Method and device for deeply treating coking wastewater through low-temperature superconducting magnetic separation

Abstract

The invention relates to a method and device for deeply treating coking wastewater through low-temperature superconducting magnetic separation, and belongs to the technical field of wastewater environment-friendly treatment methods and devices. The technical scheme of the invention is as follows: the coking wastewater enters a coagulating sedimentation unit to form magnetic flocculate, and the magnetic flocculate settled to the bottom is conveyed to a magnetic seed recycling and adding unit; the non-settled magnetic flocculate enters a low-temperature superconducting magnetic separation unit for separation treatment, and the magnetic flocculate cleaned in the cleaning box automatically flows into a magnetic seed adding and recycling unit; after being treated by the magnetic seed adding and recycling unit, the magnetic seeds enter the coagulating sedimentation unit again to be recycled, and flocculated pollutants separated in the crushing box are conveyed to a sludge treatment system to be treated. The invention has the beneficial effects of reasonable design, low operation cost, simple equipment operation and stable treatment effect.

Description

Technical Field

[0001] The invention relates to a method and a device for deep treatment of coking wastewater by low-temperature superconducting magnetic separation, belonging to the technical field of environmentally friendly wastewater treatment methods and devices. Background Art

[0002] Coking wastewater is a recognized industrial wastewater that is difficult to biodegrade. In addition to inorganic pollutants such as ammonia, cyanide and thiocyanate, it also contains heterocyclic and polycyclic aromatic compounds such as phenols, naphthalene, pyridine and quinoline. These substances are not only confirmed to be carcinogenic substances that can have long-term effects on the environment, but also have a strong inhibitory effect on microbial activity. At present, the A / O biological treatment process is generally used for coking wastewater treatment, but the COD, ammonia nitrogen and other indicators in the treated effluent cannot meet the requirements for discharge and reuse. With the continuous strengthening of national environmental protection policies and the continuous improvement of environmental protection standards, seeking an efficient and low-cost deep treatment process for coking wastewater is an urgent need for water system treatment in the current coking industry. Summary of the invention

[0003] The present invention aims to provide a method and device for deep treatment of coking wastewater by low-temperature superconducting magnetic separation, by 3 O 4 The surface is treated with organic functionalization to form a "magnetic seed" particle material with both magnetic properties and flocculation effect. Under the action of a coagulant and a flocculant, the surface-treated charged "magnetic seed" particle material is combined with pollutants in the coking wastewater to eventually generate a magnetic flocculant. The magnetic flocculant is separated from the coking wastewater under the action of a strong magnetic field generated by a low-temperature superconducting magnetic separation unit to achieve the treatment of the coking wastewater. The invention has a reasonable design, low operating cost, simple equipment operation, and stable treatment effect, and effectively solves the above-mentioned problems existing in the background technology.

[0004] The technical solution of the present invention is: a method for deep treatment of coking wastewater by low-temperature superconducting magnetic separation, comprising the following steps: (1) After A / O biological treatment, the coking wastewater enters the coagulation and sedimentation unit. In the coagulation and sedimentation unit, pollutants such as organic matter and inorganic salts in the wastewater are fully mixed with coagulants, magnetic seeds and flocculants respectively. In this process, the pollutants in the coking wastewater flocculate with the magnetic seeds and adsorb with the magnetic seeds to eventually form magnetic floccules. Part of the magnetic floccules settle to the bottom of the coagulation and sedimentation device under the action of gravity. The magnetic floccules that settle to the bottom are continuously transported to the magnetic seed recovery and dosing unit; (2) The magnetic floccules that have not settled after being treated by the coagulation and sedimentation unit enter the low-temperature superconducting magnetic separation unit for separation treatment. The low-temperature superconducting magnetic separation unit generates a strong magnetic field during operation. The magnetic floccules in the coking wastewater are adsorbed onto the circular stainless steel screen after being acted upon by the strong magnetic field. The circular stainless steel screen is driven by a chain drive motor to enter the cleaning box for cleaning, and the magnetic seed floccules on the screen are removed. The cleaned circular stainless steel screen continues to adsorb the magnetic floccules. The magnetic floccules cleaned in the cleaning box flow by gravity into the magnetic seed addition and recovery unit; (3) The magnetic flocculants from the coagulation sedimentation unit and the low-temperature superconducting magnetic separation unit cleaning box enter the crushing box of the magnetic seed recovery and dosing unit. In the crushing box, the magnetic flocculants are stirred to separate the magnetic seeds from the flocculated pollutants. The magnetic seeds containing magnetic substances are adsorbed to the magnetic seed adsorption drum on the upper part of the crushing box. After being separated by the magnetic seed scraper device on the surface of the drum, the magnetic seeds re-enter the coagulation sedimentation unit for recycling. The flocculated pollutants separated in the crushing box are sent to the sludge treatment system for treatment.

