A preparation process and device for ultra-clean high-purity ammonia water

Abstract

The present invention provides a preparation process and device for ultra-clean high-purity ammonia water. Ultra-clean high-purity ammonia water is obtained by heating gasification, pressurized impurity removal, ultra-pure water washing and impurity removal, molecular sieve adsorption column purification, ultra-pure water absorption, and ultrafiltration membrane filtration. The product has high quality and simple process. Compared with the prior art, it has lower metal and particle content, safe and reliable process, low energy consumption, no three wastes are discharged, and is environmentally friendly and practical.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic-grade chemical preparation, and specifically relates to a preparation process and a device for ultra-clean high-purity ammonia water. Background Art

[0002] With the rapid development of semiconductor industry technology, the requirements and standards for the purity of ultra-clean and high-purity reagents are also constantly improving. Due to its wide application, the preparation process of electronic grade ammonia has also received more and more attention.

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

[0004] CN102275951A discloses a method for producing ultrapure ammonia water, which gasifies liquid ammonia and introduces the ammonia gas into an ultrasonic purification tower, an ultrasonic atomizer is arranged at the bottom of the ultrasonic purification tower, and ultrapure water is contained in the ultrasonic atomizer. The ultrasonic atomizer produces fine ammonia water particles, and the fine ammonia water particles are used to absorb impurities in the ammonia gas. The obtained purified ammonia gas is filtered through a filter and enters a product absorption tower, and the ammonia gas is combined with the ultrapure water in the product absorption tower to obtain ultrapure ammonia water. This process requires the use of an ultrasonic purification tower, and the impurity removal efficiency is not high.

[0005] CN105523570A discloses a method for preparing PPT-grade ultrapure ammonia water, comprising the following steps performed sequentially and continuously: (1) gasification: using hot steam to evaporate into ammonia gas; (2) purification and filtration: ammonia gas is sequentially passed through a drainage separator and an activated carbon adsorber to obtain purified ammonia gas; (3) resin adsorption: oil removal treatment by adsorption resin; (4) washing: washing and impurity removal with ultrapure water and saturated ammonia water; (5) water-gas separation: using a water-gas separator to separate into water gas and ammonia gas; (6) multi-stage absorption: passing through an absorption tower and performing multi-stage absorption with ultrapure water to form ammonia water; (7) ultrafiltration: performing ultrafiltration treatment to obtain the PPT-grade ultrapure ammonia water. The process steps are cumbersome, and the purity and quality of the obtained product are poor.

[0006] In general, the existing disclosed preparation processes have low removal efficiency for impurity metals and particles, and the processes are relatively complicated, which cannot meet the production needs of high-grade electronic-grade ammonia and large-scale production. Summary of the invention

[0007] The present invention provides a preparation process and device of ultra-clean high-purity ammonia water, aiming to provide a new and efficient method to reduce the content of impurities such as metals and particles in electronic-grade ammonia water and improve the quality of electronic-grade ammonia water.

[0008] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a process for preparing ultra-clean high-purity ammonia water. To achieve the above technical objectives, the technical solution adopted by the present invention is:

[0009] A process for preparing ultra-clean high-purity ammonia water comprises the following steps:

[0010] Heating and gasification, pressurized impurity removal, ultrapure water washing and impurity removal, molecular sieve adsorption column purification, ultrapure water absorption, and ultrafiltration membrane filtration.

[0011] The specific steps of the process are:

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

[0013] (2) Pressurized impurity removal: the ammonia obtained in step (1) is pressurized to precipitate organic impurities, impure metals, and particles present in the ammonia;

[0014] (3) Ultrapure water washing and impurity removal: The ammonia gas obtained in step (2) is cooled in a condensation tower and then transported to a cleaning tower containing ultrapure water; after the ammonia water in the cleaning tower reaches saturation, high-purity ammonia gas is released;

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

[0016] (5) Ultrapure water absorption: The ammonia obtained in step (4) is absorbed by ultrapure water.

[0017] (6) Ultrafiltration: The product obtained in step (5) is filtered using a filtration membrane. Preferably, the heating temperature in step (1) is 50°C.

[0018] Preferably, the pressure in step (2) is 0.35-0.5 MPa and the temperature is 15° C. The pressurized impurity removal can precipitate organic impurities and metals complexed therewith, thereby effectively reducing the content of organic impurities and metal ions.

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

[0020] Preferably, the macropore diameter is 100-500 nm, the micropore diameter is 0.3-0.7 nm, and the molecular sieve specific surface area is 140-500 m2 / g.

