Filter material for waste gas treatment and preparation method

Abstract

The present invention relates to the technical field of waste gas treatment, and specifically discloses a filter material for waste gas treatment and a preparation method. A preparation method for a filter material for waste gas treatment, comprising the following steps: Step 1: modifying aluminum oxide with sodium hydroxide, modifying magnesium oxide with pullulan and acetate starch, mixing water, sodium silicate, acetate starch, and hydroxymethyl cellulose to prepare a mixed slurry; Step 2: mixing the modified aluminum oxide, modified magnesium oxide, and the mixed slurry, and then extruding a blank; Step 3: drying and roasting the blank, and then immersing it in a mixed solution of linalool and methyl salicylate at room temperature, filtering, and drying to obtain a filter material. A filter material for waste gas treatment is prepared using the preparation method of the present application. The filter material prepared in the present application has good adsorption performance and water resistance, and can effectively purify harmful substances such as hydrogen sulfide in waste gas when the humidity of the waste gas is high.

Description

Technical Field

[0001] The present invention relates to the technical field of waste gas treatment, and in particular to a filter material for waste gas treatment and a preparation method thereof. Background Art

[0002] With the development of industrialization, the treatment and purification of industrial waste gas has received increasing attention. The waste gas generated during industrial production has a complex composition, and most of it contains harmful substances such as hydrogen sulfide and nitrogen oxides. If left untreated and released directly into the air, this waste gas will cause serious damage to the natural environment and seriously affect human respiratory tract and even physical health.

[0003] Using filter media to filter is a common way to treat waste gas in life. However, using filter media to adsorb harmful substances in waste gas also has certain limitations. When the humidity of the waste gas is high, the adsorption effect of the filter media may be reduced, and the adsorption rate of the filter media on harmful substances is greatly reduced, which may eventually cause the waste gas purified by the filter media to still fail to meet the emission standards. The waste gas generated in some industrial production processes will carry a certain degree of water vapor. In the existing technology, if filter media is used to purify this type of waste gas, the waste gas will first be passed into a dehydration tower to dehydrate the waste gas before filtering it with filter media. This waste gas treatment method increases the filtration process of the waste gas and affects the purification efficiency of the waste gas. Therefore, it is necessary to further optimize the filter media to ensure that the filter media still has good adsorption performance when the humidity of the waste gas is high. Summary of the Invention

[0004] To obtain a filter material that maintains good adsorption performance even in high-humidity exhaust gas conditions, this application provides a filter material for exhaust gas treatment and a preparation method. The preparation method for the filter material for exhaust gas treatment described herein is simple to operate and amenable to industrial production. The filter material prepared in this application also exhibits excellent adsorption and water resistance, effectively purifying harmful substances such as hydrogen sulfide from exhaust gas even in high-humidity conditions.

[0005] In the first aspect, the present application provides a filter material for waste gas treatment using the following technical solution:

[0006] A method for preparing a filter material for waste gas treatment comprises the following steps:

[0007] Step 1, preprocessing:

[0008] Step 1-1, modified aluminum oxide: adding aluminum oxide to a certain concentration of sodium hydroxide solution, shaking for a period of time, taking out and washing, then neutralizing with a certain concentration of sulfuric acid solution, washing and drying, and then calcining at 500°C for 1.5 to 2 hours to obtain modified aluminum oxide; Step 1-2, modified magnesium oxide: dissolving pullulan and acetate starch in a certain amount of water, adding magnesium carbonate, and shaking for 5 to 10 minutes, drying and gradually heating to 400°C, and calcining for 2 to 3 hours to obtain modified magnesium oxide, wherein the mass ratio of magnesium carbonate, pullulan and acetate starch is 1:(1.2 to 1.4):(0.3 to 0.5);

[0009] Step 1-3, mixing slurry: mixing water, sodium silicate, acetate starch, and hydroxymethyl cellulose in a mass ratio of 1: (0.3-0.5): (0.2-0.25): (0.02-0.04) to obtain a mixed slurry;

[0010] Step 2: uniformly mixing the modified alumina, modified magnesia and mixed slurry at a mass ratio of 1: (0.3-0.4): (1.2-1.4), and then extruding into a billet of a certain particle size;

[0011] Step 3: After drying the blank to remove moisture, calcine it at 500-550°C for 0.3-0.5h to obtain the filter material.

