SCR (Selective Catalytic Reduction) catalyst based on modified basalt fiber carrier as well as preparation method and application of SCR catalyst

Abstract

The invention provides an SCR (Selective Catalytic Reduction) catalyst based on a modified basalt fiber carrier as well as a preparation method and application of the SCR catalyst. The SCR catalyst based on the modified basalt fiber carrier comprises the modified basalt fiber carrier and an active load. The preparation method of the SCR catalyst based on the modified basalt fiber carrier comprises the following steps: coating the modified basalt fiber carrier with an active slurry containing an active component, silica sol and a second auxiliary agent, and carrying out third drying and second roasting; the active component is prepared from a Cu-SSZ-13 molecular sieve. The catalyst is used for selective catalytic reduction of nitrogen oxides in a corrugated national sixth diesel engine, the reaction temperature is 100-600 DEG C, ammonia gas is used as a reducing agent, the NOx concentration is 100-1000 ppm, the ammonia-nitrogen molar ratio of the ammonia gas to NOx is 1.0-1.1, and the air speed is 30-50 kh <-1 >. The SCR catalyst based on the modified basalt fiber carrier has higher mechanical strength and high temperature resistance, and the NOx conversion rate is remarkably increased when the SCR catalyst is applied to a national sixth diesel engine.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysts, and particularly relates to an SCR catalyst based on a modified basalt fiber carrier, a preparation method thereof, and an application thereof. Background Art

[0002] Currently, the corrugated diesel engine SCR catalyst generally meets the national V standard. This is because the strength of the glass fiber carrier of the existing catalyst is difficult to meet the hydrothermal aging requirement above 700 °C of the national VI standard. Therefore, a new fiber carrier is needed to replace the glass fiber carrier to improve the high-temperature strength of the catalyst.

[0003] Basalt fiber has the characteristic of high temperature resistance. However, the composition of basalt fiber is complex. When directly replacing the glass fiber carrier with a basalt fiber carrier to prepare a catalyst, the performance decreases significantly after hydrothermal aging, and the strength also decreases. On the one hand, the presence of impurities in basalt fiber has a certain impact on the performance. On the other hand, it is inevitable that the strength of the original basalt fiber decreases after high-temperature hydrothermal aging. Based on this, seeking a scientific and efficient modification method to remove impurities in basalt fiber and improve its comprehensive strength through technical means to meet the performance and strength requirements of the national VI catalyst has important practical significance.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide an SCR catalyst based on a modified basalt fiber carrier, a preparation method thereof, and an application thereof to solve the above problems.

[0006] To achieve the above purpose, the present invention specifically adopts the following technical solutions:

[0007] An SCR catalyst based on a modified basalt fiber carrier, the catalyst comprising a modified basalt fiber carrier and an active loading; the mass ratio of the modified basalt fiber carrier to the active loading is 10:5 - 40.

[0008] Preferably, the preparation of the modified basalt fiber carrier includes: using a cleaning solution to perform impurity removal treatment and first drying on a basalt fiber paper blank, then impregnating it in a strengthening solution for modified strengthening treatment, and finally performing second drying and first calcination to obtain the modified basalt fiber carrier;

[0009] The strengthening solution includes a reinforcing agent, a first auxiliary agent, a binder, and deionized water;

[0010] Preferably, the mass ratio of the reinforcing agent, the first auxiliary agent, the binder, and deionized water is 10 - 30:1 - 5:30 - 50:30 - 60.

[0011] The impurity removal and strengthening modification means can remove the harmful components that affect the active component Cu-SSZ-13, and fill the vacancies generated by the impurities with strengthening components. This component has porous oxygen storage performance, can increase the reaction surface and reaction rate of the catalyst, and improve the catalyst performance.

