A purification and adsorption device for preparing electronic-grade potassium hydroxide

Abstract

The utility model provides a kind of purification adsorption device for electronic grade potassium hydroxide preparation, including tank body, and the upper and lower ends of the tank body are correspondingly provided with liquid inlet and liquid outlet, and rotating adsorption device and static adsorption device are arranged in the tank body.The purification adsorption device of the utility model after being passed into the solution that has been aerated, in order to prevent the gas bubble in solution too large, thereby affecting the increasing effect of the surface area of solution, the large gas bubble in solution is dispersed by the rotating device of internal force, so as to obtain uniform volume of gas bubble, to maximize the surface area of solution, so as to pass through spherical adsorption resin, so that frozen crystallization method can be suitable for the preparation of raw material with more impurity metal ions.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of potassium hydroxide preparation, and particularly relates to a purification and adsorption device for electronic-grade potassium hydroxide preparation. BACKGROUND

[0002] With the development of the chip industry and the improvement of the preparation precision, the demand for electronic-grade potassium hydroxide solution used in the silicon wafer preparation process and the demand quality are increasing year by year.

[0003] The traditional preparation process of electronic-grade potassium hydroxide solution is prepared by using the evaporation method, and in the preparation process, high-quality potassium hydroxide solution can be effectively obtained. However, with the continuous improvement of the requirements of the electronic chip industry, the existing evaporation method preparation has the disadvantages of high energy consumption and low upper limit of quality, which gradually limits the further development of the industry. As a new type of preparation process, the freeze crystallization method can obtain potassium hydroxide products close to the experimental grade by reducing the solubility through low-temperature freezing, and its energy consumption and industry prospects are far superior to the existing evaporation method preparation.

[0004] However, at present, since the freeze method is still in the experimental stage, in the process of preparing high-purity potassium hydroxide, the freeze method must be crystallized by cooling after evaporation to obtain a saturated solution, so there is no good treatment process for other metal ions before and after crystallization.

[0005] Therefore, at present, the main improvement direction of the freeze crystallization method is in the filtration of impurity metal ions, and due to the limitation of the process, it is not appropriate to add other soluble impurities such as complexing agents and the like during the preparation process, so the filtration difficulty is also objectively improved.

[0006] The mainstream method at present is to use adsorption resin for effective treatment, and the conventional method is to prolong the contact time of the solution with the adsorption resin as much as possible to obtain cleaner solution. Although the contact time can be prolonged by controlling the flow rate, in actual use, since the filter tank is often coarse, simply controlling the flow rate makes the solution concentrate into a bundle or several bundles falling down, which does not play a good role. In order to solve this problem, the flow rate is further reduced in the prior art, and the flow rate at the outlet is controlled, so that the solution can be gathered in the filter tank, but this causes the problem of uneven flow of the solution, and a small part of the solution often stays in the inside of the filter tank without flowing. SUMMARY

[0007] The present application solves the problem that impurity metal ions cannot be precipitated in the preparation process of electronic grade potassium hydroxide solution by freezing method, effectively solves the problem of unstable purity of electronic grade potassium hydroxide solution caused by differences in raw materials without introducing new soluble substances, and effectively improves the purity and yield of electronic grade potassium hydroxide solution.

[0008] To achieve the above-mentioned purpose, the specific technical scheme of the purification adsorption device for preparing electronic grade potassium hydroxide of the present application is as follows:

[0009] The potassium hydroxide preparation process based on the freezing crystallization method using the purification adsorption device of the present application includes the following steps:

[0010] S1, pressure reduction evaporation: saturated potassium hydroxide solution is prepared by pressure reduction evaporation;

[0011] S2, crystallization: the temperature of the saturated potassium hydroxide solution obtained in the previous step is lowered by heat exchange, so that the potassium hydroxide and inevitable impurities therein are crystallized, and the crystal solid material in the mixed solution is obtained by centrifuge;

[0012] S3, dissolution: the potassium hydroxide and inevitable impurities obtained in the previous step are dissolved in pure water to obtain a potassium hydroxide solution;

[0013] S4, aeration: inert gas is injected into the potassium hydroxide solution obtained in the previous step by an aeration device;

[0014] S5, first filtration: heavy metal ions in the potassium hydroxide solution obtained in the previous step are preliminarily removed by physical adsorption;

[0015] S6, second filtration: the potassium hydroxide solution obtained in the previous step is stored after being filtered for the second time by chemical filtration, and is prepared as a qualified product.

