Electronic-grade phosphoric acid purification equipment

Abstract

The utility model relates to the technical field of preparation of electronic chemicals, in particular to electronic-grade phosphoric acid purification equipment which comprises a storage tank, a crystallization container, a filtering container and a purification tower. The crystallization container is provided with a material adding pipeline for adding a crystallization solvent, the bottom of the crystallization container is provided with a communicating pipeline for communicating with the filtering container, and the filtering container is provided with a backflow assembly for conveying preliminarily purified phosphoric acid into the material storage tank; a liquid discharging assembly for discharging phosphoric acid into the purification tower is arranged on the storage tank, and a purification assembly for purifying residual impurity ions in the phosphoric acid again is arranged in the purification tower. According to the application, the removal effect on impurity ions in the electronic-grade phosphoric acid is improved, so that the purification effect on the electronic-grade phosphoric acid is improved, and the purity of the electronic-grade phosphoric acid is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of electronic chemical preparation, in particular to electronic-grade phosphoric acid purification equipment. BACKGROUND

[0002] Phosphoric acid, a colorless transparent inorganic acid, plays a crucial role in the chemical industry. It is not only a basic raw material in the fields of agriculture, chemical industry, metallurgy, national defense, food, medicine, etc., but also occupies a place in the electronic industry. Especially high-purity electronic-grade phosphoric acid has extremely strict requirements for the control of insoluble solid particles and metal ion impurities, and the impurity content usually needs to be lower than 10 ppb (i.e. 1 x 10-9), to ensure its excellent electrical properties in the microelectronic industry, such as insulation voltage resistance, corrosion resistance and resistance uniformity, etc.

[0003] In the electronic industry, electronic-grade phosphoric acid is mainly used for wet cleaning and wet etching in the production process of large-scale integrated circuits. Its processing and preparation technology mainly includes thermal method and wet method. The thermal method prepares high-purity yellow phosphorus by burning phosphorus ore through a heat treatment process, and then oxidizes and hydrates to prepare phosphoric acid. The wet method uses inorganic acid to treat phosphorus ore to prepare phosphoric acid, and then uses purification methods to control the impurity content of each component in the phosphoric acid, to produce electronic-grade phosphoric acid meeting the standards. Since the thermal method requires high energy input and is expensive, the wet method route is still dominant in the production of phosphoric acid in China. However, the wet-prepared phosphoric acid often contains various impurity ions, which can greatly reduce the quality of the product in the circuit board etching process. Therefore, it is necessary to purify the wet-prepared phosphoric acid.

[0004] The main purification method for domestic electronic-grade phosphoric acid is solvent precipitation, that is, a water-soluble organic solvent completely miscible with water is used, an alkali metal salt or ammonium salt is added to precipitate and separate out the impurities, and then the organic solvent is recovered by distillation to obtain purified phosphoric acid. Although the solvent precipitation method can remove most of the impurity ions in the phosphoric acid, trace amounts of impurity ions may still remain in the phosphoric acid, which may result in the purity of the electronic-grade phosphoric acid not meeting the requirements. CONTENT OF THE INVENTION

[0005] In order to improve the removal effect of impurity ions in electronic-grade phosphoric acid, thereby improving the purification effect of electronic-grade phosphoric acid, and further improving the purity of electronic-grade phosphoric acid, the application provides electronic-grade phosphoric acid purification equipment.

[0006] The application provides electronic-grade phosphoric acid purification equipment, which adopts the following technical scheme:

[0007] The application discloses an electronic-grade phosphoric acid purification device, which comprises a storage tank, a crystallization container, a filtering container and a purification tower, wherein the storage tank is provided with a transfusion assembly for conveying phosphoric acid into the crystallization container; the crystallization container is provided with a feeding pipeline for adding a crystallization solvent; the bottom of the crystallization container is provided with a communication pipeline for connecting the filtering container; the filtering container is provided with a reflux assembly for conveying the preliminarily purified phosphoric acid into the storage tank; the storage tank is provided with a drainage assembly for draining the phosphoric acid into the purification tower; and the purification tower is provided with a purification assembly for re-purifying residual impurity ions in the phosphoric acid.

