H2S adsorbent for generic semiconductor industry and preparation method of H2S adsorbent

Abstract

The invention discloses an H2S adsorbent for the generic semiconductor industry and a preparation method thereof, and the adsorbent comprises the following raw materials by weight: 80-90 parts of a carrier, 20-40 parts of a 30%-50% sodium permanganate solution, 1-10 parts of calcium carbonate and 1-3 parts of sodium acetate. The H2S adsorbent for the generic semiconductor industry provided by the invention adopts a carrier with a relatively stable supporting structure, is not easily limited by the drying degree of gas, can effectively adsorb hydrogen sulfide, has a relatively good effect in the field of air purification, and plays a role in protecting the environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of air purification, and particularly relates to an H2S adsorbent for the pan-semiconductor industry and a preparation method thereof. Background Art

[0002] The semiconductor manufacturing industry is currently one of the most important manufacturing industries in the world. As the core components of industrial equipment, electronic equipment, and network communication equipment, the production of semiconductor chips and the progress of its industry play a crucial role in national development and technological progress. At present, the strong demand for semiconductor chips in China has increased rapidly with the continuous development of domestic high-tech industries, which has also led to the expansion of the scale of related factories for semiconductor device manufacturing. A large number of chemicals and special gases used in the semiconductor production process will continuously generate process exhaust gases with complex compositions. These exhaust gases will directly affect the production capacity utilization rate, product yield, and the occupational health of employees. Among them, hydrogen sulfide (H2S) exhaust gas generated during the semiconductor wafer manufacturing process is a colorless, flammable and toxic gas with an extremely low olfactory threshold, which is highly harmful to the human body. Low-concentration hydrogen sulfide can cause fever, dizziness, and difficulty breathing, while high-concentration hydrogen sulfide can lead to asphyxiation, affect the cell oxidation process, cause tissue hypoxia, and thus cause extensive damage to organs. Moreover, high-concentration hydrogen sulfide can cause olfactory poisoning and miss the best escape opportunity. Industrially, the acidity and corrosiveness of hydrogen sulfide will cause serious corrosion to equipment and pipelines. Based on the above requirements, it is urgent to develop an effective deep desulfurization technology.

[0003] At present, the capture and removal technologies of H2S can be divided into two categories: dry methods and wet methods. Dry methods include adsorption method, membrane separation method, etc.; wet methods include alcohol amine solution absorption method, ionic liquid method and biological desulfurization, etc. Wet methods are mainly used for desulfurization occasions with high sulfur content and large scale. For the wafer manufacturing industry, dry methods with low energy consumption and high desulfurization activity are generally required. Among them, the adsorption method is considered because of its strong operability, high purification degree, etc. The core of its technology is to develop efficient adsorption materials. Commonly used adsorption materials include metal-organic frameworks (MOFs), zeolite molecular sieves, activated carbon and metal oxides, etc. Patent CN109529795A discloses a hydrogen sulfide adsorbent and its preparation method. The hydrogen sulfide adsorbent of this invention is prepared by calcining a magnesium-aluminum binary hydrotalcite precursor to form a composite aluminum-magnesium metal oxide. Although this metal oxide has a large specific surface area, it is easy to generate amorphous phase substances during the calcination process at 450°C - 650°C. Amorphous state is a complex structure disordered system and is in a metastable state in terms of energy. Under normal conditions, amorphous alloys will undergo structural relaxation. This aging effect changes the physical and mechanical properties of amorphous alloys, such as becoming brittle, aging, etc., and it is easily affected by drying conditions after calcination and is prone to absorb water in the gas and partially reduce to the hydrotalcite precursor before calcination, thus affecting adsorption. CN115055156A discloses a preparation method of a hydrogen sulfide adsorbent, which improves the traditional silica gel material and introduces MnO2 with strong oxidizing property into the gel material to obtain MnO2-SiO2 composite gel. This adsorbent can capture hydrogen sulfide gas by virtue of the large specific surface area and high porosity structure of the gel material, and to a certain extent, hydrogen sulfide can be removed. However, this gel has defects such as uneven structure and fragility, which limits its practical application. Summary of the Invention

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides an H2S adsorbent for the pan-semiconductor industry and its preparation method. On the basis of maintaining good structural stability, the hydrotalcite is modified to have uniformly distributed pores, which strengthens the absorption of hydrogen sulfide, achieves the purpose of purifying air, and at the same time, through formula adjustment, the adsorbent is not easily restricted by the gas drying degree, thus broadening the applicable environment.