[0012] In the above technical scheme, the present application obtains modified alumina and modified magnesium oxide with good specific surface area and adsorption performance by modifying alumina and magnesium oxide respectively. In the preparation process of modified magnesium oxide, the present application uses magnesium carbonate to decompose into magnesium oxide at high temperature, and then uses pullulan, acetate starch and magnesium carbonate to mix and roast to modify the surface of magnesium oxide, thereby significantly improving the adsorption performance and water resistance of magnesium oxide; further, the present application prepares a mixed slurry with water, sodium silicate, acetate starch and hydroxymethyl cellulose, and mixes the mixed slurry, modified alumina and modified magnesium oxide to further improve the adsorption performance and water resistance of the filter material, thereby achieving a good effect of purifying harmful substances such as hydrogen sulfide in exhaust gas.

[0013] Preferably, Wenlun glue is further added in steps 1-3, and the mass ratio of water, sodium silicate, acetate starch, hydroxymethyl cellulose and Wenlun glue is 1: (0.3-0.5): (0.2-0.25): (0.02-0.04): (0.01-0.02).

[0014] In the above technical solution, the present application significantly reduces the cracking of the surface of the prepared filter material caused by baking at 500-550°C by further adding warm wheel glue, thereby further extending the service life of the filter material.

[0015] Preferably, the specific preparation method of the mixed slurry is as follows: after uniformly mixing water, sodium silicate and hydroxymethyl cellulose, acetate starch is added and stirred to obtain a mixed slurry.

[0016] In the above technical solution, the present application stipulates that when preparing the mixed slurry, water, sodium silicate and hydroxymethyl cellulose are mixed evenly, and then acetate starch is added and stirred evenly to obtain the mixed slurry, so as to further improve the uniformity of the mixed slurry, so that the finally prepared filter material has better specific surface area and pore volume, as well as good water resistance.

[0017] Preferably, the concentration of the sodium hydroxide solution in step 1-1 is 0.5 mol / L, the oscillation period refers to oscillation at 5-10 Hz for 1-1.5 hours, the concentration of the sulfuric acid solution is 0.2 mol / L, and the neutralization time is 0.5-0.7 hours.

[0018] In the above technical solution, the present application controls the concentration of the sodium hydroxide solution, the oscillation time, the concentration of the sulfuric acid solution and the neutralization time, so that the surface of the aluminum oxide is well modified, thereby further improving the adsorption performance of the aluminum oxide.

[0019] Preferably, in step 1-2, the mass ratio of magnesium carbonate, pullulan, starch acetate and water is 1:(1.2-1.4):(0.3-0.5):20.

[0020] Preferably, in step 1-2, drying and gradually heating to 400°C, and roasting for 2 to 3 hours means drying at 40 to 50°C, then heating the roasting temperature to 400°C at a heating rate of 10 to 15°C / min while roasting, and the total roasting time is 2 to 3 hours.

[0021] In the above technical scheme, the present application controls the mass ratio of magnesium carbonate, pullulan, and acetate starch, controls the drying temperature and roasting conditions during the preparation of modified magnesium oxide, further improves the surface modification of magnesium oxide by pullulan and acetate starch, and further improves the adsorption performance of magnesium oxide, thereby achieving the effect of further improving the adsorption performance and water resistance of the filter material, and enabling the filter material to effectively purify harmful substances such as hydrogen sulfide in the exhaust gas when the exhaust gas humidity is high.

[0022] Preferably, the particle size of the modified aluminum oxide is between 50 and 60 μm, and the particle size of the modified magnesium oxide is between 5 and 10 μm.

[0023] In the above technical solution, the present application controls the particle size of modified alumina and modified magnesium oxide, which is more conducive to extruding a blank of appropriate particle size in step 2 of the present application, thereby obtaining a filter material with a higher specific surface area and better adsorption performance, and can further improve the adsorption performance and water resistance of the filter material.

[0024] Preferably, step 3 is as follows: after drying the blank to remove moisture, calcining it at 500-550° C. for 0.3-0.5 h, then immersing it in a mixed solution of linalool and methyl salicylate in a mass ratio of 2: (1-1.5) at room temperature for 3-4 h, filtering it, and drying it at 50-60° C. to obtain a filter material.