[0008] By adopting the above technical scheme, the transfusion assembly helps to convey the phosphoric acid in the storage tank into the crystallization container; the feeding pipeline helps to add the crystallization solvent into the crystallization container, so as to help the impurity ions in the phosphoric acid form difficultly soluble salt crystals in the crystallization container, and help to preliminarily purify the impurity ions in the phosphoric acid; the communication pipeline helps to convey the preliminarily purified phosphoric acid and the difficultly soluble salt crystals into the filtering container, so as to help to filter and separate the preliminarily purified phosphoric acid and the difficultly soluble salt crystals; the reflux assembly helps to convey the preliminarily purified phosphoric acid into the storage tank, so as to help to convey the preliminarily purified phosphoric acid into the crystallization container again for the crystallization and filtering separation process, and reciprocally circulate, thereby helping to purify the phosphoric acid for multiple times, helping to improve the removal effect of the impurity ions in the electronic-grade phosphoric acid, thereby helping to improve the purification effect of the electronic-grade phosphoric acid, and further helping to improve the purity of the electronic-grade phosphoric acid; the drainage assembly helps to drain the phosphoric acid purified for multiple times into the purification tower, and the purification assembly helps to re-purify the residual impurity ions in the phosphoric acid purified for multiple times, helps to further improve the removal effect of the impurity ions in the electronic-grade phosphoric acid, thereby helping to further improve the purification effect of the electronic-grade phosphoric acid, and further helping to further improve the purity of the electronic-grade phosphoric acid.

[0009] In a specific implementation, the purification assembly comprises a mounting grid plate and a resin bed, the mounting grid plate is arranged on the inner wall of the bottom of the purification tower, and the resin bed is arranged on the mounting grid plate and tightly adheres to the circumferential inner wall of the purification tower.

[0010] By adopting the above technical scheme, the mounting grid plate helps to support the resin bed and simultaneously helps to supply the phosphoric acid to pass through; the resin bed helps to remove the residual trace impurity ions in the phosphoric acid by ion exchange, helps to further improve the removal effect of the impurity ions in the electronic-grade phosphoric acid, thereby helping to further improve the purification effect of the electronic-grade phosphoric acid, and further helping to further improve the purity of the electronic-grade phosphoric acid, and guarantees the stability and reliability of the electronic-grade phosphoric acid.

[0011] In one specific implementation scheme, a temperature-controlled jacket is provided around the circumferential periphery of the crystallization container. A flow channel for supplying a temperature-controlled medium is provided inside the temperature-controlled jacket. The flow channel is fitted to the circumferential outer wall of the crystallization container and is arranged in a spiral shape. An inlet pipe communicating with the top of the flow channel is provided at the top of the temperature-controlled jacket, and an outlet pipe communicating with the bottom of the flow channel is provided at the bottom of the temperature-controlled jacket.

[0012] By adopting the above technical solution, the use of inlet and outlet pipes helps to ensure the continuous flow of the temperature control medium in the flow channel, thereby helping to maintain the internal temperature of the crystallization container within the set temperature range, and thus helping to improve the crystallization effect of impurity ions in phosphoric acid.

[0013] In one specific implementation, the crystallization container is provided with a stirring motor, the output end of the stirring motor is provided with a stirring shaft, and the axis of the stirring shaft is on the same straight line as the central axis of the crystallization container. The stirring shaft is provided with multiple stirring blades, and each stirring blade is arc-shaped.

[0014] By adopting the above technical solution, the stirring motor helps to drive the stirring shaft and multiple stirring blades to rotate, thereby helping to improve the mixing effect of the crystallization solvent and phosphoric acid, and further helping to improve the crystallization effect of impurity ions in phosphoric acid.

[0015] In one specific implementation scheme, the bottom of the filter container is provided with a plurality of closely arranged filter screens, and filter mesh plates are provided on the plurality of filter screens. The filter container is also provided with a flow-diverting component connected to the connecting pipe, and the flow-diverting component is used to divert the phosphoric acid and sparingly soluble salt crystals transported by the connecting pipe.

[0016] By adopting the above technical solution, the use of filter screens and filter sieves helps to separate sparingly soluble salt crystals from phosphoric acid. The use of flow dividers helps to separate the phosphoric acid and sparingly soluble salt crystals transported through the connecting pipeline, thereby increasing the contact area between the phosphoric acid and sparingly soluble salt crystals and the filter screens and filter sieves, and thus helping to improve the filtration and separation effect of sparingly soluble salt crystals in phosphoric acid.

