V-Fe-ZSM-5 / 11 barium slag-based cocrystallization molecular sieve and preparation method thereof

Abstract

The invention belongs to the technical field of molecular sieve adsorption and NOx catalysis, and discloses a V-Fe-ZSM-5 / 11 barium slag-based co-crystallization molecular sieve and a preparation method thereof, the preparation method comprises the following steps: S1, preparing a barium slag acidification separation solution A containing ferric ions, aluminum ions and tetravalent vanadium ions; s2, preparing silicon dioxide powder with relatively high purity by utilizing the silicon-containing barium slag; s3, preparing a low-sodium V-Fe-ZSM-5 / 11 barium slag based co-crystallization molecular sieve; s4, preparing a V-Fe-ZSM-5 / 11 barium slag based co-crystallization molecular sieve with low sodium, high iron and high vanadium; the molecular sieve material is prepared by taking the barium slag as a raw material and adopting a hydrothermal method, so that the problem of environmental pollution caused by the barium slag is solved, the adsorption and NOx catalysis performance of the V-Fe-ZSM-5 / 11 barium slag-based co-crystallization molecular sieve is improved, and resource recycling is realized.

Description

Technical Field

[0001] The invention relates to the technical field of barium slag-based co-crystallized molecular sieve adsorption and catalysis, in particular to a V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve and a preparation method thereof. Background Art

[0002] Barium slag is solid waste discharged during the production of barium carbonate from barite. The storage of barium slag not only occupies a large amount of land, but also causes serious harm to the environment. However, barium slag itself also contains a large amount of barium-containing and iron-containing compounds and associated resources, which have potential recycling value. Therefore, promoting the comprehensive utilization and green development of barium slag is the most urgent practical task at present. Molecular sieves are used to adsorb and catalyze harmful gases, such as nitrogen oxides (hereinafter referred to as NO x ), is an important way to achieve resource recovery and environmental restoration, and the type and structure of molecular sieve materials often affect NO x Adsorption and catalytic effects. Summary of the invention

[0003] The present invention aims to provide a V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve and a preparation method thereof. The molecular sieve material is prepared by a hydrothermal method using barium slag as a raw material, which not only solves the environmental pollution of barium slag, but also increases the adsorption and catalytic performance of the V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve, thereby realizing resource recycling.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A method for preparing a V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve comprises the following steps:

[0006] S1: Preparation of barium slag acidification separation solution A containing trivalent iron ions, aluminum ions, and tetravalent vanadium ions:

[0007] The barium slag is washed to neutrality, and an acid solution is added to acidify it. After stirring evenly, the supernatant is taken, and hydrogen peroxide is added to perform an aging reaction to convert the divalent iron ions in the supernatant into trivalent iron ions. After the reaction is complete, vanadyl sulfate powder and aluminum sulfate reagent are added, and the solution A is obtained by dilution;

[0008] S2: Preparation of high purity silicon dioxide powder using silicon-barium slag residue:

[0009] The barium slag residue after the supernatant is taken in step S1 is washed to neutrality, dried, and crushed by ball mill to obtain barium slag residue particles, and then gravity separation is performed with a mixed solution of tribromoethane and ethanol, and the silicon dioxide obtained by gravity separation is washed and dried to obtain silicon dioxide powder with high purity;

[0010] S3: Preparation of low sodium V-Fe-ZSM-5 / 11 barium slag based co-crystallized molecular sieve:

[0011] The alkali source and the silica powder obtained in step S2 are slurried evenly in water, and the obtained supernatant is mixed with ZSM-5 / 11 molecular sieve to obtain a mixed system B; under stirring, the solution A obtained in step S1 is dripped into the mixed system B, the temperature is increased for pre-crystallization, cooled, and transferred to a reactor for reaction to obtain a mixed system C; the mixed system C is filtered, and washed with water and an acidic solution in turn to remove sodium, and a low-sodium V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve is obtained by suction filtration and washing;

[0012] S4: Preparation of low sodium, high iron and high vanadium V-Fe-ZSM-5 / 11 barium slag based co-crystallized molecular sieve:

[0013] The low-sodium, high-iron, and high-vanadium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve is obtained by adding an iron- and vanadium-containing solution to the low-sodium V-Fe-ZSM-5 / 11 eutectic molecular sieve obtained in step S3, performing ion exchange, and then filtering, washing, drying, and calcining to obtain a low-sodium, high-iron, and high-vanadium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve.