[0005] The technical solution adopted by the present invention is as follows:

[0006] On the one hand, the present invention provides an H2S adsorbent for the pan-semiconductor industry, which contains the following raw materials according to parts by weight: 80 - 90 parts of a carrier, 20 - 40 parts of a 30% - 50% sodium permanganate solution, 1 - 10 parts of calcium carbonate, and 1 - 3 parts of sodium acetate.

[0007] In some embodiments, the carrier is a porous hydrotalcite.

[0008] The porous hydrotalcite used in the present invention is different from the conventional layered two-dimensional hydrotalcite. Its pores not only increase the specific surface area but also improve the phenomenon of lamellar stacking or aggregation caused by the electrostatic interaction between flat and smooth sheet-like structures, thereby enhancing the adsorption performance.

[0009] In some embodiments, the preparation of the porous hydrotalcite comprises the following steps:

[0010] (1) Mix the completely dissolved magnesium salt solution and aluminum salt solution together, denoted as solution A;

[0011] (2) Prepare an alkaline compound solution with a pH of 8 - 10, denoted as solution B;

[0012] (3) Take tetraethyl orthosilicate and mix it evenly with ethanol, denoted as solution C;

[0013] (4) Under stirring at 25 - 35 °C, simultaneously drop the above solution A and solution C into solution B, and react for 10 - 14 hours after the dropping is completed;

[0014] (5) After the reaction, control the pH value of the solution to be 10.0 ± 0.1, stand and crystallize at 70 - 90 °C for 12 - 16 hours, then cool to room temperature, and wash repeatedly with deionized water until the pH of the filtrate is < 8. The obtained filter cake is the porous hydrotalcite.

[0015] Preferably, the stirring temperature is 25 °C and the reaction time is 12 hours.

[0016] More preferably, the standing crystallization temperature is 80 °C and the time is 14 hours.

[0017] In the present invention, the crystallization step after the reaction can not only form a porous structure by etching the hydrolysis product silica of tetraethyl orthosilicate but also enable the porous hydrotalcite to form a stable crystal phase, overcoming problems such as easy fragmentation and aging.

[0018] In some embodiments, the molar ratio of the magnesium salt to the aluminum salt in the magnesium salt solution and the aluminum salt solution is (1 - 3):1.

[0019] Preferably, the magnesium salt solution is a magnesium chloride hexahydrate solution and the aluminum salt solution is an aluminum chloride hexahydrate solution.

[0020] More preferably, the molar concentration of the magnesium chloride hexahydrate solution is 0.5 - 0.9 mol / L, and the molar concentration of the aluminum chloride hexahydrate solution is 0.1 - 0.5 mol / L.

[0021] The magnesium chloride hexahydrate solution and the magnesium chloride hexahydrate solution of the present invention are prepared from deionized water and commercially available solids by self - making, and no special restrictions are imposed on the source of the commercially available solids.

[0022] In some embodiments, the volume ratio of tetraethyl orthosilicate to ethanol is 1:(7 - 11).

[0023] Preferably, the volume ratio of solution C to solution A is 1:(1 - 1.6).

[0024] In some embodiments, the dropping rate of solution A and solution C is 1 - 3 drops per second.

[0025] In some embodiments, the basic compound in the basic compound solution with a pH of 8 - 10 includes sodium hydroxide and / or sodium carbonate.

[0026] Preferably, the basic compound in the basic compound solution includes sodium hydroxide and sodium carbonate.

[0027] Further preferably, the molar ratio of sodium hydroxide to sodium carbonate is (4 - 6):1.

[0028] More preferably, the molar ratio of sodium hydroxide to sodium carbonate is 5:1.

[0029] Based on providing a basic environment, the basic compound solution adopted in the present invention controls the hydrolysis rate of tetraethyl orthosilicate therein by selecting sodium hydroxide and sodium carbonate with a molar ratio of (4 - 6):1. Pure sodium hydroxide accelerates the hydrolysis of tetraethyl orthosilicate, resulting in the inability of the formed silicon dioxide to be evenly distributed between magnesium aluminum hydrotalcite; while pure sodium carbonate slows down the reaction between magnesium salt and aluminum salt, resulting in the easy collapse and deformation of the formed hydrotalcite. The combined use of sodium hydroxide and sodium carbonate is beneficial to the formation of a porous hydrotalcite with a stable structure.

[0030] The present invention places no special restrictions on the sources of the sodium hydroxide and sodium carbonate, and they can be purchased commercially.