[0016] The first filtration of S5 adopts the purification adsorption device for preparing electronic grade potassium hydroxide of the present application, which includes a tank body, a liquid inlet and a liquid outlet corresponding to the upper and lower ends of the tank body, a rotating adsorption device and a stationary adsorption device arranged in the tank body.

[0017] The rotating adsorption device includes a liquid inlet pipe, a connecting seat, a rain shower structure and a rotating adsorption structure, the liquid inlet pipe is connected with the liquid inlet, the connecting seat is rotatably connected with the liquid inlet pipe, and the connecting seat can drive the rain shower structure and the rotating adsorption structure to rotate around the liquid inlet pipe as the axis.

[0018] The rain shower structure is a plurality of rain shower pipes connected around the connecting seat, and the rain shower pipes are provided with a plurality of rain shower holes towards the position of the rotating adsorption structure.

[0019] The rotating adsorption structure is connected with the connecting seat, and comprises a plurality of storage adsorption structures arranged below the rain pipe, wherein the storage adsorption structure is a box body with an open upper end, the rain pipe is arranged at the open upper end of the storage adsorption structure, the rain hole is arranged to discharge the potassium hydroxide solution into the storage adsorption structure through the open upper end, and the storage adsorption structure is filled with adsorption resin.

[0020] After the potassium hydroxide solution enters the tank body through the liquid inlet, the potassium hydroxide solution reaches the connecting seat through the liquid inlet pipe, the connecting seat divides the potassium hydroxide solution into two parts, the rain pipe transports the potassium hydroxide solution to the storage adsorption structure through the rain hole, and when the potassium hydroxide solution enters the storage adsorption structure, the potassium hydroxide solution generates an impact force on the storage adsorption structure, so that the rain structure and the rotating adsorption structure start to rotate around the liquid inlet pipe, and after the liquid flows through the adsorption resin in the storage adsorption structure, the liquid flows out of the storage adsorption structure through the liquid outlet.

[0021] The static adsorption device is arranged below the rotating adsorption device, and comprises a storage structure and a support plate, the storage structure is a plurality of storage boxes arranged closely on the support plate, and the storage boxes are filled with adsorption resin; the shape of the support plate matches and is connected with the inner side of the tank body, and a plurality of filtrate holes are arranged on the support plate, so that the potassium hydroxide solution flows to the liquid outlet at the lower end of the tank body through the filtrate holes after flowing through the adsorption resin in the storage boxes.

[0022] Further, the inner diameter of the tank body is 5-10 times the diameter of the solution inlet, and the diameter of the solution inlet is equal to the diameter of the solution outlet.

[0023] In order to further improve the adsorption effect, the storage adsorption structure is filled with spherical adsorption resin, the spherical adsorption resin is movably arranged in the storage adsorption structure, and the size ratio of the liquid outlet to the diameter of the spherical adsorption resin is 1:5 to 1:15.

[0024] In order to realize the cleaning treatment of the adsorption resin arranged in the tank body before and after use, the purification adsorption device further comprises a flushing structure, and the flushing structure is arranged on the surface of the tank body.

[0025] In order to ensure the sealing effect, the liquid inlet, the liquid outlet and the flushing hole are located on the outer surface of the tank body, and are connected with the tank body through a sealing flange.

[0026] In order to realize the detection of solution components in the purification process, the detection port is arranged on the position of the storage box on the outer surface of the tank body, the storage box can be taken out, and the adsorption resin placed in the storage box is detected.

[0027] Advantages:

[0028] The potassium hydroxide solution is filled into the purification adsorption device, the flow rate of the solution is effectively reduced through the rain structure, and the potassium hydroxide solution sprayed from the rain hole impacts the storage adsorption structure while being reduced, so that the storage adsorption device starts to rotate around the liquid inlet pipe, and the rotation of the storage adsorption structure is provided with additional driving force by the solution discharged from the liquid outlet hole, so that the aerated solution is further dispersed, so that the larger bubbles in the solution are finely and uniformly processed, and the surface area of the solution is maximized.

[0029] At the same time, the spheroidization adsorption resin is added in the storage adsorption structure, the solution is preliminarily adsorbed while rotating, the solution after rotation and dispersion is further dispersed by the spheroidization adsorption resin, and the preliminary adsorption and filtration are carried out in the dispersion process.