[0014] Furthermore, in S1, the acid solution has a concentration of 0.25 mol·L -1 The volume of sulfuric acid and the mass of barium slag are as follows: 10g barium slag is acidified for every 100ml sulfuric acid; the concentration of hydrogen peroxide is 30%, and the volume ratio of sulfuric acid to hydrogen peroxide is 1:40; the aging time is 3 to 5 hours; after the aging is completed, the supernatant is taken, and the molar ratio of each component in the solution A obtained by adding vanadium sulfate powder and aluminum sulfate reagent is Fe 3+ :V 4+ :Al 3+ =1:1:1~10.

[0015] Furthermore, in S2, the ball milling time is 5-8h, the ball-to-material ratio is 1:10, the particle size of the barium slag residue particles is 5-20μm; and the volume ratio of tribromoethane to ethanol is 5:1.

[0016] Further, in S3, the alkali source is sodium hydroxide; the molar ratio of the components in the mixed system B and the solution A in step S1 in terms of Al3+ is SiO2:NaOH:Al 3+ : H2O=20~60: 4~12: 1: 300~900.

[0017] Furthermore, in S3, the mass of the ZSM5 molecular sieve is 0.2 to 2 times the mass of the aluminum source in solution A in step S1, wherein the mass of the aluminum source is calculated based on the molecular weight of Al2O3.

[0018] Further, in S3, the temperature is raised to 75-80°C for pre-crystallization for 3 hours; the acidic solution is an ammonium chloride solution with a mass fraction of 10-15%.

[0019] Furthermore, S4 also includes mixing and slurrying the inorganic iron salt, vanadyl sulfate, water and the low sodium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve obtained in step S3 in a mass ratio of 0.3-1:0.3-1:10-100:1, performing ion exchange at 75-85°C for 1-10 hours, filtering and washing to obtain a low sodium, high iron and high vanadium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve filter cake.

[0020] A high-iron and high-vanadium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve prepared by the above-mentioned preparation method of V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve.

[0021] The principle and beneficial effects of the technical solution are:

[0022] The present invention uses barium slag containing iron compounds, aluminum compounds and vanadium compounds as raw materials to prepare V-Fe-ZSM-5 / 11 molecular sieves. After the original molecular sieve is subjected to iron ion exchange, the number, size and position of cations change. For example, after high-valent cations are exchanged for low-valent cations, the number of cations in the zeolite molecular sieve is reduced. On the one hand, the holes are blocked to a certain extent, the effective pore size is reduced, and the selective adsorption is enhanced. On the other hand, the surface of the zeolite molecular sieve modified with vanadium has a strong acid center, and a strong Coulomb field in the crystal pores plays a polarization role. These characteristics can improve the catalytic performance of the V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve. Therefore, the present invention uses barium slag as raw materials and adopts a hydrothermal method to prepare molecular sieve materials, which not only solves the pollution of barium slag to the environment, but also increases the adsorption and catalytic performance of the V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve modified by barium slag, and realizes resource recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 XRD diagrams of the ZSM-5 / 11 co-crystallized molecular sieve and the barium slag-based V-Fe-ZSM-5 / 11 co-crystallized molecular sieve of the present invention;

[0024] Figure 2 This is the XPS graph of the barium slag-based V-Fe-ZSM-5 / 11 co-crystallized molecular sieve of the present invention;

[0025] Figure 3The SEM images of the ZSM-5 / ZSM-11 co-crystallized molecular sieve and the barium slag-based V-Fe-ZSM-5 / ZSM-11 co-crystallized molecular sieve of the present invention are shown in FIG. 1 ; (a) and (b) are SEM images of the ZSM-5 / ZSM-11 co-crystallized molecular sieve, and (c) and (d) are SEM images of the V-Fe-ZSM-5 / ZSM-11 co-crystallized molecular sieve;

[0026] Figure 4 This is the EDX mapping diagram of the barium slag-based V-Fe-ZSM-5 / ZSM-11 co-crystallized molecular sieve of the present invention;

[0027] Figure 5 It is the TCD diagram of the barium slag based V-Fe-ZSM-5 / 11 co-crystallized molecular sieve and ZSM-5 / 11 of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the embodiments:

[0029] A method for preparing a V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve comprises the following steps:

[0030] S1: Preparation of barium slag acidification separation solution A containing trivalent iron ions, aluminum ions, and tetravalent vanadium ions:

[0031] Wash 10.0g of barium slag to neutrality, add 100ml of 0.25mol·L -1 The mixture was acidified with sulfuric acid and stirred evenly. The supernatant was taken and 2.5 ml of 30% hydrogen peroxide was added to carry out aging reaction for 4 hours to convert the divalent iron ions in the supernatant into trivalent iron ions. After the reaction was complete, 20-30 ml of the supernatant was taken and 4.5 g of vanadyl sulfate powder and aluminum sulfate powder were added. The mixed solution was then diluted to 500 ml to obtain solution A, so that the molar ratio of each component in solution A was Fe:Fe 3+ :V 4 + :Al 3+ =1:1:5;