[0031] The inventors found the following problems in the preparation of porous hydrotalcite: 1. The pore distribution of the porous hydrotalcite is uneven; 2. The pore sizes of the porous hydrotalcite are uneven; 3. The hydrotalcite structure is unstable. The present invention improves the above problems by regulating the ratio of solution A to solution C and the dropping rate of solution A and solution C. Especially when solution A contains a magnesium salt and an aluminum salt with a molar ratio of (1 - 3):1, and solution C is a mixture of tetraethyl orthosilicate and ethanol with a volume ratio of 1:(7 - 11), the possible reason is that on the one hand, by controlling the dropping rate of solution A and solution C, the hydrolysis rate of tetraethyl orthosilicate is matched with the formation rate of magnesium aluminum hydrotalcite, so that the hydrolysis products are evenly distributed between magnesium aluminum hydrotalcite, and then dense and uniform pores are obtained after etching. On the other hand, by controlling the ratio of solution A to solution C, the generation of excessive hydrolysis products is avoided, thereby avoiding phenomena such as unstable hydrotalcite structure and uneven pore sizes caused by agglomeration.

[0032] During the preparation of the adsorbent, 30%-50% of the sodium permanganate solution used in the present invention will cause a part of the sodium permanganate to be loaded onto the porous hydrotalcite, increasing the chemical adsorption of hydrogen sulfide.

[0033] Preferably, the content of the sodium permanganate solution is 40%.

[0034] The present invention does not impose special restrictions on the source of the sodium permanganate solution, which can be purchased commercially, including but not limited to being purchased from Guangdong Hangxin Technology Co., Ltd.

[0035] In some embodiments, the weight ratio of calcium carbonate to sodium acetate is (1-7):1.

[0036] Preferably, the weight ratio of calcium carbonate to sodium acetate is 3:1.

[0037] In some embodiments, the calcium carbonate is nano-calcium carbonate.

[0038] In some embodiments, the particle size of the nano-calcium carbonate is 30-60 nm.

[0039] The nano-calcium carbonate used in the present invention can enhance the adsorption performance of the carrier adsorbent. On the one hand, its surface is rich in active -OH, has good hydrophilicity, and a large specific surface area. The calcium ions therein can coordinate with the oxygen atoms in the carboxylic acid groups of sodium acetate, improving the agglomeration phenomenon of nano-calcium carbonate. On the other hand, nano-calcium carbonate with a particle size of 30-60 nm can partially enter the pores of the porous hydrotalcite, further increasing the specific surface area. The combination of the two enhances the adsorption performance of the adsorbent.

[0040] The present invention does not impose special restrictions on the source of the nano-calcium carbonate, which can be purchased commercially, including but not limited to being purchased from Shandong Jize Nano Materials Co., Ltd.

[0041] In some embodiments, the raw materials of the adsorbent further include 1-3 parts by weight of sodium sulfate.

[0042] Preferably, the raw materials of the adsorbent further include 2 parts by weight of sodium sulfate.

[0043] The present invention does not impose special restrictions on the source of the sodium sulfate, which can be purchased commercially.

[0044] The inventor unexpectedly found that adding a certain amount of sodium sulfate can adsorb the moisture in the gas, form a water film on the surface of the adsorbent and diffuse into the pores of the porous hydrotalcite. After hydrogen sulfide is adsorbed on the surface of the porous hydrotalcite, a small part dissolves in the water film to become hydrosulfuric acid, and the hydrosulfuric acid will react slowly with the oxygen dissolved in the water to produce elemental sulfur that is insoluble in water, enhancing the chemical adsorption of hydrogen sulfide by the adsorbent.

[0045] On the other hand, the present invention provides a method for preparing an H2S adsorbent for the general semiconductor industry, comprising the following steps:

[0046] S1: Add sodium acetate, porous hydrotalcite, and calcium carbonate to a sodium permanganate solution, mix and stir for 30 - 60 minutes, and then filter to obtain a filtered product;

[0047] S2: Directly mix the filtered product obtained in S1 with sodium sulfate by stirring, and dry to obtain the H2S adsorbent for the general semiconductor industry.

[0048] The filtered product of the present invention contains a certain amount of water. Without changing the layered structure of the hydrotalcite, sodium sulfate is transformed into powdery hydrated sodium sulfate through stirring and is distributed on the surface of the hydrotalcite, maintaining good structural stability.

