Nucleation granulation device and nucleation granulation process for recycling fluorine resources in fluorine-containing wastewater

Abstract

The invention relates to a nucleation granulation device and a nucleation granulation process for recycling fluorine resources in fluorine-containing wastewater, according to the nucleation granulation device, a nucleation granulation module and a resin adsorption module are organically coupled into a reactor, the fluorine-containing wastewater preferentially passes through a nucleation granulation reaction zone, fluorine ions in a water body are subjected to nucleation granulation under the induction of seed crystals, and the fluorine resources in the water body are recycled. Preliminary purification of fluorine-containing wastewater and resource recovery of fluorine ions are realized by adding a crystal inducing agent; and after being subjected to nucleation granulation treatment, the fluorine-containing wastewater selectively overflows to a resin adsorption area, so that further deep treatment on fluorine ions is realized. According to the nucleation granulation device and the nucleation granulation process disclosed by the invention, fluorine resources can be effectively recovered, the dosage of the crystal inducing agent in the nucleation granulation module can be reduced on the premise of ensuring that the effluent reaches the standard, the treatment cost is reduced, meanwhile, the problem of device scaling caused by excessive addition of the crystal inducing agent is also avoided, and the nucleation granulation device and the nucleation granulation process are simple and convenient in flow and high in practicability. The industrial treatment is facilitated.

Description

Technical Field

[0001] The present disclosure relates to the technical field of wastewater treatment, and in particular to a nucleus crystal granulation device and a nucleus crystal granulation process for recovering fluorine resources from fluorine-containing wastewater. Background Art

[0002] With the development of industries such as fiber-optic communications, microelectronics, and solar energy, high-purity quartz sand, as an important raw material, has become increasingly important. As we all know, in order to obtain ultra-high-quality quartz sand, it is necessary to purify it. Impurity elements in quartz sand will significantly affect the performance of quartz products. Among them, transition metals such as iron will affect the light transmittance and conductivity of quartz products; excessive content of alkali metal impurities such as potassium and sodium will reduce the high-temperature resistance of quartz products, thereby affecting its thermal stability and optical properties. At present, the methods for purifying quartz sand include magnetic separation, pickling, flotation, microbial method, and complexation method, among which pickling is an indispensable step in the purification of quartz ore. Pickling uses hydrogen ions to react with the ore phase, but the pickling process will produce a large amount of fluorine-containing waste liquid. The subsequent treatment of fluorine-containing waste liquid has become a major problem in the quartz sand industry.

[0003] The traditional chemical treatment method is to remove fluoride ions from the water by adding a certain amount of precipitant to the system and using chemical precipitation. Although this method is easy to operate and has wide adaptability, a large amount of precipitant is required if the treatment is to be within 10 mg / L (comprehensive sewage discharge standard). Excessive precipitant leads to increased treatment costs and scaling inside the device. In addition, the sludge produced by the chemical precipitation method has a loose structure, high water content and is not easy to recycle. It needs to be further coupled with a plate and frame filter press process, which greatly increases the equipment footprint and treatment costs.

[0004] In summary, how to provide a defluorination process with a simple process, low processing cost, easy cleaning of the device, and easy recovery of the treated solids has become a problem that needs to be solved at present. Summary of the invention

[0005] In order to solve the above technical problems, the present disclosure provides a nuclear crystal granulation device and a nuclear crystal granulation process for recovering fluorine resources from fluorine-containing wastewater. The nuclear crystal granulation device organically couples resin adsorption technology with nuclear crystal granulation technology, thereby realizing deep treatment of fluorine-containing wastewater and effective recovery of fluorine resources. The device occupies a small area, is economical and efficient, and is simple to clean and maintain in the later stage, which is conducive to industrial production and application.

