changes: the conductivity of the tailings wastewater after sodium phosphate precipitation decreased from 3.87, 3.79, 3.87, 3.97, and 4.06 to 0.1478, 0.1763, 0.0898, 0.1818, and 0.321 mS / cm, respectively, achieving sodium removal rates of 96.22%, 95.35%, 97.78%, 95.46%, and 92.1%, respectively.

[0055] Experimental results: It is preferable to add 9.55-23.87 mg of sodium carbonate or 9.85-19.7 mg of sodium phosphate per 100 ml of tailings wastewater; the optimal value is 9.55 mg of sodium carbonate or 19.7 mg of sodium phosphate per 100 ml of tailings wastewater.

[0056] To implement this method, the present invention provides equipment for its solid-liquid separation and capacitive adsorption desalination steps: a solid-liquid separation device and a capacitive adsorption desalination device, i.e., an FCDI device. According to the method flow, the liquid outlet of the solid-liquid separation device is connected to the liquid inlet of the capacitive adsorption desalination device.

[0057] Solid-liquid separation devices, such as Figures 2-5As shown, the device includes a workbench 1 with a slot 2 on its top surface. A rotating rod 3 is rotatably connected inside the slot 2. The rotating rod 3 is fixedly sleeved around the bottom of a barrel 4. A chamber 5 is formed inside the barrel 4. A sleeve shaft 6 is rotatably connected to the bottom surface of the chamber 5. A mesh barrel 7 is fixedly connected to the top of the sleeve shaft 6. A rotating shaft 8 is rotatably sleeved to the top of the sleeve shaft 6. A mesh barrel 9 is fixedly connected to the top of the rotating shaft 8. The mesh barrel 9 is located inside the mesh barrel 7. A crossbar 10 is fixedly connected to the top of the chamber 5. Multiple threaded rods 11 are rotatably connected to the bottom surface of the crossbar 10. The multiple threaded rods 11 are threadedly connected to a ring plate 12 and a circular plate 13. Both the mesh barrel 7 and the mesh barrel 9 use filter mesh bodies. The mesh size of the mesh barrel 7 is smaller than that of the mesh barrel 9, making it easier to separate finer sodium carbonate particles. When using the device, the required... The purified wastewater is added into the barrel 4 and then into the mesh barrel 9 inside the chamber 5. The rotating shaft 8 is rotated, which drives the mesh barrel 9. The mesh barrel 9 uses centrifugal force to throw the wastewater out and into the mesh barrel 7. The sleeve shaft 6 is rotated, which drives the mesh barrel 7 to rotate. The mesh barrel 7 further separates the wastewater, which is then discharged from the barrel 4. After separation, the rotating rod 3 is rotated, which drives the barrel 4 to rotate. After the barrel 4 rotates 180 degrees, the rotating rod 3 rotates while the threaded rod 11 rotates. The threaded rod 11 rotates, which drives the annular plate 12 and the circular plate 13 to rotate. The annular plate 12 and the circular plate 13 deliver sodium carbonate particles to the top of the mesh barrel 7 and the mesh barrel 9, where the workers collect the sodium carbonate particles.

[0058] A square cavity 14 is opened at the bottom of the barrel body 4. A motor 15 is fixedly connected to one side of the square cavity 14. A bevel gear 16 is fixedly connected to the shaft of the motor 15. The bevel gear 16 meshes with bevel gear 2 17 and bevel gear 3 18. When the motor 15 is turned on, the motor 15 rotates and drives bevel gear 16 to rotate. The rotation of bevel gear 16 drives bevel gear 2 17 and bevel gear 3 18 to rotate.

[0059] Bevel gear 2 17 is fixedly sleeved on rotating shaft 8, and bevel gear 3 18 is fixedly connected to the bottom end of sleeve shaft 6. Bevel gear 3 18 rotates and sleeves on rotating shaft 8. Bevel gear 1 16, bevel gear 2 17 and bevel gear 3 18 are located inside square cavity 14. Square cavity 14 provides normal support for bevel gear 1 16, bevel gear 2 17 and bevel gear 3 18. The rotation of bevel gear 2 17 drives the rotation of rotating shaft 8, and the rotation of bevel gear 3 18 drives the rotation of sleeve shaft 6.

