Fluorine-containing chemical agent recovery device

Abstract

The utility model discloses a fluorine-containing chemical agent recovery device, and belongs to the field of wet electronic chemicals. The device comprises a reactor body, and a rotational flow liquid mixer and a circulating guide cylinder are arranged in the reactor body; a backflow cavity is formed in the lower end of the reactor body, a returned material screening device is arranged on the upper portion of the backflow cavity, a circulating pump is arranged on the outer side of the reactor body and located at the backflow cavity, a first connecting pipe and a second connecting pipe are connected to the circulating pump, the first connecting pipe is communicated with the backflow cavity, and the second connecting pipe is communicated with the rotational flow liquid mixer. Two materials are mixed in a diagonal rotational flow mode through the rotational flow liquid mixer, the problem of local supersaturation is avoided, the return material screener is arranged at the bottom of the reactor body, and crystals and fluid mixed liquid are distributed in an umbrella shape at an inlet of a circulating fluidization area due to the arrangement of the return material cone. And meanwhile, pores formed in the screening plate can be used for carrying out particle screening on the seed crystals, so that the sizes of the seed crystals entering the circulating fluidization area are homogenized.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of wet electronic chemicals more specifically, relate to a fluorine-containing chemical agent recovery device. BACKGROUND

[0002] Electronic grade hydrofluoric acid is a high-purity chemical reagent, widely used in semiconductor manufacturing, photovoltaic industry and liquid crystal panel and other high-tech fields. However, due to the complex production process, high cost and the presence of a certain concentration of hydrofluoric acid in the waste liquid after use, how to realize efficient recycling has become the focus of the industry. At present, the traditional treatment methods mainly include neutralization treatment and simple distillation recovery. However, neutralization treatment not only wastes resources, but also generates a large amount of waste residue, increasing the difficulty of subsequent treatment; and the existing distillation technology has limited ability to remove impurities, which is difficult to meet the requirements of electronic grade purity.

[0003] With the rapid development of the semiconductor industry, the demand for high-purity chemical reagents is increasing year by year, accompanied by a significant increase in waste hydrofluoric acid emissions. This not only causes resource waste, but also poses a potential threat to the environment.

[0004] Waste hydrofluoric acid treatment methods mainly include chemical precipitation, adsorption and membrane separation methods, etc. These methods can remove fluorides to some extent, but usually have problems such as high treatment cost, limited treatment efficiency and secondary pollution. The crystallization fluidized bed technology, as a new emerging treatment technology, has gradually attracted widespread attention. The crystallization fluidized bed technology generates crystalline particles in the fluidized bed by controlling the temperature, concentration and pH of the aqueous phase, thereby converting the fluorides dissolved in water into solid crystals, achieving the purpose of removing fluoride ions. However, the crystallization fluidized bed technology also faces some challenges in the application process. First, the size and distribution of the crystalline particles in the fluidized bed have a great influence on the treatment effect, and the operating conditions need to be accurately controlled. Second, the supersaturation of fluorides and the crystallization rate need to be reasonably adjusted to avoid the situation of too fast or incomplete crystallization during the crystallization process. In addition, the design and operation of the crystallization fluidized bed need to be adjusted.

[0005] In order to improve the efficient reuse of crystallization, many researchers have carried out some research on fluidized crystallization technology.

[0006] Patent application CN111498967B discloses a crystallization fluidized bed for wastewater defluorination, phosphorus removal and hardness removal, which uses a double-layer hole plate differential water distributor instead of a multi-hole water distributor to form a swirling action on the crystal particles and block their sinking. However, it only increases the residence time of the seed particles in the bed layer, and cannot change and control the saturation and crystallization rate of the crystallization.

[0007] Patent application CN107915351B discloses a combined fluidized bed self-crystallization system for treating high-hardness wastewater, which converts calcium and magnesium ions into calcium carbonate and magnesium hydroxide by adding reagents and using chemical precipitation principle, induces crystallization reaction on the seed, and deposits on the seed, and finally removes the system outside in a bottom sludge removal mode. The supernatant is filtered and separated by a ceramic membrane for fine particles. The supersaturation of crystallization is controlled by adjusting the flow rate of fluid movement, but the size and distribution of crystalline particles cannot be adjusted, and the purity of the crystalline product cannot be controlled.