[0012] Preferably, the cleaning solution includes alkaline solutions of alkali metals or alkaline earth metals such as ammonia water solution, sodium hydroxide solution, potassium hydroxide solution, calcium hydroxide solution, etc.;

[0013] Or the cleaning solution includes soluble acid solutions such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, etc.;

[0014] Preferably, the impurity removal treatment is to soak the basalt fiber paper embryo in the cleaning solution for 2 - 24 h;

[0015] More preferably, the mass concentration of the cleaning solution is 0.1% - 30%.

[0016] Conventional technical means using deionized water for cleaning can only rinse the macroscopic surface, while the acidic and alkaline substances used in the present invention can remove the alkali metals and other harmful substances in the basalt fiber that are harmful to the catalyst, forming fillable vacancies, providing a basis for the filling and bonding of the reinforcing agent. The selection of the concentration of the cleaning agent is particularly important. If the concentration is too low, the impurities cannot be removed completely, and if the concentration is too high, it will affect the strength of the original basalt skeleton, which is not conducive to the overall enhancement of the carrier strength.

[0017] Preferably, the reinforcing agent includes one or more of micron-sized or nano-sized inorganic powders such as alumina, zirconia, silica, ceria, molecular sieve, white carbon black, pseudo-boehmite, titanium dioxide, cerium-zirconium solid solution, etc.

[0018] Preferably, the first auxiliary agent includes one or more of alkylbenzene sulfonate, fatty alcohol sulfate, polyethylene glycols, polyvinyl alcohol, polyols, alkyl alcohol amides, imidazolines, ammonia water, ethanolamine, resin, ethylene glycol, polyethylene glycol, glycerol, butanol, isobutanol, alkynes, ethers, organosilicon, mineral oil, polyethers, polycarboxylates, polyacrylic acids;

[0019] More preferably, the mass concentration of the first auxiliary agent is 0.1% - 10%.

[0020] Preferably, the binder includes one or more of silica sol, aluminum sol, silica-aluminum sol, titanium sol, zirconium sol;

[0021] Preferably, the first drying includes one or more of blast drying, hot air drying, natural air drying, microwave drying;

[0022] Preferably, the second drying includes one or more of blast drying, hot air drying, natural air drying, and microwave drying.

[0023] In the technical solution of the present invention, the enhancer needs to meet conditions such as high-temperature stability, porousness, and promotion of the catalyst reaction; the co-used additive can make the binder and the enhancer disperse evenly, have good wettability, can smoothly enter the vacancies left by impurities and adhere to the surface of the basalt fiber, and improve the strength of the carrier. Moreover, if the ratio of the enhancer to components such as the first additive and the binder is inappropriate, it will lead to poor adhesion, coating cracking and peeling, and insufficient strength as expected and other adverse consequences.

[0024] The present invention provides a method for preparing the SCR catalyst based on the modified basalt fiber carrier, including: coating an active slurry including an active component, silica sol, a second additive, and deionized water on the modified basalt fiber carrier, and then successively passing through a third drying and a second calcination to obtain it;

[0025] Preferably, the mass ratio of the active component, silica sol, the second additive, and deionized water is 40-60:20-40:1-5:30-50; the active component includes Cu-SSZ-13 molecular sieve.

[0026] Optionally, the second additive includes one or more of alkylbenzene sulfonates, fatty alcohol sulfates, polyethylene glycols, polyvinyl alcohols, polyols, alkyl alcohol amides, imidazolines, ammonia water, ethanolamine, resins, ethylene glycol, polyethylene glycol, glycerol, butanol, isobutanol, alkynes, ethers, organosilicons, mineral oils, polyethers, polycarboxylates, and polyacrylic acids;

[0027] Preferably, the mass concentration of the second additive is 0.1%-10%.

[0028] Preferably, the coating includes one or a mixture of more of dip coating, vacuum coating, dip coating, and pressure boosting coating;

[0029] Preferably, the temperature of the second calcination is 450-600 °C and the time is 2-6 h.

[0030] Under the preferred calcination process conditions of the present invention, it is beneficial for the catalyst to be completely combined with the binder, can significantly improve the adhesion, and is also beneficial to the crystallization of the active component Cu, thereby improving the activity of the catalyst.