[0060] A motor 219 is fixedly connected to the top of one side of the workbench 1. A rotating rod 3 is fixedly connected to the shaft of the motor 219. A worm gear 22 is fixedly sleeved around the circumference of the rotating rod 3. The worm gear 22 meshes with a worm wheel 23. The worm wheel 23 is fixedly sleeved with a rotating rod 24. A square cavity 21 is opened at the bottom of the barrel 4. The worm gear 22 and the worm wheel 23 are located inside the square cavity 21. The square cavity 21 provides assistance for the normal operation of the worm gear 22 and the worm wheel 23. When the motor 219 is turned on, the rotation of the motor 21 drives the rotating rod 3 to rotate. The rotation of the rotating rod 3 drives the worm gear 22 to rotate. The rotation of the worm gear 22 drives the worm wheel 23 to rotate. The rotation of the worm wheel 23 drives the rotating rod 24 to rotate.

[0061] The top periphery of the rotating rod 24 is fixedly sleeved with a sprocket 25. The sprocket 25 is connected to a chain 26, which in turn is connected to multiple sprockets 27. Multiple sprockets 27 are fixedly sleeved with multiple threaded rods 11. A chain groove 28 is opened inside the crossbar 10. The sprockets 25, 26, and 27 are located inside the chain groove 28. The chain groove 28 provides assistance for the normal operation of the sprockets 25, 26, and 27. The rotation of the rotating rod 24 drives the sprocket 25 to rotate, which in turn drives the sprocket 27 to rotate, and the rotation of the sprocket 27 drives the threaded rods 11 to rotate.

[0062] The top of the barrel 4 is rotatably connected to the cover 29. The top surface of the cover 29 is fixed and connected to the water inlet pipe 30. The bottom of the barrel 4 is fixed and connected to the drain pipe 20. Wastewater is added into the barrel 4 from the water inlet pipe 30, and the separated wastewater is discharged from the drain pipe 20.

[0063] In use, the wastewater to be purified is added into the tank 4 through the inlet pipe 30. The wastewater enters the mesh bucket 9 inside the chamber 5. Motor 15 is turned on, and its rotation drives bevel gear 16, which in turn drives bevel gear 17 and bevel gear 18. Bevel gear 17 drives the rotating shaft 8, which in turn drives the sleeve shaft 6. The rotating shaft 8 drives the mesh bucket 9, which, through centrifugal force, throws the wastewater out and into mesh bucket 7. The sleeve shaft 6 then drives mesh bucket 7 to further separate the wastewater. The mesh buckets 7 and 9 rotate in opposite directions to better separate sodium carbonate particles from the wastewater. The wastewater is discharged from the drain pipe 20 at the bottom of the tank 4. After separation, motor 219 is turned on, and its rotation drives rotating rod 13. When the moving barrel 4 rotates 180 degrees, the rotating rod 3 rotates simultaneously, driving the worm gear 22 to rotate. The worm gear 22 then drives the worm wheel 23 to rotate, which in turn drives the rotating rod 24 to rotate. This rotation drives the sprocket 25 to rotate, which in turn drives the sprocket 27 to rotate. The sprocket 27 then drives the threaded rod 11 to rotate, which in turn drives the annular plate 12 and the circular plate 13 to rotate. The annular plate 12 and the circular plate 13 deliver sodium carbonate particles to the top of the mesh barrel 7 and the mesh barrel 9. The workers open the cover 29 to collect the sodium carbonate particles. Through the cooperation of various components, the mesh barrel 7 and the mesh barrel 9 use centrifugal force to separate sodium carbonate from the wastewater. The separation effect is good and thorough, avoiding resource waste. After separation, the circular plate 13 and the annular plate 12 can push out the sodium carbonate for easy collection by the workers.

[0064] Capacitive adsorption desalination devices, such as Figures 6-8 As shown, the device includes a housing 201, with connecting pipes 202 fixedly connected to both ends of the housing. A desalination chamber 203 is fixedly installed in the middle of the housing. Ion membranes 204 are provided on both sides of the desalination chamber. Graphite electrode plates 205 are fixedly connected to the opposite sides of the ion membranes. Mounting components 208 are movably provided at the four corners of one end face of the graphite electrode plate. An end plate 206 is snapped onto the mounting components and is located on the opposite side of the graphite electrode plate 205.

[0065] The wastewater treatment tank and the collection tank are connected by water pipes 202, which have inlet and outlet ends. Graphite electrode plates 205 are connected to electrodes. The ion exchange membrane 204 consists of anion exchange membrane and cation exchange membrane, located on opposite sides of the desalination chamber 203. The ion exchange membrane 204, in conjunction with the flowing electrode of the graphite electrode plate 205, adsorbs and desalinates the wastewater flowing through the desalination chamber 203. The treated water is collected in the collection tank. When it is necessary to replace or clean the graphite electrode plate 205... During the process, the water circuit is disconnected, then the sealed box door 211 is opened, the graphite electrode plate 205 is taken out, and the graphite electrode plate can be replaced by operating the installation component 208. The disassembly of the graphite electrode plate is convenient and quick. The replacement graphite electrode plate is made to fit the end plate tightly against the graphite electrode plate through the installation component, so that the graphite electrode plate and the end plate are attached to a whole. Then the graphite electrode plate is placed into the housing. The two ends of the end plate are limited by the limiting strip 207. At the same time, the sealing strip fixed by the limiting strip 207 ensures the sealing of the connection.