[0017] In one specific implementation, the diversion assembly includes a diversion box and a diversion frustum. The diversion box is disposed on the inner top wall of the filter container and is connected to the connecting pipe. The diversion frustum is disposed on the bottom wall of the diversion box, and the radius of the side of the diversion frustum closest to the diversion box is smaller than the radius of the side furthest from the diversion box. A plurality of diversion holes are provided through the diversion frustum, and the diversion holes are connected to the interior of the diversion box.

[0018] By adopting the above technical solution, the diversion box body combined with multiple diversion holes helps to divert phosphoric acid and sparingly soluble salt crystals transported in the connecting pipeline, thereby increasing the contact area between phosphoric acid and sparingly soluble salt crystals and the filter screen and filter sieve plate, and thus helping to improve the filtration and separation effect of sparingly soluble salt crystals in phosphoric acid.

[0019] In one specific implementation, the infusion assembly includes an infusion pipeline, an infusion pump, and a first solenoid valve. One end of the infusion pipeline is fixedly connected to the storage tank, and the other end of the infusion pipeline is fixedly connected to the crystallization container. The infusion pump is disposed on the infusion pipeline, and the first solenoid valve is disposed at the end of the infusion pipeline near the storage tank.

[0020] By adopting the above technical solution, the use of a pump and a pipeline helps to transport phosphoric acid from the storage tank to the crystallization container, and the use of a first solenoid valve helps to adjust the opening and closing status of the pipeline.

[0021] In one specific implementation, the reflux assembly includes a reflux pipe, a reflux pump, and a second solenoid valve. One end of the reflux pipe is fixedly connected to the bottom of the filter container, and the other end of the reflux pipe is fixedly connected to the top of the storage tank. The reflux pump is disposed on the reflux pipe, and the second solenoid valve is disposed at the end of the reflux pipe near the filter container.

[0022] By adopting the above technical solution, the reflux pump and reflux pipeline facilitate the transport of pre-purified phosphoric acid to the storage tank. This, in turn, facilitates the transport of the pre-purified phosphoric acid to the crystallization container for further crystallization and filtration separation, in conjunction with the infusion assembly. This repeated cycle of purification of the phosphoric acid enhances the removal of impurity ions from electronic-grade phosphoric acid, thereby improving the purification effect and ultimately increasing its purity. A second solenoid valve allows for adjustment of the reflux pipeline's opening and closing status.

[0023] In one specific implementation scheme, the drainage assembly includes a drainage pipe, a drainage pump, and a third solenoid valve. One end of the drainage pipe is fixedly connected to the storage tank, and the other end of the drainage pipe is fixedly connected to the top of the purification tower. The drainage pump is installed on the drainage pipe, and the third solenoid valve is installed at the end of the drainage pipe near the storage tank.

[0024] By adopting the above technical solution, the use of a drain pump in conjunction with a drain pipeline helps to discharge the phosphoric acid, which has undergone multiple purification processes, into the purification tower. The use of a third solenoid valve facilitates the adjustment of the opening and closing status of the drain pipeline.

[0025] In summary, this application includes at least one of the following beneficial technical effects:

[0026] 1. This application, through the arrangement of a crystallization container, a filtration container, a delivery assembly, and a reflux assembly, allows the crystallization container to facilitate the formation of sparingly soluble salt crystals from impurity ions in phosphoric acid, thereby aiding in the initial purification of impurity ions in phosphoric acid. The filtration container helps to separate the initially purified phosphoric acid from the sparingly soluble salt crystals. The reflux assembly helps to transport the initially purified phosphoric acid to a storage tank, which, in conjunction with the delivery assembly, transports the initially purified phosphoric acid back to the crystallization container for further crystallization and filtration separation. This repeated cycle purifies the phosphoric acid multiple times, improving the removal efficiency of impurity ions in electronic-grade phosphoric acid, thereby enhancing the purification effect of electronic-grade phosphoric acid and ultimately improving its purity.

[0027] 2. By setting up a purification component, this application helps to further purify the residual impurity ions in phosphoric acid after multiple purifications, which helps to further improve the removal effect of impurity ions in electronic-grade phosphoric acid, thereby further improving the purification effect of electronic-grade phosphoric acid and thus further improving the purity of electronic-grade phosphoric acid. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application.

[0029] Figure 2 It is a cross-sectional view showing the specific internal structure of the crystallization container.

[0030] Figure 3 It is a cross-sectional view showing the specific internal structure of the filter container.

