An integrated device for reverse-polarity electro-adsorption and fluorite flotation and its usage method

Abstract

The present invention provides an integrated device for reverse-polarity electro-adsorption and fluorite flotation and a method for using the same, belonging to the technical field of sewage treatment. The device includes an influent treatment module, an electro-adsorption module, a fluorite flotation module, and a cationic concentrated solution treatment module. The influent treatment module includes an influent water tank and a filtration tank. The electro-adsorption module includes an electro-adsorption tank, a DC power supply, and a general control room. The fluorite flotation module is a fluorite flotation system. The cationic concentrated solution treatment module includes a separation tank and an industrial crude salt preparation device. The water treated by the influent treatment module enters the electro-adsorption module for treatment, and then flows out of the electro-adsorption module and separately flows into the fluorite flotation module and the cationic concentrated solution treatment module. The device combines electro-adsorption technology and fluorite flotation process, can simultaneously treat phosphorus gypsum washing water and yard leachate, and obtains high-quality fluorite and industrial crude salt while realizing harmless treatment of sewage.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and in particular relates to the treatment of phosphogypsum washing water and storage yard leachate, and specifically relates to an integrated device for reverse electrode electrosorption and fluorite flotation and a use method thereof. Background Art

[0002] Phosphogypsum is the main by-product produced in the production of wet phosphoric acid and fertilizers. Due to its low utilization rate, phosphogypsum is mainly disposed of in open-air piles. Under long-term natural rainfall, a large amount of phosphogypsum leachate containing phosphorus, arsenic and fluorine will cause serious pollution to the soil, surface water and groundwater environment. The groundwater environmental pollution around the phosphogypsum storage yard has become an environmental problem that needs to be solved urgently. At present, the common treatment methods for phosphogypsum leachate abroad are: continuous biological sulfate reduction method, lime-Gore membrane combination method, and double membrane filtration method. Common treatment methods in China are: chemical precipitation with lime at a pH of 12, oxidation of ammonia with hypochlorite, natural evaporation or forced evaporation, and membrane filtration process.

[0003] Chinese patent application CN114988606A discloses a treatment system and method for phosphogypsum leachate and washing water in the phosphorus chemical industry. The system includes a homogenizing tank, an ultrafiltration membrane pretreatment device, an ultrafiltration water production tank, a reverse osmosis membrane concentration device, a reverse osmosis water production tank, a crystallization reactor, a solid slag dehydration device, and a solid-liquid separation ultrafiltration membrane device; the homogenizing tank is used to fully mix the phosphogypsum slag field leachate with the gypsum washing water to obtain the inlet water of the ultrafiltration membrane pretreatment device with relatively stable water quality; the water production outlet of the ultrafiltration membrane pretreatment device is connected to the reverse osmosis membrane concentration device through the ultrafiltration water production tank, and the backwash water outlet of the ultrafiltration membrane pretreatment device is connected to the crystallization reaction tank; the concentrated water outlet of the reverse osmosis membrane concentration device is also connected to the crystallization reaction tank, and the clarified liquid outlet of the reverse osmosis membrane concentration device is connected to the reverse osmosis water production tank. The system can be used to treat phosphogypsum leachate without lime neutralization, and directly separate and concentrate soluble phosphates by membrane, without converting soluble phosphates into insoluble phosphates for recycling; the charge retention characteristics of ion exchange membranes are used to retain dissolved phosphates, sulfates, fluorosilicates, chloride ions, fluoride ions, etc. in the water in the concentrated water, and the concentrated water is subjected to the destruction of the supersaturation of scaling substances before entering the next membrane for further concentration, and finally phosphate-rich concentrated water that meets the process requirements is obtained, so that phosphates, sulfates, fluorosilicates, etc. can be recycled. However, the treatment system faces the problems of complex system, high operating costs and easy secondary pollution. Therefore, it is necessary to adopt an integrated multifunctional coupling system that takes into account the functions of desalination and anti-scaling, so as to achieve the purpose of regenerating high-concentration useful ions in the wastewater while removing pollutants in the wastewater. Summary of the invention

[0004] To solve the above problems, the present invention provides an integrated device for inverted-polarity electro-adsorption and fluorite flotation. This device combines electro-adsorption technology and fluorite flotation process, can synchronously treat phosphorus gypsum washing water and yard leachate, and obtains high-quality fluorite and industrial crude salt while achieving harmless treatment of sewage, thus achieving the purpose of simplifying the sewage treatment system and realizing resource recycling and utilization.