[0031] The present invention also provides an application of the SCR catalyst based on the modified basalt fiber carrier, using the catalyst for selective catalytic reduction of nitrogen oxides in a corrugated national VI diesel engine;

[0032] Preferably, the reaction temperature for the selective catalytic reduction of nitrogen oxides is 100 - 600 °C, with ammonia as the reducing agent, and the NO x concentration is 100 - 1000 ppm. The ammonia-nitrogen molar ratio of ammonia to NO x is 1.0 - 1.1, and the space velocity is 30k - 50kh -1 ;

[0033] More preferably, the application further includes first pressing the basalt fiber paper embryo into corrugated paper with a height of 0.8 - 4.2 mm, and then rolling and cutting it into a carrier size suitable for a corrugated National VI diesel engine SCR catalyst by a centerless winding method.

[0034] Advantages of the present invention:

[0035] The SCR catalyst based on a modified basalt fiber carrier provided by the present invention optimizes the basalt fiber carrier through modification, retains the advantage of high temperature resistance of basalt fiber, and overcomes the potential risk of the complex composition of basalt fiber leading to a decrease in catalyst strength, obtaining a catalyst that is both high temperature resistant and has higher strength.

[0036] The preparation method of the SCR catalyst based on a modified basalt fiber carrier provided by the present invention reduces the density of the catalyst, improves the catalyst conversion rate, reduces the catalyst usage volume, greatly reduces the production cost, and has simple process steps and mild conditions compared with traditional cordierite coating, which is conducive to industrial scale-up production.

[0037] Applying the catalyst provided by the present invention to a corrugated National VI diesel engine for the selective catalytic reduction of nitrogen oxides, due to its stronger strength and high temperature resistance, it better meets the working environment and performance requirements of high temperature aging of the National VI standard, and has important industrial practical value. Through experimental verification, the NO x conversion rate of the fresh catalyst can reach as high as 99.97% at 200 °C and 95.75% at 600 °C, and the compressive strength is as high as 1083.4 kpa; after 10 h of hydrothermal aging treatment at 750 °C, the NO x conversion rate of the catalyst provided by the present invention can still reach as high as 87.15% at 200 °C and 86.55% at 600 °C in the aged state, and the compressive strength is as high as 1018.4 kpa, and all performances are significantly better than the prior art. Description of the Drawings

[0038] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0039] Figure 1 Conversion rate measurement diagrams of the catalysts provided for the examples and comparative examples for NO x when in the fresh state;

[0040] Figure 2 Conversion rate measurement diagrams of the catalysts provided for the examples and comparative examples for NO x when in the aged state. Specific Embodiments

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, rather than all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0042] Example 1

[0043] Prepare an SCR catalyst based on a modified basalt fiber carrier according to the method provided by the present invention. The specific steps are as follows:

[0044] I. Prepare a modified basalt fiber carrier:

[0045] S1: Press the basalt fiber paper blank into a corrugated paper with a thickness of 2.2 mm, and roll and cut it into the required size;

[0046] S2: Immerse the basalt fiber paper blank obtained by cutting in S1 in 10% ammonia water for 6 h to remove the impurities of the basalt fiber. After washing with deionized water, dry it by microwave to obtain a basalt fiber paper blank after impurity removal treatment;

[0047] S3: Mix 10 kg of deionized water, 5 kg of silica sol, 1 kg of white carbon black, 0.05 kg of organosilicon dispersant, and 0.1 kg of mineral oil defoamer, stir, and then ball mill for 2 h to obtain a strengthening liquid;

[0048] S4: Immerse the basalt fiber paper blank after impurity removal treatment obtained in S2 in the strengthening liquid obtained in S3 for 60 - 120 s, take it out, blow it with air, and dry it with hot air at 250 °C for 4 h to obtain a modified basalt fiber carrier;

[0049] II. Preparation of SCR catalyst:

[0050] S5: Add 50 kg of deionized water, 20 kg of Cu-SSZ-13 molecular sieve, 10 kg of silica sol, 1 kg of ammonia water, 0.4 kg of ethanolamine, 60 g of polyethylene glycol and 120 g of organosilicon defoamer, and stir evenly to obtain the catalyst active slurry;

[0051] S6: Immerse the modified basalt fiber carrier obtained in S4 into the active slurry prepared in S5 for 12 min for coating, then dry it in hot air at 200 °C for 2 h, and calcine it at 450 °C for 4 h to obtain the SCR catalyst based on the modified basalt fiber carrier.

