Ultra-clean high‑purity ammonia solution preparation process, and apparatus therefor

Abstract

The present invention provides an ultra-clean high‑purity ammonia solution preparation process, and an apparatus therefor. By means of heating and vaporization, pressurized impurity removal, ultra-pure water washing for impurity removal, purification by a molecular‑sieve adsorption column, absorption by ultra-pure water, and filtration by an ultra-filtration membrane, an ultra‑clean high‑purity ammonia solution is obtained. The product has high quality, and the process is simple. Compared with the prior art, the present invention has lower metal and particle contents, a safe and reliable process, low energy consumption, and no discharge of waste gas, waste water, and solid waste during production, and is environmentally friendly and practical.

Description

Preparation process and device of ultra-clean high-purity ammonia water TECHNICAL FIELD

[0001] The present application belongs to the technical field of electronic-grade chemical preparation, and particularly relates to a preparation process and device of ultra-clean high-purity ammonia water. BACKGROUND

[0002] With the rapid development of the semiconductor industry, the purity requirements and standards of ultra-clean high-purity reagents are constantly improving. Electronic-grade ammonia water has attracted more and more attention due to its wide application.

[0003] During the production, transportation and storage of ammonia water, some metal ions, dust particles, unreacted raw materials and intermediate products are inevitably brought into the product due to the raw materials and equipment, and these impurities can easily lead to the generation of misregistration and cause breakdown. For ultra-precision integrated circuits, even a small amount of metal ions and particles can damage the entire circuit. Therefore, how to effectively remove metal ions and dust particles is a technical problem that needs to be solved.

[0004] CN102275951A discloses a method for producing ultra-pure ammonia water, which comprises the following steps: vaporizing liquid ammonia and introducing the ammonia gas into an ultrasonic purification tower, the lower part of the ultrasonic purification tower is provided with an ultrasonic atomizer, the ultrasonic atomizer is filled with ultra-pure water, the ultrasonic atomizer generates fine ammonia water particles, the fine ammonia water particles are used to adsorb impurities in the ammonia gas, the purified ammonia gas is filtered through a filter and then enters a product absorption tower, and the ammonia gas combines with the ultra-pure water in the product absorption tower to obtain ultra-pure ammonia water. This process needs to use an ultrasonic purification tower, and the impurity removal efficiency is not high.

[0005] CN105523570A discloses a preparation method of PPT-grade ultra-pure ammonia water, which comprises the following steps in sequence and continuously: (1) gasification: using hot steam to evaporate into ammonia gas; (2) purification and filtration: the ammonia gas passes through a drain separator and an activated carbon adsorber in sequence to obtain purified ammonia gas; (3) resin adsorption: oil removal treatment through adsorption resin; (4) washing: impurity removal by washing with ultra-pure water and saturated ammonia water; (5) water-gas separation: separation into water gas and ammonia gas by using a water-gas separator; (6) multi-stage absorption: multi-stage absorption by using an absorption tower and ultra-pure water to form ammonia water; (7) ultrafiltration: ultrafiltration treatment to obtain the PPT-grade ultra-pure ammonia water. The process is complicated, and the purity and quality of the obtained product are not good.

[0006] Overall, the existing disclosed preparation processes have low removal efficiency of impurity metals and particles, and the processes are complicated, which cannot meet the production and large-scale production needs of high-grade electronic-grade ammonia water. SUMMARY

[0007] The application provides a preparation process and device of super-clean high-purity ammonia water, aiming at providing a new efficient method to reduce the content of metal, particle and other impurities in electronic-grade ammonia water and improve the quality of electronic-grade ammonia water.

[0008] The application aims at overcoming the deficiencies in the prior art and providing a preparation process of super-clean high-purity ammonia water.

[0009] The preparation process of super-clean high-purity ammonia water comprises the following steps:

[0010] Heating vaporization, pressure impurity removal, ultra-pure water washing impurity removal, molecular sieve adsorption column purification, ultra-pure water absorption and ultrafiltration membrane filtration.