[0005] To achieve the above object, the present invention specifically adopts the following technical solutions:

[0006] An integrated device for inverted-polarity electro-adsorption and fluorite flotation, comprising a water inlet tank, a filtration tank, at least one electro-adsorption tank, at least one DC power supply, a general control room, a flotation system, a separation tank and an industrial crude salt preparation device; the water inlet tank is communicated with the filtration tank; the filtration tank is communicated with the electro-adsorption tank; the number of the DC power supplies corresponds to the number of the electro-adsorption tanks one by one, and each DC power supply is electrically connected to the general control room; the electro-adsorption tank includes a first water outlet communicated with the flotation system, a second water outlet communicated with the separation tank, a third water outlet, a positive electrode plate, a negative electrode plate, electrode plates and an induction and ejection device; the induction and ejection device is connected to the electrode plates and is electrically connected to the general control room; the electrode plates are located between the positive electrode plate and the negative electrode plate; the positive electrode plate and the negative electrode plate are respectively electrically connected to the DC power supply; a first detection device is arranged at the third water outlet; the separation tank is communicated with the industrial crude salt preparation device; a second detection device is arranged at the water outlet of the separation tank, and the industrial crude salt preparation device is connected to the second detection device.

[0007] In a preferred embodiment, a conditioning tank is arranged between the water inlet tank and the filtration tank, a third detection device is arranged at the outlet of the water inlet tank, the inlet of the conditioning tank is communicated with the outlet of the water inlet tank, and the outlet of the conditioning tank is connected to the third detection device and is communicated with the inlet of the filtration tank.

[0008] In a preferred embodiment, the flotation system includes a mixing tank, and the first water outlet is communicated with the mixing tank.

[0009] In a preferred embodiment, the electrode materials on the side of the electrode plate facing the positive electrode plate and the side facing the negative electrode plate are different.

[0010] The present invention also provides a method for using the integrated device for inverted-polarity electro-adsorption and fluorite flotation as described in any one of the above for treating phosphorus gypsum washing water or yard leachate, comprising the following steps:

[0011] S1. Sewage pretreatment: Take the sewage stock solution and store it in the water inlet tank, and introduce the water in the water inlet tank into the filtration tank to remove suspended solids;

[0012] S2, Electro-adsorption: Introduce the pretreated water in step S1 into the electro-adsorption tank, turn on the DC power supply to perform the electro-adsorption process, and open the valve of the third water outlet. When the first detection device detects that the conductivity of the discharged water > 20 μS / cm, return the discharged water to the filtration tank for further treatment; when the first detection device detects that the conductivity of the discharged water ≤ 20 μS / cm, directly discharge it.

[0013] S3, Wastewater recycling: When the induction and ejection device detects that the conductivity of the water in the electro-adsorption tank starts to rise, close the valve of the third water outlet. The master control room controls the polarity of the positive and negative plates to be interchanged and reduces the output voltage of the DC power supply. At the same time, the electrode plates pop out to separate the first water outlet from the second water outlet; introduce the water near the positive plate into the flotation system through the first water outlet to prepare fluorite; introduce the water near the negative plate into the separation tank through the second water outlet for separation and purification, and introduce the water in the separation tank into the industrial crude salt preparation device to prepare industrial crude salt; add a curing agent to the remaining tail liquid in the separation tank to solidify metal ions, and then detect it through the second detection device at the water outlet of the separation tank. After meeting the regulations, discharge it.