[0025] In the above technical solution, the present application further improves the pollution holding capacity of the filter material and the types of pollutants removed by immersing the calcined filter material again in a mixed solution of linalool and methyl salicylate, thereby fixing linalool and methyl salicylate on the filter material, and especially improves the adsorption rate of the filter material for sulfur-containing compounds and nitrogen-containing compounds, such as hydrogen sulfide, methyl mercaptan, methyl sulfide, dimethylamine, trimethylamine, ammonia, etc.

[0026] In the second aspect, a filter material for waste gas treatment adopts the following technical solution:

[0027] A filter material for waste gas treatment is prepared by the preparation method of the filter material for waste gas treatment described in the first aspect.

[0028] In the above technical solution, the filter material prepared in this application has a high specific surface area and pore volume, good adsorption performance and water resistance, and can effectively purify harmful substances such as hydrogen sulfide in exhaust gas when the exhaust gas humidity is high. It is particularly suitable for use when the exhaust gas humidity is high.

[0029] In summary, this application includes at least one of the following beneficial technical effects:

[0030] 1. In the preparation process of modified magnesium oxide in the present application, magnesium carbonate is decomposed into magnesium oxide at high temperature, and then pullulan, starch acetate and magnesium carbonate are mixed and roasted. During the roasting process, pullulan and starch acetate have a positive modification effect on the surface of magnesium oxide, achieving an unexpected effect of improving the adsorption performance and water resistance of magnesium oxide.

[0031] 2. The present application improves the adsorption performance and water resistance of the filter material by mixing a mixed slurry, modified alumina, and modified magnesium oxide, and bonding the modified alumina and modified magnesium oxide together through the mixed slurry. At the same time, the acetate starch in the mixed slurry decomposes at high temperature, thereby further increasing the specific surface area and pore volume of the filter material, thereby further improving the adsorption performance of the filter material.

[0032] 3. The present application further adds Wenlun glue to the mixed slurry. The Wenlun glue interacts with sodium silicate and hydroxymethyl cellulose to significantly reduce the surface cracking of the filter material and further extend the service life of the filter material.

[0033] 4. In the present application, the calcined filter material is immersed in a mixed solution of linalool and methyl salicylate in a mass ratio of 2: (1 to 1.5) at room temperature. Linalool and methyl salicylate are fixed in the pores of the filter material, and the synergistic effect of the two further improves the adsorption rate of the filter material for sulfur-containing compounds and nitrogen-containing compounds. DETAILED DESCRIPTION

[0034] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0035] Preparation Example 1

[0036] A modified alumina, the preparation method is as follows:

[0037] Alumina was added to a 0.5 mol / L sodium hydroxide solution, shaken at a low speed of 5 Hz for 1.5 h, taken out and washed, and then neutralized with a 0.2 mol / L sulfuric acid solution for 0.5 h, washed, dried at 80 ° C, and then calcined at 500 ° C for 2 h to obtain modified alumina with a particle size between 50 and 60 μm.

[0038] Preparation Example 2

[0039] A modified alumina, different from Preparation Example 1, is prepared as follows:

[0040] Alumina was added to 0.5 mol / L sodium hydroxide solution, shaken at low speed at 10 Hz for 1 hour, taken out and washed, and then neutralized with 0.2 mol / L sulfuric acid solution for 0.7 hours, washed, dried at 100 ° C, and then calcined at 500 ° C for 1.5 hours to obtain modified alumina with a particle size between 50 and 60 μm.

[0041] Preparation Example 3

[0042] A modified magnesium oxide, the preparation method is as follows:

[0043] Pullulan and starch acetate are dissolved in a certain amount of water, magnesium carbonate is added, and then the mixture is oscillated at 5 Hz for 10 minutes, dried at 40°C, and then calcined while increasing the temperature to 400°C at a heating rate of 10°C / min. The total calcination time is 3 hours to obtain modified magnesium oxide with a particle size between 5 and 10 μm.

[0044] Among them, the mass ratio of magnesium carbonate, pullulan, acetate starch and water is 1:1.2:0.5:20.

[0045] Among them, pullulan was purchased from Shandong Jianyou Bioengineering Co., Ltd.