[0006] In a first aspect, the present disclosure provides a nucleus crystal granulation device for recovering fluorine resources from fluorine-containing wastewater, comprising:

[0007] Fluoride removal unit;

[0008] A wastewater feeding unit, used for passing fluorine-containing wastewater into the defluorination unit;

[0009] A crystal inducing agent feeding unit, used for passing the crystal inducing agent into the defluorination unit;

[0010] and, the first water outlet unit and / or the second water outlet unit are used to store purified water after defluorination;

[0011] The defluorination unit comprises a nuclear crystal granulation-resin adsorption coupling reactor; the nuclear crystal granulation-resin adsorption coupling reactor comprises an inner cylinder and an outer cylinder arranged vertically; the inner cylinder is open at the top and closed at the bottom, and is used to fill the defluorination seed crystals; the interlayer space formed between the side walls and the bottom of the outer cylinder and the inner cylinder is used to fill the adsorption resin;

[0012] A wastewater feed pipe is connected to the lower end of the side wall of the inner cylinder, and the wastewater feed pipe is connected to the wastewater feed unit;

[0013] The lower end of the side wall of the inner cylinder is also connected to a crystal inducing agent feeding pipe, and the crystal inducing agent feeding pipe is connected to the crystal inducing agent feeding unit;

[0014] The bottom of the inner cylinder is connected to a granulation body discharge pipe that passes through the outer cylinder;

[0015] A first water outlet pipe is connected to the lower end of the side wall of the outer cylinder, and the first water outlet pipe is connected to the first water outlet unit;

[0016] A second water outlet pipe is connected to the upper end of the side wall of the outer cylinder and at a position higher than the upper opening of the inner cylinder, and the second water outlet pipe is connected to the second water outlet unit;

[0017] The bottom of the outer cylinder is connected with a resin discharge pipe.

[0018] The nuclear crystal granulation device disclosed in the present invention organically couples the nuclear crystal granulation module and the resin adsorption module into a reactor, and the fluorine-containing wastewater preferentially passes through the nuclear crystal granulation reaction zone (inner cylinder area), and the fluorine ions in the water body are induced by the crystal seeds, and the preliminary purification of the fluorine-containing wastewater quality and the resource recovery of fluorine ions are achieved through the addition of crystal inducing agents; after the preliminary nuclear crystal granulation treatment, the fluorine-containing wastewater selectively overflows to the resin adsorption area (the interlayer area between the inner cylinder and the outer cylinder), and the module further deeply treats the fluorine ions in the wastewater, so that the effluent meets more stringent emission standards. The coupling design disclosed in the present invention can not only effectively recover fluorine resources, but also reduce the amount of crystal inducing agents in the nuclear crystal granulation module while ensuring that the effluent meets the standards, thereby reducing the processing cost and avoiding the problem of device scaling caused by excessive addition of crystal inducing agents.

[0019] Furthermore, the arrangement of the first water outlet unit and the second water outlet unit can flexibly adapt to the fluctuating water quality and meet various water outlet requirements. If the discharge standard is low, the fluorine-containing wastewater only passes through the nucleus crystal granulation reaction zone (inner cylinder area) and then is discharged through the second water outlet pipe (at this time, the first water outlet unit is closed); if it is necessary to treat to a lower content, the fluorine-containing wastewater can be made to pass through the nucleus crystal granulation reaction zone (inner cylinder area) and the resin adsorption area (the interlayer area between the inner cylinder and the outer cylinder) in succession, and then be discharged from the first water outlet pipe (at this time, the second water outlet unit is closed).

[0020] The following are preferred technical solutions of the present disclosure, but are not intended to be limitations of the technical solutions provided by the present disclosure. Through the following technical solutions, the technical objectives and beneficial effects of the present disclosure can be better achieved and realized.

[0021] As a preferred technical solution of the present disclosure, a toothed overflow weir is provided at the upper opening of the inner cylinder.

[0022] As a preferred technical solution of the present disclosure, the wastewater feeding unit includes a wastewater storage tank, a wastewater lifting pump, a wastewater flow meter and a wastewater valve connected in sequence, and the wastewater valve is connected to the wastewater feeding pipe.

[0023] As a preferred technical solution of the present disclosure, the inducing agent feeding unit includes an inducing agent storage tank, an inducing agent lifting pump, an inducing agent flowmeter and an inducing agent valve which are connected in sequence, and the inducing agent valve is connected to the inducing agent feeding pipe.