[0014] In a preferred embodiment, step S1 further includes a step of detecting the raw sewage solution. When the raw sewage solution meets at least one of the conditions of conductivity > 4800 μS / cm, COD > 130 mg / L, turbidity > 4 NTU, solid suspended matter > 4 mg / L, oil > 2 mg / L, alkalinity > 130 mg / L, first condition the raw sewage solution and then introduce it into the filtration tank. The conditioned water needs to meet all of the following conditions simultaneously: conductivity ≤ 4800 μS / cm, COD ≤ 130 mg / L, turbidity ≤ 4 NTU, solid suspended matter ≤ 4 mg / L, oil ≤ 2 mg / L, alkalinity ≤ 130 mg / L.

[0015] In a preferred embodiment, when performing the electro-adsorption process in step S2, the output voltage of the DC power supply is 1.2 - 2 V.

[0016] In a preferred embodiment, in step S3, the output voltage of the DC power supply is reduced to 0.4 - 0.6 V.

[0017] In a preferred embodiment, the curing agent in step S3 is an HD-type curing agent, which consists of the following components: 30 wt% steel slag, 50 wt% slag, 9 wt% gypsum, 8 wt% calcium oxide, 0.7 wt% triethanolamine, 1.2 wt% sodium formate, and 1.1 wt% sodium chloride.

[0018] In a preferred embodiment, the distance between the positive electrode plate and the negative electrode plate is 1-2 cm, the sizes of the positive electrode plate and the negative electrode plate are both 200 mm × 100 mm × 2 mm, and the size of the electrode plate is 300 mm × 100 mm × 3 mm.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The integrated device of inverted-pole electro-adsorption and fluorite flotation in the present invention combines the electro-adsorption technology and the fluorite flotation process, achieving the purpose of synchronously harmless treatment and resource recycling of phosphogypsum washing water or yard leachate. (2) The electrode plates in the electro-adsorption tank of the device can make the fluoride ion concentration at the water outlet connected to the fluorite flotation system higher and the cation concentration at the water outlet connected to the industrial crude salt preparation device higher, thus being more conducive to the preparation of higher-quality fluorite and industrial crude salt. (3) Using quicklime and curing agent synergistically to modify the occurrence states of various pollutants in the tail liquid after flotation, stabilizing the toxic heavy metals, and making the finally discharged water meet the regulations of GB5085.3-2007. Brief Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of the integrated device of inverted-pole electro-adsorption and fluorite flotation for Example 1;

[0021] Figure 2 It is a schematic structural diagram of the integrated device of inverted-pole electro-adsorption and fluorite flotation for Example 3.

[0022] In the figure: 1. Water inlet tank; 2. Filter tank; 3. Electro-adsorption tank; 31. Positive electrode plate; 32. Negative electrode plate; 33. Electrode plate; 34. Induction and ejection device; 35. First water outlet; 36. Second water outlet; 37. Third water outlet; 4. DC power supply; 5. General control room; 6. Flotation system; 61. Mixing tank; 7. Separation tank; 8. Industrial crude salt preparation device; 91. First detection device; 92. Second detection device; 93. Third detection device; 10. Conditioning tank; 101. Inlet of the conditioning tank; 102. Outlet of the conditioning tank; 111. First pipeline; 112. Second pipeline; 113. Third pipeline. The dotted lines in the figure represent electrical connections. Detailed Embodiments

[0023] The following content describes the technical solutions of the present invention clearly and completely in combination with embodiments, so that those skilled in the art can fully understand the present invention. Obviously, the described embodiments are only some preferred embodiments of the present invention, rather than all embodiments. Any equivalent transformation or substitution made to the following embodiments by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] Example 1

[0025] As Figure 1 shown, this embodiment provides an integrated device for inverse-polarity electro-adsorption and fluorite flotation, which includes a water inlet tank 1, a filtration tank 2, an electro-adsorption tank 3, a DC power supply 4, a general control room 5, a flotation system 6, a separation tank 7, and an industrial crude salt preparation device 8.

[0026] The water inlet tank 1 is connected to the filtration tank 2 through a pipeline. The filtration tank 2 is connected to the electro-adsorption tank 3 through a pipeline. The DC power supply 4 is electrically connected to the general control room 5.

