A production process of electronic chemical ammonia water

Abstract

This application relates to the technical field of ammonia water production, and specifically discloses a production process for electronic chemical ammonia water. A production process for electronic chemical ammonia water includes the following steps: subjecting liquid ammonia to deoiling and purification, low-temperature evaporation, adsorption, filtration, cooling, primary mixing and absorption, stripping, secondary mixing and absorption, cooling, membrane filtration purification, and formulation to obtain electronic chemical ammonia water. In this application, deoiling and purification are first carried out to remove oily impurities in liquid ammonia, and then low-temperature evaporation and adsorption are performed to remove impurities such as metal ions and TOC in the raw materials. Subsequently, through a series of operations such as filtration, stripping, and membrane filtration purification, particles and other impurities are further removed, thereby improving the purity of the prepared ammonia water.

Description

Technical Field

[0001] This application relates to the technical field of ammonia water production, and in particular to a production process of electronic chemical ammonia water. Background Art

[0002] With the rapid development of the domestic semiconductor industry, the demand for high-purity electronic chemicals has increased sharply. High-purity electronic-grade ammonia water plays an important role in the manufacturing industries such as integrated circuits and LCDs. Using the weak alkalinity of ammonia water, it is possible to remove particles and some metal impurities on the surface of activated silicon wafers and microparticles. Common ammonia water production processes include batch distillation method, membrane filtration absorption method, resin filtration method, etc. However, the ammonia water prepared by these processes has insufficient purity and is difficult to be used in the field of electronic chemistry. Summary of the Invention

[0003] In order to improve the purity of the prepared ammonia water, this application provides a production process of electronic chemical ammonia water.

[0004] A production process of electronic chemical ammonia water provided by this application adopts the following technical solutions:

[0005] A production process of electronic chemical ammonia water includes the following steps:

[0006] Perform defatting purification, low-temperature evaporation, adsorption, filtration, cooling, primary mixing absorption, stripping, secondary mixing absorption, cooling, filter membrane purification, and blending on liquid ammonia to obtain electronic chemical ammonia water.

[0007] By adopting the above technical solutions, first perform defatting purification to remove oily impurities in liquid ammonia, then perform low-temperature evaporation and adsorption to remove impurities such as metal ions and TOC in the raw materials, and then through a series of operations such as filtration, stripping, and filter membrane purification, remove particles and other impurities, thereby improving the purity of the prepared ammonia water.

[0008] In a specific feasible implementation, perform pretreatment before defatting purification of liquid ammonia, add a treatment agent to the liquid ammonia, and the treatment agent includes a mixture composed of polyoxyethylene fatty acid ester and polyoxyethylene laurate.

[0009] By adopting the above technical solutions, polyoxyethylene fatty acid ester and polyoxyethylene laurate can dissolve in the oily impurities in liquid ammonia, separate the ammonia water, and polyoxyethylene laurate can also promote the dispersion of the treatment agent, so that the oily impurities in liquid ammonia can be better separated, facilitating defatting purification.

[0010] In a specific feasible implementation, the weight ratio of the treatment agent to the liquid ammonia is 1:(150 - 250).

[0011] By adopting the above technical solution, the ratio of the treating agent to liquid ammonia is further defined in the present application, thereby improving the purification effect of oil removal and purification.

[0012] In a specific feasible embodiment, in the oil removal and purification step, an oil-water separator is used for oil removal and purification, and a graphene composite membrane is provided in the oil-water separator; the preparation method of the graphene composite membrane includes the following steps:

[0013] Dimethylvinyl ethoxysilane, ethanol, and water are stirred and mixed evenly to obtain a spraying solution; the graphite oxide powder is stirred, and during the stirring process, the spraying solution is sprayed on the graphite oxide powder and dried to obtain a modified powder;

[0014] The modified powder is added to water, stirred evenly to obtain a dispersion, and the dispersion is filtered by a microporous filter membrane so that the modified powder is loaded on the microporous filter membrane, and vacuum dried to obtain a graphene composite membrane.

