Fe-Mn-ZSM5 / 11 barium slag-based cocrystallization molecular sieve and preparation method thereof

Abstract

The invention belongs to the technical field of co-crystallization molecular sieves, and discloses a Fe-Mn-ZSM5 / 11 barium slag based co-crystallization molecular sieve and a preparation method thereof.The preparation method comprises the steps that S1, a barium slag acidification separation solution A containing ferric ions, aluminum ions and divalent manganese ions is prepared; s2, preparing a reaction solution B by using the silicon-containing barium slag; s3, preparing a low-sodium Fe-Mn-ZSM5 / 11 barium slag based co-crystallization molecular sieve; and S4, preparing the high iron and high manganese Fe-Mn-ZSM5 / 11 barium slag based co-crystallization molecular sieve. The high-iron high-manganese Fe-Mn-ZSM5 / 11 barium slag-based co-crystallization molecular sieve is prepared by taking the barium slag as a raw material and adopting a hydrothermal method, the recovery efficiency of barium is high, no additional pollution product is generated, the pollution of the barium slag to the environment is solved, and the resource waste is also reduced.

Description

Technical Field

[0001] The invention relates to the technical field of co-crystallized molecular sieves, in particular to a Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieve and a preparation method thereof. Background Art

[0002] Barium slag is a solid waste that is inevitably produced in the industrial production of barium carbonate from barite. It not only occupies a large amount of valuable land resources and poses a severe challenge to the balance of the local ecosystem, but may also pollute groundwater, soil and air through infiltration and other means, causing far-reaching and irreversible impacts on the environment. Therefore, the treatment of barium slag has always attracted much attention. However, after in-depth research on the composition of barium slag, relevant personnel found that the barium slag contains rich barium-containing and iron-containing compounds and other co-existing resources. These components give the barium slag potential recycling value, which means that they have the potential to be converted into valuable secondary resources with potential recycling value.

[0003] However, among the common treatment methods for barium slag, such as ball milling, water dissolution, acidification, etc., the recovery efficiency and resource utilization rate of barium in barium slag still need to be improved, and the resource waste rate is relatively high; and new pollutants may be generated during the treatment process, such as organic impurities and insoluble barium salts, which need further treatment, increasing the environmental burden. Summary of the invention

[0004] The present invention is intended to provide a Fe-Mn-ZSM5 / 11 barium slag-based eutectic molecular sieve and a preparation method thereof, wherein the barium slag is used as a raw material, and a high-iron and high-manganese Fe-Mn-ZSM5 / 11 barium slag-based eutectic molecular sieve is prepared by a hydrothermal method, which has high barium recovery efficiency and does not produce additional polluting products, thereby not only solving the problem of environmental pollution caused by barium slag, but also reducing resource waste. The problem in the background technology is solved.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieve comprises the following steps:

[0007] S1, preparing barium slag acidification separation solution A containing trivalent iron ions, aluminum ions, and divalent manganese ions

[0008] The silicon-barium slag is washed to neutrality, then an acid solution is added to acidify it, and after stirring evenly, the supernatant is taken, and hydrogen peroxide is added to carry out an aging reaction to convert the divalent iron ions in the supernatant into trivalent iron ions. After the reaction is complete, manganese chloride powder and aluminum sulfate reagent are added to dilute to obtain solution A;

[0009] S2, using silicon-barium slag residue to prepare reaction solution B

[0010] The barium slag residue in step S1 is washed to neutrality and dried, and then the barium slag residue is crushed by ball milling to obtain barium slag residue particles, which are then soaked in a strong alkaline solution. After the aging reaction is completed, the supernatant is taken to obtain a reaction solution B;

[0011] S3. Preparation of low sodium Fe-Mn-ZSM5 / 11 barium slag based co-crystallized molecular sieve

[0012] Dispersing ZSM5 / 11 molecular sieve into solution A, heating to accelerate ion exchange, and obtaining mixed system C; after the reaction is completed, dripping the reaction solution B obtained in step S2 into the mixed system C under stirring, heating for pre-crystallization, and transferring to a reactor for reaction after cooling to obtain a mixed system D; filtering the mixed system D, and after washing, obtaining a low-sodium Fe-Mn-ZSM5 / 11 barium slag-based cocrystallized molecular sieve;