[0027] The electro-adsorption tank 3 includes a positive electrode plate 31, a negative electrode plate 32, an electrode plate 33, an induction and ejection device 34, a first water outlet 35, a second water outlet 36, and a third water outlet 37. The electrode plate 33 is located between the positive electrode plate 31 and the negative electrode plate 32; the positive electrode plate 31 and the negative electrode plate 32 are respectively electrically connected to the DC power supply 4. The induction and ejection device 34 is connected to the electrode plate 33 and is electrically connected to the general control room 5. The first water outlet 35 is close to the positive electrode plate 31 and is connected to the flotation system 6 through a pipeline, and the second water outlet 36 is close to the negative electrode plate and is connected to the separation tank 7 through a pipeline. A first detection device 91 is connected at the third water outlet 37.

[0028] The separation tank 7 is connected to the industrial crude salt preparation device 8 through a pipeline. A second detection device 92 is connected at the water outlet of the separation tank 7. The water outlet of the industrial crude salt preparation device 8 is connected to the second detection device 92.

[0029] Embodiment 2

[0030] As Figure 1 shown, this embodiment provides a method for using an integrated device for inverse-polarity electro-adsorption and fluorite flotation, including the following steps:

[0031] S1. Sewage pretreatment

[0032] Take the leachate from the phosphogypsum yard in Xiaogan City, Hubei Province for detection. The measured conductivity is 3520 μS / cm, COD is 67.1 mg / L, turbidity is 2 NTU, the content of solid suspended matter is 2 mg / L, the oil content is 1.2 mg / L, the alkalinity is 88 mg / L, and the fluoride ion concentration is 87.4 mg / L. Store the leachate in the water inlet tank 1. Pump the sewage in the water inlet tank 1 into the filtration tank 2 to intercept the suspended matter in the sewage.

[0033] S2. Electro-adsorption

[0034] The sewage flowing out of the filtration tank 2 enters the electro-adsorption tank 3 through a pipeline. The distance between the positive electrode plate 31 and the negative electrode plate 32 of the electro-adsorption tank 3 is 1.5 cm, and the sizes of the positive electrode plate 31 and the negative electrode plate 32 are both 200 mm × 100 mm × 2 mm. The DC power supply 4 is turned on, and a voltage of 1.5 V is output to the electro-adsorption tank 3, so that the positive electrode plate 31 adsorbs a large amount of anions in the sewage, and the negative electrode plate 32 adsorbs a large amount of cations in the sewage; at the same time, the valve of the third water outlet 37 (not shown in the figure) is opened for drainage, and the drained water is detected by the first detection device 91. When the first detection device 91 detects that the conductivity of the drained water > 20 μS / cm, the drained water is returned to the filtration tank 2 for further treatment; when the first detection device 91 detects that the conductivity of the drained water ≤ 20 μS / cm, it is directly discharged, and the electro-adsorption continues.

[0035] S3. Wastewater recycling

[0036] When the induction and ejection device 34 detects that the conductivity of the water (conductivity ≤ 20 μS / cm) in the electro-adsorption tank 3 begins to rise, the third water outlet 37 is closed, the polarity of the positive and negative electrode plates of the electro-adsorption tank 3 is inverted by the master control room 5, and the output voltage of the DC power supply 4 is controlled to be 0.5 V. At the same time, the electrode plate 33 is ejected to separate the first water outlet 35 and the second water outlet 36. The polarity of the side of the electrode plate 33 facing the positive electrode plate 31 is negative, and the polarity of the side facing the negative electrode plate 32 is positive; the electrode materials on both sides of the electrode plate 33 are different; the size of the electrode plate 33 is 300 mm × 100 mm × 3 mm. After the master control room inverts the polarity of the positive and negative electrode plates of the electro-adsorption tank 3, the original polarity of the positive electrode plate 31 becomes negative, and the original polarity of the negative electrode plate 32 becomes positive, and ion desorption begins in the electro-adsorption tank. Reducing the output voltage of the DC power supply 4 can make the desorption rate of ions on the positive electrode plate 31 and the negative electrode plate 32 relatively slow. At the same time, the presence of the electrode plate 33 prevents the anions desorbed from the positive electrode plate 31 and the cations desorbed from the negative electrode plate 32 from mixing in large quantities, so that the anion concentration in the water near the first water outlet 35 is higher than the cation concentration, and the cation concentration in the water near the second water outlet 36 is higher than the anion concentration. The water flowing out of the first water outlet 35 (containing a large amount of anions, with a fluoride ion concentration of 65.8 mg / L) enters the flotation system 6 for fluorite flotation. The water flowing out of the second water outlet 36 (containing a large amount of cations) enters the separation tank 7. After being separated and purified through filtration and evaporation steps in the separation tank 7, the water in the separation tank 7 is introduced into the industrial crude salt preparation device 8 for preparing industrial crude salt. The remaining tail liquid remains in the separation tank 7, and the HD-type curing agent is added to solidify metal ions, and then it is discharged after being detected by the second detection device 92 at the water outlet of the separation tank 7 and meeting the requirements of GB 5085.3-2007 "Identification Standard for Toxicity of Leachate from Hazardous Wastes".

