Silicon and fluorine removal device for coking wastewater zero-discharge membrane high-power concentrated solution

Abstract

The utility model relates to a silicon and fluorine removal device for a coking wastewater zero-discharge membrane high-power concentrated solution. The silicon and fluorine removal device comprises a deep silicon removal unit, an alternate fluorine removal precipitation unit and an accurate fluorine removal unit which are sequentially connected in series, the deep silicon removal unit comprises a silicon removal reaction tank and a silicon removal sedimentation tank which are connected in series, a silicon removal stirrer is arranged in the silicon removal reaction tank, and a first flocculant adding device and a first liquid alkali adding device are arranged on the silicon removal reaction tank; the alternate defluorination sedimentation unit comprises a defluorination sedimentation tank, a defluorination stirrer is arranged in the defluorination sedimentation tank, effluent of the defluorination sedimentation tank is conveyed into the defluorination sedimentation tank, and a first sulfuric acid adding device is arranged on a pipeline between the defluorination sedimentation tank and the defluorination sedimentation tank; the precise defluorination unit comprises a second-stage defluorination reaction tank and a second-stage defluorination clarification tank which are connected in series, a water inlet pipeline of the second-stage defluorination reaction tank is provided with a second flocculant adding device and a second sodium hydroxide adding device, and effluent of the defluorination sedimentation tank is fed into the second-stage defluorination reaction tank.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to a desiliconizing and defluorinating device for zero-discharge membrane high-concentration liquid of coking wastewater. Background Art

[0002] Coking is an energy conversion industry that uses coal as raw material to produce coke through dry distillation. Coking wastewater contains high concentrations of characteristic pollutants such as phenols, ammonia, sulfides, cyanides, pyridine, tar, etc. It also contains a large amount of salt, fluoride, hardness, and silicon. It is a difficult-to-treat industrial wastewater. The treatment route of coking wastewater has developed from biochemical treatment, physical and chemical treatment, and further to zero-discharge treatment of coking wastewater.

[0003] Among the zero-discharge treatment processes for coking wastewater, the mainstream and most widely used is the salt separation process route, which involves subjecting the coking wastewater to physical and chemical treatment, biochemical treatment, membrane concentration treatment, and membrane salt separation treatment (separation into high-concentration sodium sulfate and sodium chloride solutions), and finally entering crystallization treatment to crystallize into Na2SO4 and NaCl, respectively, and produce a small amount of miscellaneous salts.

[0004] As mentioned above, specifically, coking wastewater needs to go through the following processes after being treated in conventional physical and chemical and biochemical sections: First is the pre-membrane pretreatment process, whose function is to remove hardness, reduce turbidity, reduce COD, and control the concentration of scaling ions in the water from the biochemical section, so as to reduce problems such as membrane fouling and scaling in the subsequent membrane concentration process, and at the same time reduce the concentration of the above pollutants as much as possible to improve the water recovery rate of the subsequent membrane system. Next is the membrane concentration process, whose function is to make full use of the separation, screening and desalination characteristics of various membranes to concentrate and reduce the wastewater. Depending on the concentration ratio, 85%-95% of the water will be recovered and reused in industrial production activities, and most of the pollutants will be re-enriched into the membrane high-concentrate liquid, and then enter the membrane high-concentrate liquid pretreatment and its membrane salt separation process. The sodium chloride and sodium sulfate concentrates enter the subsequent crystallization process to produce solid sodium sulfate, sodium chloride and miscellaneous salts, achieving zero wastewater discharge.

[0005] The total dissolved solids (TDS) content of the high-concentration liquid of zero-emission membrane coking wastewater is usually above 30,000 mg / L, the CODcr is 350-800 mg / L, and the fluoride and silica contents exceed 100 mg / L and 50 mg / L respectively. Silicon and fluorine can cause scaling of the evaporator and corrosion of the evaporation core equipment (usually titanium). Utility Model Content

[0006] In order to solve the problems existing in the above-mentioned technologies, the utility model provides a desiliconization and defluorination device for coking wastewater zero-discharge membrane high-concentration liquid, comprising a deep desiliconization unit (1), an alternating defluorination precipitation unit (2) and a precise defluorination unit (3) connected in series in sequence;