[0046] Among them, acetate starch was purchased from Shandong Jianyou Bioengineering Co., Ltd.

[0047] Preparation Example 4

[0048] A modified magnesium oxide, different from Preparation Example 3, is prepared as follows:

[0049] Pullulan and starch acetate are dissolved in a certain amount of water, magnesium carbonate is added, and then the mixture is oscillated at 10 Hz for 5 minutes, dried at 50°C, and then calcined while increasing the temperature to 400°C at a heating rate of 15°C / min. The total calcination time is 2 hours to obtain modified magnesium oxide with a particle size between 5 and 10 μm.

[0050] Among them, the mass ratio of magnesium carbonate, pullulan, acetate starch and water is 1:1.4:0.3:20.

[0051] Preparation Example 5

[0052] A modified magnesium oxide, which is different from Preparation Example 3 in that the mass ratio of magnesium carbonate, pullulan, acetate starch and water is 1:1.3:0.4:20.

[0053] Preparation Example 6

[0054] A modified magnesium oxide, which is different from Preparation Example 3 in that it does not contain pullulan.

[0055] Preparation Example 7

[0056] A modified magnesium oxide, which is different from Preparation Example 3 in that it does not contain starch acetate.

[0057] Preparation Example 8

[0058] A modified magnesium oxide, which is different from Preparation Example 3 in that the mass ratio of magnesium carbonate, pullulan, acetate starch and water is 1:1.1:0.2:20.

[0059] Preparation Example 9

[0060] A modified magnesium oxide, which is different from Preparation Example 3 in that the mass ratio of magnesium carbonate, pullulan, acetate starch and water is 1:1.5:0.6:20.

[0061] Preparation Example 10

[0062] A mixed pulp is prepared as follows:

[0063] After mixing water, sodium silicate and hydroxymethyl cellulose evenly, add acetate starch and stir evenly to obtain a mixed slurry.

[0064] Among them, the mass ratio of water, sodium silicate, acetate starch and hydroxymethyl cellulose is 1:0.3:0.25:0.02.

[0065] Among them, sodium silicate was purchased from Tianjin Jindong Tianzheng Fine Chemical Reagent Factory.

[0066] Among them, hydroxymethyl cellulose was purchased from Shandong Jianyou Bioengineering Co., Ltd.

[0067] Preparation Example 11

[0068] A mixed slurry, which is different from Preparation Example 10 in that the mass ratio of water, sodium silicate, acetate starch and hydroxymethyl cellulose is 1:0.5:0.2:0.04.

[0069] Preparation Example 12

[0070] A mixed slurry, which is different from Preparation Example 10 in that the mass ratio of water, sodium silicate, acetate starch and hydroxymethyl cellulose is 1:0.4:0.22:0.03.

[0071] Preparation Example 13

[0072] A mixed pulp, different from Preparation Example 10, is prepared as follows:

[0073] After mixing water, sodium silicate, hydroxymethyl cellulose and Wenlun gum evenly, add acetate starch and stir evenly to obtain a mixed slurry.

[0074] Among them, the mass ratio of water, sodium silicate, acetate starch, hydroxymethyl cellulose and Wenlun glue is 1:0.3:0.25:0.02:0.01.

[0075] Among them, Wenlun glue was purchased from Jiangsu Caiwei Biotechnology Co., Ltd., product number: feacw.

[0076] Preparation Example 14

[0077] A mixed slurry, which is different from Preparation Example 13 in that the mass ratio of water, sodium silicate, acetate starch, hydroxymethyl cellulose and Wenlun rubber is 1:0.3:0.25:0.02:0.02.

[0078] Preparation Example 15

[0079] A mixed slurry, different from that of Preparation Example 7, does not contain acetate starch.

[0080] Preparation Example 16

[0081] A mixed pulp, different from that in Preparation Example 7, does not contain hydroxymethyl cellulose.

[0082] Example 1

[0083] A filter material for waste gas treatment comprises the following preparation steps:

[0084] Step 1, preprocessing:

[0085] Step 1-1, modified alumina: refer to Preparation Example 1.

[0086] Step 1-2, modified magnesium oxide: refer to Preparation Example 3.

[0087] Steps 1-3, mixing slurry: refer to Preparation Example 10.