[0008] Patent application CN219823716U discloses a fluorine removal device, which mixes the reagent with the waste liquid through a pipeline, enters the reaction barrel, and realizes the sequential and gradual entry of the waste liquid into the system through the alternating use of the water inlet pipe and the distribution pipe, so that the powdered fluorine removal agent and the granular fluorine removal agent are transported to the inside of the mixing box. However, it is not possible to distribute the crystallization during the process, and it is also not possible to guarantee the crystallization rate.

[0009] Patent application CN117843108A discloses a crystallization fluidized bed device, which is divided into sections by a partition, and the crystals are fluidized and rise with the sewage, circulate back to the water side after passing through the baffle, and are crystallized. The device realizes the circulation of particles, but it is difficult to realize the homogenization and classification of particles, and it is difficult to provide uniform nuclei for crystallization.

[0010] In summary, the crystallization fluidized bed technology has obvious improvements in liquid distribution, crystal circulation and operation control, but there are still problems in crystal nucleus homogenization, supersaturation control (crystallization rate control) and crystal disintegration. Therefore, there is still room for improvement in improving the crystallization efficiency and increasing the crystallization purity. Therefore, we propose a fluorine-containing chemical agent recycling device. Practical new type content

[0011] The purpose of the present application is to provide a fluorine-containing chemical agent recycling device to solve the problems in the above background technology.

[0012] To achieve the above purpose, the present application provides the following technical scheme:

[0013] A fluorine-containing chemical agent recycling device, comprising a reactor body, a cyclone liquid mixer and a circulating guide cylinder are arranged inside the reactor body, and the circulating guide cylinder is located between the cyclone liquid mixer and the inner wall of the reactor body;

[0014] A reflux cavity is arranged at the lower end of the reactor body, a return material sieve classifier is arranged at the upper part of the reflux cavity, the return material sieve classifier is a conical sieve net structure, a circulating pump is arranged at the reflux cavity outside the reactor body, a first connecting pipe and a second connecting pipe are connected to the circulating pump, the first connecting pipe communicates with the reflux cavity, and the second connecting pipe communicates with the cyclone liquid mixer;

[0015] The return material screen classifier comprises a return material cone and a screen plate, the bottom surface of the return material cone is connected with the top surface of the screen plate, the conical surface of the return material cone is arranged upwards, and the outer side surface of the screen plate is a slope.

[0016] Preferably, the liquid inlet pipe A and the third connecting pipe are arranged through the two side surfaces of the reactor body, the third connecting pipe is connected with the second connecting pipe, the liquid inlet pipe B is arranged through the top of the reactor body, and the liquid outlet pipe is further arranged on the side surface of the reactor body, and the height of the liquid outlet pipe in the vertical position is located between the liquid inlet pipe B and the third connecting pipe.

[0017] The reactor body is provided with a crystal discharge port above the return material screen classifier, and the inner wall of the reactor body is coated with an anti-fouling material.

[0018] Preferably, the cross-sectional area of the cyclone mixing device is 4.5-6.5 times the total cross-sectional area of the liquid inlet pipe A and the third connecting pipe.

[0019] Preferably, the reactor body above the return material screen classifier is provided with a slope structure, and the crystal discharge port is arranged at the slope structure.

[0020] Preferably, the reactor body above the slope structure is a crystallization cavity, and the cross-sectional area of the reflux cavity is 30%-50% of the cross-sectional area of the crystallization cavity.

[0021] Preferably, the cross-sectional area of the circulating flow guide cylinder accounts for 50%-70% of the cross-sectional area of the crystallization cavity.

[0022] The height of the circulating flow guide cylinder accounts for 30%-50% of the total height of the reactor body.

[0023] Preferably, the cyclone mixing device comprises a shell, the two side surfaces of the shell are respectively provided with a first feeding pipe and a second feeding pipe, the top of the cyclone mixing device is provided with a third feeding pipe, the first feeding pipe is communicated with the liquid inlet pipe A, the second feeding pipe is communicated with the third connecting pipe, and the third feeding pipe is communicated with the liquid inlet pipe B.