[0015] By adopting the above technical solution, dimethylvinyl ethoxysilane is first dissolved in ethanol, then sprayed on the surface of the graphite oxide powder and dried. Dimethylvinyl ethoxysilane coats the graphite oxide powder to complete the modification of the graphite oxide powder, so that the graphite oxide powder is evenly loaded on the microporous filter membrane to obtain a graphene composite membrane; the addition of the graphite oxide powder can improve the purification effect of oil removal and purification; in addition, the graphite oxide powder also has a good adsorption effect, so that the raw material can be further purified, and thus the purity of the prepared ammonia water is further improved.

[0016] In a specific feasible embodiment, the weight ratio of the dimethylvinyl ethoxysilane to the graphite oxide powder is 1:(65 - 75).

[0017] By adopting the above technical solution, the ratio of dimethylvinyl ethoxysilane to graphite oxide powder is further defined in the present application, so that dimethylvinyl ethoxysilane can better coat the graphite oxide powder, thereby improving the modification effect of the graphite oxide powder.

[0018] In a specific feasible embodiment, in the low-temperature evaporation step, a liquid ammonia evaporation device is used for low-temperature evaporation; the liquid ammonia evaporation device includes a cylinder body and an electric heating element arranged on the cylinder body, a feed port is opened on the bottom wall of the cylinder body, a discharge pipe is arranged on the top wall of the cylinder body, and a demister is installed on the discharge pipe.

[0019] By adopting the above technical solution, by using the above liquid ammonia evaporation device, impurities such as metal ions and TOC in the raw material can be effectively removed.

[0020] In a specific feasible embodiment, the temperature in the low-temperature evaporation step is 20-30°C.

[0021] In a specific feasible embodiment, in both the primary mixing absorption and the secondary mixing absorption steps, a microchannel mixing absorber is used for mixing absorption.

[0022] In a specific feasible embodiment, in the stripping step, stripping is carried out using a stripping column.

[0023] In a specific feasible embodiment, in the filtration step, filtration is carried out through a 10-nm microchannel.

[0024] In summary, the present application includes at least one of the following beneficial technical effects:

[0025] 1. In the present application, first, oil removal and purification are carried out to remove oily impurities in liquid ammonia, and then low-temperature evaporation and adsorption are carried out to remove impurities such as metal ions and TOC in the raw material. Then, through a series of operations such as filtration, stripping, and membrane purification, particles and other impurities are removed, thus improving the purity of the prepared ammonia water.

[0026] 2. In the present application, a treatment agent is used to pretreat liquid ammonia first. The polyoxyethylene fatty acid ester and polyoxyethylene laurate in the treatment agent can dissolve in the oily impurities in liquid ammonia, separating the ammonia water. Moreover, polyoxyethylene laurate can also promote the dispersion of the treatment agent, so that the oily impurities in liquid ammonia can be better separated, facilitating oil removal and purification.

[0027] 3. In the present application, dimethylethenyl ethoxysilane is first dissolved in ethanol, and then sprayed on the surface of graphite oxide powder and dried. Dimethylethenyl ethoxysilane coats the graphite oxide powder, completing the modification of the graphite oxide powder, so that the graphite oxide powder is uniformly loaded on the microporous filter membrane to obtain a graphene composite membrane; the addition of graphite oxide powder can improve the purification effect of oil removal and purification; in addition, graphite oxide powder also has a good adsorption effect, so that impurities in the raw material can be further removed, thus further improving the purity of the prepared ammonia water. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic structural diagram showing the overall liquid ammonia evaporation equipment in Embodiment 1 of the present application.

[0029] Description of the reference numerals: 1, cylinder body; 2, electric heating element; 3, feed inlet; 4, discharge pipe; 5, demister. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The following further details the present application in conjunction with embodiments.

[0031] All raw materials in the examples are commercially available.