[0031] Figure 4 It is a cross-sectional view showing the specific internal structure of the purification tower.

[0032] Explanation of reference numerals in the attached drawings: 1. Storage tank; 2. Crystallization container; 3. Filter container; 4. Purification tower; 5. Infusion assembly; 51. Infusion pipeline; 52. Infusion pump; 53. First solenoid valve; 6. Feeding pipeline; 7. Connecting pipeline; 8. Reflux assembly; 81. Reflux pipeline; 82. Reflux pump; 83. Second solenoid valve; 9. Drainage assembly; 91. Drainage pipeline; 92. Drainage pump; 93. Third solenoid valve; 10. Purification assembly; 101. Mounting screen plate; 102. Resin bed; 11. Temperature control jacket; 12. Flow channel; 13. Inlet pipe; 14. Outlet pipe; 15. Stirring motor; 16. Stirring shaft; 17. Stirring blades; 18. Filter sieve plate; 19. Filter screen plate; 20. Diversion assembly; 201. Diversion box; 202. Diversion frustum; 2021. Diversion flow hole; 21. Pipeline valve; 22. Output pipeline. Detailed Implementation

[0033] The present application will be further described in detail below with reference to the accompanying drawings.

[0034] This application discloses an electronic-grade phosphoric acid purification device, referring to... Figure 1 The system includes a storage tank 1, on which an infusion assembly 5 is provided. The infusion assembly 5 includes an infusion pipe 51, an infusion pump 52, and a first solenoid valve 53. One end of the infusion pipe 51 is fixedly connected to the storage tank 1, and the other end of the infusion pipe 51 is fixedly connected to a crystallization container 2. The infusion pump 52 is fixedly installed on the infusion pipe 51 and connected to the infusion pipe 51. The first solenoid valve 53 is fixedly installed at the end of the infusion pipe 51 near the storage tank 1.

[0035] Reference Figure 1 When purifying phosphoric acid, the first solenoid valve 53 is opened to connect the infusion pipeline 51, and the infusion pump 52 is started to draw phosphoric acid from the storage tank 1 and transport it to the crystallization container 2 through the infusion pipeline 51.

[0036] Reference Figure 1 and Figure 2 A feeding pipe 6 is fixedly connected to the top of the crystallization container 2, and a vertically arranged connecting pipe 7 is fixedly connected to the bottom of the crystallization container 2. A filter container 3 is fixedly connected to the end of the connecting pipe 7 away from the crystallization container 2, and a pipe valve 21 is fixedly installed on the connecting pipe 7. A temperature control jacket 11 is fixedly fitted around the circumference of the crystallization container 2. A flow channel 12 is opened inside the temperature control jacket 11. The flow channel 12 fits against the circumferential outer wall of the crystallization container 2 and is arranged in a spiral shape. An inlet pipe 13 is fixedly installed at the top of the temperature control jacket 11 and is connected to the top of the flow channel 12. An outlet pipe 14 is fixedly installed at the bottom of the temperature control jacket 11 and is connected to the bottom of the flow channel 12. A stirring motor 15 is fixedly installed at the center of the top surface of the crystallization container 2. The output end of the stirring motor 15 extends downward and is coaxially fixedly connected to a stirring shaft 16. The axis of the stirring shaft 16 is on the same straight line as the central axis of the crystallization container 2. Multiple arc-shaped stirring blades 17 are fixedly installed on the circumference of the stirring shaft 16.

[0037] Reference Figure 1 and Figure 2 When phosphoric acid is transported into the crystallization container 2, crystallization solvent is added into the crystallization container 2 through the feeding pipe 6, so that the impurity ions in the phosphoric acid react with the crystallization solvent to form insoluble salt crystals, thereby initially purifying the impurity ions in the phosphoric acid.

[0038] Reference Figure 1 and Figure 2Meanwhile, a temperature-controlled medium is introduced into the flow channel 12 through the inlet pipe 13, and the temperature-controlled medium flows out of the flow channel 12 through the outlet pipe 14, so that the temperature-controlled medium flows continuously in the flow channel 12. In turn, the internal temperature of the crystallization container 2 is maintained in the temperature range of -5℃ to 5℃ by the temperature-controlled medium, which helps to improve the crystallization effect of impurity ions in phosphoric acid.