[0005] In the step (1), the coagulant, magnetic seed and flocculant are added while stirring.

[0006] In the step (2), a superconducting coil device is provided outside the inlet and outlet pipes of the low-temperature superconducting magnetic separation unit, and the helium refrigerator and the superconducting excitation unit provide the superconducting coil device with direct current and the low-temperature environment required for operation, so that the superconducting coil device generates a high-intensity magnetic field environment in the inlet and outlet pipes.

[0007] In the step (3), the magnetic seeds and the flocculated pollutants are separated in the crushing box. To ensure the separation effect, mechanical stirring is used.

[0008] A low-temperature superconducting magnetic separation device for deep treatment of coking wastewater, comprising a coagulation sedimentation unit, a low-temperature superconducting magnetic separation unit and a magnetic seed recovery and addition unit, wherein the output end of the coagulation sedimentation unit is respectively connected to the low-temperature superconducting magnetic separation unit and the magnetic seed recovery and addition unit, and the low-temperature superconducting magnetic separation unit is connected to the magnetic seed recovery and addition unit; The coagulation and sedimentation unit includes a coagulation tank, a magnetic seed tank, a flocculation tank and a sedimentation tank, which are arranged from left to right. The bottom of the coagulation tank and the magnetic seed tank are connected by a pipeline, the magnetic seed tank and the upper part of the flocculation tank are connected, and the bottom of the flocculation tank and the sedimentation tank are connected by a pipeline. The low-temperature superconducting magnetic separation unit includes an inlet and outlet pipe, a chain, a cleaning box and a circular stainless steel screen. The inlet and outlet pipes are connected to the upper part of the outlet of the sedimentation tank. The cleaning box is arranged on the upper part of the inlet and outlet pipes. The chain passes through the inlet and outlet pipes and the cleaning box. The chain is driven by a chain traction motor to circulate in the inlet and outlet pipes and the cleaning box. The circular stainless steel screen is installed on the chain. The magnetic seed recovery and addition unit includes a buffer box, a crushing box, a magnetic seed adsorption box, a magnetic seed recovery and addition box and a pollutant collection box. The bottom of the sedimentation tank and the cleaning box is connected to the buffer box, the top of the buffer box is connected to the crushing box, the top of the crushing box is connected to the magnetic seed adsorption box, and the magnetic seed adsorption box is respectively connected to the magnetic seed recovery and addition box and the pollutant collection box.

[0009] The coagulation and sedimentation unit is constructed of one of concrete and metal.

[0010] The invention also comprises a coagulation dosing device, a flocculation dosing device and a magnetic seed delivery pump. The coagulant is delivered to the coagulation tank through the coagulation dosing device. The coagulant is polyaluminium chloride. The magnetic seed delivery pump is arranged at the bottom of the magnetic seed recovery and dosing box. The magnetic seed is added to the magnetic seed tank through the magnetic seed delivery pump. The magnetic seed material is Fe with a carboxyl film on the surface. 3 O 4 The particle size of the magnetic seed material is in the range of 2 μm to 75 μm; the flocculant is transported to the flocculation tank through a flocculation dosing device, and the flocculant is polyacrylamide.

[0011] A first guide plate is arranged between the coagulation tank and the magnetic seed tank, a second guide plate is arranged between the magnetic seed tank and the flocculation tank, and a third guide plate is arranged between the flocculation tank and the sedimentation tank. The first guide plate, the second guide plate and the third guide plate are fixedly connected to the side wall of the coagulation sedimentation unit.

[0012] It also includes a coagulation stirring motor, a magnetic seed stirring motor and a flocculation stirring motor. The coagulation stirring motor is a paddle type and is arranged at the upper part of the coagulation tank; the magnetic seed stirring motor is a frame type and is arranged at the upper part of the magnetic seed tank; the flocculation stirring motor is a spiral type and is arranged at the upper part of the flocculation tank; the coagulation stirring motor, the magnetic seed stirring motor and the flocculation stirring motor are all variable frequency motors.

[0013] A superconducting coil device is installed outside the inlet and outlet pipes, the superconducting coil device is powered by a high-precision superconducting excitation power supply, a helium refrigerator is arranged outside the superconducting coil device, and a circulating water system is arranged outside the helium refrigerator.

[0014] The chain is connected end to end to form a ring structure. The number of circular stainless steel screens is more than one and they are evenly arranged on the chain. The diameter of the circular stainless steel screen is smaller than the diameter of the inlet and outlet pipes.