[0024] As a preferred technical solution of the present disclosure, the first water outlet unit includes a first water outlet tank and a first water outlet valve connected in sequence, and the first water outlet valve is connected to the first water outlet pipe.

[0025] As a preferred technical solution of the present disclosure, the core crystal granulation device further includes a desorbent feeding unit, and the desorbent feeding unit includes a desorbent storage tank, a desorbent lifting pump, a desorbent flowmeter and a desorbent valve connected in sequence;

[0026] A desorbent feed pipe is connected to the upper end of the side wall of the outer cylinder and at a position lower than the upper opening of the inner cylinder. The desorbent feed pipe is connected to the desorbent valve.

[0027] The present invention realizes the reuse of adsorption resin by adding a desorbent feeding unit.

[0028] As a preferred technical solution of the present disclosure, the second water outlet unit includes a second water outlet tank and a second water outlet valve connected in sequence, and the second water outlet valve is connected to the second water outlet pipe.

[0029] In a second aspect, the present disclosure further provides a nucleus crystal granulation process for recovering fluorine resources from fluorine-containing wastewater, wherein the nucleus crystal granulation process is performed using the nucleus crystal granulation device as described in the first aspect, and the nucleus crystal granulation process comprises the following steps:

[0030] (1) filling the inner cylinder of the core crystal granulation-resin adsorption coupling reactor with seed crystals for defluorination; filling the interlayer space formed between the side walls and the bottom of the outer cylinder and the inner cylinder with adsorption resin;

[0031] (2) introducing fluorine-containing wastewater and a crystal inducing agent into the inner cylinder respectively, so that the defluorination seed crystals are in a fluidized state and react;

[0032] The first purified water obtained after the reaction overflows from the upper opening of the inner cylinder and flows downward through the adsorption resin to obtain the second purified water, and the second purified water enters the first water outlet unit through the first water outlet pipe; the granules obtained after the reaction are discharged from the granule outlet pipe;

[0033] Or the first purified water obtained after the reaction overflows from the upper opening of the inner cylinder and enters the second water outlet unit through the second water outlet pipe; the granules obtained after the reaction are discharged from the granule discharge pipe.

[0034] The core crystal granulation process using the core crystal granulation device described in the present invention can effectively treat high-concentration fluoride-containing wastewater (fluoride ion concentration is not less than 800 mg / L), and the process flow is simple, the amount of reagents used is small, the treatment cost is low, the device is easy to clean, the water content of the treated solid is low and easy to recover, and the operation and maintenance are simple.

[0035] As a preferred technical solution of the present disclosure, the defluorination seed crystals in step (1) include one or more of quartz sand, dolomite or galena;

[0036] Preferably, the defluorination is performed by surface modification of seed crystals;

[0037] Preferably, the surface modification method comprises: first washing the defluorination seed crystals with ultrapure water, then drying, and then soaking them in ultrapure water for 12-24 hours to obtain surface-activated defluorination seed crystals, wherein the soaking time is selected such as 12 hours, 16 hours, 20 hours or 24 hours, etc., but is not limited to the listed values, and other values ​​not listed within the above range are also applicable.

[0038] Preferably, the filling height of the defluorination seed crystals in step (1) is 15-25% of the height of the inner cylinder, such as 15%, 17%, 20%, 23% or 25%, etc., but is not limited to the listed values, and other unlisted values ​​within the above range are also applicable.

[0039] Preferably, the particle size of the defluorination seed crystals in step (1) is 80-120 mesh, such as 80 mesh, 90 mesh, 100 mesh, 110 mesh or 120 mesh, but is not limited to the listed values, and other values ​​not listed within the above range are also applicable.

[0040] Preferably, the adsorption resin in step (1) comprises a cross-linked polystyrene-based resin (trade model: CH-87) and / or nano-metal aluminum modified resin (product model: LX-760).

[0041] As a preferred technical solution of the present disclosure, the order of introducing the fluorine-containing wastewater and the crystal-inducing agent in step (2) includes: firstly introducing the fluorine-containing wastewater into the inner cylinder of the nuclear crystal granulation-resin adsorption coupling reactor to make the defluorination seed crystals fluidized, and then introducing the crystal-inducing agent into the inner cylinder of the nuclear crystal granulation-resin adsorption coupling reactor.