[0021] The preparation process of macroporous-microporous silicon molecular sieve is as follows: at room temperature (20°C), a certain amount of anhydrous ethanol and deionized water are mixed evenly, and ammonia water is added and stirred. Tetraethyl orthosilicate is added dropwise and stirring is continued. Centrifugation and drying are performed to obtain silica microspheres.

[0022] The silica microspheres are dispersed in a mixed solution of tetrapropylammonium hydroxide aqueous solution and anhydrous ethanol, and ultrasonicated. The mixed raw materials are dried to obtain a dry gel. The dry gel is transferred to a reactor, and an appropriate amount of deionized water is placed at the bottom of the reactor. After a period of steam-assisted crystallization, the dry gel is taken out, washed, dried, and calcined in an air atmosphere to obtain a macroporous-microporous 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 drying of the mixed raw materials is gradient drying, and specifically preferably drying at 40° C. for 6 hours and drying at 60° C. for 2 hours.

[0026] Optionally, the calcination temperature is 400-600°C; more preferably 500-560°C.

[0027] The macroporous-microporous silicon molecular sieve is used without introducing other impurities. At the same time, through the synergistic effect of macropores and micropores, it can more effectively adsorb ultrafine particles, metals, and various ionic organic impurities to improve product purity.

[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. Preferably, the pore size is 0.03-0.1 micron.

[0031] Fluoropolymer ultrafiltration membranes are used because of the hydrophobic nature of fluoropolymers and their

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

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

[0034] (2) The number of distillations is reduced, no special equipment is used, energy consumption is reduced, and the separation process is simple, without causing additional environmental pollution problems, which is environmentally friendly and practical.

[0035] (3) The pressurized deposition method can be used to deposit organic impurities and metals complexed with them, thereby effectively reducing the content of organic impurities and metal ions.

[0036] (4) The microporous-macroporous silicon molecular sieve adsorption column is used. The micropores and macropores work together to effectively reduce the content of particles and metal ions, and improve the quality grade of ultra-clean high-purity ammonia water. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a purification device for ultra-clean high-purity ammonia water, including: 1 - evaporator; 2 - pressure tank; 3 - condensation tower; 4 - cleaning tower; 5 - adsorption column; 6 - absorption tower; 7 - ultrafiltration membrane filter; 8 - collection tank. DETAILED DESCRIPTION

[0038] The following embodiments are merely examples covered by the present invention and do not constitute any limitation to the scope of implementation.

[0039] Example 1

[0040] A purification process for ultra-clean high-purity ammonia water, which adopts Figure 1 This is achieved by the device shown.

[0041] Specifically, industrial-grade ammonia water is sent from the raw material tank to the evaporator 1, heated to 50°C, and evaporated into ammonia gas; then the ammonia gas is sent to the pressure tank 2, and is pressurized at 0.3Mpa and 15°C for 30 minutes; the ammonia gas passes through the condensation tower 3 and enters the cleaning tower 4 containing ultrapure water, and the cleaned ammonia gas is released after the ammonia gas in the cleaning tower is saturated; 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 ultrapure water; finally, it is filtered through the ultrafiltration membrane filter 7 at a pressure of 1Mpa. Then it enters the collection tank 8.

[0042] The specific preparation process of the molecular sieve used above is as follows: At room temperature (20°C), 100 ml of anhydrous ethanol and 100 ml of deionized water are mixed evenly, 30 ml of ammonia water is added and stirred for 30 minutes. 65 ml of tetraethyl orthosilicate is added dropwise and stirring is continued for 6 hours. Centrifuge and dry to obtain silica microspheres. The particle size of the microspheres is about 520 nm.

[0043] 5g of silica microspheres were dispersed in a mixed solution of tetrapropylammonium hydroxide aqueous solution (2M) and 20ml of anhydrous ethanol, with a molar ratio of tetrapropylammonium hydroxide to silica microspheres of 0.15, and ultrasonicated for 1h. The mixed raw materials were dried at 40°C for 6h and 60°C for 2h to obtain a dry gel. The dry gel was transferred to a reactor, and an appropriate amount of deionized water was placed at the bottom of the reactor. After 24h of steam-assisted crystallization at 180°C, it was taken out, washed, dried, and calcined at 560°C in an air atmosphere for 8h to obtain a macroporous-microporous molecular sieve. The obtained molecular sieve has a specific surface area of ​​370m2 / g, a total pore volume of 0.25cm3 / g, a macropore diameter of 150-500nm, and a micropore diameter of 0.3-0.7nm.