[0015] The cleaning box is provided with a cleaning water inlet, a cleaning water nozzle and a cleaning water outlet. The cleaning water inlet introduces cleaning water, and the position of the cleaning water nozzle matches the circular stainless steel screen; the cleaning water outlet is arranged at the bottom of the cleaning box, and the cleaning box is connected to the buffer box through the cleaning water outlet, and the cleaning box is provided with an inclination angle.

[0016] A stirring device is arranged in the crushing box, and the stirring device is driven by a stirring motor of the crushing box.

[0017] A magnetic seed adsorption roller is provided on the top of the magnetic seed adsorption box, which is driven by a magnetic seed adsorption roller motor. A magnetic seed scraper is provided on the upper side of the magnetic seed adsorption roller. The magnetic seed scraper is tilted and covers the pollutant collection box. The magnetic seed scraper terminal is connected to the magnetic seed recovery and addition box.

[0018] It also includes a pollutant delivery pump, the pollutant collection box is connected to the pollutant delivery pump through a bottom pipeline, and the pollutant delivery pump is connected to the sludge treatment system.

[0019] An observation port is arranged on the top of the magnetic seed recovery and addition box.

[0020] The beneficial effects of the present invention are: by 3 O 4 The surface is treated with organic functionalization to form a "magnetic seed" particle material with both magnetic properties and flocculation effect. Under the action of coagulants and flocculants, the surface-treated charged "magnetic seed" particle material is combined with the pollutants in the coking wastewater to finally generate magnetic floccules. The magnetic floccules are separated from the coking wastewater under the action of the strong magnetic field generated by the low-temperature superconducting magnetic separation unit to achieve the treatment of coking wastewater. The design is reasonable, the operating cost is low, the equipment operation is simple, and the treatment effect is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a structural schematic diagram of a low-temperature superconducting magnetic separation unit of the present invention; Figure 3 It is a schematic diagram of the structure of the circular stainless steel screen of the present invention; In the figure: coagulation tank 1, magnetic seed tank 2, flocculation tank 3, sedimentation tank 4, coagulation dosing device 5, coagulation stirring motor 6, magnetic seed stirring motor 7, flocculation dosing device 8, flocculation stirring motor 9, inlet and outlet pipelines 10, superconducting coil device 11, high-precision superconducting excitation power supply 12, helium refrigerator 13, chain 14, chain traction motor 15, cleaning box 16, circular stainless steel screen 17, cleaning water inlet 18, cleaning water nozzle 19, cleaning water outlet 20, buffer box 21, crushing box 22, crushing box stirring motor 23, stirring device 24, magnetic seed adsorption box 25, magnetic seed adsorption roller 26, magnetic seed adsorption roller motor 27, magnetic seed scraper 28, magnetic seed delivery pump 29, magnetic seed recovery and addition box 30, pollutant collection box 31, pollutant delivery pump 32. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the invention implementation cases clearer, the technical solutions in the implementation cases of the present invention will be clearly and completely described below in conjunction with the drawings in the implementation cases. Obviously, the implementation cases described are only a small part of the implementation cases of the present invention, rather than all the implementation cases. Based on the implementation cases in the present invention, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] A method for deep treatment of coking wastewater by low-temperature superconducting magnetic separation comprises the following steps: (1) After A / O biological treatment, the coking wastewater enters the coagulation and sedimentation unit. In the coagulation and sedimentation unit, pollutants such as organic matter and inorganic salts in the wastewater are fully mixed with coagulants, magnetic seeds and flocculants respectively. In this process, the pollutants in the coking wastewater flocculate with the magnetic seeds and adsorb with the magnetic seeds to eventually form magnetic floccules. Part of the magnetic floccules settle to the bottom of the coagulation and sedimentation device under the action of gravity. The magnetic floccules that settle to the bottom are continuously transported to the magnetic seed recovery and dosing unit; (2) The magnetic floccules that have not settled after being treated by the coagulation and sedimentation unit enter the low-temperature superconducting magnetic separation unit for separation treatment. The low-temperature superconducting magnetic separation unit generates a strong magnetic field during operation. The magnetic floccules in the coking wastewater are adsorbed onto the circular stainless steel screen after being acted upon by the strong magnetic field. The circular stainless steel screen is driven by a chain drive motor to enter the cleaning box for cleaning, and the magnetic seed floccules on the screen are removed. The cleaned circular stainless steel screen continues to adsorb the magnetic floccules. The magnetic floccules cleaned in the cleaning box flow by gravity into the magnetic seed addition and recovery unit; (3) The magnetic flocculants from the coagulation sedimentation unit and the low-temperature superconducting magnetic separation unit cleaning box enter the crushing box of the magnetic seed recovery and dosing unit. In the crushing box, the magnetic flocculants are stirred to separate the magnetic seeds from the flocculated pollutants. The magnetic seeds containing magnetic substances are adsorbed to the magnetic seed adsorption drum on the upper part of the crushing box. After being separated by the magnetic seed scraper device on the surface of the drum, the magnetic seeds re-enter the coagulation sedimentation unit for recycling. The flocculated pollutants separated in the crushing box are sent to the sludge treatment system for treatment.