[0007] The deep desiliconization unit (1) comprises a desiliconization reaction tank (14) and a desiliconization clarification tank (16) connected in series, a desiliconization agitator (15) is provided in the desiliconization reaction tank (14), and a first flocculant dosing device (11) and a first liquid alkali dosing device (12) are provided on the desiliconization reaction tank (14);

[0008] The alternating defluorination precipitation unit (2) comprises a defluorination precipitation tank, a defluorination agitator is provided in the defluorination precipitation tank, the effluent of the desiliconization clarification tank (16) is transported to the defluorination precipitation tank, and a first sulfuric acid dosing device (18) is provided on the pipeline between the desiliconization clarification tank (16) and the defluorination precipitation tank;

[0009] The precise defluorination unit (3) comprises a secondary defluorination reaction tank (31) and a secondary defluorination clarification tank (32) connected in series. A second flocculant dosing device (35) and a second sodium hydroxide (36) dosing device are provided on the water inlet pipe of the secondary defluorination reaction tank (31). The effluent of the defluorination sedimentation tank is fed into the secondary defluorination reaction tank (31).

[0010] The alternating defluorination sedimentation unit (2) comprises a first defluorination sedimentation tank (21) and a second defluorination sedimentation tank (22), and a first defluorination mixer (23) and a second defluorination mixer (24) are respectively provided in the two defluorination sedimentation tanks;

[0011] The two defluorination sedimentation tanks are connected in parallel, and a defluorination water inlet alternating valve group (25) is provided on the pipeline between the two defluorination sedimentation tanks and the desiliconization clarification tank (16), and the defluorination water inlet alternating valve group (25) is located downstream of the first sulfuric acid dosing device (18);

[0012] The effluents from the two defluorination sedimentation tanks are both fed into the secondary defluorination reaction tank (31).

[0013] The precise defluorination unit (3) further comprises a three-stage defluorination reaction tank (33) and a three-stage defluorination clarification tank (34) connected in series, the effluent of the two-stage defluorination clarification tank (32) is transported to the three-stage defluorination reaction tank (33) through a pipeline, and a third flocculant dosing device (38) is provided on the pipeline between the two-stage defluorination clarification tank (32) and the three-stage defluorination reaction tank (33).

[0014] It also includes a filter material enhanced filtration unit (4);

[0015] The filter material enhanced filtration unit (4) comprises a filter tank water inlet box (41), a filter tank (43), and a mud-water separator (45) connected in series, wherein the mud-water separator (45) returns the separated filter material to the filter tank (43);

[0016] The effluent from the three-stage defluorination clarification tank (34) is transported to the filter tank water inlet box (41).

[0017] It also includes a sludge unit (5);

[0018] The sludge unit (5) includes a sludge thickening tank (52);

[0019] The mud-water separator (45), the silicon removal clarifier (16), the first defluorination sedimentation tank (21), the second defluorination sedimentation tank (22), the secondary defluorination clarifier (32) and the tertiary defluorination clarifier (34)

[0020] The sludge is discharged into the sludge thickening tank (52).

[0021] Wherein, pH meters are provided in the silicon removal clarification tank (16), the secondary fluoride removal clarification tank (32), and the tertiary fluoride removal clarification tank (34).

[0022] A pH meter is provided on the pipeline between the first sulfuric acid dosing device (18) and the defluorination water inlet alternating valve group (25).

[0023] A desiliconization pipeline mixer (13) is provided on the water inlet pipe of the desiliconization reaction tank (14), and the first flocculant dosing device (11) and the first liquid alkali dosing device (12) are both connected to the desiliconization pipeline mixer (13).

[0024] Wherein, the third-stage defluorination reaction tank (33) and the second-stage defluorination reaction tank (31) are both provided with variable frequency impeller stirrers.

[0025] The top outlet areas of the silicon removal clarifier (16), the secondary fluoride removal clarifier (32), and the tertiary fluoride removal clarifier (34) are all provided with inclined tube layers.