[0042] In the present disclosure, the flow rates of fluorine-containing wastewater and crystal-inducing agent can be calculated by those skilled in the art based on hydraulic and water chemical parameters, and can be precisely regulated.

[0043] Preferably, the fluorine-containing wastewater in step (2) is first adjusted with a pH regulator before being introduced into the nuclear crystal granulation-resin adsorption coupling reactor.

[0044] Preferably, the pH adjuster comprises a sodium hydroxide solution with a concentration of 30-50wt%, such as 30wt%, 35wt%, 40wt%, 45wt% or 50wt%, etc., but is not limited to the listed values, and other unlisted values ​​within the above range are also applicable.

[0045] Preferably, the pH of the fluorine-containing wastewater is adjusted to 6-8, such as 6, 7 or 8, but is not limited to the listed values, and other values ​​not listed within the above range are also applicable.

[0046] Preferably, the crystal inducing agent in step (2) comprises one or more of calcium hydroxide solution, calcium chloride solution or magnesium chloride solution, for example, a composition of calcium hydroxide solution and calcium chloride solution, a combination of calcium chloride solution and magnesium chloride solution, etc.

[0047] Preferably, the concentration of the inducing agent in step (2) is 30-60wt%, for example, 30wt%, 35wt%, 40wt%, 45wt%, 50wt% or 60wt%, etc., but is not limited to the listed values, and other values ​​not listed within the above range are also applicable.

[0048] Preferably, after the adsorption resin in step (2) is saturated with adsorption, a desorbent is introduced for desorption, and the obtained desorbed liquid enters the first water outlet unit.

[0049] Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

[0050] (1) On the one hand, the core crystal granulation device disclosed in the present invention organically couples the core crystal granulation module and the resin adsorption module into one reactor, thereby achieving deep treatment of fluorine-containing wastewater and effective recovery of fluorine resources; on the other hand, the organic combination of the two reduces the equipment footprint and is easier to implement than the modification of existing devices;

[0051] (2) The water treatment capacity of the core crystal granulation device disclosed in the present disclosure is wide, and multiple water outlet units are provided so that enterprises can flexibly select the defluorination process according to the discharge requirements;

[0052] (3) The nucleus crystal granulation process using the nucleus crystal granulation device disclosed in the present invention can effectively treat high-concentration fluorine-containing wastewater, and the process flow is simple, the amount of reagents used is small, the treatment cost is low, the device is easy to clean, the water content of the treated solid is low and easy to recover, and the operation and maintenance are simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0054] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0055] Figure 1 It is a schematic structural diagram of a nucleus crystal granulation device for recovering fluorine resources from fluorine-containing wastewater according to a specific embodiment of the present disclosure.

[0056] Among them, 1. inner cylinder; 2. outer cylinder; 3. wastewater feed pipe; 4. crystal-inducing agent feed pipe; 5. granulation body discharge pipe; 6. first water outlet pipe; 7. second water outlet pipe; 8. resin discharge pipe; 9. toothed overflow weir; 10. wastewater storage tank; 11. wastewater lifting pump; 12. wastewater flow meter; 13. wastewater valve; 14. crystal-inducing agent storage tank; 15. crystal-inducing agent lifting pump; 16. crystal-inducing agent flow meter; 17. crystal-inducing agent valve; 18. first water outlet tank; 19. first water outlet valve; 20. desorbent storage tank; 21. desorbent lifting pump; 22. desorbent flow meter; 23. desorbent valve; 24. desorbent feed pipe; 25. second water outlet tank; 26. second water outlet valve. DETAILED DESCRIPTION

[0057] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0058] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0059] The present invention discloses a nucleus crystal granulation device for recovering fluorine resources from fluorine-containing wastewater, and the structural schematic diagram is as follows Figure 1 The nucleus crystal granulation device comprises:

[0060] A wastewater feeding unit, used for passing fluorine-containing wastewater into the defluorination unit;

[0061] A crystal inducing agent feeding unit, used for passing the crystal inducing agent into the defluorination unit;