[0024] In the step (1), the coagulant, magnetic seed and flocculant are added while stirring.

[0025] In the step (2), a superconducting coil device is provided outside the inlet and outlet pipes of the low-temperature superconducting magnetic separation unit, and the helium refrigerator and the superconducting excitation unit provide the superconducting coil device with direct current and the low-temperature environment required for operation, so that the superconducting coil device generates a high-intensity magnetic field environment in the inlet and outlet pipes.

[0026] In the step (3), the magnetic seeds and the flocculated pollutants are separated in the crushing box. To ensure the separation effect, mechanical stirring is used.

[0027] A low-temperature superconducting magnetic separation device for deep treatment of coking wastewater, comprising a coagulation sedimentation unit, a low-temperature superconducting magnetic separation unit and a magnetic seed recovery and addition unit, wherein the output end of the coagulation sedimentation unit is respectively connected to the low-temperature superconducting magnetic separation unit and the magnetic seed recovery and addition unit, and the low-temperature superconducting magnetic separation unit is connected to the magnetic seed recovery and addition unit; The coagulation and sedimentation unit comprises a coagulation tank 1, a magnetic seed tank 2, a flocculation tank 3 and a sedimentation tank 4, which are arranged from left to right. The bottom of the coagulation tank 1 and the magnetic seed tank 2 are connected by a pipeline, the upper part of the magnetic seed tank 2 and the flocculation tank 3 are connected, and the bottom of the flocculation tank 3 and the sedimentation tank 4 are connected by a pipeline. The low-temperature superconducting magnetic separation unit comprises an inlet and outlet pipe 10, a chain 14, a cleaning box 16 and a circular stainless steel screen 17. The inlet and outlet pipe 10 is connected to the upper part of the outlet of the sedimentation tank 4. The cleaning box 16 is arranged at the upper part of the inlet and outlet pipe 10. The chain 14 passes through the inlet and outlet pipe 10 and the cleaning box 16. The chain 14 is driven by a chain traction motor 15 to circulate in the inlet and outlet pipe 10 and the cleaning box 16. The circular stainless steel screen 17 is installed on the chain 14. The magnetic seed recovery and addition unit includes a buffer box 21, a crushing box 22, a magnetic seed adsorption box 25, a magnetic seed recovery and addition box 30 and a pollutant collection box 31. The bottom of the sedimentation tank 4 and the cleaning box 16 are connected to the buffer box 21, the top of the buffer box 21 is connected to the crushing box 22, the top of the crushing box 22 is connected to the magnetic seed adsorption box 25, and the magnetic seed adsorption box 25 is respectively connected to the magnetic seed recovery and addition box 30 and the pollutant collection box 31.

[0028] The coagulation and sedimentation unit is constructed of one of concrete and metal.

[0029] The invention also comprises a coagulation dosing device 5, a flocculation dosing device 8 and a magnetic seed delivery pump 29. The coagulant is delivered to the coagulation tank 1 through the coagulation dosing device 5. The coagulant is polyaluminium chloride. The magnetic seed delivery pump 29 is arranged at the bottom of the magnetic seed recovery and dosing box 30. The magnetic seed is added to the magnetic seed tank 2 through the magnetic seed delivery pump 29. The magnetic seed material is Fe with a carboxyl film on the surface. 3 O 4 The particle size of the magnetic seed material is in the range of 2 μm to 75 μm. The flocculant is transported to the flocculation tank 3 through the flocculation dosing device 8, and the flocculant is polyacrylamide.

[0030] A first guide plate is arranged between the coagulation tank 1 and the magnetic seed tank 2, a second guide plate is arranged between the magnetic seed tank 2 and the flocculation tank 3, and a third guide plate is arranged between the flocculation tank 3 and the sedimentation tank 4. The first guide plate, the second guide plate and the third guide plate are fixedly connected to the side wall of the coagulation sedimentation unit.