[0066] The desalination chamber 203 has a U-shaped structure, which allows wastewater to flow smoothly inside. The middle of both ends of the desalination chamber 203 are respectively provided with connection holes, and the connection holes are connected to the connecting pipe 202. The connecting pipe is divided into an inlet end and an outlet end. The connection with the desalination chamber allows wastewater to flow in and out through the connecting pipe respectively.

[0067] A sealing door 211 is hinged to one side of the housing. The inside of the housing can be disassembled or cleaned by opening the sealing door, and the housing can be sealed by closing the sealing door.

[0068] Limiting strips 207 are fixedly connected to both sides inside the housing, and sealing strips are fixedly connected to the opposite side of the limiting strips. The limiting strips 207 abut against the end plate 206. The graphite electrode plate 205 is placed into the housing. The two ends of the end plate are limited by the limiting strips, and the sealing strips fixed to the limiting strips ensure the sealing of the connection.

[0069] Mounting holes 261 are provided at the four corners of the end plate, and mounting components 208 are slidably fitted into the mounting holes 261.

[0070] Furthermore, the graphite electrode plate 205 has movable slots 251 at its four corners. The mounting assembly 208 includes a movable rod 281, a base 282, a toggle part 283, a strong spring 284, and a limiting plate 285. The limiting plate 285 is slidably sleeved in the movable slot 251. One end of the limiting plate 285 is fixedly connected to the movable rod 281. The strong spring 284 is movably sleeved outside the movable rod 281. One end of the strong spring 284 is fixedly connected to the limiting plate 285, and the other end of the strong spring 284 is fixedly connected to the inner wall of one end of the movable slot 251. The end of the movable rod 281 away from the limiting plate 285 is fixedly connected to the base 282. The base 282 is hinged to the toggle part 283 after moving through the mounting hole 261. The toggle part 283 abuts against the outside of the end plate 206.

[0071] When the graphite electrode plate 205 needs to be replaced or cleaned, the water circuit is disconnected. Then, the sealed box door 211 is opened, the graphite electrode plate 205 is taken out, and the mounting assembly 208 is operated. The U-shaped actuating part 283 is moved so that its length is aligned with the length of the movable rod 281. At this point, the end plate 206 can be removed. The actuating part 283 passes through the mounting hole 261 in the end plate, allowing the graphite electrode plate to be replaced. The disassembly of the graphite electrode plate is convenient and quick. The mounting assembly on the replaced graphite electrode plate passes through the end plate 206. The mounting hole 261 is then opened, and the actuating part 283 is pulled to pass through the mounting hole 261. The actuating part 283 is then moved to make it perpendicular to the base 282. After the actuating part 283 is released, the elastic force of the strong spring 284 causes the movable rod 281 to retract into the movable groove 251. At the same time, the movable rod 281 causes the fixed base 282 to move. The base 282 causes the hinged actuating part 283 to abut against the end plate 206. The actuating part then causes the end plate to press tightly against the graphite electrode plate, so that the graphite electrode plate and the end plate are bonded together as a whole.

[0072] In use, the wastewater tank to be treated and the collection tank are connected by water pipes 202, which are divided into an inlet and an outlet. Graphite electrode plate 205 is connected to the electrode. The ion exchange membrane 204 is divided into an anion exchange membrane and a cation exchange membrane, which are located on both sides of the desalination chamber 203. The ion exchange membrane 204, in conjunction with the flowing electrode of the graphite electrode plate 205, adsorbs and desalinates the wastewater flowing through the desalination chamber 203. The treated water is collected in the collection tank. When the graphite electrode plate 205 needs to be replaced or cleaned, the water circuit is disconnected, the sealed box door 211 is opened, the graphite electrode plate 205 is taken out, and the installation component 208 is operated. The U-shaped actuating part 283 is moved so that the length of the actuating part 283 is aligned with the length of the movable rod 281. At this time, the end plate 206 can be removed. The actuating part 283 passes through the installation hole 261 opened in the end plate 206, and the graphite electrode plate 205 can be replaced. The graphite electrode plate 205 is easy and quick to disassemble. The mounting component 208 on the replacement graphite electrode plate 205 passes through the mounting hole 261 of the end plate 206. Then, pull the actuating part 283 so that the actuating part 283 passes through the mounting hole 261. Then, move the actuating part 283 so that it is perpendicular to the base 282. After releasing the actuating part 283, under the elastic force of the strong spring 284, the movable rod 281 is driven to retract into the movable groove 251. At the same time, the movable part 283 is moved. Rod 281 drives the fixed base 282 to move, and base 282 drives hinged actuating part 283 to abut against end plate 206. Actuating part 283 then drives end plate 206 to press tightly against graphite electrode plate 205, so that graphite electrode plate 205 and end plate 206 are bonded together as a whole. Then graphite electrode plate 205 is placed into housing 201. The two ends of end plate 206 are limited by limiting strip 207. At the same time, the sealing strip fixed to the limiting strip ensures the sealing of the connection.