[0011] The specific process of each step is as follows:

[0012] (1) Heating vaporization: industrial-grade ammonia water is heated and evaporated into ammonia gas;

[0013] (2) Pressure impurity removal: the ammonia gas obtained in step (1) is subjected to pressure deposition of organic impurities, impurity metals and particles existing in the ammonia gas;

[0014] (3) Ultra-pure water washing impurity removal: the ammonia gas obtained in step (2) is cooled by a condensation tower and then delivered to a washing tower containing ultra-pure water; after the ammonia water in the washing tower reaches saturation, high-purity ammonia gas is released;

[0015] (4) Molecular sieve column purification: the high-purity ammonia gas obtained in step (3) is purified by passing through an adsorption column filled with molecular sieve;

[0016] (5) Ultra-pure water absorption: the ammonia gas obtained in step (4) is absorbed by ultra-pure water

[0017] (6) Ultrafiltration membrane filtration: the product obtained in step (5) is subjected to filtration treatment by using a filtration membrane. Preferably, the heating temperature in step (1) is 50℃.

[0018] Preferably, the pressure in step (2) is 0.35-0.5Mpa and the temperature is 15℃. The pressure impurity removal can deposit organic impurities and metals complexed with the organic impurities, thereby effectively reducing the content of organic impurities and metal ions.

[0019] Preferably, in step (4), the adsorption column is filled with a macroporous-microporous molecular sieve.

[0020] Preferably, the macroporous pore size is 100-500nm, the microporous pore size is 0.3-0.7nm, and the specific surface area of the molecular sieve is 140-500m2 / g.

[0021] The preparation process of the macroporous-microporous type silicon molecular sieve is as follows: a certain amount of anhydrous ethanol, deionized water is mixed uniformly at room temperature (20℃), and ammonia water is added and stirred. Tetraethyl orthosilicate is added dropwise, and stirring is continued. Centrifugation, drying, and obtaining silica microspheres.

[0022] The silica microspheres are dispersed in a mixed solution of tetrapropylammonium hydroxide aqueous solution and anhydrous ethanol, and ultrasonic. The mixed raw materials are dried to obtain a dry gel. The dry gel is transferred to a reaction kettle, a certain amount of deionized water is placed at the bottom of the kettle, and the steam assisted crystallization is carried out for a period of time, then the kettle is taken out, washed, dried, and calcined in air atmosphere to obtain the macroporous-microporous type silicon molecular sieve.

[0023] Optionally, the volume ratio of anhydrous ethanol to deionized water is 10:1 to 1:1.

[0024] Optionally, the molar ratio of silica microspheres to tetrapropylammonium hydroxide is 1:0.1-0.5.

[0025] Optionally, the mixed raw materials are dried by gradient drying, and the specific preferred drying conditions are 40℃ for 6h and 60℃ for 2h.

[0026] Optionally, the calcination temperature is 400-600℃, and further preferably 500-560℃.

[0027] The macroporous-microporous type silicon molecular sieve does not introduce other impurities, and at the same time, through the synergistic effect of macropores and micropores, it can more effectively adsorb ultrafine particles, metals, various ionic organic impurities, and improve the purity of the product.

[0028] Preferably, the ultrafiltration membrane in step (6) is preferably a polymer ultrafiltration membrane.

[0029] Further preferably, it is a fluorine-containing polymer ultrafiltration membrane.

[0030] More preferably, it is a PVDF ultrafiltration membrane. The preferred pore size is 0.03-0.1 microns.

[0031] The use of fluorine-containing polymer ultrafiltration membrane has the advantages of hydrophobicity and the

[0032] Compared with the prior art, the present application has the following advantages and beneficial effects.

[0033] (1) The process flow and equipment used in the present application have high production capacity for producing ultra-clean high-purity ammonia water, stable product quality, and strong practicability for industrial production.

[0034] (2) The number of distillations is reduced, special equipment is not used, energy consumption is reduced, the separation process is simple, no additional environmental pollution problems are generated, and it is environmentally friendly and practical.

[0035] (3) The organic impurities and the metals complexed with the organic impurities can be deposited by using the pressure deposition method, and thus the content of the organic impurities and the metal ions can be effectively reduced.

[0036] (4) The microporous-macroporous type silica molecular sieve adsorption column is used, the micropores and the macropores jointly act, the content of the particles and the metal ions is effectively reduced, and the quality grade of the ultra-clean high-purity ammonia water is improved. BRIEF DESCRIPTION OF DRAWINGS

[0037] Fig. 1 is a purification device of ultra-clean high-purity ammonia water, wherein: 1 - evaporator; 2 - pressurized tank; 3 - condensation tower; 4 - washing tower; 5 - adsorption column; 6 - absorption tower; 7 - ultrafiltration membrane filter; 8 - collection tank. DETAILED DESCRIPTION

[0038] The following examples are merely examples encompassed by the present application, and do not constitute any limitation on the scope of implementation.