[0031] It also includes a coagulation stirring motor 6, a magnetic seed stirring motor 7 and a flocculation stirring motor 9. The coagulation stirring motor 6 is a paddle type and is arranged on the upper part of the coagulation tank 1; the magnetic seed stirring motor 7 is a frame type and is arranged on the upper part of the magnetic seed tank 2; the flocculation stirring motor 9 is a spiral type and is arranged on the upper part of the flocculation tank 3; the coagulation stirring motor 6, the magnetic seed stirring motor 7 and the flocculation stirring motor 9 are all variable frequency motors.

[0032] A superconducting coil device 11 is installed outside the inlet and outlet pipes 10 . The superconducting coil device 11 is powered by a high-precision superconducting excitation power supply 12 . A helium refrigerator 13 is arranged outside the superconducting coil device 11 . A circulating water system is arranged outside the helium refrigerator 13 .

[0033] The chain 14 is connected end to end to form a ring structure. The number of the circular stainless steel screens 17 is more than one and they are evenly arranged on the chain 14 . The diameter of the circular stainless steel screens 17 is smaller than the diameter of the inlet and outlet pipes 10 .

[0034] The cleaning box 16 is provided with a cleaning water inlet 18, a cleaning water nozzle 19 and a cleaning water outlet 20. The cleaning water inlet 18 introduces cleaning water, and the position of the cleaning water nozzle 19 matches the circular stainless steel screen 17; the cleaning water outlet 20 is arranged at the bottom of the cleaning box 16, and the cleaning box 16 is connected to the buffer box 21 through the cleaning water outlet 20, and the cleaning box 16 is provided with an inclination angle.

[0035] The crushing box 22 is provided with a stirring device 24 , and the stirring device 24 is driven by a crushing box stirring motor 23 .

[0036] A magnetic seed adsorption roller 26 is provided on the top of the magnetic seed adsorption box 25, and the magnetic seed adsorption roller 26 is driven by a magnetic seed adsorption roller motor 27. A magnetic seed scraper 28 is provided on the upper side of the magnetic seed adsorption roller 26. The magnetic seed scraper 28 is tilted and covers the pollutant collection box 31. The terminal of the magnetic seed scraper 28 is connected to the magnetic seed recovery and addition box 30.

[0037] It also includes a pollutant delivery pump 32. The pollutant collection box 31 is connected to the pollutant delivery pump 32 through a bottom pipeline, and the pollutant delivery pump 32 is connected to the sludge treatment system.

[0038] The top of the magnetic seed recovery and addition box 30 is provided with an observation port.