[0030] Finally, the adsorption resin arranged in the static adsorption device further adsorbs the solution which has been sufficiently aerated, so that the adsorption effect of the adsorption resin on the impurity metal ions is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The figure is a structure schematic diagram of the electronic-grade potassium hydroxide preparation purification adsorption device of the application;

[0032] Figure 2 The figure is a structure schematic diagram of the electronic-grade potassium hydroxide preparation purification adsorption device of the application;

[0033] Figure 3 The figure is a structure schematic diagram of the electronic-grade potassium hydroxide preparation purification adsorption device of the application;

[0034] Figure 4 The figure is a structure schematic diagram of the electronic-grade potassium hydroxide preparation purification adsorption device of the application;

[0035] Figure 5 The figure is a structure schematic diagram of the electronic-grade potassium hydroxide preparation purification adsorption device of the application;

[0036] Marked description in the figure: 1000, tank body; 2000, rotating adsorption device; 3000, static adsorption device; 1001, liquid inlet; 1002, liquid outlet; 1003, detection port; 1004, flushing port; 2100, liquid inlet pipe; 2200, connecting seat; 2310, rain pipe; 2311, rain hole; 2400, rotating adsorption structure; 2410, storage adsorption structure; 2411, porous surface; 2412, closed surface; 2413, liquid outlet hole; 3010, support plate; 3011, filtrate hole; 3020, storage structure; 3021, storage box. DETAILED DESCRIPTION

[0037] In order to better understand the purpose, structure and function of the present application, the present application of a kind of electronic grade potassium hydroxide preparation is further described in detail below with the drawings.

[0038] Implementation example:

[0039] A kind of electronic grade potassium hydroxide preparation is used in purification adsorption device, including tank body 1000, rotating adsorption device 2000 and static adsorption device 3000 are arranged in tank body 1000.

[0040] Rotating adsorption device 2000 includes liquid inlet pipe 2100, connecting seat 2200, rain structure and rotating adsorption structure 2400, potassium hydroxide solution is entered into liquid inlet pipe 2100 after entering liquid inlet 1001 on the surface of tank body 1000, is gathered in connecting seat 2200, connecting seat 2200 distributes liquid to rain structure, rain structure is with circumferential ring around way connecting in connecting seat 2200 on multiple rain pipes 2310, rain pipe 2310 is evenly provided with rain hole 2311, rain hole 2311 is opened towards the upper end of rotating adsorption structure 2400.

[0041] Rotating adsorption structure 2400 is connected in circumferential ring around way on multiple storage adsorption structures 2410 of connecting seat 2200, storage adsorption structure 2410 is the upper end opening box body corresponding to being arranged below rain pipe 2310, storage adsorption structure 2410 and rain pipe 2310 can rotate with liquid inlet pipe 2100 as the axis; Storage adsorption structure 2410 is divided into porous surface 2411 and closed surface 2412 in rotating direction, porous surface 2411 surface is provided with liquid outlet hole 2413, corresponding closed surface 2412 is closed closed structure, all storage adsorption structures 2410 are uniformly distributed towards connecting seat 2200 around connection; Storage adsorption structure 2410 is filled with spherical adsorption resin, spherical adsorption resin can move freely in storage adsorption structure 2410, and the size ratio of liquid outlet hole 2413 and the diameter of spherical adsorption resin is 1:5 to 1:15.

[0042] The static adsorption device 3000 is located below the rotary adsorption device 2000, comprising a storage structure 3020 and a support plate 3010, the storage structure 3020 comprises a plurality of storage boxes 3021 closely arranged on the support plate 3010, and the inside is filled with layered adsorption resin; the shape of the support plate 3010 is matched with the inner side of the tank body 1000 and is fixedly connected, and the support plate 3010 is provided with a filtrate hole 3011.

[0043] The surface of the tank body 1000 is provided with a detection port 1003 at the position corresponding to the storage box 3021, and the storage box 3021 can be taken out from the detection port 1003, and the adsorption resin in the storage box 3021 is used to judge the purification adsorption effect.