[0037] Among them, the HD-type curing agent is composed of the following components by mass percentage: 30% steel slag, 50% slag, 9% gypsum, 8% calcium oxide, 0.7% triethanolamine, 1.2% sodium formate, and 1.1% sodium chloride.

[0038] The steps of fluorite flotation are as follows:

[0039] According to the fluoride ion concentration in the water flowing out from the first water outlet 35, quicklime is added to the flotation system 6, and the mass of the quicklime is 1.2 - 1.6 times the mass of the fluoride ions. Based on the mass of the fluoride ions, 150 g / t of sodium carbonate as a regulator, 250 g / t of water glass as an inhibitor, and 200 g / t of oleic acid as a collector are sequentially added to the flotation system 6 for rough selection of fluorite. After rough selection, three times of cleaning are carried out. During the cleaning process, 50 g / t of a mixed collector and 300 g / t of acidified water glass are added. At the end of the cleaning, fluorite with a grade of 75% is obtained. The mixed collector is obtained by mixing oleic acid and ethanol in a mass ratio of 10:1, and the acidified water glass is obtained by mixing water glass and sulfuric acid in a mass ratio of 1:1.

[0040] Example 3

[0041] As Figure 1 shown, the usage method of the integrated device of inverted electrode electroadsorption and fluorite flotation in this example is basically the same as that in Example 2, except that: in step S2, the distance between the positive electrode plate 31 and the negative electrode plate 32 of the electroadsorption cell 3 is 1.0 cm; the DC power supply 4 is turned on, and a voltage of 1.2 V is output to the electroadsorption cell 3; in step S3, the total control room 5 inverts the polarity of the positive and negative electrode plates of the electroadsorption cell 3 and controls the output voltage of the DC power supply 4 to be 0.4 V.

[0042] Example 4

[0043] As Figure 2 shown, this example provides an integrated device of inverted electrode electroadsorption and fluorite flotation, including a water inlet tank 1, a filtration tank 2, two electroadsorption cells 3, two DC power supplies 4, a total control room 5, a flotation system 6, a separation tank 7, an industrial crude salt preparation device 8, and a conditioning tank 10.