[0026] The beneficial effects of the utility model are:

[0027] (1) Through the alternating cycle of water filling-standing-sludge discharge in two defluorination sedimentation tanks, the fluorine precipitates can be discharged from the system during the first defluorination, which not only ensures the saving of reagents in the subsequent second and third precise dosing defluorination, but also reduces the sludge sedimentation load of the subsequent defluorination clarification tank and reduces the area occupied by the defluorination clarification tank;

[0028] (2) By removing fluoride by two precise dosings, the stability of the defluoridated effluent can be enhanced while maintaining the same final fluoride removal rate, thus avoiding fluctuations in fluoride indicators;

[0029] (3) By setting up an automated filter media enhanced filtration unit, the total effluent turbidity of the device can be further reduced on the basis of removing fluoride and clarifying the effluent. There is no membrane filtration and no need to replace the filter media, thus avoiding the cost of membrane cleaning and membrane replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0031] Figure 1 It is a work flow chart of the utility model;

[0032] Figure 2 It is a schematic diagram of the combination of various mechanisms of the present utility model.

[0033] Description of Reference Numerals

[0034] 1-deep desiliconization unit; 11-first flocculant dosing device; 12-first liquid alkali dosing device; 13-desiliconization pipeline mixer; 14-desiliconization reaction tank; 15-desiliconization agitator; 16-desiliconization clarifier; 17-desiliconization reaction pH meter; 18-first sulfuric acid dosing device; 19-desiliconization product water pH meter;

[0035] 2- alternating defluorination sedimentation unit; 21- first defluorination sedimentation tank; 22- second defluorination sedimentation tank; 23- first defluorination sedimentation tank agitator; 24- second defluorination sedimentation agitator; 25- defluorination water inlet alternating valve group;

[0036] 3-precision defluorination unit; 31-secondary defluorination reaction tank; 32-secondary defluorination clarification tank; 33-tertiary defluorination reaction tank; 34-tertiary defluorination clarification tank; 35-secondary flocculant dosing device; 36-secondary liquid alkali dosing device; 37-pH meter for secondary defluorination clarification tank; 38-third flocculant dosing device; 39-pH meter for tertiary defluorination clarification tank;

[0037] 4- filter media enhanced filtration unit; 41- filter tank water inlet box; 42- filter tank water inlet pump; 43- filter tank; 44- filter media circulation pump; 45- mud-water separator;

[0038] 5- sludge unit; 51- sludge pump; 52- sludge thickening tank. DETAILED DESCRIPTION

[0039] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0040] like Figure 2As shown, the present application is a desiliconization and defluorination device for coking zero-emission membrane high-concentration liquid, including a deep desiliconization unit 1, an alternating defluorination precipitation unit 2, a precise defluorination unit 3, an automatic filter material enhanced filtration unit 4, and a sludge unit 5.

[0041] The deep desiliconization unit 1 includes a first flocculant dosing device 11, a first liquid alkali dosing device 12, a desiliconization pipeline mixer 13, a desiliconization reaction tank 14, a desiliconization agitator 15, a desiliconization clarifier 16, a desiliconization reaction pH meter 17, a first sulfuric acid dosing device 18, and a desiliconization produced water pH meter 19. The first flocculant dosing device 12 and the first liquid alkali dosing device 12 are connected to the desiliconization pipeline mixer 13 through their respective dosing pipes. The desiliconization pipeline mixer 13 is connected to the water inlet pipe of the desiliconization reaction tank 14 through a flange. The desiliconization agitator 15 is arranged at the center position of the desiliconization reaction tank 14. The bottom water inlet of the desiliconization clarifier 16 is connected to the top water outlet of the desiliconization reaction tank 14 through a pipe. The desiliconization reaction pH meter 17 is arranged in the desiliconization clarifier 16. The first sulfuric acid dosing device 18 is connected and arranged on the outlet pipe of the desiliconization clarifier 16. The desiliconization water pH meter 19 is installed on the outlet pipe of the desiliconization clarifier 16 at a position 20-30 meters behind the first sulfuric acid dosing device 18. The first flocculant dosing device 12 is used to add desiliconizer.