[0039] Example 1

[0040] A purification process of ultra-clean high-purity ammonia water is realized by using the device shown in Fig. 1.

[0041] Specifically, the industrial-grade ammonia water is sent from a raw material tank to the evaporator 1, heated to 50℃, and evaporated into ammonia gas; then the ammonia gas is sent into the pressurized tank 2, and is subjected to pressurization treatment at 0.3Mpa and 15℃ for 30min; the ammonia gas enters the washing tower 4 containing ultra-pure water after passing through the condensation tower 3, and the ammonia gas is released after the ammonia gas in the washing tower is saturated; then the ammonia gas enters the adsorption column 5 filled with molecular sieve for purification; finally, the purified ammonia gas enters the absorption tower 6, and the entering ammonia gas is absorbed by the ultra-pure water; finally, the ammonia gas is filtered by the ultrafiltration membrane filter 7 under the pressure of 1Mpa. Then the ammonia gas enters the collection tank 8.

[0042] The specific preparation process of the above-mentioned molecular sieve is as follows: 100ml of anhydrous ethanol, 100ml of deionized water, and 30ml of ammonia water are uniformly mixed at room temperature (20℃), and stirred for 30min. 65ml of tetraethyl orthosilicate is added dropwise, and stirring is continued for 6h. Centrifugation and drying are performed to obtain silica microspheres. The particle size of the microspheres is about 520nm.

[0043] 5g of silica microspheres were dispersed in a mixed solution of aqueous tetrapropylammonium hydroxide (2M) and 20ml of anhydrous ethanol, the molar ratio of tetrapropylammonium hydroxide to silica microspheres being 0.15, and ultrasonic treatment was performed for 1h. The mixed raw materials were dried at 40°C for 6h and at 60°C for 2h to obtain a dry gel. The dry gel was transferred to a reaction kettle, deionized water was placed in the bottom of the kettle, and steam-assisted crystallization was performed at 180°C for 24h. After removal, washing, drying, and calcination at 560°C for 8h in an air atmosphere, a macroporous-microporous molecular sieve was obtained. The specific surface area of the obtained molecular sieve was 370m2 / g, the total pore volume was 0.25cm3 / g, the macropore size was 150-500nm, and the micropore size was 0.3-0.7nm.

[0044] For pore volume calculation, the volume of macropores was evaluated by the conventional mercury porosimetry method in the art, and the volume of micropores and macropores was tested by nitrogen physical adsorption method.

[0045] The ultrafiltration membrane used was a PVDF ultrafiltration membrane with a pore size of 0.1 microns.

[0046] Example 2

[0047] A purification process for ultra-clean high-purity ammonia water is realized by using the device shown in Figure 1.

[0048] Specifically, the industrial-grade ammonia water is sent from the raw material tank to the evaporator 1 by using a compressor to evaporate into ammonia gas by using hot steam; then the ammonia gas is sent to the pressurized tank 2 for pressurization treatment at 0.3Mpa and 15°C; after passing through the condensation tower 3, the ammonia gas enters the washing tower 4 containing ultra-pure water, and the ammonia gas is released after being saturated in the washing tower; then it enters the adsorption column 5 filled with molecular sieves for purification; finally, the purified ammonia gas enters the absorption tower 6, and the entering ammonia gas is absorbed by ultra-pure water; finally, it is filtered by the ultrafiltration membrane filter 7 under a pressure of 1Mpa. Then it enters the collection tank 8.

[0049] The specific preparation process of the above-mentioned molecular sieve is as follows: 100ml of anhydrous ethanol, 50ml of deionized water, and 30ml of ammonia water were mixed uniformly at room temperature (20°C) and stirred for 30min. 65ml of tetraethyl orthosilicate was added dropwise, and stirring was continued for 6h. Centrifugation and drying were performed to obtain silica microspheres. The particle size of the microspheres was about 520nm.

[0050] 5 g of silica microspheres were dispersed in a mixed solution of aqueous tetrapropylammonium hydroxide (2 M) and 20 ml of anhydrous ethanol, the molar ratio of tetrapropylammonium hydroxide to silica microspheres being 0.15, and ultrasonic treatment was performed for 1 h. The mixed raw materials were dried at 40°C for 6 h and at 60°C for 2 h to obtain a dry gel. The dry gel was transferred to a reaction kettle, deionized water was placed in the bottom of the kettle, and steam-assisted crystallization was performed at 180°C for 18 h, after which the product was removed, washed, dried, and calcined at 550°C for 8 h in an air atmosphere to obtain a macroporous-microporous molecular sieve. The specific surface area of the obtained molecular sieve was 392 m2 / g, the total pore volume was 0.28 cm3 / g, the macropore size was 150-400 nm, and the micropore size was 0.3-0.6 nm.