[0052] Example 2

[0053] Prepare the SCR catalyst based on the modified basalt fiber carrier according to the method provided by the present invention. The specific steps are as follows:

[0054] I. Preparation of modified basalt fiber carrier:

[0055] S1: Press the basalt fiber paper blank into a corrugated paper with a thickness of 1.8 mm, and roll and cut it into dimensions;

[0056] S2: Immerse the basalt fiber paper blank obtained by cutting in S1 in a 10% hydrochloric acid solution for 8 h to remove the impurities of the basalt fiber, wash it with deionized water and then dry it by microwave to obtain the basalt fiber paper blank after impurity removal treatment;

[0057] S3: Mix 10 kg of deionized water, 4 kg of aluminum sol, 1.1 kg of pseudo-boehmite, 0.06 kg of polyether dispersant and 0.12 kg of alkyne defoamer, stir evenly and then ball mill for 2 h to obtain the strengthening liquid;

[0058] S4: Immerse the basalt fiber paper blank after impurity removal treatment obtained in S2 in the strengthening liquid obtained in S3 for 60 - 120 s, take it out and blow it with air, and dry it in hot air at 200 °C for 2 h to obtain the modified basalt fiber carrier;

[0059] II. Preparation of SCR catalyst:

[0060] S5: Add 50 kg of deionized water, 20 kg of Cu-SSZ-13 molecular sieve, 10 kg of silica sol, 0.9 kg of ammonia water, 0.5 kg of ethanolamine, 55 g of fatty alcohol sulfate and 110 g of polyether defoamer, and stir evenly to obtain the catalyst active slurry;

[0061] S6: Immerse the modified basalt fiber support obtained in S4 into the active slurry prepared in S5 for 10 min to achieve coating, then dry it by microwave at 250 °C for 3 h, and calcine it at 550 °C for 3 h to obtain the SCR catalyst based on the modified basalt fiber support.

[0062] Example 3

[0063] Prepare the SCR catalyst based on the modified basalt fiber support according to the method provided by the present invention. The specific steps are as follows:

[0064] I. Prepare the modified basalt fiber support:

[0065] S1: Press the basalt fiber paper blank into corrugated paper with a thickness of 3.3 mm, roll it by the centerless winding method and cut it into the size of;

[0066] S2: Immerse the basalt fiber paper blank obtained by cutting in S1 in an 8% nitric acid solution for 6 h to remove the impurities of the basalt fiber, wash it with deionized water and then dry it by microwave to obtain the basalt fiber paper blank after impurity removal treatment;

[0067] S3: Mix 10 kg of deionized water, 4.5 kg of titanium sol, 1.2 kg of cerium-zirconium solid solution, 0.04 kg of polyethylene glycol dispersant, and 0.08 kg of silicone defoamer, stir and then ball mill for 2 h to obtain the strengthening liquid;

[0068] S4: Immerse the basalt fiber paper blank after impurity removal treatment obtained in S2 in the strengthening liquid obtained in S3, immerse it for 60 - 120 s, take it out and blow it with air, and dry it by blowing at 150 °C for 8 h to obtain the modified basalt fiber support;

[0069] II. Prepare the SCR catalyst:

[0070] S5: Add 50 kg of deionized water, 20 kg of Cu-SSZ-13 molecular sieve, 10 kg of silica sol, 0.8 kg of ammonia water, 0.6 kg of ethanolamine, 65 g of polyethylene glycol dispersant and 130 g of silicone defoamer, stir evenly to obtain the catalyst active slurry;

[0071] S6: Immerse the modified basalt fiber support obtained in S4 into the active slurry prepared in S5 for 15 min to achieve coating, then dry it by microwave at 250 °C for 3 h, and calcine it at 550 °C for 3 h to obtain the SCR catalyst based on the modified basalt fiber support.