[0042] The alternating defluorination sedimentation unit 2 is used to receive the effluent from the deep defluorination unit 1, and includes a first defluorination sedimentation tank 21, a second defluorination sedimentation tank 22, a first defluorination sedimentation tank mixer 23, a second defluorination sedimentation tank mixer 24, and a defluorination water inlet alternating valve group 25. The water inlets of the first defluorination sedimentation tank 21 and the second defluorination sedimentation tank 22 are respectively connected to the outlet main pipe of the deep defluorination unit 1 through pipelines. The first defluorination sedimentation tank mixer 23 is located at the center of the first defluorination sedimentation tank 21, and the second defluorination sedimentation tank mixer 24 is located at the center of the second defluorination sedimentation tank 22. The defluorination water inlet alternating valve group 25 is used to control which defluorination sedimentation tank the effluent from the deep defluorination unit 1 flows to.

[0043] The precise defluorination unit 3 includes a secondary defluorination reaction tank 31, a secondary defluorination clarification tank 32, a tertiary defluorination reaction tank 33, a tertiary defluorination clarification tank 34, a second flocculant dosing device 35, a second liquid alkali dosing device 36, a secondary defluorination clarification tank pH meter 37, a third flocculant dosing device 37, and a tertiary defluorination clarification tank pH meter 39. The bottom water inlet pipe of the secondary defluorination reaction tank 31 is connected to the outlet pipes of the two defluorination sedimentation tanks of the alternating defluorination sedimentation unit 2. The second flocculant dosing device 35 and the second liquid alkali dosing device 36 are respectively connected to the water inlet pipe of the secondary defluorination reaction tank 31 through a dosing pipe. The bottom water inlet of 32 is connected to the top water outlet of the secondary defluorination reaction tank 21 through a pipeline, the pH meter 37 of the secondary defluorination clarifier is installed in the secondary defluorination clarifier 32, the bottom water inlet pipe of the tertiary defluorination reaction tank 33 is connected to the top water outlet of the secondary defluorination clarifier 32, the third flocculant dosing device 38 is connected to the water inlet pipe of the tertiary defluorination reaction tank 33 through a dosing pipe, the bottom water inlet pipe of the tertiary defluorination clarifier 34 is connected to the top outlet of the tertiary defluorination reaction tank 33, the pH meter 39 of the tertiary defluorination clarifier is installed in the tertiary defluorination clarifier 34, and the second flocculant dosing device 35 is used to add defluorination agent.

[0044] The filter material enhanced filtration unit 4 includes a filter tank water inlet box 41, a filter tank water inlet pump 42, a filter tank 43, a filter material circulation pump 44, and a mud-water separator 45. The water inlet pipe at the top of the filter tank water inlet box 41 is connected to the water outlet pipe of the precise defluorination unit 3, the water inlet of the filter tank water inlet pump 42 is connected to the water outlet at the bottom of the filter tank water inlet box 41, the water inlet of the filter tank 43 is connected to the water outlet of the filter tank water inlet pump 42 through a pipeline, the water outlet of the filter tank 43 is located at the bottom of the tank body, and its outlet water enters the subsequent water treatment process, the feed port of the filter material circulation pump 44 is connected to the discharge port at the bottom of the filter tank 43 through a pipeline, the feed port of the mud-water separator 45 is connected to the discharge port of the filter material circulation pump 44 through a pipeline, the discharge port of the mud-water separator 45 is connected to the feed port at the top of the filter tank 43 through a pipeline, and the mud outlet of the mud-water separator 45 is connected to the sludge thickening tank 52.

[0045] The sludge unit 5 includes a sludge pump 51 and a sludge thickening tank 52. The inlet of the sludge pump 51 is connected to the bottom mud outlet of the silicon removal clarifier 16, the bottom mud outlet of the first defluorination sedimentation tank 21, the bottom mud outlet of the second defluorination sedimentation tank 22, the bottom mud outlet of the secondary defluorination clarifier 32, the bottom mud outlet of the tertiary defluorination clarifier 34, and the mud-water separator 45 through pipelines. The mud inlet of the sludge thickening tank 52 is connected to the mud outlet of the sludge pump 51 through a pipeline. The bottom mud outlet of the sludge thickening tank 52 is connected to the subsequent sludge dewatering system. The supernatant outlet of the sludge thickening tank 52 is connected to the secondary defluorination reaction tank 31 through a pipeline.