[0044] For pore volume calculation, the conventional mercury porosimetry method in the art was used to evaluate the volume of macropores, and the nitrogen physical adsorption method was used to test the volume of micropores and macropores.

[0045] The ultrafiltration membrane used is PVDF ultrafiltration membrane with a pore size of 0.1 micron.

[0046] Example 2

[0047] A purification process for ultra-clean high-purity ammonia water, which adopts Figure 1 This is achieved by the device shown.

[0048] Specifically, industrial-grade ammonia water is pressed from a raw material tank to an evaporator 1 by a compressor and evaporated into ammonia gas by hot steam; then the ammonia gas is sent to a pressure tank 2 and pressurized at 0.3Mpa and 15°C; the ammonia gas passes through a condensation tower 3 and enters a cleaning tower 4 containing ultrapure water, and the cleaned ammonia gas is released after the ammonia gas in the cleaning tower is saturated; then it enters an adsorption column 5 filled with a molecular sieve for purification; finally, the purified ammonia gas enters an absorption tower 6 and is absorbed by ultrapure water; finally, it is filtered through an ultrafiltration membrane filter 7 at a pressure of 1Mpa. Then it enters a collection tank 8.

[0049] The specific preparation process of the molecular sieve used above is as follows: At room temperature (20°C), 100 ml of anhydrous ethanol and 50 ml of deionized water are mixed evenly, and 30 ml of ammonia water is added and stirred for 30 minutes. 65 ml of tetraethyl orthosilicate is added dropwise, and stirring is continued for 6 hours. Centrifuge and dry to obtain silica microspheres. The particle size of the microspheres is about 520 nm.

[0050] 5g of silica microspheres were dispersed in a mixed solution of tetrapropylammonium hydroxide aqueous solution (2M) and 20ml of anhydrous ethanol, with a molar ratio of tetrapropylammonium hydroxide to silica microspheres of 0.15, and ultrasonicated for 1h. The mixed raw materials were dried at 40°C for 6h and 60°C for 2h to obtain a dry gel. The dry gel was transferred to a reactor, and an appropriate amount of deionized water was placed at the bottom of the reactor. After 18h of steam-assisted crystallization at 180°C, it was taken out, washed, dried, and calcined at 550°C in an air atmosphere for 8h to obtain a macroporous-microporous molecular sieve. The molecular sieve obtained had a specific surface area of ​​392m2 / g, a total pore volume of 0.28cm3 / g, a macropore diameter of 150-400nm, and a micropore diameter of 0.3-0.6nm.

[0051] For pore volume calculation, the conventional mercury porosimetry method in the art was used to evaluate the volume of macropores, and the nitrogen physical adsorption method was used to test the volume of micropores and mesopores.

[0052] The ultrafiltration membrane used is PVDF ultrafiltration membrane with a pore size of 0.1 micron.

[0053] Example 3

[0054] A purification process for ultra-clean high-purity ammonia water, which adopts Figure 1 This is achieved by the device shown.

[0055] Specifically, industrial-grade ammonia water is pressed from a raw material tank to an evaporator 1 by a compressor and evaporated into ammonia gas by hot steam; then the ammonia gas is sent to a pressure tank 2 and pressurized at 0.5 MPa and 20°C; the ammonia gas passes through a condensation tower 3 and enters a cleaning tower 4 containing ultrapure water, and the cleaned ammonia gas is released after the ammonia gas in the cleaning tower is saturated; then it enters an adsorption column 5 filled with a molecular sieve for purification; finally, the purified ammonia gas enters an absorption tower 6 and is absorbed by ultrapure water; finally, it is filtered through an ultrafiltration membrane filter 7 at a pressure of 1 MPa. Then it enters a collection tank 8.

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

[0057] Comparative Example 1

[0058] A purification process for ultra-clean high-purity ammonia water, which uses similar Figure 1 The device shown in the figure is used to implement the process, omitting the pressurized tank 2 and the corresponding steps.

[0059] Specifically, a compressor is used to pressurize industrial-grade ammonia water from a raw material tank to an evaporator 1 to be evaporated into ammonia gas by hot steam; the ammonia gas passes through a condensation tower 3 and enters a cleaning tower 4 containing ultrapure water, and the cleaned ammonia gas is released after the ammonia gas in the cleaning tower is saturated; then the cleaned ammonia gas enters an adsorption column 5 filled with a molecular sieve for purification; finally, the purified ammonia gas enters an absorption tower 6, and the entering ammonia gas is absorbed by ultrapure water; finally, the ammonia gas is filtered through an ultrafiltration membrane filter 7 at a pressure of 1 MPa, and then enters a collection tank 8.