[0039] Reference Figure 1 and Figure 2 The stirring motor 15 is started, which drives the stirring shaft 16 and multiple stirring blades 17 to rotate, thereby improving the mixing effect of the crystallization solvent and phosphoric acid, which in turn helps to further improve the crystallization effect of impurity ions in phosphoric acid.

[0040] Reference Figure 1 and Figure 3 The bottom of the filter container 3 is densely arranged with multiple filter screens 18, and a filter mesh plate 19 is placed on the multiple filter screens 18. A flow-dividing assembly 20 is also provided inside the filter container 3 above the filter mesh plate 19. The flow-dividing assembly 20 includes a flow-dividing box 201 and a flow-dividing frustum 202. The flow-dividing box 201 is fixedly installed on the top wall of the filter container 3 and is connected to the bottom end of the connecting pipe 7. The flow-dividing frustum 202 is fixedly installed on the bottom wall of the flow-dividing box 201, and the top radius of the flow-dividing frustum 202 is smaller than the bottom radius. Multiple flow-dividing holes 2021 are opened through the flow-dividing frustum 202, and the top of the flow-dividing holes 2021 is connected to the inside of the flow-dividing box 201.

[0041] Reference Figure 1 and Figure 3 After the initial purification of impurity ions in phosphoric acid is completed, the pipeline valve 21 is opened, connecting the pipeline 7. This allows the phosphoric acid and sparingly soluble salt crystals in the crystallization container 2 to flow into the diversion box 201 through the connecting pipeline 7, and then flow into the filter container 3 through multiple diversion holes 2021. The sparingly soluble salt crystals are then filtered and separated from the phosphoric acid by the filter screen 19 and filter sieve 18. The multiple diversion holes 2021 help to divert the phosphoric acid and sparingly soluble salt crystals transported by the connecting pipeline 7, thereby increasing the contact area between the phosphoric acid and sparingly soluble salt crystals and the filter screen 19 and filter sieve 18, and thus improving the filtration and separation effect of sparingly soluble salt crystals in phosphoric acid.

[0042] Reference Figure 1The bottom of the filter container 3 is provided with a reflux assembly 8, which includes a reflux pipe 81, a reflux pump 82, and a second solenoid valve 83. One end of the reflux pipe 81 is fixedly connected to the bottom of the filter container 3, and the other end of the reflux pipe 81 is fixedly connected to the top of the storage tank 1. The reflux pump 82 is fixedly installed on the reflux pipe 81 and connected to the reflux pipe 81. The second solenoid valve 83 is fixedly installed at the end of the reflux pipe 81 near the filter container 3.

[0043] Reference Figure 1 After separating the sparingly soluble salt crystals from the phosphoric acid through filtration, the second solenoid valve 83 is opened, connecting the reflux pipe 81. The reflux pump 82 is then activated to draw phosphoric acid from the filter container 3, and the preliminarily purified phosphoric acid is transported to the storage tank 1 through the reflux pipe 81. The preliminarily purified phosphoric acid is then sequentially transported to the crystallization container 2 and the filter container 3 for the next crystallization and filtration separation process. This cycle is repeated multiple times to purify the phosphoric acid, which helps improve the removal of impurity ions from electronic-grade phosphoric acid, thereby enhancing the purification effect and ultimately improving the purity of the electronic-grade phosphoric acid.

[0044] Reference Figure 1 The storage tank 1 is also equipped with a drainage assembly 9, which includes a drainage pipe 91, a drainage pump 92 and a third solenoid valve 93. One end of the drainage pipe 91 is fixedly connected to the bottom of the storage tank 1, and the other end of the drainage pipe 91 is fixedly installed with a purification tower 4. The top of the purification tower 4 is connected to the drainage pipe 91, and the bottom end of the purification tower 4 is fixedly connected to an output pipe 22. The drainage pump 92 is fixedly installed on the drainage pipe 91 and connected to the drainage pipe 91. The third solenoid valve 93 is fixedly installed at the end of the drainage pipe 91 near the storage tank 1.

[0045] Reference Figure 1 and Figure 4 The purification tower 4 is also equipped with a purification component 10, which includes a mounting mesh plate 101 and a resin bed 102. The mounting mesh plate 101 is fixedly installed on the bottom inner wall of the purification tower 4, and the resin bed 102 is fixedly placed on the mounting mesh plate 101, with the circumferential sidewall of the resin bed 102 tightly fitted to the circumferential inner wall of the purification tower 4.