[0088] Step 2: Evenly mix the modified alumina, modified magnesia and mixed slurry in a mass ratio of 1:0.3:1.4, and then extrude the granular blank.

[0089] Step 3: After drying the blank to remove moisture, calcine it at 500°C for 0.5h to obtain the filter material.

[0090] Example 2

[0091] A filter material for waste gas treatment, which differs from Example 1 in that it comprises the following preparation steps:

[0092] Step 1, preprocessing:

[0093] Step 1-1, modified alumina: refer to Preparation Example 2.

[0094] Step 1-2, modified magnesium oxide: refer to Preparation Example 4.

[0095] Steps 1-3, mixing slurry: refer to Preparation Example 11.

[0096] Step 2: Evenly mix the modified alumina, modified magnesia and mixed slurry in a mass ratio of 1:0.4:1.2, and then extrude the granular blank.

[0097] Step 3: After drying the blank to remove moisture, calcine it at 550°C for 0.3h to obtain the filter material.

[0098] Example 3

[0099] A filter material for waste gas treatment, which differs from Example 1 in that it comprises the following preparation steps:

[0100] Step 1, preprocessing:

[0101] Step 1-1, modified alumina: refer to Preparation Example 2.

[0102] Step 1-2, modified magnesium oxide: refer to Preparation Example 5.

[0103] Steps 1-3, mixing slurry: refer to Preparation Example 12.

[0104] Step 2: Evenly mix the modified alumina, modified magnesia and mixed slurry in a mass ratio of 1:0.35:1.3, and then extrude the granular blank.

[0105] Step 3: After drying the blank to remove moisture, calcine it at 550°C for 0.3h to obtain the filter material.

[0106] Example 4

[0107] A filter material for waste gas treatment, which is different from Example 1 in that:

[0108] The preparation of the mixed slurry refers to Preparation Example 13.

[0109] Example 5

[0110] A filter material for waste gas treatment, which is different from Example 1 in that:

[0111] The preparation of the mixed slurry refers to Preparation Example 14.

[0112] Example 6

[0113] A filter material for waste gas treatment, which is different from Example 4 in that step 3 is as follows:

[0114] The blank was dried to remove moisture, calcined at 500°C for 0.5h, and then immersed in a mixed solution of linalool and methyl salicylate in a mass ratio of 2:1 at room temperature for 4h. The blank was filtered and dried at 60°C to obtain a filter material.

[0115] Linalool was purchased from Shandong Guohua Chemical Co., Ltd. with CAS number: 78-70-6.

[0116] Among them, methyl salicylate was purchased from Henan Tianchou Chemical Products Co., Ltd., CAS No.: 119-36-8.

[0117] Example 7

[0118] A filter material for waste gas treatment, which is different from Example 4 in that step 3 is as follows:

[0119] The blank was dried to remove moisture, calcined at 500°C for 0.5h, and then immersed in a mixed solution of linalool and methyl salicylate in a mass ratio of 2:1.5 at room temperature for 3h. The blank was filtered and dried at 50°C to obtain a filter material.

[0120] Comparative Example 1

[0121] A filter material for waste gas treatment, which is different from Example 1 in that:

[0122] The preparation of modified magnesium oxide refers to Preparation Example 6.

[0123] Comparative Example 2

[0124] A filter material for waste gas treatment, which is different from Example 1 in that:

[0125] The preparation of modified magnesium oxide refers to Preparation Example 7.

[0126] Comparative Example 3

[0127] A filter material for waste gas treatment, which is different from Example 1 in that:

[0128] The preparation of modified magnesium oxide refers to Preparation Example 8.

[0129] Comparative Example 4

[0130] A filter material for waste gas treatment, which is different from Example 1 in that:

[0131] The preparation of modified magnesium oxide refers to Preparation Example 9.

[0132] Comparative Example 5

[0133] A filter material for waste gas treatment, which is different from Example 1 in that:

[0134] The preparation of the mixed slurry refers to Preparation Example 15.

[0135] Comparative Example 6

[0136] A filter material for waste gas treatment, which is different from Example 1 in that:

[0137] The preparation of the mixed slurry refers to Preparation Example 16.