[0044] The water inlet tank 1 and the filtration tank 2 are connected through a first pipeline 111, and a third detection device 93 is connected to the first pipeline 111. A conditioning tank 10 is arranged between the water inlet tank 1 and the filtration tank 2. The water inlet 101 of the conditioning tank is connected to the first pipeline 111 through a second pipeline 112, and the water outlet 102 of the conditioning tank is connected to the first pipeline 111 through a third pipeline 113, and the water outlet 102 of the conditioning tank is connected to the third detection device 93. When any one of the conductivity > 4800 μS / cm, COD > 130 mg / L, turbidity > 4 NTU, solid suspended matter > 4 mg / L, oil > 2 mg / L, and alkalinity > 130 mg / L detected by the third detection device 93 for the water flowing out of the water inlet tank 1 meets the requirements, the valve of the water inlet of the filtration tank 2 (not shown in the figure) is closed, so that the water flow in the first pipeline 111 enters the conditioning tank 10 through the second pipeline 112 and the water inlet 101 of the conditioning tank. After being conditioned in the conditioning tank 10, the water flowing out of the water outlet 102 of the conditioning tank is detected by the third detection device 93. When all the conditions of conductivity ≤ 4800 μS / cm, COD ≤ 130 mg / L, turbidity ≤ 4 NTU, solid suspended matter ≤ 4 mg / L, oil ≤ 2 mg / L, and alkalinity ≤ 130 mg / L are met, it then flows through the third pipeline 113 to the first pipeline 111, and the valve of the water inlet of the filtration tank 2 is opened, so that the conditioned water enters the filtration tank 2 through the first pipeline 111. When all the conditions of conductivity ≤ 4800 μS / cm, COD ≤ 130 mg / L, turbidity ≤ 4 NTU, solid suspended matter ≤ 4 mg / L, oil ≤ 2 mg / L, and alkalinity ≤ 130 mg / L are met for the water flowing out of the water inlet tank 1 detected by the third detection device 93, the valve of the water inlet 101 of the conditioning tank (not shown in the figure) is closed, and the valve of the water inlet of the filtration tank 2 is opened, so that the water flowing out of the water inlet tank 1 directly flows into the filtration tank 2 through the first pipeline 111.

[0045] The filtration tank 2 is respectively connected to each of the electro - adsorption cells 3 through pipelines. Each DC power supply 4 is electrically connected to the master control room 5. The composition structures of each of the electro - adsorption cells 3 are the same, and each of the electro - adsorption cells 3 is correspondingly electrically connected to one of the DC power supplies 4.

[0046] Each electro-sorption cell 3 includes a positive electrode plate 31, a negative electrode plate 32, an electrode plate 33, an induction and ejection device 34, a first water outlet 35, a second water outlet 36, and a third water outlet 37. The electrode plate 33 is located between the positive electrode plate 31 and the negative electrode plate 32; the positive electrode plate 31 and the negative electrode plate 32 are respectively electrically connected to the DC power supply 4. The induction and ejection device 34 is connected to the electrode plate 33 and is electrically connected to the master control room 5. The first water outlet 35 is close to the positive electrode plate 31 and is connected to the mixing tank 61 through a pipeline, and the second water outlet 36 is close to the negative electrode plate and is connected to the separation tank 7 through a pipeline. A first detection device 91 is connected to the third water outlet 37.

[0047] The flotation system 6 includes a mixing tank 61. The mixing tank 61 is used to receive the water flowing out from the first water outlet 35.

[0048] The separation tank 7 is connected to the industrial crude salt preparation device 8 through a pipeline. A second detection device 92 is connected to the water outlet of the separation tank 7. The water outlet of the industrial crude salt preparation device 8 is connected to the second detection device 92.

[0049] The usage method of the inverting electrode electro-sorption and fluorite flotation integrated device includes the following steps:

[0050] S1. Sewage pretreatment

[0051] Take the leachate from the phosphogypsum yard in Yichang City, Hubei Province for detection. The measured conductivity is 5000 μS / cm, the COD is 97.6 mg / L, the turbidity is 3 NTU, the solid suspended matter content is 4.2 mg / L, the oil content is 1.2 mg / L, the alkalinity is 108 mg / L, and the fluoride ion concentration is 185.0 mg / L. Store the leachate in the water inlet tank 1. Pump the sewage in the water inlet tank 1 into the conditioning tank 10 and add quicklime (for pre-precipitating SO4 2- 、PO4 3- etc.). The water after conditioning flows out from the water outlet of the conditioning tank 10 and is detected by the third detection device 93. When the detection results simultaneously meet the conditions of conductivity ≤ 4800 μS / cm, COD ≤ 130 mg / L, turbidity ≤ 4 NTU, solid suspended matter ≤ 4 mg / L, oil ≤ 2 mg / L, and alkalinity ≤ 130 mg / L, the conditioned water flows out from the conditioning tank 10 and flows into the filtration tank 2 through the first pipeline. The filtration tank 2 intercepts the suspended matter in the sewage.