[0024] Compared with the prior art, the beneficial effects of the utility model lie in that:

[0025] (1) The utility model mixes two materials diagonally by the cyclone mixing device, the negative pressure area in the middle continuously inhales the reaction agent, which is beneficial to reduce the supersaturation degree of the reaction and avoid local supersaturation problems; in the working condition of existing crystals, the crystal nucleus grows and crystallizes under the condition of low saturation.

[0026] (2) The utility model discloses a return material screener is arranged at the bottom of reactor body, and the setting of return material cone makes the umbrella -shaped distribution of crystal and fluid mixture in the circulation fluidization area entrance, and the aperture of the setting of screen board can carry out particle screening to the crystal seed, makes the crystal seed scale of entering circulation fluidization area homogenization, and the environment of fluidized crystallization is more gentle. Small particle crystal continues to circulate and crystallize, and the directional crystallization of uniform crystal seed is completed in the effective height range, and the uniform coarse crystal seed provides high rising flow rate for circulation, and the surface adhesion rate of calcium fluoride is not high, and the crystallization purity of calcium fluoride is improved.

[0027] (3) The utility model discloses setting circulation flow guide cylinder in the reactor body middle, and circulation flow guide cylinder separates mixing and fluidized crystallization, and the difference of circulation flow guide cylinder inner and outer barrel flow rate realizes the controllable of crystallization, and further increases the reaction of crystal seed and solution crystallization material, and further provides the condition of crystal seed crystallization growth. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is whole structure schematic diagram of the utility model;

[0029] Figure 2 It is whole structure cross section schematic diagram of the utility model;

[0030] Figure 3 It is cyclone mixing liquid ware structure schematic diagram of the utility model;

[0031] Figure 4 It is return material screener structure schematic diagram of the utility model.

[0032] Mark number explanation in drawing: 1, reactor body;101, reflux chamber;102, crystallization chamber;2, cyclone mixing liquid ware;201, shell;202, first feed pipe;203, second feed pipe;204, third feed pipe;3, circulation flow guide cylinder;4, return material screener;401, return material cone;402, screen board;403, recess;5, circulation pump;6, first connecting pipe;7, second connecting pipe;8, liquid inlet pipe A;9, third connecting pipe;10, liquid inlet pipe B;11, liquid outlet pipe;12, crystal discharge port. DETAILED DESCRIPTION

[0033] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments.

[0034] Embodiment:

[0035] Please refer to Figures 1-4A fluorine-containing chemical reagent recovery device includes a reactor body 1, characterized in that: a cyclone mixer 2 and a circulation guide cylinder 3 are arranged inside the reactor body 1, the cyclone mixer 2 is located inside the circulation guide cylinder 3 near the upper end, and the circulation guide cylinder 3 is located between the cyclone mixer 2 and the inner wall of the reactor body 1; through the arrangement of the cyclone mixer 2, the fluorine waste liquid and the seed crystal particles are mixed in a cyclone manner, the feed and the seed crystals are fed in a bidirectional cyclone manner, and the negative pressure generated at the center of the cyclone draws in the calcium liquid to be reacted, thereby realizing a gradual concentration mixing with the crystal nucleus as the core.

[0036] A reflux chamber 101 is provided at the lower end of the reactor body 1, and a return material screen 4 is provided at the upper part of the reflux chamber 101. The return material screen 4 has a conical screen structure. A circulation pump 5 is provided on the outside of the reactor body 1 at the reflux chamber 101. A first connecting pipe 6 and a second connecting pipe 7 are connected to the circulation pump 5. The first connecting pipe 6 is connected to the reflux chamber 101, and the second connecting pipe 7 is connected to the cyclone mixer 2. The return material screen 4 is provided directly below the cyclone mixer 2. Crystals smaller than the sieve hole size of the return material screen 4 fall into the reflux chamber 101 and enter the next cycle under the action of the circulation pump 5. After expanding, the seed crystals are returned to the fluidization zone.

[0037] Among them, such as Figure 2 As shown, the arrows indicate the direction of liquid flow in the circulating fluidized zone; the inside of the cyclone mixer 2 is the liquid inlet mixing zone, used for preliminary mixing of fluorine-containing waste liquid and seed crystal particles; the seed crystal screening zone is composed of the return material screener 4, whose main function is to screen seed crystal particles of different sizes. The return material screener 4 adopts a porous screen structure, and the pore size is adjustable according to the working conditions.