[0062] and, the first water outlet unit and / or the second water outlet unit are used to store purified water after defluorination;

[0063] The defluorination unit comprises a nuclear crystal granulation-resin adsorption coupling reactor; the nuclear crystal granulation-resin adsorption coupling reactor comprises an inner cylinder 1 and an outer cylinder 2 arranged vertically; the inner cylinder 1 is open at the top and closed at the bottom, and is used to fill the defluorination seed crystals; the interlayer space formed between the outer cylinder 2 and the side wall and the bottom of the inner cylinder 1 is used to fill the adsorption resin;

[0064] A wastewater feed pipe 3 is connected to the lower end of the side wall of the inner cylinder 1, and the wastewater feed pipe 3 is connected to the wastewater feed unit;

[0065] The lower end of the side wall of the inner cylinder 1 is also connected to a crystal inducing agent feeding pipe 4, and the crystal inducing agent feeding pipe 4 is connected to the crystal inducing agent feeding unit;

[0066] The bottom of the inner cylinder 1 is connected to a granulation discharge pipe 5 that passes through the outer cylinder 2;

[0067] The lower end of the side wall of the outer tube 2 is connected with a first water outlet pipe 6, and the first water outlet pipe 6 is connected to the first water outlet unit;

[0068] A second water outlet pipe 7 is connected to the upper end of the side wall of the outer tube 2 and at a position higher than the upper opening of the inner tube 1. The second water outlet pipe 7 is connected to the second water outlet unit.

[0069] A resin discharge pipe 8 is connected to the bottom of the outer cylinder 2 .

[0070] Furthermore, a tooth-shaped overflow weir 9 is provided at the upper opening of the inner tube 1; it should be noted that Figure 1 The toothed overflow weir 9 extends upward on both sides, and the line connected to the top of the outer cylinder 2 represents the long strip connecting component between the inner cylinder 1 and the outer cylinder 2.

[0071] Furthermore, the wastewater feeding unit comprises a wastewater storage tank 10 , a wastewater lifting pump 11 , a wastewater flow meter 12 and a wastewater valve 13 which are connected in sequence, and the wastewater valve 13 is connected to the wastewater feeding pipe 3 .

[0072] Furthermore, the inducing agent feeding unit comprises an inducing agent storage tank 14 , an inducing agent lifting pump 15 , an inducing agent flowmeter 16 and an inducing agent valve 17 which are connected in sequence, and the inducing agent valve 17 is connected to the inducing agent feeding pipe 4 .

[0073] Furthermore, the first water outlet unit includes a first water outlet tank 18 and a first water outlet valve 19 which are connected in sequence, and the first water outlet valve 19 is connected to the first water outlet pipe 6 .

[0074] Furthermore, the nucleus crystal granulation device further comprises a desorbent feeding unit, and the desorbent feeding unit comprises a desorbent storage tank 20, a desorbent lifting pump 21, a desorbent flowmeter 22 and a desorbent valve 23 connected in sequence;

[0075] A desorbent feed pipe 24 is connected to the upper end of the side wall of the outer cylinder 2 and at a position lower than the upper opening of the inner cylinder 1 . The desorbent feed pipe 24 is connected to the desorbent valve 23 .

[0076] Furthermore, the second water outlet unit includes a second water outlet tank 25 and a second water outlet valve 26 which are connected in sequence, and the second water outlet valve 26 is connected to the second water outlet pipe 7 .

[0077] Example 1

[0078] This embodiment provides a nucleus crystal granulation device and a nucleus crystal granulation process for recovering fluorine resources in fluorine-containing wastewater. The nucleus crystal granulation device refers to the nucleus crystal granulation device in the specific implementation manner. Specifically, the height of the inner cylinder 1 is 1.2m; the height of the outer cylinder 2 is 2m.