[0013] S4. Preparation of high iron and high manganese Fe-Mn-ZSM5 / 11 barium slag based co-crystallized molecular sieve

[0014] Add iron-containing and manganese-containing solutions to the low-sodium Fe-Mn-ZSM5 / 11 barium slag-based eutectic molecular sieve obtained in step S3, heat it to carry out ion exchange, and then wash, dry and calcine it to prepare a high-iron and high-manganese Fe-Mn-ZSM5 / 11 barium slag-based eutectic molecular sieve.

[0015] Furthermore, in S1, the acid solution has a concentration of 0.25 mol·L -1 of sulfuric acid, and the volume of sulfuric acid and the mass of barium slag are based on 100ml of sulfuric acid for 10g of barium slag; 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 5h.

[0016] Furthermore, the molar ratio of each component in the prepared solution A is Fe 3+ :Mn 2+ :Al 3+ It is 2:1:2~20.

[0017] Furthermore, in S2, the ball milling time is 5-8h, and the ball-to-material ratio is 1:10. The particle size of the barium slag residue particles after ball milling is 5-20μm. The strong alkali solution has a concentration of 0.25mol·L -1 of sodium hydroxide.

[0018] Further, in the prepared reaction solution B, each component and the solution A in step S1 are Al 3+ The molar ratio is SiO2:NaOH:Al 3+ :H2O is 10~30:5~15:0.2~1:100~600.

[0019] Further, in S3, after the mixed system D is filtered, it is washed with water and an acidic solution in sequence by suction filtration to remove sodium.

[0020] Furthermore, the acidic solution is an ammonium sulfate solution or an ammonium chloride solution with a mass fraction of 10 to 15%.

[0021] Furthermore, in S3, the temperature for accelerating the ion exchange and the temperature for pre-crystallization are both 75-85° C., and the pre-crystallization time is 5 hours.

[0022] Furthermore, in S3, during the process of dispersing the ZSM5 / 11 molecular sieve into solution A, the mass of the ZSM5 / 11 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.

[0023] Furthermore, in S4, before adding the iron-containing and manganese-containing solution to the low-sodium Fe-Mn-ZSM5 / 11 barium slag-based eutectic molecular sieve, an inorganic iron salt, manganese tetrachloride, water and the low-sodium Fe-Mn-ZSM5 / 11 obtained in step S3 in a mass ratio of 0.3 to 1:0.3 to 1:4 to 10:1 are mixed and slurried, and exchanged at 75 to 85°C for 1 to 10 hours, filtered and washed to obtain a low-sodium, high-iron, high-manganese Fe-Mn-ZSM5 / 11 molecular sieve filter cake.

[0024] Furthermore, in S4, the temperature for ion exchange is raised to 75-85°C, and the solution containing iron and manganese is a mixed solution of inorganic iron salt, manganese chloride and water.

[0025] The Fe-Mn-ZSM5 / 11 barium slag-based eutectic molecular sieve prepared by the above-mentioned preparation method of the Fe-Mn-ZSM5 / 11 barium slag-based eutectic molecular sieve.

[0026] The principle and beneficial effects of the technical solution are:

[0027] 1. The present invention provides a method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based eutectic molecular sieve, which comprises dissolving metal ions such as iron and aluminum in the barium slag through an acidification reaction, and oxidizing divalent iron ions into trivalent iron ions using hydrogen peroxide to increase the stability and catalytic activity of the iron ions; adding manganese chloride powder and aluminum sulfate reagent to provide a manganese source and an aluminum source; dissolving silicon in the barium slag residue through ball milling and strong alkali soaking to form a sodium silicate solution to provide a silicon source for subsequent molecular sieve synthesis.