[0052] S2. Electro-sorption

[0053] The sewage flowing out from the filtration tank 2 enters two electro-adsorption cells 3 through pipelines respectively. The distance between the positive electrode plate 31 and the negative electrode plate 32 of the electro-adsorption cell 3 is 2 cm, and the sizes of the positive electrode plate 31 and the negative electrode plate 32 are both 200 mm × 100 mm × 2 mm. At the same time, each DC power supply 4 electrically connected to the electro-adsorption cell is turned on, and a voltage of 2 V is output to each electro-adsorption cell respectively, so that the positive electrode plate 31 adsorbs a large amount of anions in the sewage, and the negative electrode plate 32 adsorbs a large amount of cations in the sewage; meanwhile, the valve of the third water outlet 37 (not shown in the figure) is opened for drainage, and the drained water is detected by the first detection device 91. When the first detection device 91 detects that the conductivity of the drained water > 20 μS / cm, the drained water is returned to the filtration tank 2 for further treatment; when the first detection device 91 detects that the conductivity of the drained water ≤ 20 μS / cm, it is directly discharged, and electro-adsorption continues.

[0054] S3. Wastewater recycling

[0055] When the induction and ejection device 34 in a single electro-adsorption cell 3 detects that the conductivity of the water (conductivity ≤ 20 μS / cm) in the electro-adsorption cell 3 starts to rise, the third water outlet 37 is closed. The main control room 5 reverses the polarity of the positive and negative plates of the electro-adsorption cell 3 and controls the output voltage of the DC power supply 4 to be 0.6V. At the same time, the electrode plate 33 is ejected to separate the first water outlet 35 and the second water outlet 36. The polarity of the side of the electrode plate 33 facing the positive plate 31 is negative, and the polarity of the side facing the negative plate 32 is positive; the electrode materials on both sides of the electrode plate 33 are different; the size of the electrode plate 33 is 300mm × 100mm × 3mm. After the main control room reverses the polarity of the positive and negative plates of the electro-adsorption cell 3, the original positive plate 31 becomes negative, and the original negative plate 32 becomes positive. Ion desorption starts in the electro-adsorption cell 3. Reducing the output voltage of the DC power supply 4 can make the desorption rate of ions on the positive plate 31 and the negative plate 32 slower. At the same time, the presence of the electrode plate 33 prevents the anions desorbed from the positive plate 31 and the cations desorbed from the negative plate 32 from mixing in large quantities, so that the concentration of anions in the water near the first water outlet 35 is higher than that of cations, and the concentration of cations in the water near the second water outlet 36 is higher than that of anions. The water (containing a large amount of anions) flowing out from the first water outlet 35 enters the mixing tank 61 in the flotation system 6, and quicklime with a mass 1.2 - 1.6 times that of fluoride ions is added to the mixing tank 61 for fluorite flotation in the flotation system 6 (for the specific method, see Example 2). The water (containing a large amount of cations) flowing out from the second water outlet 36 enters the separation tank 7. After being separated and purified through the steps of filtration and evaporation in the separation tank 7, the water in the separation tank 7 is introduced into the industrial crude salt preparation device 8 for preparing industrial crude salt. The working process of each electro-adsorption cell 3 is the same. HD-type curing agent (with the same composition as in Example 2) is added to the remaining tail liquid in the separation tank 7 to solidify metal ions, and then it is discharged after being detected by the second detection device 92 at the water outlet of the separation tank 7 and meeting the requirements of GB5085.3 - 2007 "Identification Standard for Toxicity of Leaching of Hazardous Wastes".

[0056] The above are only the preferred embodiments of the present invention and are not used to limit the protection scope of the present invention. For any person skilled in the art, various changes and modifications can be made to the present invention. Any simple equivalent changes and modifications made according to the protection scope of the present invention application and the content of the specification should be included in the protection scope of the present invention.