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

[0061] Comparative Example 2

[0062] A purification process for ultra-clean high-purity ammonia water, which adopts Figure 1 This is achieved by the device shown.

[0063] Specifically, industrial-grade ammonia water is pressed from a raw material tank to an evaporator 1 by a compressor and evaporated into ammonia gas by hot steam; then the ammonia gas is sent to a pressure tank 2 and pressurized at 0.3Mpa and 15°C; the ammonia gas passes through a condensation tower 3 and enters a cleaning tower 4 containing ultrapure water, and the cleaned ammonia gas is released after the ammonia gas in the cleaning tower is saturated; then it enters an adsorption column 5 filled with a molecular sieve for purification; finally, the purified ammonia gas enters an absorption tower 6 and is absorbed by ultrapure water; finally, it is filtered through an ultrafiltration membrane filter 7 at a pressure of 1Mpa. Then it enters a collection tank 8.

[0064] The molecular sieve adopts the existing microporous molecular sieve ZSM-22.

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

[0066] Determination method:

[0067] Determination of metal ion mass fraction: Determination by Agilent 7700sICP-MS with inductively coupled plasma mass spectrometer. Weigh 5g of sample to an accuracy of 0.01g, slowly put it into a 50mL volumetric flask containing a small amount of ultrapure water, cool to room temperature, dilute to scale with water, and shake well. Determine the signal intensity of each element in the sample under the same analytical conditions as the standard solution series, and perform a blank test at the same time.

[0068] Particle size determination: The particle size was determined using a laser liquid particle counter.

[0069] See Table 1 for specific test data:

[0070]

[0071]

[0072] The above embodiments and test data are only some applications and implementations of the present invention, and cannot limit the protection scope of the present invention. Through the above description, any technician in the relevant technical field can see that the present invention is innovated by adopting novel ideas and means, and has obvious practicality and creativity.

Claims

1. A process for preparing ultra-clean high-purity ammonia water, characterized in that: The specific steps are: (1) Heating and gasification: Industrial-grade ammonia water is heated and evaporated into ammonia gas; (2) Pressurized impurity removal: The ammonia obtained in step (1) is pressurized to precipitate organic impurities, impure metals, and particles present in the ammonia; (3) Ultrapure water washing and impurity removal: The ammonia gas obtained in step (2) is cooled in a condensation tower and then transported to a cleaning tower containing ultrapure water; after the ammonia water in the cleaning tower reaches saturation, high-purity ammonia gas is released; (4) Molecular sieve column purification: the high-purity ammonia obtained in step (3) is purified by passing it through an adsorption column filled with molecular sieves; (5) Ultrapure water absorption: The ammonia obtained in step (4) is absorbed by ultrapure water. (6) Ultrafiltration membrane filtration: filtering the product obtained in step (5) using a filtration membrane; The pressurization conditions of step (2) are as follows: the pressure is set to 0.3Mpa-0.6Mpa and the temperature is set to 10-20°C; The molecular sieve in step (4) is a macroporous-microporous molecular sieve; the macropore diameter is 100-500nm, the micropore diameter is 0.3-0.7nm, and the specific surface area of ​​the molecular sieve is 140-500m 2 / g; the molecular sieve preparation process is: at room temperature, a certain amount of anhydrous ethanol and deionized water are mixed evenly, and ammonia water is added for stirring; tetraethyl orthosilicate is added dropwise and stirring is continued; centrifugation and drying are performed to obtain silica microspheres; the silica microspheres are dispersed in a mixed solution of tetrapropylammonium hydroxide aqueous solution and anhydrous ethanol, and ultrasonication is performed; the mixed raw materials are dried to obtain a dry glue; the dry glue is transferred to a reaction kettle, an appropriate amount of deionized water is placed at the bottom of the kettle, and after steam-assisted crystallization for a period of time, it is taken out, washed, dried, and calcined in an air atmosphere to obtain a macroporous-microporous molecular sieve.

2. The preparation process according to claim 1, characterized in that: The mixed raw material is dried in a gradient manner, specifically, dried at 40° C. for 6 h and then dried at 60° C. for 2 h; the calcination temperature is 560° C.

3. The preparation process according to claim 1, characterized in that: The ultrafiltration membrane is a polymer ultrafiltration membrane.

4. The preparation process according to claim 3, characterized in that: The ultrafiltration membrane is a fluorine-containing polymer ultrafiltration membrane.

5. The preparation process according to claim 4, characterized in that: The ultrafiltration membrane is a PVDF ultrafiltration membrane with a pore size of 0.1 micron.

Images