[0038] The return material screener 4 includes a return cone 401 and a screening plate 402. The bottom surface of the return cone 401 is connected to the top surface of the screening plate 402, and the cone surface of the return cone 401 faces upward. The outer surface of the screening plate 402 is inclined. The screening plate 402 adopts a multi-hole screen structure, and the size of the holes can be adjusted according to the working conditions.

[0039] Fluorine-containing waste liquid is pumped into the cyclone mixer 2 through a pipeline and injected into the circulating guide tube 3 through a nozzle to form a swirling motion. Seed crystal particles are added through the feed port. The slight negative pressure generated by the swirling cavity draws in the reagent (such as calcium ion solution) or the reagent is pumped in through a pipeline to ensure that the waste liquid and the seed crystals are in full contact within the mixer.

[0040] In the application, the reactor body 1 is provided with a liquid inlet pipe A8 and a third connecting pipe 9 penetrating through the two side surfaces, the liquid inlet pipe A8 is used for pumping waste liquid into the cyclone mixing device 2, the third connecting pipe 9 is connected with the second connecting pipe 7 and is used for circulating small particle crystals into the cyclone mixing device 2, the reactor body 1 is provided with a liquid inlet pipe B10 penetrating through the top, which is used for feeding waste liquid or medicament into the cyclone mixing device 2, and the reactor body 1 is further provided with a liquid outlet pipe 11, which is used for discharging the reacted waste liquid, wherein the height of the liquid outlet pipe 11 in the vertical position is located between the liquid inlet pipe B10 and the third connecting pipe 9; the liquid inlet pipe A8 and the liquid inlet pipe B10 are both provided with valve bodies, which are used for controlling the flow rate of the liquid feeding. The liquid inlet pipe A8 and the liquid inlet pipe B10 can be used for feeding waste liquid or medicament.

[0041] The reactor body 1 is provided with a crystal discharge port 12 above the return screen classifier 4, which is used for discharging large particle crystals; the inner wall of the reactor body 1 is coated with an anti-fouling material, which reduces the adhesion of calcium fluoride crystals and ensures the long-term and high-efficiency operation of the equipment; the circulating guide cylinder 3 adopts a tapered design, which enhances the uniformity of the internal fluid flow and avoids local insufficient turbulence.

[0042] In the application, the cyclone mixing device 2 comprises an outer shell 201, the outer shell 201 is provided with a first feeding pipe 202 and a second feeding pipe 203 on the two sides respectively, and the cyclone mixing device 2 is provided with a third feeding pipe 204 on the top, wherein the connection mode of the pipes on the cyclone mixing device 2 is as follows: the first feeding pipe 202 is communicated with the liquid inlet pipe A8, the second feeding pipe 203 is communicated with the third connecting pipe 9, the third feeding pipe 204 is communicated with the liquid inlet pipe B10, and the lower end of the third feeding pipe 204 extends into the outer shell 201.

[0043] In the application, the cross-sectional area of the cyclone mixing device 2 is 4.5-6.5 times the total cross-sectional area of the liquid inlet pipe A8 and the third connecting pipe 9.

[0044] The reactor body 1 is provided with a slope structure above the return screen classifier 4, and the crystal discharge port 12 is arranged at the slope structure, so that the crystal discharge is facilitated.

[0045] In the application, the reactor body 1 above the slope structure is a crystallization cavity 102, and the cross-sectional area of the reflux cavity 101 is 30%-50% of the cross-sectional area of the crystallization cavity 102.

[0046] In the application, the cross-sectional area of the circulating guide cylinder 3 accounts for 50%-70% of the cross-sectional area of the crystallization cavity 102.

[0047] The height of the circulating guide cylinder 3 accounts for 30%-50% of the total height of the reactor body 1.

[0048] Work flow:

[0049] Operation of the cyclone mixer 2: the fluorine-containing waste liquid enters the cyclone mixer 2 and is mixed with the seed particles and the reagent driven by the cyclone. By adjusting the cyclone intensity and the reagent dosage, the supersaturation of the waste liquid is controlled within a set range, reducing the disintegration of the seed particles or the generation of fine particles caused by supersaturation. By adjusting the reagent dosage and the cyclone speed, the supersaturation is reduced to a stable range, significantly reducing the generation of fine particles.