[0039] In practical applications, the coking wastewater after the existing A / O biological treatment first enters the upper part of the coagulation tank 1 of the coagulation sedimentation unit, and a certain concentration of coagulant solution is transported to the coagulation tank 1 through the coagulation dosing device 5. To ensure the coagulation effect, the coagulation stirring motor 6 on the upper part of the coagulation tank 1 is used for stirring, so that the organic and inorganic substances in the coking wastewater are coagulated to form small particle flocs. The generated small particle flocs enter the magnetic seed tank 2 through the pipeline connected to the magnetic seed tank 2 at the bottom. The magnetic seeds transported by the magnetic seed delivery pump 29 of the magnetic seed recovery and dosing box 30 in the magnetic seed tank 2 are added to the magnetic seed tank 2. To ensure sufficient contact between the magnetic seeds and the small particle flocs, the magnetic seed stirring motor 7 on the upper part of the magnetic seed tank 2 is used for stirring. After the particle flocs are fully contacted, the coking wastewater flows into the flocculation tank 3. A flocculation solution of a certain concentration is transported to the flocculation tank 3 through the flocculation dosing device 8. To ensure the flocculation effect, the flocculation stirring motor 9 on the upper part of the flocculation tank 3 is used for stirring, so that the magnetic seeds and small particle flocs form magnetic flocs. The generated magnetic flocs enter the sedimentation tank 4 through the connecting pipe at the bottom. Part of them is deposited at the bottom of the sedimentation tank 4 under the action of gravity. Relying on the deadweight of the water pressure, they are continuously transported to the buffer box 21 through the pipeline. The magnetic flocs without sedimentation flow into the inlet and outlet pipes 10 of the low-temperature superconducting unit along the outlet pipe. The superconducting coil device 11 is installed on the outside of the inlet and outlet pipes 10. The high-precision superconducting excitation power supply 12 module transmits 220V The alternating current is converted into 52A stable direct current to power the superconducting coil device 11. To ensure the low-temperature environment required for the operation of the superconducting coil device 11, a helium refrigerator 13 is arranged outside the superconducting coil device 11 to establish a low-temperature environment for the superconducting coil device. The heat generated during the operation of the helium refrigerator 13 is output by the circulating water system outside the helium refrigerator 13. A chain 14 is provided in the inlet and outlet pipes 10 and the cleaning box 16. The chain 14 is driven by a chain traction motor 15 to circulate in the inlet and outlet pipes 10 and the cleaning box 16. A plurality of circular stainless steel screens 17 with diameters smaller than the inlet and outlet pipes 10 are evenly installed on the chain 14. The circular stainless steel screens 17 are driven by the chain 14 to transmit in the inlet and outlet pipes 10 and the cleaning box 16. When the circular stainless steel screens 17 pass through the inlet and outlet pipes 10, the magnetic field lines of the internal magnetic field concentrate through the circular stainless steel screens 17. When the coking wastewater flows through the circular stainless steel screens 17, the magnetic flocculants therein are affected by the strong magnetic field and adsorbed onto the circular stainless steel screens 17, thereby realizing efficient separation of the magnetic flocculants and the coking wastewater. The coking wastewater with the magnetic flocculants removed is discharged from the outlet.The circular stainless steel screen 17 adsorbed with magnetic flocculants enters the cleaning box 16 for cleaning under the drive of the chain traction motor 15. The cleaning box 16 is located at the upper part of the inlet and outlet pipes 10. Cleaning water with a certain pressure enters from the cleaning water inlet 18, and the magnetic flocculants adsorbed on the circular stainless steel screen 17 are cleaned through the cleaning water nozzle 19. After cleaning, the circular stainless steel screen 17 continues to move to the inlet and outlet pipes 10 for adsorption under the drive of the chain 14. The cleaned magnetic flocculants flow into the buffer box 21 from the cleaning water outlet 20 at the bottom of the cleaning box 16. In order to ensure the discharge of the magnetic flocculants, the cleaning box 16 is installed and arranged at a certain angle. The magnetic flocculants from the bottom of the sedimentation tank 4 and the cleaning tank 16 enter the buffer box 21. After being buffered by the buffer box 21, the magnetic flocculants flow into the crushing box 22 to separate the magnetic seeds from the flocculated pollutants. The separation of the magnetic seeds from the flocculated pollutants is carried out by mechanical stirring by the stirring device 24 driven by the stirring motor 23 of the crushing box. The separated magnetic seeds and the flocculated pollutants overflow into the magnetic seed adsorption box 25 together. The top of the magnetic seed adsorption box 25 is provided with a magnetic seed adsorption roller 26. The magnetic seed adsorption roller 26 is composed of a magnetic seed adsorption roller 26. The adsorption drum motor 27 drives the uninterrupted rotation. When the separated magnetic seeds and flocculated pollutants pass through the surface of the magnetic seed adsorption drum 26, the magnetic seeds are adsorbed to the surface of the magnetic seed adsorption drum 26. A magnetic seed scraper 28 is provided on the upper side of the magnetic seed adsorption drum 26. The magnetic seed scraper 28 separates the magnetic seeds adsorbed on the surface of the magnetic seed adsorption drum 26. The separated magnetic seeds flow into the magnetic seed recovery and addition box 30 by gravity. The magnetic seed recovery and addition box 30 is connected to the magnetic seed delivery pump 29 through the bottom pipeline to deliver the magnetic seeds to the magnetic seed pool 2. The flocculated pollutants flow into the pollutant collection box 31. The pollutant collection box 31 is connected to the pollutant delivery pump 32 through the bottom pipeline to deliver the flocculated pollutants to the sludge treatment system for treatment. In the process of recycling the magnetic seeds, a certain loss is inevitable. When magnetic seeds need to be added, they are added in the observation port at the top of the magnetic seed recovery and addition box 30.

[0040] The coagulant and flocculant described in the present invention are added by an integrated dosing device, which is a complete set of equipment integrating dosing, stirring, liquid conveying and automatic control.

[0041] Compared with the traditional coking wastewater deep treatment process, the present invention has the advantages of stable operation, thorough treatment effect and low treatment cost, which are specifically reflected in the following aspects: First, the low-temperature superconducting magnetic separation system has high processing efficiency, wide processing capacity, fast speed, and is not affected by natural temperature. The daily processing capacity can range from hundreds of tons to tens of thousands of tons.

[0042] Secondly, through the addition of magnetic seeds, non-magnetic organic matter, inorganic salts and other pollutants are fully combined with the magnetic seeds under the action of coagulants and flocculants, and then subjected to low-temperature superconducting magnetic separation treatment. The magnetic seed recovery and addition unit will recover the added magnetic seeds to avoid losses caused by the loss of magnetic seeds and the impact on subsequent water treatment and use.

[0043] Third, it also has a strong separation ability for extremely fine suspended matter and low-concentration industrial wastewater, occupies a small area, does not require frequent maintenance, consumes little power, and can achieve unattended automatic operation and remote control.