[0049] Preferably, the mixing and stirring time is 45 minutes.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] In the synthesis process of the hydrotalcite, the present invention modifies the hydrotalcite with magnesium salt, aluminum salt, and tetraethyl orthosilicate in a specific ratio, making it have a pore structure with uniform size and dense distribution, increasing the specific surface area, improving the adsorption performance of hydrogen sulfide, reducing air pollution, and maintaining the stable layered structure of the hydrotalcite on the basis of adding pores, making it not easy to collapse. In addition, by regulating the component ratio, the obtained H2S adsorbent is not limited by the gas drying degree, can effectively adsorb hydrogen sulfide, and oxidize part of the adsorbed hydrogen sulfide, thereby achieving the effect of purifying air and protecting the environment. Specific Embodiments

[0052] The following will illustrate the present invention in conjunction with specific implementation examples. It should be noted that the following examples are examples of the present invention, only used to illustrate the present invention, and not used to limit the present invention. Other combinations and various improvements within the concept of the present invention can be made without departing from the main idea or scope of the present invention.

[0053] Example 1

[0054] An H2S adsorbent for the general semiconductor industry, calculated by weight, comprises the following raw materials: 85 parts of a carrier, 30 parts of a 40% sodium permanganate solution, 6 parts of calcium carbonate, 2 parts of sodium acetate, and 2 parts of sodium sulfate.

[0055] The carrier is porous hydrotalcite.

[0056] The preparation of the porous hydrotalcite comprises the following steps:

[0057] (1) Mix a completely dissolved magnesium chloride hexahydrate solution and an aluminum chloride hexahydrate solution together, denoted as solution A;

[0058] (2) Prepare an alkaline compound solution with a pH of 8 - 10, denoted as Solution B;

[0059] (3) Mix tetraethyl orthosilicate and ethanol uniformly, denoted as Solution C;

[0060] (4) Under stirring at 30 °C, drop the above Solution A and Solution C into Solution B together, and react for 12 hours after the dropping is completed;

[0061] (5) After the reaction, control the pH value of the solution to be 10.0 ± 0.1, stand and crystallize at 80 °C for 14 hours, then cool to room temperature, wash repeatedly with deionized water until the pH of the filtrate < 8, and the obtained filter cake is the porous hydrotalcite.

[0062] The molar ratio of magnesium chloride hexahydrate to aluminum chloride hexahydrate in the magnesium chloride hexahydrate solution and the aluminum chloride hexahydrate solution is 2:1.

[0063] The molar concentration of the magnesium chloride hexahydrate solution is 0.7 mol / L, and the molar concentration of the aluminum chloride hexahydrate solution is 0.3 mol / L.

[0064] The volume ratio of tetraethyl orthosilicate to ethanol is 1:9.

[0065] The volume ratio of Solution C to Solution A is 1:1.3.

[0066] The dropping rate of Solution A and Solution C is 2 drops / second.

[0067] The alkaline compound in the alkaline compound solution with a pH of 8 - 10 consists of sodium hydroxide and sodium carbonate, and the molar ratio is 5:1.

[0068] The calcium carbonate is nano calcium carbonate, the particle size of the nano calcium carbonate is 30 - 60 nm, and it is purchased from Shandong Jiaze Nano Materials Co., Ltd.

[0069] The preparation method of the H2S adsorbent for the pan-semiconductor industry in this example includes the following steps:

[0070] S1: Add sodium acetate, porous hydrotalcite and calcium carbonate to the sodium permanganate solution, mix and stir for 45 minutes, then filter to obtain a filtered product;

[0071] S2: Directly mix and stir the filtered product obtained in S1 with sodium sulfate, and dry to obtain the H2S adsorbent for the pan-semiconductor industry.

[0072] Example 2

[0073] An H2S adsorbent for the pan-semiconductor industry, calculated by weight, comprises the following raw materials: 80 parts of a carrier, 20 parts of a 40% sodium permanganate solution, 1 part of calcium carbonate, 1 part of sodium acetate and 1 part of sodium sulfate.

[0074] The carrier is porous hydrotalcite.

[0075] The preparation of the porous hydrotalcite comprises the following steps:

[0076] (1) Mix the completely dissolved magnesium chloride hexahydrate solution and aluminium chloride hexahydrate solution together, denoted as solution A;

[0077] (2) Prepare an alkaline compound solution with a pH of 8 - 10, denoted as solution B;

[0078] (3) Take tetraethyl orthosilicate and mix it evenly with ethanol, denoted as solution C;

[0079] (4) Under stirring at 25°C, drop the above-mentioned solution A and solution C into solution B together, and react for 10 hours after the dropping is completed;

[0080] (5) After the reaction is completed, control the pH value of the solution to be 10.0 ± 0.1, stand and crystallize at 70°C for 12 hours, then cool to room temperature, and wash repeatedly with deionized water until the pH of the filtrate < 8. The obtained filter cake is the porous hydrotalcite.

[0081] The molar ratio of magnesium chloride hexahydrate to aluminium chloride hexahydrate in the magnesium chloride hexahydrate solution and aluminium chloride hexahydrate solution is 2:1.