[0050] Crystallization reaction in the circulating fluidization zone: the waste liquid and the seed particles move downward to the circulating fluidization zone. In this zone, the seed particles gradually grow and crystallize to form calcium fluoride, and the particles are homogenized through continuous fluidization. The crystallization process in the circulating fluidization zone is continuous, avoiding the reduction of crystallization efficiency caused by liquid stagnation or insufficient turbulence in local areas.

[0051] Screening and circulation of the return screen 4: the liquid containing seed particles of different particle sizes reaches the return screen, and after being separated by the screen, the large particles return to the circulating fluidization zone for further reaction, and the small particles fall into the reflux cavity 101. The small particles in the reflux cavity 101 are sent back to the cyclone mixer 2 by the circulating pump 5, realizing closed-loop operation.

[0052] Seed growth and calcium fluoride purification: as the seed particles grow, the particle size of the seed gradually increases, and the screening efficiency gradually improves. After multiple cycles, the seed is purified through repeated crystallization.

[0053] Experimental Example 1:

[0054] A photovoltaic cell factory produces electronic-grade hydrofluoric acid liquid with a flow rate of 50 m 3 / h, F ion concentration not less than 5000 mg / L, and pH value of 0.1. The patent technology of the present application is used to convert it into high-purity calcium fluoride as a raw material for the preparation of electronic-grade hydrofluoric acid, realizing the recycling of electronic-grade hydrofluoric acid. A cyclone mixer 2 is arranged inside the reactor body 1, the cross-sectional area of the cyclone mixer 2 is 0.11 m 2 , the length is 0.5 m, the suction reaction liquid is 8% Ca(OH)2, the inlet B pipe diameter is DN25; the circulating guide cylinder 3 inside the reactor body 1 has an inner diameter of 1.2 m and a length of 3.5 m; the return screen 4 at the bottom of the reactor body 1 has a return screen cone angle of 30°, a screen plate 402 with a horizontal angle of 45°, and a screen plate with 50 meshes; the screen plate area at the bottom of the reactor body 1 is linked to the seed internal circulating pump 5, the instantaneous speed of which into the cyclone mixer 2 is 5.0 m / s; the water outlet pipe at the top of the reactor normally produces water, and after the reactor operates for 4 hours, the discharge valve is opened to remove the crystals inside the reactor body 1 to the outside, completing a working cycle. The results are shown in Table 1.

[0055] Experimental Example 2:

[0056] A semiconductor manufacturing plant produces electronic grade hydrofluoric acid liquid is 80m 3 / h, F ion concentration is not less than 4000mg / L, pH value is 0.1. The utility model discloses a patent technology, realize electronic grade hydrofluoric acid recycling. The inside of reactor body 1 is equipped with cyclone liquid mixer 2, and the cross section area of cyclone liquid mixer 2 is 0.18m 2 , length 0.75m, and the suction reaction liquid is 8%Ca (OH) 2, and the inlet B pipe diameter is DN32;The inside diameter of circulating flow guide cylinder 3 in the inside of reactor body 1 is 1.5m, and the length is 4.8m;The cone angle of return material screen classifier 4 in the bottom of reactor body 1 is 45°, and the screen plate and horizontal angle is 60°, and the screen plate is 32 mesh;The screen zone link crystal seed internal circulating pump 5 in the bottom of reactor body 1, and the instantaneous speed of entering the liquid mixer is 5.0m / s;The water pipe of reactor top normally produces water, after reactor operation 4.5h, opens the discharge valve, and the crystal of reactor body 1 inside is excluded system, and a working cycle is completed. The results are shown in table 1.