[0044] In use, the potassium hydroxide solution enters the tank body 1000 through the liquid inlet 1001 on the surface of the tank body 1000, and then reaches the connecting seat 2200 through the liquid inlet pipe 2100, the connecting seat 2200 divides the potassium hydroxide solution into the rain pipe 2310, the rain pipe 2310 transports the potassium hydroxide solution to the storage adsorption structure 2410 through the rain hole 2311, and the potassium hydroxide solution generates an impact force on the storage adsorption structure 2410 when entering the storage adsorption structure 2410, so that the rain structure and the rotary adsorption structure 2400 start to rotate around the liquid inlet pipe 2100, and the liquid flows out of the liquid outlet hole 2413 after flowing through the spherical adsorption resin in the storage adsorption structure 2410, and the potassium hydroxide solution also adds a driving force to the rotation when flowing out of the storage adsorption structure 2410; then the potassium hydroxide solution falls to the static adsorption device 3000, and flows to the liquid outlet 1002 at the lower end of the tank body 1000 through the filtrate hole 3011 after passing through the adsorption resin in the storage box 3021.

[0045] It can be understood that the present application is described by some embodiments, and those skilled in the art know that various changes or equivalent replacements can be made to the features and embodiments without departing from the spirit and scope of the present application. In addition, under the guidance of the present application, the features and embodiments can be modified to adapt to specific conditions and materials without departing from the spirit and scope of the present application. Therefore, the present application is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application are within the scope of the present application.

Claims

1. A purification and adsorption device for the preparation of electronic grade potassium hydroxide, characterized by, The application relates to a purification and adsorption device, which comprises a tank body, a liquid inlet and a liquid outlet arranged at the upper and lower ends of the tank body respectively, a rotating adsorption device and a static adsorption device arranged in the tank body. The rotating adsorption device comprises a liquid inlet pipe, a connecting seat, a rain structure and a rotating adsorption structure, the liquid inlet pipe is connected with the liquid inlet, the connecting seat is rotatably connected with the liquid inlet pipe, and the connecting seat can drive the rain structure and the rotating adsorption structure to rotate around the liquid inlet pipe as the axis. The rain structure is a plurality of rain pipes connected with the connecting seat, and the rain pipes are provided with a plurality of rain holes at the positions facing the rotating adsorption structure. The rotating adsorption structure is connected with the connecting seat and comprises a plurality of storage adsorption structures arranged below the rain pipes correspondingly, the storage adsorption structure is a box body with an open upper end, the rain pipe is arranged at the open upper end of the storage adsorption structure, the rain holes discharge potassium hydroxide solution into the storage adsorption structure through the open upper end, and the storage adsorption structure is filled with adsorption resin; the storage adsorption structure is divided into a porous surface and a closed surface in the rotating direction, the porous surface is provided with a plurality of liquid discharge holes, the closed surface is a closed structure, and all the storage adsorption structures are arranged around the connecting seat in the same direction. The static adsorption device is arranged below the rotating adsorption device and comprises a storage structure and a supporting plate, the storage structure is a plurality of storage boxes closely arranged on the supporting plate, and the storage boxes are filled with adsorption resin; the supporting plate is matched with and connected with the inner side of the tank body, the supporting plate is provided with a plurality of filtrate holes, and the potassium hydroxide solution flows to the liquid outlet at the lower end of the tank body through the filtrate holes after passing through the adsorption resin in the storage boxes.

2. The purification and adsorption device for preparing electronic grade potassium hydroxide according to claim 1, characterized in that, The inner diameter of the tank body is 5-10 times of the diameter of the solution inlet, and the diameter of the solution inlet is equal to the diameter of the solution outlet.

3. The purification and adsorption device for preparing electronic grade potassium hydroxide according to claim 1, characterized in that, The storage adsorption structure is filled with spherical adsorption resin, the spherical adsorption resin is movably arranged in the storage adsorption structure, and the size ratio of the liquid discharge hole to the diameter of the spherical adsorption resin is 1:5-1:

15.

4. The purification and adsorption device for preparing electronic grade potassium hydroxide according to claim 1, characterized in that, The purification and adsorption device further comprises a flushing structure, the flushing structure is arranged on the surface of the tank body, and the flushing structure can clean the adsorption resin arranged in the tank body before and after use.

5. The purification and adsorption device for preparing electronic grade potassium hydroxide according to claim 4, characterized in that, The liquid inlet, the liquid outlet and the flushing hole are arranged on the outer surface of the tank body and connected with the tank body through a sealing flange.

6. The purification and adsorption device for preparing electronic grade potassium hydroxide according to claim 1, characterized in that, The tank body is provided with a detection port at the position corresponding to the storage box, the detection port can take out the storage box, and the adsorption resin placed in the storage box can be detected.

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