[0082] The molar concentration of the magnesium chloride hexahydrate solution is 0.7 mol / L, and the molar concentration of the aluminium chloride hexahydrate solution is 0.3 mol / L.

[0083] The volume ratio of tetraethyl orthosilicate to ethanol is 1:9.

[0084] The volume ratio of solution C to solution A is 1:1.3.

[0085] The dropping rate of solution A and solution C is 2 drops / second.

[0086] The alkaline compound in the alkaline compound solution with a pH of 8 - 10 consists of sodium hydroxide and sodium carbonate, and the molar ratio is 4:1.

[0087] The calcium carbonate is nano calcium carbonate, the particle size of the nano calcium carbonate is 30 - 60 nm, and it is purchased from Shandong Jiaze Nano Materials Co., Ltd.

[0088] The preparation method of the H2S adsorbent for the pan-semiconductor industry in this example comprises the following steps:

[0089] S1: Add sodium acetate, porous hydrotalcite and calcium carbonate to the sodium permanganate solution, mix and stir for 35 minutes, and then filter to obtain a filtered product;

[0090] S2: Directly mix and stir the filtered product obtained in S1 with sodium sulfate, and dry to obtain the H2S adsorbent for the pan-semiconductor industry.

[0091] Example 3

[0092] An H2S adsorbent for the pan-semiconductor industry, by weight, comprises the following raw materials: 90 parts of a carrier, 40 parts of a 40% sodium permanganate solution, 7 parts of calcium carbonate, 1 part of sodium acetate, and 3 parts of sodium sulfate.

[0093] The carrier is porous hydrotalcite.

[0094] The preparation of the porous hydrotalcite comprises the following steps:

[0095] (1) Mix the completely dissolved magnesium chloride hexahydrate solution and aluminum chloride hexahydrate solution together, denoted as solution A;

[0096] (2) Prepare an alkaline compound solution with a pH of 8 - 10, denoted as solution B;

[0097] (3) Take tetraethyl orthosilicate and mix it evenly with ethanol, denoted as solution C;

[0098] (4) Under stirring at 35 °C, drop the above solution A and solution C into solution B together, and react for 14 hours after the dropping is completed;

[0099] (5) After the reaction, control the pH value of the solution to be 10.0 ± 0.1, stand for crystallization at 90 °C for 16 hours, then cool to room temperature, and wash repeatedly with deionized water until the pH of the filtrate < 8. The obtained filter cake is the porous hydrotalcite.

[0100] The molar ratio of magnesium chloride hexahydrate to aluminum chloride hexahydrate in the magnesium chloride hexahydrate solution and aluminum chloride hexahydrate solution is 2:1.

[0101] The molar concentration of the magnesium chloride hexahydrate solution is 0.7 mol / L, and the molar concentration of the aluminum chloride hexahydrate solution is 0.3 mol / L.

[0102] The volume ratio of tetraethyl orthosilicate to ethanol is 1:9.

[0103] The volume ratio of solution C to solution A is 1:1.3.

[0104] The dropping rate of solution A and solution C is 2 drops / second.

[0105] The alkaline compound in the alkaline compound solution with a pH of 8 - 10 consists of sodium hydroxide and sodium carbonate, and the molar ratio is 6:1.

[0106] The calcium carbonate is nano calcium carbonate, the particle size of the nano calcium carbonate is 30 - 60 nm, and it is purchased from Shandong Jize Nano Materials Co., Ltd.

[0107] The preparation method of the H2S adsorbent for the pan-semiconductor industry in this example comprises the following steps:

[0108] S1: Add sodium acetate, porous hydrotalcite, and calcium carbonate to a sodium permanganate solution, mix and stir for 55 minutes, then filter to obtain a filtered product.

[0109] S2: Directly mix the filtered product obtained in S1 with sodium sulfate by stirring, and obtain the H2S adsorbent for the pan-semiconductor industry after drying.

[0110] Example 4

[0111] An H2S adsorbent for the pan-semiconductor industry, by weight, comprises the following raw materials: 85 parts of a carrier, 30 parts of a 40% sodium permanganate solution, 6 parts of calcium carbonate, 2 parts of sodium acetate, and 2 parts of sodium sulfate.

[0112] The carrier is hydrotalcite.

[0113] The preparation of hydrotalcite comprises the following steps:

[0114] (1) Mix a completely dissolved magnesium chloride hexahydrate solution and an aluminum chloride hexahydrate solution together, denoted as solution A;

[0115] (2) Prepare an alkaline compound solution with a pH of 8 - 10, denoted as solution B;

[0116] (3) Under stirring at 30 °C, add solution A dropwise to solution B, and react for 12 hours after the addition is complete;

[0117] (4) After the reaction, control the pH value of the solution to be 10.0 ± 0.1, stand and crystallize at 80 °C for 14 hours, then cool to room temperature, and wash repeatedly with deionized water until the pH of the filtrate < 8. The obtained filter cake is hydrotalcite.