[0046] Furthermore, a variable frequency impeller agitator (not shown) is provided at the center of the secondary defluorination reaction tank 31 and the tertiary defluorination reaction tank 33 to adjust the agitation intensity in the defluorination reaction tank and thereby enhance the defluorination reaction efficiency.

[0047] Furthermore, the top outlet areas of the silicon removal clarification tank 16, the secondary fluoride removal clarification tank 32, and the tertiary fluoride removal clarification tank 34 are all provided with inclined tube layers, which serve to enhance the clarification efficiency of each tank.

[0048] The working principle of this application is to Figure 1 and Figure 2 For example, where both the desiliconizing agent and the defluorinating agent are unmodified polyaluminium chloride, the coking wastewater zero-emission membrane highly concentrated wastewater enters the deep desiliconization unit 1, and first enters the desiliconization pipeline mixer 13, where it is first mixed with the flocculant added by the first flocculant dosing device 11. The function of the flocculant at this time is to remove silicon. The dosage of the first flocculant dosing device 11 is determined by the silica content in the wastewater entering the deep desiliconization unit 1, and is added according to the silica to calcium-free polyaluminium chloride mass concentration ratio of 1:20-27. The addition ratio is slightly excessive. The wastewater in the desiliconization pipeline mixer 13 is then mixed with the liquid alkali added by the first liquid alkali dosing device 12. The addition of liquid alkali is to keep the pH of the desiliconization reaction at 9-9.5. The addition of liquid alkali The dosage of device 12 is adjusted with reference to the value of the desiliconization reaction pH meter 17 set in the desiliconization clarification tank 16. The effluent of the desiliconization pipeline mixer 13 enters the desiliconization reaction tank 14. The desiliconization reaction occurs under the continuous stirring of the desiliconization stirrer 15 in the tank. The speed of the stirrer can adapt to different water flow rates. The effluent of the desiliconization reaction tank 14 enters the desiliconization clarification tank 16, where the wastewater flow rate is reduced and the desiliconization product will settle to the bottom of the tank. The effluent of the desiliconization clarification tank 16 is mixed with the sulfuric acid added by the first sulfuric acid dosing device 18 in the pipeline. The addition of sulfuric acid is to keep the pH of the water entering the alternating defluorination precipitation unit 2 at 6.7-7.3. The dosage of the first sulfuric acid dosing device 18 is adjusted with reference to the value of the desiliconization water pH meter 17 set thereafter.