[0079] The core crystal granulation process using the core crystal granulation device comprises the following steps:

[0080] (1) Filling the inner cylinder 1 of the nuclear crystal granulation-resin adsorption coupling reactor with quartz sand of 80 meshes, the filling height of which is 15% of the height of the inner cylinder 1; filling the interlayer space formed between the outer cylinder 2 and the side wall and the bottom of the inner cylinder 1 with cross-linked polystyrene-based resin (i.e. CH-87 adsorption resin);

[0081] (2) A 30 wt % sodium hydroxide solution is used to adjust the pH of the fluoride-containing wastewater with a fluoride ion concentration of 1000 mg / L to 6, and then the solution is introduced into the inner tube 1 at a flow rate of 30 L / h to fluidize the quartz sand, and then a 30 wt % calcium hydroxide solution is introduced at a flow rate of 0.5 L / h to react; the first purified water obtained after the reaction overflows from the upper opening of the inner tube 1 and enters the second water outlet unit through the second water outlet pipe 7 (the first water outlet valve 19 is closed at this time) for 0.5 h; then the second water outlet valve 26 is closed, and the first purified water obtained at this time overflows from the upper opening of the inner tube 1 and flows downward through the adsorption resin to obtain the second purified water, and the second purified water enters the first water outlet unit through the first water outlet pipe 6 for 1 h; the granules obtained after the reaction are discharged from the granule discharge pipe 5.

[0082] (3) After the adsorption resin is saturated with adsorption, acetone is introduced for desorption, and the obtained desorption liquid enters the first water outlet unit through the first water outlet pipe 6.

[0083] Example 2

[0084] This embodiment provides a nucleus crystal granulation device and a nucleus crystal granulation process for recovering fluorine resources from fluorine-containing wastewater. The nucleus crystal granulation device refers to the nucleus crystal granulation device in Example 1, but differs in that there is no desorbent feed unit and desorbent feed pipe.

[0085] The core crystal granulation process using the core crystal granulation device comprises the following steps:

[0086] (1) Filling the inner cylinder 1 of the core crystal granulation-resin adsorption coupling reactor with 100 mesh quartz sand, the filling height of which is 20% of the height of the inner cylinder 1; filling the interlayer space formed between the outer cylinder 2 and the side wall and the bottom of the inner cylinder 1 with quartz sand of 100 mesh; LX-760 adsorption resin;

[0087] (2) A 40 wt % sodium hydroxide solution is used to adjust the pH of the fluoride-containing wastewater having a fluoride ion concentration of 800 mg / L to 7, and then the solution is introduced into the inner tube 1 at a flow rate of 40 L / h to fluidize the quartz sand, and then a 40 wt % calcium hydroxide solution is introduced at a flow rate of 0.8 L / h to cause a reaction; the first purified water obtained after the reaction overflows from the upper opening of the inner tube 1 and enters the second water outlet unit through the second water outlet pipe 7 (the first water outlet valve 19 is closed at this time) for 0.5 h; then the second water outlet valve 26 is closed, and the first purified water obtained at this time overflows from the upper opening of the inner tube 1 and flows downward through the adsorption resin to obtain the second purified water, and the second purified water enters the first water outlet unit through the first water outlet pipe 6 for 1 h; the granules obtained after the reaction are discharged from the granule discharge pipe 5.

[0088] (3) After the adsorption resin is saturated, it is discharged from the resin discharge pipe 8 and replaced with new adsorption resin.

[0089] Example 3

[0090] This embodiment provides a nucleus crystal granulation device and a nucleus crystal granulation process for recovering fluorine resources in fluorine-containing wastewater. The nucleus crystal granulation device refers to the nucleus crystal granulation device in Example 1.

[0091] The core crystal granulation process using the core crystal granulation device comprises the following steps:

[0092] (1) Filling the inner tube 1 of the core crystal granulation-resin adsorption coupling reactor with 100 mesh quartz sand, the filling height of which is 25% of the height of the inner tube 1; filling the interlayer space formed between the outer tube 2 and the side wall and the bottom of the inner tube 1 with quartz sand of 100 mesh; LX-860 adsorption resin;