[0118] The molar ratio of magnesium chloride hexahydrate to aluminum chloride hexahydrate in the magnesium chloride hexahydrate solution and the aluminum chloride hexahydrate solution is 2:1.

[0119] The molar concentration of the magnesium chloride hexahydrate solution is 0.7 mol / L, and the molar concentration of the aluminum chloride hexahydrate solution is 0.3 mol / L.

[0120] The dropping rate of solution A is 2 drops / second.

[0121] The alkaline compound in the alkaline compound solution with a pH of 8 - 10 consists of sodium hydroxide and sodium carbonate, and the molar ratio is 5:1.

[0122] The calcium carbonate is nano calcium carbonate, the particle size of the nano calcium carbonate is 30 - 60 nm, and it is purchased from Shandong Jiaze Nano Materials Co., Ltd.

[0123] The preparation method of the H2S adsorbent for the pan-semiconductor industry in this example comprises the following steps:

[0124] S1: Add sodium acetate, hydrotalcite, and calcium carbonate to the sodium permanganate solution. After mixing and stirring for 45 minutes, filter to obtain a filtered product.

[0125] S2: Directly mix the filtered product obtained in S1 with sodium sulfate by turning and stirring. After drying, the H2S adsorbent for the semiconductor industry is obtained.

[0126] Example 5

[0127] An H2S adsorbent for the semiconductor industry contains the following raw materials by weight: 82 parts of a carrier, 22 parts of a 40% sodium permanganate solution, 2 parts of calcium carbonate, and 1 part of sodium acetate.

[0128] The carrier is porous hydrotalcite.

[0129] The preparation of the porous hydrotalcite includes the following steps:

[0130] (1) Mix the completely dissolved magnesium chloride hexahydrate solution and aluminum chloride hexahydrate solution together, denoted as solution A;

[0131] (2) Prepare an alkaline compound solution with a pH of 8 - 10, denoted as solution B;

[0132] (3) Mix tetraethyl orthosilicate and ethanol evenly, denoted as solution C;

[0133] (4) Under stirring at 25°C, drop the above solution A and solution C into solution B together. After the dropping is completed, react for 10 hours;

[0134] (5) After the reaction, control the pH value of the solution to be 10.0 ± 0.1. Let it stand and crystallize at 70°C for 12 hours, then cool to room temperature. Wash repeatedly with deionized water until the pH of the filtrate < 8. The obtained filter cake is the porous hydrotalcite.

[0135] The molar ratio of magnesium chloride hexahydrate to aluminum chloride hexahydrate in the magnesium chloride hexahydrate solution and aluminum chloride hexahydrate solution is 1:1.

[0136] The molar concentration of the magnesium chloride hexahydrate solution is 0.5 mol / L, and the molar concentration of the aluminum chloride hexahydrate solution is 0.1 mol / L.

[0137] The volume ratio of tetraethyl orthosilicate to ethanol is 1:7.

[0138] The volume ratio of solution C to solution A is 1:1.

[0139] The dropping rate of solution A and solution C is 1 drop / second.

[0140] The alkaline compound in the alkaline compound solution with a pH of 8 - 10 consists of sodium hydroxide and sodium carbonate, and the molar ratio is 5:1.

[0141] The calcium carbonate is nano-calcium carbonate with a particle size of 30 - 60 nm, purchased from Shandong Jiaze Nano Materials Co., Ltd.

[0142] In this embodiment, the preparation method of the H2S adsorbent for the pan-semiconductor industry comprises the following steps:

[0143] S1: Add sodium acetate, porous hydrotalcite and calcium carbonate to the sodium permanganate solution, mix and stir for 45 minutes, then filter to obtain a filtered product.

[0144] S2: Dry the filtered product obtained in S1 to obtain the H2S adsorbent for the pan-semiconductor industry.

[0145] Example 6

[0146] An H2S adsorbent for the pan-semiconductor industry, by weight, comprises the following raw materials: 88 parts of a carrier, 38 parts of a 40% sodium permanganate solution, 7 parts of calcium carbonate, and 1 part of sodium acetate.

[0147] The carrier is porous hydrotalcite.

[0148] The preparation of porous hydrotalcite comprises the following steps:

[0149] (1) Mix the completely dissolved magnesium chloride hexahydrate solution and aluminum chloride hexahydrate solution together, denoted as solution A.