[0046] Reference Figure 1 and Figure 4After the phosphoric acid in storage tank 1 has undergone multiple purification processes, the third solenoid valve 93 is opened, connecting the drain pipe 91. The drain pump 92 is then activated to draw the purified phosphoric acid from storage tank 1 and transport it to the purification tower 4 via the drain pipe 91. Once inside the purification tower 4, the phosphoric acid passes through the resin bed 102 and the mesh plate 101 before being output through the output pipe 22. As the phosphoric acid passes through the resin bed 102, the resin bed 102 helps adsorb and remove residual trace impurity ions from the phosphoric acid through ion exchange. This further enhances the removal of impurity ions from the electronic-grade phosphoric acid, thereby improving the purification effect, purity, and stability and reliability of the electronic-grade phosphoric acid.

[0047] The implementation principle of this application embodiment is as follows: when purifying phosphoric acid, the first solenoid valve 53 is opened, so that the infusion pipeline 51 is in a connected state, the infusion pump 52 is started, the phosphoric acid in the storage tank 1 is drawn, and the phosphoric acid is transported to the crystallization container 2 through the infusion pipeline 51.

[0048] After phosphoric acid is delivered into the crystallization container 2, a crystallization solvent is added to the container through the feeding pipe 6. This causes impurity ions in the phosphoric acid to react with the crystallization solvent to form sparingly soluble salt crystals, thus initially purifying the impurity ions in the phosphoric acid. Simultaneously, a temperature-controlled medium is introduced into the flow channel 12 through the inlet pipe 13 and flows out of the flow channel 12 through the outlet pipe 14. This continuous flow of the temperature-controlled medium within the flow channel 12 maintains the internal temperature of the crystallization container 2 within a range of -5°C to 5°C, which helps improve the crystallization effect of impurity ions in the phosphoric acid. The stirring motor 15 is then activated, driving the stirring shaft 16 and multiple stirring blades 17 to rotate, thereby improving the mixing effect of the crystallization solvent and phosphoric acid, further enhancing the crystallization effect of impurity ions in the phosphoric acid.

[0049] After the initial purification of impurity ions in phosphoric acid is completed, the pipeline valve 21 is opened, so that the connecting pipeline 7 is in a connected state, thereby allowing the phosphoric acid and sparingly soluble salt crystals in the crystallization container 2 to flow into the diversion box 201 through the connecting pipeline 7, and then flow into the filter container 3 through multiple diversion holes 2021. The sparingly soluble salt crystals are filtered and separated from the phosphoric acid through the filter screen plate 19 and the filter sieve plate 18.

[0050] After separating the sparingly soluble salt crystals from the phosphoric acid filtration, the second solenoid valve 83 is opened, connecting the reflux pipe 81. The reflux pump 82 is then started to draw phosphoric acid from the filter container 3, and the preliminarily purified phosphoric acid is transported to the storage tank 1 through the reflux pipe 81. The preliminarily purified phosphoric acid is then sequentially transported to the crystallization container 2 and the filter container 3 for the next crystallization and filtration separation process. This cycle is repeated multiple times to purify the phosphoric acid, which helps improve the removal of impurity ions from electronic-grade phosphoric acid, thereby enhancing the purification effect and ultimately improving the purity of the electronic-grade phosphoric acid.

[0051] After the phosphoric acid in storage tank 1 has undergone multiple purification processes, the third solenoid valve 93 is opened, connecting the drain pipe 91. The drain pump 92 is then activated to draw the purified phosphoric acid from storage tank 1 and transport it to the purification tower 4 via the drain pipe 91. Once inside the purification tower 4, the phosphoric acid passes through the resin bed 102 and the mesh plate 101 before being output through the output pipe 22. As the phosphoric acid passes through the resin bed 102, the resin bed 102 helps adsorb and remove residual trace impurity ions from the phosphoric acid through ion exchange. This further enhances the removal of impurity ions from the electronic-grade phosphoric acid, thereby improving the purification effect, purity, and stability of the electronic-grade phosphoric acid.