Claims

1. A method for deep treatment of coking wastewater by low-temperature superconducting magnetic separation, characterized in that The following steps are involved: The coking wastewater after A / O biological treatment enters the coagulation and sedimentation unit, where pollutants such as organic matter and inorganic salts in the wastewater are fully mixed with coagulants, magnetic seeds and flocculants respectively. In this process, the pollutants in the coking wastewater flocculate with the magnetic seeds and adsorb with the magnetic seeds to eventually form magnetic floccules. Part of the magnetic floccules settle to the bottom of the coagulation and sedimentation device under the action of gravity, and the magnetic floccules settled to the bottom are continuously transported to the magnetic seed recovery and dosing unit; The magnetic floccules that have not settled after being treated by the coagulation and sedimentation unit enter the low-temperature superconducting magnetic separation unit for separation treatment. The low-temperature superconducting magnetic separation unit generates a strong magnetic field during operation. The magnetic floccules in the coking wastewater are adsorbed onto the circular stainless steel screen after being acted upon by the strong magnetic field. The circular stainless steel screen is driven by a chain drive motor to enter the cleaning box for cleaning, and the magnetic seed floccules on the screen are removed. The cleaned circular stainless steel screen continues to adsorb the magnetic floccules, and the magnetic floccules cleaned in the cleaning box flow by gravity into the magnetic seed addition and recovery unit; The magnetic flocculants from the coagulation sedimentation unit and the low-temperature superconducting magnetic separation unit cleaning box enter the crushing box of the magnetic seed recovery and dosing unit. In the crushing box, the magnetic flocculants are stirred to separate the magnetic seeds from the flocculated pollutants. The magnetic seeds containing magnetic substances are adsorbed to the magnetic seed adsorption drum on the upper part of the crushing box. After separation by the magnetic seed scraper device on the surface of the drum, the magnetic seeds re-enter the coagulation sedimentation unit for recycling. The flocculated pollutants separated in the crushing box are sent to the sludge treatment system for treatment.

2. The method for deep treatment of coking wastewater by low-temperature superconducting magnetic separation according to claim 1, characterized in that: In the step (1), the coagulant, magnetic seed and flocculant are added while stirring; in the step (2), a superconducting coil device is provided outside the inlet and outlet pipes of the low-temperature superconducting magnetic separation unit, and the helium refrigerator and the superconducting excitation unit provide the superconducting coil device with direct current and the low-temperature environment required for operation, so that the superconducting coil device generates a high-intensity magnetic field environment in the inlet and outlet pipes.

3. The method for deep treatment of coking wastewater by low-temperature superconducting magnetic separation according to claim 1, characterized in that: In the step (3), the magnetic seeds and the flocculated pollutants are separated in the crushing box, and mechanical stirring is used to ensure the separation effect.

4. A device for deep treatment of coking wastewater by low-temperature superconducting magnetic separation, characterized in that: It comprises a coagulation precipitation unit, a low-temperature superconducting magnetic separation unit and a magnetic seed recovery and addition unit, wherein the output end of the coagulation precipitation unit is respectively connected to the low-temperature superconducting magnetic separation unit and the magnetic seed recovery and addition unit, and the low-temperature superconducting magnetic separation unit is connected to the magnetic seed recovery and addition unit; The coagulation and sedimentation unit comprises a coagulation tank (1), a magnetic seed tank (2), a flocculation tank (3) and a sedimentation tank (4), which are arranged in sequence from left to right. The bottoms of the coagulation tank (1) and the magnetic seed tank (2) are connected via a pipeline, the upper part of the magnetic seed tank (2) and the flocculation tank (3) are connected, and the bottoms of the flocculation tank (3) and the sedimentation tank (4) are connected via a pipeline. The low-temperature superconducting magnetic separation unit comprises an inlet and outlet pipe (10), a chain (14), a cleaning box (16) and a circular stainless steel screen (17); the inlet and outlet pipe (10) is connected to the upper part of the outlet of the sedimentation tank (4); the cleaning box (16) is arranged on the upper part of the inlet and outlet pipe (10); the chain (14) passes through the inlet and outlet pipe (10) and the cleaning box (16); the chain (14) is driven by a chain traction motor (15) to circulate in the inlet and outlet pipe (10) and the cleaning box (16); and the circular stainless steel screen (17) is installed on the chain (14); The magnetic seed recovery and addition unit comprises a buffer box (21), a crushing box (22), a magnetic seed adsorption box (25), a magnetic seed recovery and addition box (30) and a pollutant collection box (31); the bottoms of the sedimentation tank (4) and the cleaning box (16) are connected to the buffer box (21); the top of the buffer box (21) is connected to the crushing box (22); the top of the crushing box (22) is connected to the magnetic seed adsorption box (25); and the magnetic seed adsorption box (25) is respectively connected to the magnetic seed recovery and addition box (30) and the pollutant collection box (31).