[0150] (2) Prepare an alkaline compound solution with a pH of 8 - 10, denoted as solution B.

[0151] (3) Take tetraethyl orthosilicate and ethanol and mix them evenly, denoted as solution C.

[0152] (4) Under stirring at 35°C, drop the above solution A and solution C into solution B together, and react for 14 hours after the dropping is completed.

[0153] (5) After the reaction, control the pH value of the solution to be 10.0 ± 0.1, stand and crystallize at 90°C for 16 hours, then cool to room temperature, wash repeatedly with deionized water until the pH of the filtrate < 8, and the obtained filter cake is the porous hydrotalcite.

[0154] The molar ratio of magnesium chloride hexahydrate to aluminum chloride hexahydrate in the magnesium chloride hexahydrate solution and aluminum chloride hexahydrate solution is 3:1.

[0155] The molar concentration of the magnesium chloride hexahydrate solution is 0.9 mol / L, and the molar concentration of the aluminum chloride hexahydrate solution is 0.5 mol / L.

[0156] The volume ratio of tetraethyl orthosilicate to ethanol is 1:11.

[0157] The volume ratio of solution C to solution A is 1:1.6.

[0158] The dropping rate of Solution A and Solution C is 3 drops per second.

[0159] In the alkaline compound solution with a pH of 8 - 10, the alkaline compound consists of sodium hydroxide and sodium carbonate, and the molar ratio is 5:1.

[0160] The calcium carbonate is nano - calcium carbonate with a particle size of 30 - 60 nm, purchased from Shandong Jiaze Nano Materials Co., Ltd.

[0161] In this example, the preparation method of the H2S adsorbent for the pan - semiconductor industry includes the following steps:

[0162] S1: Add sodium acetate, porous hydrotalcite, and calcium carbonate to the sodium permanganate solution, mix and stir for 45 minutes, and then filter to obtain a filtered product.

[0163] S2: Dry the filtered product obtained in S1 to obtain the H2S adsorbent for the pan - semiconductor industry.

[0164] Example 7

[0165] This example provides an H2S adsorbent for the pan - semiconductor industry and its preparation method. The specific implementation method is the same as that of Example 1, except that the raw materials include 10 parts of calcium carbonate and 1 part of sodium acetate.

[0166] Example 8

[0167] This example provides an H2S adsorbent for the pan - semiconductor industry and its preparation method. The specific implementation method is the same as that of Example 1, except that the raw materials include 1 part of calcium carbonate and 3 parts of sodium acetate.

[0168] Example 9

[0169] This example provides an H2S adsorbent for the pan - semiconductor industry and its preparation method. The specific implementation method is the same as that of Example 1, except that the particle size of calcium carbonate is 2.8 microns, purchased from Changxing Omya Calcium Industry Co., Ltd.

[0170] Example 10

[0171] This example provides an H2S adsorbent for the pan - semiconductor industry and its preparation method. The specific implementation method is the same as that of Example 1, except that the molar ratio of magnesium chloride hexahydrate solution and aluminum chloride hexahydrate solution is 1:2.

[0172] Example 11

[0173] This example provides an H2S adsorbent for the pan - semiconductor industry and its preparation method. The specific implementation method is the same as that of Example 1, except that the molar ratio of magnesium chloride hexahydrate solution and aluminum chloride hexahydrate solution is 4:1.

[0174] Example 12

[0175] This embodiment provides an H2S adsorbent for the pan-semiconductor industry and its preparation method. The specific implementation is the same as that of Example 1, except that the volume ratio of tetraethyl orthosilicate to ethanol is 1:5.

[0176] Example 13

[0177] This embodiment provides an H2S adsorbent for the pan-semiconductor industry and its preparation method. The specific implementation is the same as that of Example 1, except that the volume ratio of tetraethyl orthosilicate to ethanol is 1:14.

[0178] Example 14

[0179] This embodiment provides an H2S adsorbent for the pan-semiconductor industry and its preparation method. The specific implementation is the same as that of Example 1, except that the volume ratio of Solution C to Solution A is 1:0.8, and the dropping rate of Solution A into Solution C is 1 drop every 2 seconds.

[0180] Example 15

[0181] This embodiment provides an H2S adsorbent for the pan-semiconductor industry and its preparation method. The specific implementation is the same as that of Example 1, except that the volume ratio of Solution C to Solution A is 1:2, and the dropping rate of Solution A into Solution C is 4 drops per second.