[0057] Table 1: the experimental example 1, the experimental example 2, the experimental results of comparative example 1, comparative example 2 are compared:

[0058]

[0059]

[0060] In table 1, the experimental example 1, the experimental example 2, comparative example 1, comparative example 2 are all added with the same amount of reaction liquid and hydrofluoric acid liquid, and the reaction liquid and hydrofluoric acid liquid are added according to a certain proportion, and the total flow of electronic grade hydrofluoric acid liquid in comparative example 1 is 50m 3 / h, F ion concentration is not less than 5000mg / L, pH value is 0.1, and is directly mixed with reaction liquid 8%Ca (OH) 2. The total flow of electronic grade hydrofluoric acid liquid in comparative example 2 is 50m 3 / h, and reaction liquid 8%Ca (OH) 2 is mixed by water cap cloth liquid. As can be seen from the data in table 1, when the device of the utility model is used to mix electronic grade hydrofluoric acid liquid and reaction liquid, the obtained crystal is larger, and the purity of calcium fluoride is also higher.

[0061] The above shows and describes the basic principle, main features and advantages of the utility model. The skilled person in the art should understand that the utility model is not limited by the above examples, and the above examples and descriptions in the specification are only preferred examples of the utility model, and are not used to limit the utility model, various changes and improvements of the utility model can be made without departing from the spirit and scope of the utility model, and these changes and improvements all fall within the scope of the claimed utility model. The scope of protection of the utility model is defined by the appended claims and their equivalents.

Claims

1. A device for recovering fluorine-containing chemical reagents, comprising a reactor body (1), characterized in that: The reactor body (1) is equipped with a swirl mixer (2) and a circulation guide tube (3) inside, and the circulation guide tube (3) is located between the swirl mixer (2) and the inner wall of the reactor body (1). The reactor body (1) is provided with a reflux chamber (101) at the lower end, and a return material screen (4) is provided at the upper part of the reflux chamber (101). The return material screen (4) is a conical screen structure. A circulation pump (5) is provided on the outside of the reactor body (1) at the reflux chamber (101). A first connecting pipe (6) and a second connecting pipe (7) are connected to the circulation pump (5). The first connecting pipe (6) is connected to the reflux chamber (101), and the second connecting pipe (7) is connected to the cyclone mixer (2).

2. The fluorine-containing chemical reagent recovery device according to claim 1, characterized in that: The inner wall of the reactor body (1) is coated with anti-scaling material. The reactor body (1) is provided with an inlet pipe A (8) and a third connecting pipe (9) through both sides. The third connecting pipe (9) is connected to the second connecting pipe (7). The top of the reactor body (1) is provided with an inlet pipe B (10). The side of the reactor body (1) is also provided with an outlet pipe (11). The height of the outlet pipe (11) in the vertical position is between the inlet pipe B (10) and the third connecting pipe (9). The lower end of the reactor body (1) is provided with a crystal discharge port (12) above the return material screener (4).

3. The fluorine-containing chemical reagent recovery device according to claim 2, characterized in that: The cyclone mixer (2) includes a shell (201), a first feed pipe (202) and a second feed pipe (203) are respectively provided on both sides of the shell (201), and a third feed pipe (204) is provided on the top of the cyclone mixer (2). The first feed pipe (202) is connected to the liquid inlet pipe A (8), the second feed pipe (203) is connected to the third connecting pipe (9), and the third feed pipe (204) is connected to the liquid inlet pipe B (10). The lower end of the third feed pipe (204) extends into the shell (201).

4. The fluorine-containing chemical reagent recovery device according to claim 3, characterized in that: The cross-sectional area of ​​the vortex mixer (2) is 4.5-6.5 times the sum of the cross-sectional areas of the inlet pipe A (8) and the third connecting pipe (9).

5. The fluorine-containing chemical reagent recovery device according to claim 2, characterized in that: The reactor body (1) is located above the return material screener (4) and is configured as an inclined structure, and the crystal discharge port (12) is located at the inclined structure.

6. The fluorine-containing chemical reagent recovery device according to claim 5, characterized in that: The reactor body (1) is located above the inclined structure as a crystallization chamber (102), and the cross-sectional area of ​​the reflux chamber (101) is 30%-50% of the cross-sectional area of ​​the crystallization chamber (102).

7. The fluorine-containing chemical reagent recovery device according to claim 6, characterized in that: The cross-sectional area of ​​the circulating guide tube (3) accounts for 50%-70% of the cross-sectional area of ​​the crystallization cavity (102); The height of the circulating guide tube (3) accounts for 30%-50% of the total height of the reactor body (1).

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