[0138] Experimental Example 1

[0139] The filter materials with a particle size of 3 to 5 mm prepared in the above embodiments and comparative examples were observed for cracks on their surface and the observation results were recorded in Table 1.

[0140] Experimental Example 2

[0141] Testing the specific surface area and pore volume of the filter material: The specific surface area and pore volume of the filter materials with a particle size of 3 to 5 mm prepared in the above embodiments and comparative examples were analyzed using a specific surface area and porosity analyzer - Kubo-X1000. The test results are shown in Table 1.

[0142] Experimental Example 3

[0143] Test the adsorption performance of filter materials on hydrogen sulfide.

[0144] Sample: the filter materials of the above embodiments and comparative examples.

[0145] The adsorption column used in the experiment is a straight glass tube with a diameter of 16 mm and a height of 20 cm. The sample particle size is 3 to 5 mm, the filling amount is 10 g, and the hydrogen sulfide concentration in the input gas is 100 mg / m 3 , the rest is nitrogen, the gas temperature is 20℃, the gas flow rate is 300mL / min, and the saturated adsorption capacity (mg / g) and breakthrough time (min) are tested at gas humidity of 20%, 80%, and 95%. The test results are shown in Table 2.

[0146] Table 1:

[0147]

[0148]

[0149] Table 2:

[0150]

[0151]

[0152] In combination with Examples 1-7, Comparative Examples 1-6, and Tables 1 and 2, it can be found that the filter materials of Examples 1-7 have good specific surface area and pore volume, which gives Examples 1-7 good adsorption performance. Furthermore, Examples 1-7 have unexpectedly good water resistance and still have good adsorption performance even under conditions of 95% gas humidity.

[0153] Specifically combined with the analysis of Example 1 and Comparative Examples 1-2, the preparation process of the modified magnesium oxide of Comparative Examples 1-2 and Example 1 is inconsistent, Comparative Example 1 does not add pullulan, and Comparative Example 2 does not add acetate starch. The adsorption performance and water resistance of Example 1 are better than those of Comparative Examples 1-2 to a certain extent. From this analysis, it can be concluded that the present application achieves a good effect of modifying magnesium oxide by mixing pullulan, acetate starch and magnesium carbonate and roasting them, and pullulan and acetate starch have a good effect of modifying magnesium oxide, which can give magnesium oxide better adsorption performance and water resistance. Combined with the analysis of Comparative Example 3-4, the difference between Comparative Example 3-4 and Example 1 is that the mass ratio of magnesium carbonate, pullulan and acetate starch in Comparative Example 3-4 is not in the range of 1: (1.2-1.4): (0.3-0.5), and the adsorption performance and water resistance of Example 1 are better than those of Comparative Example 3-4 to a certain extent. From this further analysis, it can be obtained that only when the mass ratio of magnesium carbonate, pullulan and acetate starch is in the range of 1: (1.2-1.4): (0.3-0.5), pullulan and acetate starch have a good effect of modifying magnesium oxide, and can improve the adsorption performance and water resistance of magnesium oxide, thereby improving the adsorption performance and water resistance of the filter material.

[0154] Specifically analyzing in combination with Example 1 and Comparative Examples 5-6, it is found that the mixed slurry preparation processes of Comparative Examples 5-6 and Example 1 are inconsistent, no acetate starch is added in Comparative Example 5, and no hydroxymethyl cellulose is added in Comparative Example 6. The adsorption performance and water resistance of Example 1 are better than those of Comparative Examples 5-6 to a certain extent. From this analysis, it can be concluded that the present application adds acetate starch and hydroxymethyl cellulose to the mixed slurry at the same time, and acetate starch and hydroxymethyl cellulose interact with other components in the filter material, which can well adjust the adsorption performance and water resistance of the filter material, thereby promoting a balance between the adsorption performance and water resistance of the filter material.

[0155] Specifically combining the analysis of Example 1 and Example 4-5, the mixed slurry preparation process of Example 4-5 is inconsistent with that of Example 1, and Example 4-5 adds Wenlun glue. The appearance, adsorption performance and water resistance of Example 4-5 are better than those of Example 1 to a certain extent. From this analysis, it can be concluded that the present application further adds Wenlun glue to the mixed slurry. Wenlun glue can not only significantly reduce the surface cracking of the filter material, further extend the service life of the filter material, but also cooperate with other components in the filter material to further improve the adsorption performance and water resistance of the filter material.