[0032] S2: Preparation of high-purity silicon dioxide powder using silicon-barium slag residue:

[0033] The barium slag residue after the supernatant is taken in step S1 is washed to neutrality, dried, and the barium slag residue is crushed by ball milling, the ball milling time is 6 hours, and the ball-to-material ratio is 1:10, to obtain barium slag residue particles, and the particle size of the barium slag residue particles is 5-20 μm; then gravity separation is performed with a mixed solution of 300 ml of tribromoethane and 60 ml of ethanol, and the silicon dioxide obtained by gravity separation is washed and dried, the drying temperature is 100° C., and the drying time is 5 hours, to obtain 2.0 g of high-purity silicon dioxide powder;

[0034] S3: Preparation of low sodium V-Fe-ZSM-5 / 11 barium slag based co-crystallized molecular sieve:

[0035] 0.35g NaOH and 2.0g silica powder obtained in step S2 are slurried evenly in 350ml water, and 1.50g ZSM5 / 11 molecular sieve is added to the supernatant to obtain a mixed system B. Under stirring, 500ml of solution A obtained in step S1 is dripped into the mixed system B, and the mixture is heated to 75-80°C for pre-crystallization for 3h, and then cooled and transferred to a reactor to react at 180°C for 24h to obtain a mixed system C; the mixed system C is filtered, washed with water for 8-10 times, and washed with an acidic ammonium chloride solution with a mass fraction of 15% for 2-3 times to remove sodium, and low-sodium 2.4g V-Fe-ZSM-5 / 11 barium slag-based cocrystallized molecular sieve is obtained by suction filtration and washing;

[0036] Among them, the XRD test patterns of ZSM-5 / 11 co-crystallized molecular sieve and barium slag-based V-Fe-ZSM-5 / 11 co-crystallized molecular sieve are as follows: Figure 1 As shown; the XPS test diagram of the barium slag-based V-Fe-ZSM-5 / 11 co-crystallized molecular sieve is as follows Figure 2 As shown; SEM images of ZSM-5 / ZSM-11 co-crystallized molecular sieve and barium slag-based V-Fe-ZSM-5 / ZSM-11 co-crystallized molecular sieve are shown Figure 3 As shown; the EDX mapping of the barium slag-based V-Fe-ZSM-5 / ZSM-11 co-crystallized molecular sieve is shown as Figure 4 As shown; the TCD diagram of barium slag based V-Fe-ZSM-5 / 11 co-crystallized molecular sieve and ZSM-5 / 11 is as follows Figure 5 As shown;

[0037] S4: Preparation of high iron and high vanadium V-Fe-ZSM-5 / 11 barium slag based co-crystallized molecular sieve:

[0038] 0.9 g of inorganic iron salt, 0.9 g of vanadyl sulfate, 150 g of water and 2.4 g of the low sodium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve obtained in step S3 are mixed and slurried evenly, ion exchange is carried out at 95°C for 5 hours, and the mixture is filtered and washed to obtain 2.8 g of low sodium, high iron and high vanadium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve filter cake. The obtained low sodium, high iron and high vanadium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve filter cake is dried and calcined at 500°C for 3 hours to obtain a low sodium, high iron and high vanadium barium slag-based eutectic molecular sieve with high iron and vanadium content.

[0039] The high-iron and high-vanadium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve is prepared by the above-mentioned preparation method of V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve.

[0040] The barium slag-based co-crystallized molecular sieve prepared by the invention has excellent adsorption performance, which not only solves the environmental pollution caused by barium slag, but also increases the adsorption and catalytic performance of the barium slag-modified V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve, thus realizing resource recycling.

[0041] In summary, the present invention uses barium slag containing iron compounds, aluminum compounds and vanadium compounds as raw materials to prepare V-Fe-ZSM-5 / 11 molecular sieves. After the zeolite molecular sieve is exchanged with iron ions, the number, size and position of cations change. For example, after high-valent cations are exchanged for low-valent cations, the number of cations in the zeolite molecular sieve is reduced. On the one hand, the holes are blocked to a certain extent, the effective pore size is reduced, and the selective adsorption is enhanced. On the other hand, the surface of the zeolite molecular sieve modified with vanadium has a strong acid center, and there is a strong Coulomb field in the crystal pores to play a polarization role. These characteristics can also increase the adsorption and catalytic performance of the V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve. Therefore, the present invention uses barium slag as a raw material and adopts a hydrothermal method to prepare molecular sieve materials, which not only solves the pollution of barium slag to the environment, but also improves the catalytic performance of the V-Fe-ZSM-5 / 11 molecular sieve catalyst modified by barium slag, and realizes resource recycling.