5. The device for deep treatment of coking wastewater by low-temperature superconducting magnetic separation according to claim 4 is characterized in that: It also comprises a coagulation dosing device (5), a flocculation dosing device (8) and a magnetic seed delivery pump (29), wherein the coagulant is delivered to the coagulation tank (1) through the coagulation dosing device (5), and the coagulant is polyaluminium chloride; the magnetic seed delivery pump (29) is arranged at the bottom of the magnetic seed recovery and dosing box (30), and the magnetic seed is added to the magnetic seed tank (2) through the magnetic seed delivery pump (29), and the magnetic seed material is Fe3O4 magnetic seed material with a carboxyl film on the surface, and the particle size range is 2 μm to 75 μm; the flocculant is delivered to the flocculation tank (3) through the flocculation dosing device (8), and the flocculant is polyacrylamide.

6. The device for deep treatment of coking wastewater by low-temperature superconducting magnetic separation according to claim 4 is characterized in that: A first guide plate is provided between the coagulation tank (1) and the magnetic seed tank (2), a second guide plate is provided between the magnetic seed tank (2) and the flocculation tank (3), and a third guide plate is provided between the flocculation tank (3) and the sedimentation tank (4). The first guide plate, the second guide plate and the third guide plate are fixedly connected to the side wall of the coagulation and sedimentation unit.

7. The device for deep treatment of coking wastewater by low-temperature superconducting magnetic separation according to claim 4 is characterized in that: It also comprises a coagulation stirring motor (6), a magnetic seed stirring motor (7) and a flocculation stirring motor (9); the coagulation stirring motor (6) is of a paddle type and is arranged at the upper part of the coagulation tank (1); the magnetic seed stirring motor (7) is of a frame type and is arranged at the upper part of the magnetic seed tank (2); the flocculation stirring motor (9) is of a spiral type and is arranged at the upper part of the flocculation tank (3); the coagulation stirring motor (6), the magnetic seed stirring motor (7) and the flocculation stirring motor (9) are all variable frequency motors.

8. The device for deep treatment of coking wastewater by low-temperature superconducting magnetic separation according to claim 4 is characterized in that: A superconducting coil device (11) is installed outside the inlet and outlet pipes (10). The superconducting coil device (11) is powered by a high-precision superconducting excitation power supply (12). A helium refrigerator (13) is provided outside the superconducting coil device (11). A circulating water system is provided outside the helium refrigerator (13).

9. The device for deep treatment of coking wastewater by low-temperature superconducting magnetic separation according to claim 4, characterized in that: The chain (14) is connected end to end to form a ring structure. The number of the circular stainless steel screens (17) is more than one and is evenly arranged on the chain (14). The diameter of the circular stainless steel screens (17) is smaller than the diameter of the inlet and outlet pipes (10).

10. The device for deep treatment of coking wastewater by low-temperature superconducting magnetic separation according to claim 4, characterized in that: The cleaning box (16) is provided with a cleaning water inlet (18), a cleaning water nozzle (19) and a cleaning water outlet (20); the cleaning water inlet (18) is used to introduce cleaning water; the position of the cleaning water nozzle (19) matches the circular stainless steel screen (17); the cleaning water outlet (20) is arranged at the bottom of the cleaning box (16); the cleaning box (16) is connected to the buffer box (21) via the cleaning water outlet (20); and the cleaning box (16) is provided with an inclination angle.

11. The device for deep treatment of coking wastewater by low-temperature superconducting magnetic separation according to claim 4, characterized in that: The crushing box (22) is provided with a stirring device (24), which is driven by a crushing box stirring motor (23); a magnetic seed adsorption roller (26) is provided on the top of the magnetic seed adsorption box (25), which is driven by a magnetic seed adsorption roller motor (27); a magnetic seed scraper (28) is provided on the upper side of the magnetic seed adsorption roller (26), the magnetic seed scraper (28) is tilted and covers the top of the pollutant collection box (31), and the terminal of the magnetic seed scraper (28) is connected to a magnetic seed recovery and addition box (30); an observation port is provided on the top of the magnetic seed recovery and addition box (30).

12. The device for deep treatment of coking wastewater by low-temperature superconducting magnetic separation according to claim 4, characterized in that: It also comprises a pollutant delivery pump (32), the pollutant collection box (31) is connected to the pollutant delivery pump (32) via a bottom pipeline, and the pollutant delivery pump (32) is connected to the sludge treatment system.

Images