[0072] Example 4

[0073] Prepare the SCR catalyst based on the modified basalt fiber support according to the method provided by the present invention. The specific steps are as follows:

[0074] I. Preparation of modified basalt fiber carrier:

[0075] S1: Press the basalt fiber paper embryo into corrugated paper with a thickness of 1.2 mm, roll it by the method of centerless winding and cut it into dimensions;

[0076] S2: Immerse the basalt fiber paper embryo obtained by cutting in S1 in 3% sodium hydroxide solution for 2 h to remove impurities of basalt fiber. After washing with deionized water and air-drying naturally, the basalt fiber paper embryo after impurity removal treatment is obtained;

[0077] S3: Mix 10 kg of deionized water, 4.5 kg of zirconium sol, 1.1 kg of nano-titanium dioxide, 0.04 kg of polyethylene glycol dispersant, and 0.08 kg of silicone defoamer, stir and then ball-mill for 2 h to obtain a strengthening liquid;

[0078] S4: Immerse the basalt fiber paper embryo after impurity removal treatment obtained in S2 in the strengthening liquid obtained in S3 for 60 - 120 s, take it out and blow it with air, and dry it in a blast dryer at 150 °C for 8 h to obtain a modified basalt fiber carrier;

[0079] II. Preparation of SCR catalyst:

[0080] S5: Add 50 kg of deionized water, 20 kg of Cu-SSZ-13 molecular sieve, 10 kg of silica sol, 0.9 kg of ammonia water, 0.7 kg of ethanolamine, 75 g of polyethylene glycol dispersant and 140 g of polycarboxylic acid defoamer, and stir evenly to obtain a catalyst active slurry;

[0081] S6: Immerse the modified basalt fiber carrier obtained in S4 into the active slurry prepared in S5 for 6 min for coating, then air-dry it for 24 h, and calcine it at 580 °C for 4 h to obtain an SCR catalyst based on the modified basalt fiber carrier.

[0082] Comparative Example 1

[0083] The difference from Example 3 is that the reagent used for impurity removal treatment in S2 is deionized water, that is, 8% nitric acid solution is replaced by deionized water, and the rest of the process is the same.

[0084] Comparative Example 2

[0085] The difference from Example 3 is that steps S3 and S4 are not included, that is, the modified strengthening treatment of the basalt fiber paper embryo after impurity removal with the strengthening liquid is not included, and the rest of the process is the same.

[0086] Comparative Example 3

[0087] The difference from Example 3 is that deionized water is used to replace 8% of the nitric acid solution in S2, and steps S3 and S4 are not included, that is, the impurity removal treatment of the cleaning solution is not included, nor is the modified strengthening treatment of the basalt fiber paper embryo using the strengthening solution. Instead, the catalyst is prepared by coating the active slurry on the original basalt fiber carrier after cutting.

[0088] The selective catalytic reduction application performance of the catalysts prepared in Examples 1-4 and Comparative Examples 1-3 for nitrogen oxides was tested. Samples of the same size V = 8.1 mL were taken. At the programmed temperature, the concentrations at the inlet and outlet of the catalyst before and after the reaction were measured using a flue gas analyzer to calculate the catalytic activity of the low-temperature SCR catalyst. Test conditions: NO x = 1000 mg / m 3 , ammonia was used as the reducing agent, the ammonia-nitrogen molar ratio was 1:1, and the volume percentage of O 2 was 6%, and the space velocity was 35 Kh -1 . Hydrothermal aging conditions: NO x = 500 ppm, NH 3 and NO x ammonia-nitrogen molar ratio was 1.0, space velocity 50 kh -1 , the content of H 2 O steam was 10%, and the volume percentage of O 2 was 8%, T = 750 °C, and the time was 10 h.