[0156] Specifically combining the analysis of Example 4 and Example 6-7, in step 3 of Example 6-7, the impregnation method was continued to be used to fix linalool and methyl salicylate on the filter material. The adsorption performance of Example 6-7 was better than that of Example 4 to a certain extent. From this analysis, it can be concluded that linalool and methyl salicylate have a certain synergistic effect, which can further increase the adsorption performance of the filter material for sulfur-containing compounds.

[0157] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for preparing a filter material for waste gas treatment, characterized in that: The method comprises the following preparation steps: Step 1, preprocessing: Step 1-1, modified alumina: add alumina to a certain concentration of sodium hydroxide solution, shake for a period of time, remove and wash, then neutralize with a certain concentration of sulfuric acid solution, wash and dry, and then calcine at 500°C for 1.5-2 hours to obtain modified alumina; Step 1-2, modified magnesium oxide: dissolve pullulan and starch acetate in a certain amount of water, add magnesium carbonate, shake for 5-10 minutes, dry and gradually heat to 400°C, and calcine for 2-3 hours to obtain modified magnesium oxide, wherein the mass ratio of magnesium carbonate, pullulan and starch acetate is 1:(1.2-1.4):(0.3-0.5); Step 1-3, mixing slurry: mixing water, sodium silicate, acetate starch, and hydroxymethyl cellulose in a mass ratio of 1: (0.3-0.5): (0.2-0.25): (0.02-0.04) to obtain a mixed slurry; Step 2: Mix the modified alumina, modified magnesia and mixed slurry in a mass ratio of 1: (0.3~0.4): (1.2~1.4) and extrude into billets of a certain particle size; Step 3: After drying the blank to remove moisture, calcine it at 500-550℃ for 0.3-0.5h to obtain the filter material.

2. The method for preparing a filter material for waste gas treatment according to claim 1, characterized in that: In the steps 1-3, Wenlun glue is further added, and the mass ratio of water, sodium silicate, acetate starch, hydroxymethyl cellulose and Wenlun glue is 1: (0.3-0.5): (0.2-0.25): (0.02-0.04): (0.01-0.02).

3. The method for preparing a filter material for waste gas treatment according to claim 1, characterized in that: The specific preparation method of the mixed slurry is as follows: after uniformly mixing water, sodium silicate and hydroxymethyl cellulose, acetate starch is added and stirred to obtain a mixed slurry.

4. The method for preparing a filter material for waste gas treatment according to claim 1, characterized in that: In the step 1-1, the concentration of the sodium hydroxide solution is 0.5 mol / L, the oscillation period is 1 to 1.5 hours at 5 to 10 Hz, the concentration of the sulfuric acid solution is 0.2 mol / L, and the neutralization time is 0.5 to 0.7 hours.

5. The method for preparing a filter material for waste gas treatment according to claim 1, characterized in that: The mass ratio of magnesium carbonate, pullulan, starch acetate and water in step 1-2 is 1: (1.2-1.4): (0.3-0.5):

20.

6. The method for preparing a filter material for waste gas treatment according to claim 1, characterized in that: In the step 1-2, drying and gradually heating to 400° C. and roasting for 2-3 hours means drying at 40-50° C. and then heating the roasting temperature to 400° C. at a heating rate of 10-15° C. / min while roasting, and the total roasting time is 2-3 hours.

7. The method for preparing a filter material for waste gas treatment according to claim 1, characterized in that: The particle size of the modified aluminum oxide is between 50 and 60 μm, and the particle size of the modified magnesium oxide is between 5 and 10 μm.

8. The method for preparing a filter material for waste gas treatment according to claim 2, characterized in that: The step 3 is as follows: After drying the blank to remove moisture, it is calcined at 500-550°C for 0.3-0.5h, and then immersed in a mixed solution of linalool and methyl salicylate in a mass ratio of 2:(1-1.5) at room temperature for 3-4h. After filtering and drying at 50-60°C, a filter material is obtained.

9. A filter material for waste gas treatment, characterized in that: The filter material is prepared by the method for preparing the filter material for waste gas treatment according to any one of claims 1 to 8.

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