[0182] Performance test:

[0183] The ammonia sulfide-containing gas used in this experiment is obtained by mixing hydrogen sulfide and nitrogen. The gas flow rate is 88 mL / min, and the hydrogen sulfide concentration is 200 mg / m 3 . The hydrogen sulfide-containing gas passes through a U-shaped glass reactor (inner diameter 12 mm, height 20 cm) containing 1 g of the adsorbent. After 20 minutes of gas introduction, it is collected in series by two absorption bottles containing zinc acetate, and the outlet concentration is calculated by iodometric titration test. The tail gas is first absorbed by NaOH solution and then discharged into the air to prevent environmental pollution. The adsorbent needs to be pretreated before the desulfurization experiment. Nitrogen is introduced at 100 °C at a flow rate of 200 mL / min for 2 h to eliminate the influence of adsorbed other gases. The results are shown in Table 1.

[0184] Table 1 Hydrogen sulfide tail gas concentration

[0185]

[0186]

[0187] As can be seen from the data in Table 1, the H2S adsorbents prepared in Examples 1-15 all have a certain adsorption of hydrogen sulfide. Among them, the porous hydrotalcite as a carrier can greatly improve the adsorption of hydrogen sulfide, reduce the pollution to the atmosphere, and effectively protect the environment. It can be seen from Examples 5-6 that the addition of sodium sulfate promotes the absorption of hydrogen sulfide. In Examples 7-8, the content and ratio of calcium carbonate and sodium acetate affect the adsorption performance of the adsorbent. It can be seen from Examples 1 and 9 that the change in the particle size of calcium carbonate affects the adsorption of hydrogen sulfide. It can be seen from Examples 10-15 that the ratio of magnesium salt and aluminum salt, the concentration of tetraethyl orthosilicate solution, and the relative dosage and dropping rate of the above two both affect the formation of the structure of porous hydrotalcite, thereby resulting in a poor adsorption capacity.

[0188] The above-described embodiments do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or equivalents by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An H2S adsorbent for the pan-semiconductor industry, characterized in that, By weight, it contains the following raw materials: 80-90 parts of a carrier, 20-40 parts of a 30%-50% sodium permanganate solution, 1-10 parts of calcium carbonate, and 1-3 parts of sodium acetate.

2. The H2S adsorbent for the pan-semiconductor industry according to claim 1, wherein The carrier is a porous hydrotalcite.

3. The H2S adsorbent for the pan-semiconductor industry according to claim 2, characterized in that, The preparation of the porous hydrotalcite includes the following steps: (1) Mix the completely dissolved magnesium salt solution and aluminum salt solution together, denoted as solution A; (2) Prepare an alkaline compound solution with a pH of 8-10, denoted as solution B; (3) Mix tetraethyl orthosilicate and ethanol evenly, denoted as solution C; (4) Under stirring at 25-35 °C, simultaneously drop the above solution A and solution C into solution B, and react for 10-14 hours after the dropping is completed; (5) After the reaction, control the pH value of the solution to be 10.0 ± 0.1, stand and crystallize at 70-90 °C for 12-16 hours, then cool to room temperature, and wash repeatedly with deionized water until the pH of the filtrate is <8. The obtained filter cake is the porous hydrotalcite.

4. The H2S adsorbent for the pan-semiconductor industry according to claim 3, characterized in that, The molar ratio of the magnesium salt to the aluminum salt in the magnesium salt solution and aluminum salt solution is (1-3):

1.

5. The H2S adsorbent for the pan-semiconductor industry according to claim 3, characterized in that, The alkaline compound in the alkaline compound solution includes sodium hydroxide and / or sodium carbonate.

6. The H2S adsorbent for the pan-semiconductor industry according to claim 1, wherein The weight ratio of the calcium carbonate to the sodium acetate is (1-7):

1.

7. The H2S adsorbent for the pan-semiconductor industry according to claim 6, characterized in that, The calcium carbonate is nano-calcium carbonate.

8. The H2S adsorbent for the pan-semiconductor industry according to claim 7, wherein, The particle size of the nano-calcium carbonate is 30-60 nm.

9. The H2S adsorbent for the pan-semiconductor industry according to any one of claims 1-8, characterized in that, The raw materials of the adsorbent further include 1-3 parts by weight of sodium sulfate.

10. The preparation method of the H2S adsorbent for the pan-semiconductor industry according to claim 9, characterized in that, It includes the following steps: S1: Add sodium acetate, porous hydrotalcite, and calcium carbonate to a 30%-50% sodium permanganate solution, mix and stir for 30-60 minutes, and then filter to obtain a filtered product; S2: Directly mix and stir the filtered product obtained in S1 with sodium sulfate, and dry to obtain the H2S adsorbent for the pan-semiconductor industry.

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