[0032] Preparation Example

[0033] Preparation Example 1

[0034] Preparation Example 1 provides a method for preparing a graphene composite membrane, comprising the following steps:

[0035] Stir and mix dimethylethenyl ethoxysilane, ethanol, and water evenly to obtain a spraying solution; add graphite oxide powder to a high-speed mixer, and during stirring, spray the spraying solution onto the graphite oxide powder. After spraying, stir for another 0.5 h, and then dry at 50 °C for 2 h to obtain a modified powder; wherein the weight ratio of dimethylethenyl ethoxysilane, ethanol, and water in the spraying solution is 5:18:2; the weight ratio of dimethylethenyl ethoxysilane to graphite oxide powder is 1:60;

[0036] Add the modified powder to water, stir evenly to obtain a dispersion, filter the dispersion using a microporous membrane, so that the modified powder is loaded on the microporous membrane, and vacuum dry at 30 °C for 24 h to obtain a graphene composite membrane; wherein the weight ratio of the modified powder to water in the dispersion is 1:5.

[0037] Preparation Example 2

[0038] The difference between Preparation Example 2 and Preparation Example 1 is that the weight ratio of dimethylethenyl ethoxysilane to graphite oxide powder is 1:65; the remaining steps are the same as those in Preparation Example 1.

[0039] Preparation Example 3

[0040] The difference between Preparation Example 3 and Preparation Example 1 is that the weight ratio of dimethylethenyl ethoxysilane to graphite oxide powder is 1:70; the remaining steps are the same as those in Preparation Example 1.

[0041] Preparation Example 4

[0042] The difference between Preparation Example 4 and Preparation Example 1 is that the weight ratio of dimethylethenyl ethoxysilane to graphite oxide powder is 1:75; the remaining steps are the same as those in Preparation Example 1.

[0043] Preparation Example 5

[0044] The difference between Preparation Example 5 and Preparation Example 1 is that the weight ratio of dimethylethenyl ethoxysilane to graphite oxide powder is 1:80; the remaining steps are the same as those in Preparation Example 1.

[0045] Example

[0046] Example 1

[0047] Example 1 provides a liquid ammonia evaporation device.

[0048] Reference Figure 1 , an ammonia evaporation device, including a cylinder body 1, an electric heating element 2 is installed on the cylinder body 1, a feed port 3 is opened on the bottom wall of the cylinder body 1, a discharge pipe 4 is communicated and arranged on the top wall of the cylinder body 1, and a demister 5 is installed on the discharge pipe 4.

[0049] Example 1 also provides a production process of electronic chemical ammonia water, including the following steps:

[0050] Add liquid ammonia into an oil-water separator for deoiling and purification. The graphene composite membrane in the oil-water separator is selected as the graphene composite membrane in Preparation Example 1; then the deoiled and purified liquid ammonia enters the cylinder body 1 through the feed port 3 for low-temperature evaporation at 20 °C to obtain ammonia gas, which is adsorbed by high-purity Teflon material, then filtered through a 10-nm microchannel, and cooled by a cooler; the cooled ammonia gas is added into a microchannel mixing absorber, and at the same time, ultrapure water is added for primary mixing absorption, and then air stripping is carried out by an air stripping tower; the air-stripped ammonia gas is added into the microchannel mixing absorber again, and at the same time, ultrapure water is added for secondary mixing absorption, and then cooled by a cooler; finally, purification is carried out by a nanofiltration membrane, and preparation is carried out by ultrapure water to obtain electronic chemical ammonia water.

[0051] Examples 2-5

[0052] As shown in Table 1, the main difference between Examples 2-5 and Example 1 lies in the selection of the graphene composite membrane.

[0053] Table 1 Selection of graphene composite membrane in Examples 2-5

[0054] Sample Selection of Graphene Composite Film Example 1 Preparation Example 1 Example 2 Preparation Example 2 Example 3 Preparation Example 3 Example 4 Preparation Example 4 Example 5 Preparation Example 5

[0055] Example 6

[0056] The difference between Example 6 and Example 3 is that a treatment agent is added to the liquid ammonia and stirred evenly to obtain treated liquid ammonia; the treated liquid ammonia is added into an oil-water separator for deoiling and purification; the treatment agent includes a mixture composed of polyoxyethylene fatty acid ester and polyoxyethylene laurate, and the weight ratio of polyoxyethylene fatty acid ester to polyoxyethylene laurate is 2:1; the weight ratio of the treatment agent to the liquid ammonia is 1:100; the remaining steps are the same as those in Example 3.