[0051] For pore volume calculation, the volume of macropores was evaluated by mercury porosimetry, and the volume of micropores and mesopores was tested by nitrogen physical adsorption.

[0052] The ultrafiltration membrane used was a PVDF ultrafiltration membrane with a pore size of 0.1 microns.

[0053] Example 3

[0054] A purification process for super-clean high-purity ammonia water was realized using the device shown in Figure 1.

[0055] Specifically, industrial-grade ammonia water was sent from a raw material tank to an evaporator 1 using a compressor, and evaporated into ammonia gas using hot steam; then the ammonia gas was sent to a pressurizing tank 2, and pressurized at 0.5 MPa and 20°C; after passing through a condensation tower 3, the ammonia gas entered a washing tower 4 containing ultra-pure water, and the ammonia gas was released after being saturated in the washing tower; then the ammonia gas entered an adsorption column 5 filled with molecular sieves for purification; finally, the purified ammonia gas entered an absorption tower 6, and the ammonia gas was absorbed by ultra-pure water; finally, the ammonia gas was filtered through an ultrafiltration membrane filter 7 under a pressure of 1 MPa, and then entered a collection tank 8.

[0056] The materials used in the molecular sieve adsorption column and the PVDF ultrafiltration membrane were the same as in Example 1.

[0057] Comparative Example 1

[0058] A purification process for super-clean high-purity ammonia water was realized using a device similar to that shown in Figure 1, and the pressurizing tank 2 and the corresponding steps were omitted.

[0059] Specifically, the industrial grade ammonia water is compressed by a compressor from a raw material tank to an evaporator 1 to be evaporated into ammonia gas by using hot steam; the ammonia gas enters a cleaning tower 4 containing ultrapure water after passing through a condensing tower 3, and the ammonia gas is released after being saturated in the cleaning tower; then the ammonia gas enters a molecular sieve filled adsorption column 5 for purification; finally, the purified ammonia gas enters an absorption tower 6 to absorb the ammonia gas by using ultrapure water; and finally, the ammonia gas is filtered by an ultrafiltration membrane filter 7 under a pressure of 1 Mpa. Then the ammonia gas enters a collection tank 8.

[0060] The material for the molecular sieve adsorption column and the PVDF ultrafiltration membrane are the same as in Example 1.

[0061] Comparative Example 2

[0062] A purification process of ultraclean high-purity ammonia water is realized by using the device shown in Fig. 1.

[0063] Specifically, the industrial grade ammonia water is compressed by a compressor from a raw material tank to an evaporator 1 to be evaporated into ammonia gas by using hot steam; then the ammonia gas is sent to a pressurized tank 2 for pressurization treatment under a pressure of 0.3 Mpa and a temperature of 15℃; the ammonia gas enters a cleaning tower 4 containing ultrapure water after passing through a condensing tower 3, and the ammonia gas is released after being saturated in the cleaning tower; then the ammonia gas enters a molecular sieve filled adsorption column 5 for purification; finally, the purified ammonia gas enters an absorption tower 6 to absorb the ammonia gas by using ultrapure water; and finally, the ammonia gas is filtered by an ultrafiltration membrane filter 7 under a pressure of 1 Mpa. Then the ammonia gas enters a collection tank 8.

[0064] The molecular sieve is a microporous molecular sieve ZSM-22.

[0065] The ultrafiltration membrane is a PVDF ultrafiltration membrane with a pore size of 0.1 microns.

[0066] Measurement method:

[0067] Determination of the mass fraction of metal ions: Agilent 7700s ICP-MS of inductively coupled plasma mass spectrometer is used for determination. 5 g of sample is weighed to 0.01 g, slowly put into a 50 mL volumetric flask containing a small amount of ultrapure water, cooled to room temperature, diluted with water to the mark, and shaken uniformly. The signal intensity of each element in the sample is determined under the same analysis conditions as the standard solution series, and a blank test is performed at the same time.

[0068] Determination of particles: a laser liquid particle counter is used for determination.