[0049] The timing opening and closing of the defluorination water inlet alternating valve group 25 will cause the total effluent of the deep desiliconization unit 2 to alternately enter the first defluorination sedimentation tank 21 and the second defluorination sedimentation tank 22, that is, only one defluorination sedimentation tank is inflowing at the same time. Specifically, when the first defluorination sedimentation tank 21 is inflowing, the wastewater is defluorinated by using a slightly excessive amount of flocculant under the action of the first defluorination sedimentation mixer 23. After 8-10 minutes, the first defluorination sedimentation mixer 23 is shut down, and the defluorination sedimentation alternating valve group 25 is switched to the second defluorination sedimentation tank 22 for water inflow. The second defluorination sedimentation mixer 24 is started synchronously to start stirring. The two defluorination sedimentation tanks are inflowing according to the timing. The above steps are alternately carried out in a cycle of "water inlet-stirring-standing-water inlet". The effluent from the first defluorination sedimentation tank 21 (or the second defluorination sedimentation tank 22) enters the precise defluorination unit 3. The water in the water pipe is first mixed with the flocculant added by the second flocculant dosing device 35. The flocculant at this time acts to remove fluoride. The dosage of the second flocculant dosing device 35 is determined by the fluoride content in the wastewater entering the precise defluorination unit 3 and is added at a molar ratio of fluoride to flocculant of 1:10-15. The wastewater is then mixed with the liquid alkali added by the second liquid alkali dosing device 36. The addition of liquid alkali is to adjust the pH and maintain it at 7.4. -7.8, the dosage of the second liquid alkali adding device 36 is adjusted with reference to the value of the pH meter 37 of the second defluorination clarifier. After the pH is adjusted, the wastewater enters the secondary defluorination reaction tank 31. After being fully stirred by the mixer to strengthen the secondary defluorination reaction, the wastewater enters the secondary defluorination clarifier 32. After the secondary defluorination product is fully settled, it is mixed with the third flocculant 38. The dosage of the third flocculant adding device 38 is determined by the residual fluoride content in the wastewater entering the tertiary defluorination reaction tank and is added according to the molar ratio of fluoride to flocculant of 1:6-8. The wastewater then enters the tertiary defluorination reaction tank 33 and is filled with water by the mixer. After the three-stage defluorination reaction is strengthened by stirring, it enters the three-stage defluorination clarifier 34. The pH meter 39 of the three-stage defluorination clarifier is used to monitor the final effluent pH of the precise defluorination unit 3. The wastewater finally enters the filter media enhanced filtration unit 4, first enters the filter water inlet box 41, and then is pumped into the filter tank 43 by the filter tank water inlet pump 42. The wastewater enters the top of the filter tank 43 and flows out from the bottom. The produced water enters the subsequent treatment process. In addition, the filter media circulation pump 44 continuously transfers the water-containing filter media in the filter tank 43 to the mud-water separator 45. The mud-water separator 45 separates the filter media from the sludge, and the filter media flows back into the filter tank 43. The mud and water enter the subsequent sludge unit 5.

[0050] The use process of the sludge unit 5 of the present invention is described as follows: the silicon removal clarifier 16 discharges sludge once every 8-10 hours, and then the sludge pump 51 starts to pump the sludge into the sludge thickening tank 52. Similarly, the first defluorination sedimentation tank 16 discharges sludge once every six to eight hours, the secondary defluorination sedimentation tank 22 discharges sludge once every fourteen to eighteen hours, the secondary defluorination clarifier 32 discharges sludge once every sixteen to twenty-four hours, and the tertiary defluorination clarifier 33 discharges sludge once every twenty to twenty-eight hours. The supernatant of the sludge thickening tank 52 is returned to the secondary defluorination reaction tank 31, and the sludge with lower moisture content at the bottom of the sludge thickening tank enters the subsequent sludge drying system.

[0051] It is worth mentioning that the utility model selects calcium-free polyaluminium chloride as a flocculant for silicon removal and fluorine removal, and is also suitable for various types of compound silicon removal agents and fluorine removal agents with stable effects, low costs and low sludge production on the current market, thereby avoiding the modification of the reaction system when the relevant coking wastewater treatment enterprises use new silicon removal or fluorine removal agents, and is conducive to the technical personnel in the relevant industries to select silicon removal agents, fluorine removal agents and reaction conditions suitable for their own water quality characteristics, and creates conditions for promoting the advancement of silicon removal and fluorine removal application technology in the industry.

[0052] Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

Claims

1. A desiliconization and defluorination device for coking wastewater zero-emission membrane high-concentration liquid, characterized in that: It comprises a deep silicon removal unit (1), an alternating fluorine removal precipitation unit (2) and a precise fluorine removal unit (3) which are sequentially connected in series; The deep desiliconization unit (1) comprises a desiliconization reaction tank (14) and a desiliconization clarification tank (16) connected in series, a desiliconization agitator (15) is provided in the desiliconization reaction tank (14), and a first flocculant dosing device (11) and a first liquid alkali dosing device (12) are provided on the desiliconization reaction tank (14); The alternating defluorination precipitation unit (2) comprises a defluorination precipitation tank, a defluorination agitator is provided in the defluorination precipitation tank, the effluent of the desiliconization clarification tank (16) is transported to the defluorination precipitation tank, and a first sulfuric acid dosing device (18) is provided on the pipeline between the desiliconization clarification tank (16) and the defluorination precipitation tank; The precise defluorination unit (3) comprises a secondary defluorination reaction tank (31) and a secondary defluorination clarification tank (32) connected in series. A second flocculant dosing device (35) and a second sodium hydroxide (36) dosing device are provided on the water inlet pipe of the secondary defluorination reaction tank (31). The effluent of the defluorination sedimentation tank is fed into the secondary defluorination reaction tank (31).