[0057] Example 7

[0058] The difference between Example 7 and Example 6 is that the weight ratio of the treatment agent to the liquid ammonia is 1:150; the remaining steps are the same as those in Example 6.

[0059] Example 8

[0060] Example 8 is different from Example 6 in that the weight ratio of the treatment agent to liquid ammonia is 1:200; the remaining steps are the same as those in Example 6.

[0061] Example 9

[0062] Example 9 is different from Example 6 in that the weight ratio of the treatment agent to liquid ammonia is 1:250; the remaining steps are the same as those in Example 6.

[0063] Example 10

[0064] Example 10 is different from Example 6 in that the weight ratio of the treatment agent to liquid ammonia is 1:300; the remaining steps are the same as those in Example 6.

[0065] Example 11

[0066] Example 11 is different from Example 8 in that the treatment agent is polyoxyethylene fatty acid ester; the remaining steps are the same as those in Example 8.

[0067] Example 12

[0068] Example 12 is different from Example 8 in that the treatment agent is polyoxyethylene laurate; the remaining steps are the same as those in Example 8.

[0069] Example 13

[0070] Example 13 is different from Example 8 in that the deoiled and purified liquid ammonia enters the cylinder 1 through the feed port 3 and undergoes low-temperature evaporation at 25 °C to obtain ammonia gas; the remaining steps are the same as those in Example 8.

[0071] Example 14

[0072] Example 14 is different from Example 8 in that the deoiled and purified liquid ammonia enters the cylinder 1 through the feed port 3 and undergoes low-temperature evaporation at 30 °C to obtain ammonia gas; the remaining steps are the same as those in Example 8.

[0073] Comparative Example

[0074] Comparative Example 1

[0075] Electronic chemical grade ammonia water was prepared by batch distillation.

[0076] Performance detection test Purity detection: The electronic chemical grade ammonia water in each example and comparative example was detected to obtain the contents of metal ions and anions in the ammonia water. The lower the contents of metal ions and anions, the higher the purity of sulfuric acid; sodium ions were taken as an example for metal ions; chloride ions were taken as an example for anions.

[0077] Table 2 Performance detection results of electronic chemical grade ammonia water

[0078] Sample Metal Ion (ppt) Anion (ppb) Example 1 ＜10 ＜10 Example 2 ＜8 ＜8 Example 3 ＜8 ＜7 Example 4 ＜8 ＜8 Example 5 ＜10 ＜10 Example 6 ＜6 ＜6 Example 7 ＜4 ＜5 Example 8 ＜4 ＜5 Example 9 ＜4 ＜5 Example 10 ＜6 ＜6 Example 11 ＜10 ＜10 Example 12 ＜9 ＜9 Example 13 ＜3 ＜4 Example 14 ＜3 ＜3 Comparative Example 1 ＜50 ＜45

[0079] Combined with Example 1 and Comparative Example 1, the purity of the electronic chemical ammonia water in Example 1 is relatively high. It can be seen that by using the production process of the electronic chemical ammonia water in this application, first, oil removal and purification are carried out to remove oily impurities in liquid ammonia, and then low-temperature evaporation is carried out to remove impurities such as metal ions and TOC in the raw materials. Then, through a series of operations such as filtration, stripping, and membrane purification, particles and other impurities are further removed, thereby improving the purity of the prepared ammonia water.

[0080] Combined with Examples 1-5, the purity of the electronic chemical ammonia water in Examples 2-4 is relatively high. It can be seen that when preparing the graphene composite membrane, the ratio of dimethylvinyl ethoxysilane to graphite oxide powder is preferably 1:(65-75), and the separation effect of the prepared graphene composite membrane is better, which is beneficial to further improving the purity of ammonia water.