[0093] (2) A 50 wt % sodium hydroxide solution is used to adjust the pH of the fluoride-containing wastewater having a fluoride ion concentration of 1200 mg / L to 8, and then the solution is introduced into the inner tube 1 at a flow rate of 50 L / h to fluidize the quartz sand, and then a 60 wt % calcium chloride solution is introduced at a flow rate of 1 L / h to cause a reaction; the first purified water obtained after the reaction overflows from the upper opening of the inner tube 1 and enters the second water outlet unit through the second water outlet pipe 7 (the first water outlet valve 19 is closed at this time) for 0.5 h; then the second water outlet valve 26 is closed, and the first purified water obtained at this time overflows from the upper opening of the inner tube 1 and flows downward through the adsorption resin to obtain the second purified water, and the second purified water enters the first water outlet unit through the first water outlet pipe 6 for 1 h; the granules obtained after the reaction are discharged from the granule discharge pipe 5.

[0094] (3) After the adsorption resin is saturated with adsorption, acetone is introduced for desorption, and the obtained desorption liquid enters the first water outlet unit through the first water outlet pipe 6.

[0095] In Examples 1-3, the fluoride ion concentration and fluoride ion removal rate of the first purified water, the fluoride ion concentration and fluoride ion removal rate of the second purified water, and the purity of the granules obtained are all shown in Table 1.

[0096] Table 1

[0097]

[0098] The core crystal granulation device disclosed in the present invention organically couples the core crystal granulation module and the resin adsorption module into a reactor, thereby realizing the deep treatment of high-concentration fluorine-containing wastewater (concentration not less than 800 mg / L) and the effective recovery of fluorine resources, and the enterprise can flexibly select the treatment process according to the emission requirements; in the first purified water obtained only through the core crystal granulation process, the fluoride ion removal rate is more than 95%; in the second purified water obtained through the core crystal granulation process and the resin adsorption process, the fluoride ion removal rate is more than 99.6%; the purity of the obtained granules is more than 90.2%.

[0099] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0100] The above description is only a specific embodiment of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to the embodiments described herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A nucleus crystal granulation device for recovering fluorine resources from fluorine-containing wastewater, characterized in that: include: Fluoride removal unit; A wastewater feeding unit, used for passing fluorine-containing wastewater into the defluorination unit; A crystal inducing agent feeding unit, used for passing the crystal inducing agent into the defluorination unit; and, the first water outlet unit and / or the second water outlet unit are used to store purified water after defluorination; The defluorination unit comprises a nuclear crystal granulation-resin adsorption coupling reactor; the nuclear crystal granulation-resin adsorption coupling reactor comprises an inner cylinder and an outer cylinder arranged vertically; The inner cylinder is open at the top and closed at the bottom, and is used to fill the defluorination seed crystals; the interlayer space formed between the side walls and the bottom of the outer cylinder and the inner cylinder is used to fill the adsorption resin; A wastewater feed pipe is connected to the lower end of the side wall of the inner cylinder, and the wastewater feed pipe is connected to the wastewater feed unit; The lower end of the side wall of the inner cylinder is also connected to a crystal inducing agent feeding pipe, and the crystal inducing agent feeding pipe is connected to the crystal inducing agent feeding unit; The bottom of the inner cylinder is connected to a granulation body discharge pipe that passes through the outer cylinder; A first water outlet pipe is connected to the lower end of the side wall of the outer cylinder, and the first water outlet pipe is connected to the first water outlet unit; A second water outlet pipe is connected to the upper end of the side wall of the outer cylinder and at a position higher than the upper opening of the inner cylinder, and the second water outlet pipe is connected to the second water outlet unit; The bottom of the outer cylinder is connected with a resin discharge pipe.

2. The nucleus crystal granulation device according to claim 1, characterized in that: A tooth-shaped overflow weir is arranged at the opening above the inner cylinder.

3. The nucleus crystal granulation device according to claim 1 or 2, characterized in that: The wastewater feeding unit comprises a wastewater storage tank, a wastewater lifting pump, a wastewater flow meter and a wastewater valve which are connected in sequence, and the wastewater valve is connected to the wastewater feeding pipe.

4. The nucleus crystal granulation device according to any one of claims 1 to 3, characterized in that: The inducing agent feeding unit comprises an inducing agent storage tank, an inducing agent lifting pump, an inducing agent flow meter and an inducing agent valve which are connected in sequence, and the inducing agent valve is connected to the inducing agent feeding pipe.