Claims

1. An integrated device for reverse-polarity electro-adsorption and fluorite flotation, characterized in that It includes a water inlet tank, a filtration tank, at least one electro-adsorption cell, at least one DC power supply, a master control room, a flotation system, a separation tank and an industrial crude salt preparation device; the water inlet tank is communicated with the filtration tank; the filtration tank is communicated with the electro-adsorption cell; the number of the DC power supplies corresponds one by one to the number of the electro-adsorption cells, and each DC power supply is electrically connected to the master control room; the electro-adsorption cell includes a first water outlet communicated with the flotation system, a second water outlet communicated with the separation tank, a third water outlet, a positive plate, a negative plate, electrode plates and an induction and ejection device; the induction and ejection device is connected to the electrode plates and is electrically connected to the master control room; the electrode plates are located between the positive plate and the negative plate; the positive plate and the negative plate are respectively electrically connected to the DC power supply; a first detection device is arranged at the third water outlet; the separation tank is communicated with the industrial crude salt preparation device; a second detection device is arranged at the water outlet of the separation tank, and the industrial crude salt preparation device is connected to the second detection device.

2. The integrated device for reverse-polarity electro-adsorption and fluorite flotation according to claim 1, characterized in that A conditioning tank is arranged between the water inlet tank and the filtration tank, a third detection device is arranged at the outlet of the water inlet tank, the inlet of the conditioning tank is communicated with the outlet of the water inlet tank, and the outlet of the conditioning tank is connected to the third detection device and is communicated with the inlet of the filtration tank.

3. The integrated device for reverse-polarity electro-adsorption and fluorite flotation according to claim 1, characterized in that The flotation system includes a mixing tank, and the first water outlet is communicated with the mixing tank.

4. The integrated device for reverse-polarity electro-adsorption and fluorite flotation according to claim 1, characterized in that The electrode materials on the side of the electrode plate facing the positive plate and the side facing the negative plate are different.

5. A method for using the integrated device for reverse-polarity electro-adsorption and fluorite flotation according to any one of claims 1 to 4, characterized in that It includes the following steps: S1. Sewage pretreatment: Take the raw sewage and store it in the water inlet tank, and introduce the water in the water inlet tank into the filtration tank to remove suspended solids. S2. Electro-adsorption: Introduce the water pretreated in step S1 into the electro-adsorption cell, turn on the DC power supply to perform the electro-adsorption procedure, and open the valve of the third water outlet. When the first detection device detects that the conductivity of the discharged water > 20 μS / cm, return the discharged water to the filtration tank for further treatment; when the first detection device detects that the conductivity of the discharged water ≤ 20 μS / cm, directly discharge it. S3. Wastewater recycling: When the induction and ejection device detects that the conductivity of the water in the electro-adsorption cell starts to rise, close the valve of the third water outlet, the master control room controls the polarity of the positive plate and the negative plate to be interchanged and reduces the output voltage of the DC power supply. At the same time, the electrode plates pop out to separate the first water outlet from the second water outlet; introduce the water near the positive plate into the flotation system through the first water outlet to prepare fluorite; introduce the water near the negative plate into the separation tank through the second water outlet for separation and purification, and introduce the water in the separation tank into the industrial crude salt preparation device to prepare industrial crude salt; add a curing agent to the remaining tail liquid in the separation tank to solidify metal ions, and then detect it through the second detection device at the water outlet of the separation tank, and discharge it after meeting the regulations.

6. The method for using according to claim 5, characterized in that Step S1 further includes a step of detecting the raw sewage. When the raw sewage meets at least one of the conditions of conductivity > 4800 μS / cm, COD > 130 mg / L, turbidity > 4 NTU, solid suspended matter > 4 mg / L, oil > 2 mg / L, and alkalinity > 130 mg / L, the raw sewage is first conditioned and then introduced into the filtration tank.

7. The method for using according to claim 5, characterized in that When performing the electro-adsorption process in step S2, the output voltage of the DC power supply is 1.2 - 2V.

8. The method for using according to claim 5, characterized in that In step S3, the output voltage of the DC power supply is reduced to 0.4 - 0.6V.

9. The method for using according to claim 5, characterized in that In step S3, the curing agent is composed of the following components: 30 wt% steel slag, 50 wt% slag, 9 wt% gypsum, 8 wt% calcium oxide, 0.7 wt% triethanolamine, 1.2 wt% sodium formate, and 1.1 wt% sodium chloride.

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