[0089] The test results are shown in Table 1 below and Figure 1 , Figure 2 as shown, where Figure 1 is the conversion rate of NO x by the fresh catalysts provided in Examples 1-4 and Comparative Examples 1-3, and Figure 2 is the conversion rate of NO x by the aged catalysts provided in Examples 1-4 and Comparative Examples 1-3. It can be seen from Figure 1 that in the fresh state, when the temperature is lower than 500 °C, the difference in the conversion rate of NO x by the catalysts provided in the examples and the comparative examples is small. When the temperature reaches about 600 °C, the conversion rate of NO x by the catalysts provided in the examples with the modified and strengthened basalt carriers is significantly higher than that of the catalysts prepared in the comparative examples, indicating that under the same other conditions, the modified basalt carriers provided by the present invention significantly improve the catalytic activity of the catalyst.

[0090] It can be seen from Figure 2 combined with Figure 1 that first, under the same temperature conditions, the conversion rate of NO x by the fresh catalysts is significantly higher than that of the aged catalysts. However, overall, the performance of the aged catalysts provided in the examples of the present invention is still significantly better than that of the comparative examples.

[0091] Table 1 Test Results of NO Conversion Efficiency of Fresh and Aged Catalysts in Examples and Comparative Examples x Table

[0092]

[0093] As can be seen from Table 1, the impurity removal and strengthening modification technical means provided by the present invention all play relatively obvious roles in improving the performance of the catalyst respectively. Moreover, when the impurity removal treatment and strengthening modification are comprehensively applied and synergistically function, the performance exhibited by the catalyst is further significantly improved. This is because pickling and alkali washing can remove the impurity components in basalt fibers, but the residual chloride ions and alkali metals may affect the catalyst performance. Porous materials such as silica, pseudoboehmite, and titanium dioxide can increase the surface area of the catalyst and have a certain improvement on the catalyst performance. However, as an oxygen storage material, cerium-zirconium solid solution can increase the reaction rate of the catalyst and further improve the performance of the catalyst.

[0094] The compressive strength of the catalysts provided in the examples and comparative examples was tested. The test conditions were as follows: the sample size was 100 mm × 100 mm × 100 mm, the test speed was 10 mm / min, and the mechanical strength test performance is shown in Table 2:

[0095] Table 2 Test Results of Mechanical Strength of Fresh and Aged Catalysts in Examples and Comparative Examples

[0096]

[0097] As can be seen from Table 2, the weak improvement in strength is caused by the incomplete removal of impurity substances by ammonia water cleaning. Hydrochloric acid cleaning is thorough, but the residual chloride ions cause the carrier to become crumbly after being strengthened with pseudoboehmite, resulting in a certain degree of decrease in strength. The combination tightness of cerium-zirconium solid solution and titanium dioxide with the carrier after impurity removal is strong, and the strength improvement is relatively obvious.

[0098] Please note that the technical features of the above examples can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above examples are described. However, as long as the combinations of these technical features do not conflict, they should all be considered as the scope recorded in this specification. The above examples only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An SCR catalyst based on a modified basalt fiber carrier, characterized in that, the catalyst comprises a modified basalt fiber carrier and an active loading; the mass ratio of the modified basalt fiber carrier to the active loading is 10:5 - 40.

2. The catalyst according to claim 1, characterized in that, the preparation of the modified basalt fiber carrier comprises: using a cleaning solution to perform impurity removal treatment and first drying on a basalt fiber paper blank, then impregnating it in a strengthening solution for modified strengthening treatment, and finally through second drying and first calcination to obtain the modified basalt fiber carrier; the strengthening solution comprises a reinforcing agent, a first auxiliary agent, a binder and deionized water; preferably, the mass ratio of the reinforcing agent, the first auxiliary agent, the binder and deionized water is 10 - 30:1 - 5:30 - 50:30 - 60.