5. The nucleus crystal granulation device according to any one of claims 1 to 4, characterized in that: The first water outlet unit includes a first water outlet tank and a first water outlet valve which are connected in sequence, and the first water outlet valve is connected to the first water outlet pipe.

6. The nucleus crystal granulation device according to any one of claims 1 to 5, characterized in that: The nucleus crystal granulation device further comprises a desorbent feeding unit, wherein the desorbent feeding unit comprises a desorbent storage tank, a desorbent lifting pump, a desorbent flow meter and a desorbent valve connected in sequence; A desorbent feed pipe is connected to the upper end of the side wall of the outer cylinder and at a position lower than the upper opening of the inner cylinder. The desorbent feed pipe is connected to the desorbent valve.

7. The nucleus crystal granulation device according to any one of claims 1 to 6, characterized in that: The second water outlet unit includes a second water outlet tank and a second water outlet valve connected in sequence, and the second water outlet valve is connected to the second water outlet pipe.

8. A nuclear crystal granulation process for recovering fluorine resources from fluorine-containing wastewater, characterized in that: The core crystal granulation process is carried out using the core crystal granulation device according to any one of claims 1 to 7, and the core crystal granulation process comprises the following steps: (1) filling the inner cylinder of the core crystal granulation-resin adsorption coupling reactor with seed crystals for defluorination; filling the interlayer space formed between the side walls and the bottom of the outer cylinder and the inner cylinder with adsorption resin; (2) introducing fluorine-containing wastewater and a crystal inducing agent into the inner cylinder respectively, so that the defluorination seed crystals are in a fluidized state and react; The first purified water obtained after the reaction overflows from the upper opening of the inner cylinder and flows downward through the adsorption resin to obtain the second purified water, and the second purified water enters the first water outlet unit through the first water outlet pipe; the granules obtained after the reaction are discharged from the granule outlet pipe; Or the first purified water obtained after the reaction overflows from the upper opening of the inner cylinder and enters the second water outlet unit through the second water outlet pipe; the granules obtained after the reaction are discharged from the granule discharge pipe.

9. The core crystal granulation process according to claim 8, characterized in that: The defluorination seed crystals in step (1) include one or more of quartz sand, dolomite or galena; Preferably, the defluorination is performed by surface modification of seed crystals; Preferably, the surface modification method comprises: first washing the defluorination seed crystal with ultrapure water, then drying, and then soaking in ultrapure water for 12-24 hours to obtain surface activated defluorination seed crystal; Preferably, the filling height of the defluorination seed crystals in step (1) is 15-25% of the height of the inner cylinder; Preferably, the particle size of the defluorination seed crystals in step (1) is 80-120 mesh; Preferably, the adsorption resin in step (1) comprises a cross-linked polystyrene-based resin and / or a nano-metal aluminum modified resin.

10. The core crystal granulation process according to claim 8 or 9, characterized in that: The order of introducing the fluorine-containing wastewater and the crystal-inducing agent in step (2) includes: firstly introducing the fluorine-containing wastewater into the inner cylinder of the nuclear crystal granulation-resin adsorption coupling reactor to make the fluorine removal seed crystals in a fluidized state, and then introducing the crystal-inducing agent into the inner cylinder of the nuclear crystal granulation-resin adsorption coupling reactor; Preferably, the fluorine-containing wastewater in step (2) is first adjusted with a pH regulator before being introduced into the nuclear crystal granulation-resin adsorption coupling reactor; Preferably, the pH regulator comprises a sodium hydroxide solution having a concentration of 30-50 wt%; Preferably, the pH of the fluorine-containing wastewater is adjusted to 6-8; Preferably, the crystal inducing agent in step (2) comprises one or more of a calcium hydroxide solution, a calcium chloride solution or a magnesium chloride solution; Preferably, the concentration of the inducing agent in step (2) is 30-60wt%; Preferably, after the adsorption resin in step (2) is saturated with adsorption, a desorbent is introduced for desorption, and the obtained desorbed liquid enters the first water outlet unit.

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