[0042] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the technical solution of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for preparing a V-Fe-ZSM-5 / 11 barium slag-based cocrystallized molecular sieve, characterized in that: The following steps are involved: S1: Preparation of barium slag acidification separation solution A containing trivalent iron ions, aluminum ions, and tetravalent vanadium ions: The barium slag is washed to neutrality, and an acid solution is added to acidify it. After stirring evenly, the supernatant is taken, and hydrogen peroxide is added to perform an aging reaction to convert the divalent iron ions in the supernatant into trivalent iron ions. After the reaction is complete, vanadyl sulfate powder and aluminum sulfate reagent are added, and the solution A is obtained by dilution; S2: Preparation of high purity silicon dioxide powder using silicon-barium slag residue: The barium slag residue after the supernatant is taken in step S1 is washed to neutrality, dried, and crushed by ball mill to obtain barium slag residue particles, and then gravity separation is performed with a mixed solution of tribromoethane and ethanol, and the silicon dioxide obtained by gravity separation is washed and dried to obtain silicon dioxide powder with high purity; S3: Preparation of low sodium V-Fe-ZSM-5 / 11 barium slag based co-crystallized molecular sieve: The alkali source and the silica powder obtained in step S2 are slurried evenly in water, and the obtained supernatant is mixed with ZSM-5 / 11 molecular sieve to obtain a mixed system B; under stirring, the solution A obtained in step S1 is dripped into the mixed system B, the temperature is increased for pre-crystallization, cooled, and transferred to a reactor for reaction to obtain a mixed system C; the mixed system C is filtered, and washed with water and an acidic solution in turn to remove sodium, and a low-sodium V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve is obtained by suction filtration and washing; S4: Preparation of low sodium, high iron and high vanadium V-Fe-ZSM-5 / 11 barium slag based co-crystallized molecular sieve: The low-sodium, high-iron, and high-vanadium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve is obtained by adding an iron- and vanadium-containing solution to the low-sodium V-Fe-ZSM-5 / 11 eutectic molecular sieve obtained in step S3, performing ion exchange, and then filtering, washing, drying, and calcining to obtain a low-sodium, high-iron, and high-vanadium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve.

2. The method for preparing a V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve according to claim 1, characterized in that: In S1, the acid solution has a concentration of 0.25 mol·L -1 The volume of sulfuric acid and the mass of barium slag are as follows: 10g barium slag is acidified for every 100ml sulfuric acid; the concentration of hydrogen peroxide is 30%, and the volume ratio of sulfuric acid to hydrogen peroxide is 1:40; the aging time is 3 to 5 hours; after the aging is completed, the supernatant is taken, and the molar ratio of each component in the solution A obtained by adding vanadium sulfate powder and aluminum sulfate reagent is Fe 3+ :V 4+ :Al 3+ =1:1:1~10.

3. The method for preparing a V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve according to claim 1, characterized in that: In S2, the ball milling time is 5-8h, the ball-to-material ratio is 1:10, the particle size of the barium slag residue particles is 5-20μm; and the volume ratio of tribromoethane and ethanol is 5:

1.

4. The method for preparing a V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve according to claim 1, characterized in that: In S3, the alkali source is sodium hydroxide; the components in the mixed system B and the solution A in step S1 with Al 3+ The molar ratio is SiO2:NaOH:Al 3+ : H2O=20~60: 4~12: 1: 300~900.

5. The method for preparing a V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve according to claim 1, characterized in that: In S3, the mass of the ZSM5 molecular sieve is 0.2 to 2 times the mass of the aluminum source in solution A in step S1, wherein the mass of the aluminum source is calculated based on the molecular weight of Al2O3.

6. The method for preparing a V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve according to claim 1, characterized in that: In S3, the temperature is raised to 75-80°C for pre-crystallization for 3 hours; the acidic solution is an ammonium chloride solution with a mass fraction of 10-15%.

7. The method for preparing a V-Fe-ZSM-5 / 11 barium slag-based co-crystallized molecular sieve according to claim 1, characterized in that: S4 also includes mixing and slurrying the inorganic iron salt, vanadyl sulfate, water and the low sodium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve obtained in step S3 in a mass ratio of 0.3-1:0.3-1:10-100:1, performing ion exchange at 75-85°C for 1-10 hours, filtering and washing to obtain a low sodium, high iron and high vanadium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve filter cake.

8. A high-iron and high-vanadium V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve prepared by the method for preparing a V-Fe-ZSM-5 / 11 barium slag-based eutectic molecular sieve as described in any one of claims 1 to 7.

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