Claims

1. A method for treating tailings wastewater containing calcium chloride, characterized in that... Includes the following steps: a. Add sodium carbonate or sodium phosphate to tailings wastewater containing calcium chloride and stir for 6 hours to mix thoroughly; b. The mixture is subjected to solid-liquid separation to obtain calcium-based precipitate and sodium-containing wastewater; c. Dry the calcium-based precipitate after solid-liquid separation to obtain calcium carbonate or calcium phosphate; d. The sodium-containing wastewater after solid-liquid separation is purified in a capacitive adsorption desalination device to obtain reclaimed water; In step a, 9.55 mg of sodium carbonate or 19.7 mg of sodium phosphate is added to every 100 ml of tailings wastewater. The apparatus for implementing the method includes a solid-liquid separation device and a capacitive adsorption desalination device; the liquid outlet of the solid-liquid separation device is connected to the liquid inlet of the capacitive adsorption desalination device. The solid-liquid separation device includes a workbench (1), a slot (2) on the top surface of the workbench (1), a rotating rod (3) rotatably connected inside the slot (2), the rotating rod (3) being fixedly sleeved around the bottom of a barrel (4), a chamber (5) being formed inside the barrel (4), a sleeve shaft (6) rotatably connected to the bottom surface inside the chamber (5), a mesh barrel (7) being fixedly connected to the top of the sleeve shaft (6), a rotating shaft (8) being rotatably sleeved to the sleeve shaft (6), and a mesh being fixedly connected to the top of the rotating shaft (8). Bucket 2 (9), the second net bucket (9) is located inside the first net bucket (7); a square cavity 1 (14) is opened at the bottom of the bucket body (4), a motor 1 (15) is fixedly connected to one side inside the square cavity 1 (14), and a bevel gear 1 (16) is fixedly connected to the shaft of the motor 1 (15); the bevel gear 1 (16) simultaneously meshes with bevel gear 2 (17) and bevel gear 3 (18) to drive the rotating shaft (8) and the sleeve shaft (6) respectively to drive the second net bucket (9) and the first net bucket (7) to rotate in opposite directions; The capacitive adsorption desalination device includes a shell (201), with connecting pipes (202) fixedly connected to both ends of the shell (201). A desalination chamber (203) is fixedly installed in the middle of the shell (201). Ion membranes (204) are provided on both sides of the desalination chamber (203). Graphite electrode plates (205) are fixedly connected to the opposite sides of the ion membranes (204). Movable grooves (251) are respectively opened at the four corners of the graphite electrode plates (205). The graphite electrode plate (205) is provided with mounting components (208) at its four corners. The mounting components (208) are snapped with end plates (206). The end plates (206) are located on the opposite side of the graphite electrode plate (205). The graphite electrode plate (205) is detachably connected to the end plates (206) through the mounting components (208). The desalination chamber (203) has a U-shaped structure. The middle of both ends of the desalination chamber (203) are provided with connection holes, and the connection holes are all connected to the connecting pipe (202). The mounting assembly (208) includes a movable rod (281), a base (282), a toggle part (283), a strong spring (284), and a limiting plate (285). The limiting plate (285) is slidably sleeved in the movable groove (251). One end of the limiting plate (285) is fixedly connected to the movable rod (281). The strong spring (284) is movably sleeved outside the movable rod (281). One end of the strong spring (284) is fixedly connected to the limiting plate (285). The other end of the strong spring (284) is fixedly connected to the inner wall of one end of the movable groove (251). The end of the movable rod (281) away from the limiting plate (285) is fixedly connected to the base (282). The end plate (206) is provided with a mounting hole (261). The base (282) is hinged to the toggle part (283) after it moves through the mounting hole (261). The toggle part (283) abuts against the outside of the end plate (206).

2. The method according to claim 1, characterized in that: The top of the barrel (4) is rotatably connected to the cover (29), the top surface of the cover (29) is fixed and connected to the water inlet pipe (30), and the bottom of the barrel (4) is fixed and connected to the drain pipe (20).

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