[0052] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An electronic-grade phosphoric acid purification device, characterized in that: The system includes a storage tank (1), a crystallization container (2), a filter container (3), and a purification tower (4). The storage tank (1) is equipped with a delivery assembly (5) for conveying phosphoric acid to the crystallization container (2). The crystallization container (2) is equipped with a feeding pipe (6) for adding crystallization solvent. The bottom of the crystallization container (2) is equipped with a connecting pipe (7) for connecting to the filter container (3). The filter container (3) is equipped with a reflux assembly (8) for conveying the pre-purified phosphoric acid to the storage tank (1). The storage tank (1) is equipped with a discharge assembly (9) for discharging phosphoric acid into the purification tower (4). The purification tower (4) is equipped with a purification assembly (10) for further purifying the residual impurity ions in the phosphoric acid.

2. The electronic-grade phosphoric acid purification equipment according to claim 1, characterized in that: The purification component (10) includes a mounting mesh plate (101) and a resin bed (102). The mounting mesh plate (101) is disposed on the bottom inner wall of the purification tower (4), and the resin bed (102) is disposed on the mounting mesh plate (101), and the resin bed (102) is tightly fitted to the circumferential inner wall of the purification tower (4).

3. The electronic-grade phosphoric acid purification equipment according to claim 1, characterized in that: A temperature control jacket (11) is provided around the crystallization container (2). A flow channel (12) for supplying the temperature control medium is provided inside the temperature control jacket (11). The flow channel (12) is fitted to the outer circumferential wall of the crystallization container (2) and is arranged in a spiral shape. An inlet pipe (13) communicating with the top of the flow channel (12) is provided at the top of the temperature control jacket (11). An outlet pipe (14) communicating with the bottom of the flow channel (12) is provided at the bottom of the temperature control jacket (11).

4. The electronic-grade phosphoric acid purification equipment according to claim 1, characterized in that: The crystallization container (2) is equipped with a stirring motor (15), and the output end of the stirring motor (15) is equipped with a stirring shaft (16). The axis of the stirring shaft (16) is on the same straight line as the central axis of the crystallization container (2). The stirring shaft (16) is equipped with multiple stirring blades (17), and each stirring blade (17) is arc-shaped.

5. The electronic-grade phosphoric acid purification equipment according to claim 1, characterized in that: The filter container (3) has a plurality of closely arranged filter screens (18) at its inner bottom, and filter mesh plates (19) are provided on the plurality of filter screens (18). The filter container (3) also has a diversion component (20) connected to the connecting pipe (7). The diversion component (20) is used to divert the phosphoric acid and sparingly soluble salt crystals transported by the connecting pipe (7).

6. The electronic-grade phosphoric acid purification device according to claim 5, characterized in that: The diversion assembly (20) includes a diversion box (201) and a diversion frustum (202). The diversion box (201) is disposed on the inner top wall of the filter container (3) and is connected to the connecting pipe (7). The diversion frustum (202) is disposed on the bottom wall of the diversion box (201). The radius of the side of the diversion frustum (202) close to the diversion box (201) is smaller than the radius of the side away from the diversion box (201). A plurality of diversion holes (2021) are provided through the diversion frustum (202), and the diversion holes (2021) are connected to the interior of the diversion box (201).

7. The electronic-grade phosphoric acid purification equipment according to claim 1, characterized in that: The infusion assembly (5) includes an infusion pipe (51), an infusion pump (52), and a first solenoid valve (53). One end of the infusion pipe (51) is fixedly connected to the storage tank (1), and the other end of the infusion pipe (51) is fixedly connected to the crystallization container (2). The infusion pump (52) is mounted on the infusion pipe (51), and the first solenoid valve (53) is mounted on the end of the infusion pipe (51) near the storage tank (1).

8. The electronic-grade phosphoric acid purification equipment according to claim 1, characterized in that: The reflux assembly (8) includes a reflux pipe (81), a reflux pump (82), and a second solenoid valve (83). One end of the reflux pipe (81) is fixedly connected to the bottom of the filter container (3), and the other end of the reflux pipe (81) is fixedly connected to the top of the storage tank (1). The reflux pump (82) is installed on the reflux pipe (81), and the second solenoid valve (83) is installed at one end of the reflux pipe (81) near the filter container (3).

9. The electronic-grade phosphoric acid purification equipment according to claim 1, characterized in that: The drainage assembly (9) includes a drainage pipe (91), a drainage pump (92), and a third solenoid valve (93). One end of the drainage pipe (91) is fixedly connected to the storage tank (1), and the other end of the drainage pipe (91) is fixedly connected to the top of the purification tower (4). The drainage pump (92) is installed on the drainage pipe (91), and the third solenoid valve (93) is installed at one end of the drainage pipe (91) near the storage tank (1).

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