3. The catalyst according to claim 2, characterized in that, the cleaning solution comprises an alkaline solution of an alkali metal or alkaline earth metal such as an ammonia water solution, a sodium hydroxide solution, a potassium hydroxide solution, a calcium hydroxide solution, etc.; or the cleaning solution comprises a soluble acid solution such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, etc.; preferably, the impurity removal treatment is to soak the basalt fiber paper blank in the cleaning solution for 2 - 24 h; preferably, the mass concentration of the cleaning solution is 0.1% - 30%.

4. The catalyst according to claim 2, characterized in that, the reinforcing agent comprises one or more of micron - sized or nano - sized inorganic powders such as alumina, zirconia, silica, ceria, molecular sieve, white carbon black, pseudo - boehmite, titanium dioxide, cerium - zirconium solid solution, etc.

5. The catalyst according to claim 2, characterized in that, the first auxiliary agent comprises one or more of alkylbenzene sulfonate, fatty alcohol sulfate, polyethylene glycols, polyvinyl alcohol, polyols, alkyl alcohol amides, imidazolines, ammonia water, ethanolamine, resins, ethylene glycol, polyethylene glycol, glycerol, butanol, isobutanol, alkynes, ethers, organosilicons, mineral oils, polyethers, polycarboxylates, polyacrylic acids; preferably, the mass concentration of the first auxiliary agent is 0.1% - 10%.

6. The catalyst according to claim 2 or 4, characterized in that, the binder comprises one or more of silica sol, aluminum sol, silica - aluminum sol, titanium sol, zirconium sol; preferably, the first drying comprises one or more of blast drying, hot - air drying, natural air drying, microwave drying; preferably, the second drying comprises one or more of blast drying, hot - air drying, natural air drying, microwave drying.

7. A preparation method of an SCR catalyst based on a modified basalt fiber carrier according to any one of claims 1 - 6, characterized in that, comprises: coating an active slurry comprising an active component, silica sol, a second auxiliary agent and deionized water on the modified basalt fiber carrier, and then successively through third drying and second calcination to obtain it; preferably, the mass ratio of the active component, silica sol, the second auxiliary agent and deionized water is 40 - 60:20 - 40:1 - 5:30 - 50; The active component includes Cu-SSZ-13 molecular sieve.

8. The preparation method according to claim 7, characterized in that the second auxiliary agent includes one or more of alkyl benzene sulfonate, fatty alcohol sulfate, polyethylene glycols, polyvinyl alcohol, polyols, alkyl alcohol amides, imidazolines, ammonia water, ethanolamine, resins, ethylene glycol, polyethylene glycol, glycerol, butanol, isobutanol, alkynes, ethers, organosilicons, mineral oils, polyethers, polycarboxylates, polyacrylic acids; Preferably, the mass concentration of the second auxiliary agent is 0.1%-10%.

9. The preparation method according to claim 7, characterized in that the coating includes one or a mixture of more of dip coating, vacuum coating, dip coating, pressure boosting coating; Preferably, the temperature of the second calcination is 450-600 °C and the time is 2-6 h.

10. An application of the SCR catalyst based on a modified basalt fiber carrier according to any one of claims 1-6, characterized in that the catalyst is used for selective catalytic reduction of nitrogen oxides in a corrugated National VI diesel engine; Preferably, the reaction temperature for the selective catalytic reduction of nitrogen oxides is 100 to 600 °C, with ammonia as the reducing agent, and the NO x concentration is 100 - 1000 ppm. The ammonia-nitrogen molar ratio of ammonia to NO x is 1.0 - 1.1, and the space velocity is 30k - 50kh -1 ; Preferably, the application further includes first pressing the basalt fiber paper embryo into a corrugated paper with a height of 0.8-4.2 mm, and then rolling and cutting it into a carrier size suitable for the SCR catalyst of the corrugated National VI diesel engine by a centerless winding method.

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