2. The desiliconization and defluorination device for coking wastewater zero-emission membrane high-concentration liquid according to claim 1 is characterized in that: The alternating defluorination precipitation unit (2) comprises a first defluorination precipitation tank (21) and a second defluorination precipitation tank (22), wherein a first defluorination mixer (23) and a second defluorination mixer (24) are respectively provided in the two defluorination precipitation tanks; The two defluorination sedimentation tanks are connected in parallel, and a defluorination water inlet alternating valve group (25) is provided on the pipeline between the two defluorination sedimentation tanks and the desiliconization clarification tank (16), and the defluorination water inlet alternating valve group (25) is located downstream of the first sulfuric acid dosing device (18); The effluents from the two defluorination sedimentation tanks are both fed into the secondary defluorination reaction tank (31).

3. The desiliconization and defluorination device for coking wastewater zero-emission membrane high-concentration liquid according to claim 2 is characterized in that: The precise defluorination unit (3) further comprises a three-stage defluorination reaction tank (33) and a three-stage defluorination clarification tank (34) connected in series, the effluent of the two-stage defluorination clarification tank (32) is transported to the three-stage defluorination reaction tank (33) through a pipeline, and a third flocculant dosing device (38) is provided on the pipeline between the two-stage defluorination clarification tank (32) and the three-stage defluorination reaction tank (33).

4. The desiliconization and defluorination device for coking wastewater zero-emission membrane high-concentration liquid according to claim 3 is characterized in that: It also includes a filter material enhanced filtration unit (4); The filter material enhanced filtration unit (4) comprises a filter tank water inlet box (41), a filter tank (43), and a mud-water separator (45) connected in series, wherein the mud-water separator (45) returns the separated filter material to the filter tank (43); The effluent from the three-stage defluorination clarification tank (34) is transported to the filter tank water inlet box (41).

5. The desiliconization and defluorination device for coking wastewater zero-emission membrane high-concentration liquid according to claim 4 is characterized in that: Also included is a sludge unit (5); The sludge unit (5) includes a sludge thickening tank (52); The mud-water separator (45), the silicon removal clarifier (16), the first defluorination sedimentation tank (21), the second defluorination sedimentation tank (22), the secondary defluorination clarifier (32) and the tertiary defluorination clarifier (34) The sludge is discharged into the sludge thickening tank (52).

6. A desiliconization and defluorination device for coking wastewater zero-emission membrane high-concentration liquid according to claim 4 or 5, characterized in that: A pH meter is provided in the desiliconization clarification tank (16), the secondary defluorination clarification tank (32), and the tertiary defluorination clarification tank (34).

7. A desiliconization and defluorination device for coking wastewater zero-emission membrane high-concentration liquid according to claim 4 or 5, characterized in that: A pH meter is provided on the pipeline between the first sulfuric acid dosing device (18) and the defluorination water inlet alternating valve group (25).

8. A desiliconization and defluorination device for coking wastewater zero-emission membrane high-concentration liquid according to any one of claims 1 to 5, characterized in that: A desiliconization pipeline mixer (13) is provided on the water inlet pipe of the desiliconization reaction tank (14), and the first flocculant dosing device (11) and the first liquid alkali dosing device (12) are both connected to the desiliconization pipeline mixer (13).

9. A desiliconization and defluorination device for coking wastewater zero-emission membrane high-concentration liquid according to any one of claims 3 to 5, characterized in that: The third-stage defluorination reaction tank (33) and the second-stage defluorination reaction tank (31) are both provided with variable frequency impeller stirrers.

10. A desiliconization and defluorination device for coking wastewater zero-emission membrane high-concentration liquid according to any one of claims 3 to 5, characterized in that: The top outlet areas of the silicon removal clarifier (16), the secondary fluoride removal clarifier (32), and the tertiary fluoride removal clarifier (34) are all provided with inclined tube layers.

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