[0081] Combined with Example 3 and Example 6, the purity of the electronic chemical ammonia water in Example 6 is relatively high. It can be seen that before carrying out oil removal and purification on liquid ammonia, using a mixture composed of polyoxyethylene fatty acid ester and polyoxyethylene laurate to pretreat liquid ammonia can separate ammonia water in the oily impurities, which is convenient for oil removal and purification.

[0082] Combined with Example 6 and Examples 7-10, the purity of the electronic chemical ammonia water in Examples 7-9 is relatively high. It can be seen that when using a treatment agent to pretreat liquid ammonia, the ratio of the treatment agent to liquid ammonia is preferably 1:(150-250), and the treatment effect on liquid ammonia is better.

[0083] Combined with Example 8, Example 11 and Example 12, the purity of the electronic chemical ammonia water in Example 8 is the highest. It can be seen that when using a treatment agent to pretreat liquid ammonia, the treatment agent is preferably a mixture composed of polyoxyethylene fatty acid ester and polyoxyethylene laurate. Polyoxyethylene laurate can promote the dispersion of polyoxyethylene fatty acid ester, so that the oily impurities in liquid ammonia can be better separated, thus improving the purity of the prepared ammonia water.

[0084] Combined with Example 8, Example 13 and Example 14, it can be seen that when using a liquid ammonia evaporation device for evaporation, at a temperature of 20-30°C, increasing the evaporation temperature can improve the purity of the prepared ammonia water.

[0085] This specific embodiment is only an explanation of this application, and it is not a limitation of this application. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as it is within the scope of the claims of this application, it is protected by the patent law.

Claims

1. An ammonia water production process for electronic chemicals, characterized in that: It includes the following steps: First, a treating agent is added to liquid ammonia for pretreatment, and then the pretreated liquid ammonia is added to an oil-water separator for oil removal purification, low-temperature evaporation, adsorption, filtration, cooling, primary mixing absorption, stripping, secondary mixing absorption, cooling, membrane filtration purification, and blending to obtain electronic chemical ammonia water; the treating agent includes a mixture composed of polyoxyethylene fatty acid ester and polyoxyethylene laurate, and the weight ratio of polyoxyethylene fatty acid ester to polyoxyethylene laurate is 2:1; the weight ratio of the treating agent to the liquid ammonia is 1:(150 - 250); a graphene composite membrane is provided in the oil-water separator; the preparation method of the graphene composite membrane includes the following steps: Dimethylvinyl ethoxysilane, ethanol, and water are stirred and mixed evenly to obtain a spraying liquid; graphite oxide powder is stirred, and during the stirring process, the spraying liquid is sprayed on the graphite oxide powder and dried to obtain modified powder; the weight ratio of dimethylvinyl ethoxysilane to the graphite oxide powder is 1:(65 - 75); The modified powder is added to water and stirred evenly to obtain a dispersion liquid, and the dispersion liquid is filtered using a microporous membrane so that the modified powder is loaded on the microporous membrane, and vacuum drying is performed to obtain a graphene composite membrane; In the low-temperature evaporation step, low-temperature evaporation is carried out using a liquid ammonia evaporation device; the liquid ammonia evaporation device includes a cylinder body (1) and an electric heating element (2) provided on the cylinder body (1), a feed port (3) is opened on the bottom wall of the cylinder body (1), a discharge pipe (4) is provided on the top wall of the cylinder body (1), and a demister (5) is installed on the discharge pipe (4).

2. The ammonia water production process of an electronic chemical according to claim 1, characterized in that: In the low-temperature evaporation step, the temperature is 20 - 30°C.

3. The ammonia water production process of an electronic chemical according to claim 1, characterized in that: In the primary mixing absorption and the secondary mixing absorption steps, a microchannel mixing absorber is used for mixing absorption.

4. The ammonia water production process of an electronic chemical according to claim 1, wherein: In the stripping step, stripping is carried out using a stripping tower.

5. The production process of electronic chemical ammonia water according to claim 1, characterized in that: In the filtration step, filtration is carried out through a 10nm microchannel.

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