[0069] Specific test data are shown in Table 1:

[0070] The above examples and test data are only some applications and embodiments of the present application, and cannot limit the protection scope of the present application. Through the above description, any person skilled in the art can see that the present application is innovated by using novel ideas and means, and has obvious practicability and creativity.

Claims

1. A process for preparing ultra-clean high-purity ammonia water, comprising the following steps: heating and vaporizing ammonia water, pressurizing to remove impurities, washing with ultra-pure water to remove impurities, purifying with a molecular sieve adsorption column, absorbing with ultra-pure water, and filtering with an ultrafiltration membrane. The specific steps are as follows:

2. The manufacturing process of claim 1, wherein, (1) heating and vaporizing: heating and evaporating industrial-grade ammonia water to obtain ammonia gas; (2) pressurizing to remove impurities: pressurizing the ammonia gas obtained in step (1) to deposit organic impurities, impurity metals, and particles in the ammonia gas; (3) washing with ultra-pure water to remove impurities: cooling the ammonia gas obtained in step (2) in a condensation tower and then conveying it to a washing tower containing ultra-pure water; after the ammonia water in the washing tower reaches saturation, high-purity ammonia gas is released; (4) purifying with a molecular sieve column: purifying the high-purity ammonia gas obtained in step (3) with an adsorption column filled with a molecular sieve; (5) absorbing with ultra-pure water: absorbing the ammonia gas obtained in step (4) with ultra-pure water (6) filtering with an ultrafiltration membrane: filtering the product obtained in step (5) with a filtration membrane. In step (2), the pressurizing condition is that the pressure is set to 0.3-0.6 MPa and the temperature is set to 10-20℃.

3. The manufacturing process of claim 2, wherein: In step (4), the molecular sieve is a macroporous-microporous molecular sieve.

4. The manufacturing process of claim 2, wherein: The preparation process of the molecular sieve is as follows: at room temperature, a certain amount of anhydrous ethanol and deionized water are mixed uniformly, ammonia water is added and stirred, tetraethyl orthosilicate is added dropwise, and stirring is continued; centrifugation, drying, and obtaining silica microspheres are performed; Preferably, the macroporous pore size is 100-500 nm, the microporous pore size is 0.3-0.7 nm, and the specific surface area of the molecular sieve is 140-500 m 2 / g.

5. The manufacturing process of claim 4, wherein: the silica microspheres are dispersed in a mixed solution of a four-propylammonium hydroxide aqueous solution and anhydrous ethanol, and ultrasonic treatment is performed; the mixed raw materials are dried to obtain dry glue; the dry glue is transferred to a reaction kettle, a proper amount of deionized water is placed at the bottom of the kettle, and the kettle is subjected to steam-assisted crystallization for a period of time, then taken out, washed, dried, and calcined in an air atmosphere to obtain a macroporous-microporous molecular sieve. The drying of the mixed raw materials is gradient drying, and is preferably 40℃ drying for 6 h and 60℃ drying for 2 h; the calcination temperature is 560℃.

6. The manufacturing process of claim 5, wherein: The ultrafiltration membrane is a polymer ultrafiltration membrane.

7. The manufacturing process of claim 1, wherein: The ultrafiltration membrane is a fluoropolymer ultrafiltration membrane.

8. The manufacturing process of claim 7, wherein: The ultrafiltration membrane is a PVDF ultrafiltration membrane with a pore size of 0.1 microns.

9. The manufacturing process of claim 8, wherein: 10.A device for producing ultra-clean high-purity ammonia water by the process of claim 1, comprising, in sequence, an evaporator (1), a pressurizing tank (2), a condensation tower (3), a washing tower (4), an adsorption column (5), an absorption tower (6), an ultrafiltration device (7), and a collection tank (8); industrial-grade ammonia water is sent from a raw material tank to the evaporator, heated and evaporated to become ammonia gas; then the ammonia gas is sent to the pressurizing tank for pressurizing treatment; after passing through the condensation tower, the ammonia gas enters a washing tower containing ultra-pure water, and after the ammonia gas in the washing tower reaches saturation, the washed ammonia gas is released; then the ammonia gas enters the adsorption column filled with a molecular sieve for purification; finally, the purified ammonia gas enters the absorption tower, and the ammonia gas is absorbed with ultra-pure water; finally, the ammonia gas is filtered through an ultrafiltration membrane filter; and then enters the collection tank. ​

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