[0028] 2. The present invention provides a method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieve. The ZSM5 / 11 molecular sieve is used as a carrier. The iron, manganese and aluminum ions in solution A are introduced into its skeleton or pores through ion exchange, which can change the catalytic performance of the molecular sieve; solution B is dropped into the mixed system C, and the silicon source is combined with the metal ions through a hydrothermal synthesis method; more iron and manganese are introduced into the molecular sieve through ion exchange to further improve its catalytic activity.

[0029] 3. The present invention provides a method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieve, which uses barium slag as a raw material and converts it into a valuable molecular sieve through chemical treatment, thereby realizing effective recovery and reuse of resources; using barium slag as a raw material reduces the pollution of the environment by the barium slag, and at the same time, the preparation process of the molecular sieve is environmentally friendly and will not produce secondary pollution; and by introducing metal ions such as iron, manganese and aluminum, the catalytic performance of the molecular sieve is changed.

[0030] In summary, the present invention uses barium slag containing iron compounds, aluminum compounds and manganese compounds as raw materials to prepare Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized 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 pores 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 manganese has a strong acid center, and there is a strong Coulomb field in the crystal pores to play a polarization role. These characteristics increase the catalytic performance of the Fe-Mn-ZSM5 / 11 barium slag-based molecular sieve, which not only solves the pollution of barium slag to the environment, but also increases the catalytic performance of the Fe-Mn-ZSM5 / 11 molecular sieve modified by barium slag, and realizes resource recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of a method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieve according to the present invention;

[0032] Figure 2 XRD diagrams of ZSM-5 / 11 molecular sieve and the barium slag-based Fe-Mn-ZSM5 / 11 co-crystallized molecular sieve prepared by the present invention;

[0033] Figure 3 The XPS spectrum of the barium slag-based Fe-Mn-ZSM5 / 11 co-crystallized molecular sieve prepared by the present invention;

[0034] Figure 4 The SEM images of ZSM-5 / ZSM-11 molecular sieve and the barium slag-based Fe-Mn-ZSM5 / ZSM-11 co-crystallized molecular sieve prepared by the present invention;

[0035] In the figure, (a) is a SEM image of ZSM-5, (b) is a SEM image of ZSM-11; (c) is a SEM image of Fe-Mn-ZSM5, (d) is a SEM image of Fe-Mn-ZSM-11;

[0036] Figure 5 This is the EDX mapping diagram of the barium slag-based Fe-Mn-ZSM5 / ZSM-11 co-crystallized molecular sieve prepared by the present invention;

[0037] Figure 6 The TCD diagrams of the barium slag-based Fe-Mn-ZSM5 / ZSM-11 co-crystallized molecular sieve and ZSM-5 / ZSM-11 prepared in the present invention. DETAILED DESCRIPTION

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments:

[0039] like Figure 1 As shown, a method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieve comprises the following steps:

[0040] S1: Preparation of barium slag acidification separation solution A containing trivalent iron ions, aluminum ions, and divalent manganese ions

[0041] Wash 10.0g of barium slag until it is neutral, 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 for aging reaction for 4 h to convert the divalent iron ions in the supernatant into trivalent iron ions. After the reaction was complete, 0.5 g of manganese tetrachloride powder and 2 g of 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 3+ :Mn 2+ :Al 3+ =2:1:2~20;

[0042] S2: Preparation of high concentration sodium silicate solution B using silicon-barium slag residue

[0043] 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. The particle size of the barium slag residue particles is 5-20 μm. Then 0.25 mol·L -1 Sodium hydroxide solution with a volume of 100 ml is used for soaking, and the aging reaction time is about 5 hours, and the supernatant is taken to obtain sodium silicate solution B;

[0044] S3: Preparation of low sodium Fe-Mn-ZSM5 / 11 barium slag based co-crystallized molecular sieve

[0045] Disperse ZSM5 / 11 molecular sieve into solution A, heat it to 80°C to accelerate ion exchange, and obtain mixed system C; after the reaction is completed, under stirring, drip 500ml of sodium silicate solution B obtained in step S2 into mixed system C, heat it to 80°C for pre-crystallization for 3h, then cool it and transfer it to a reactor to react at 180°C for 24h to obtain mixed system D; filter mixed system D, wash it with water for 8-10 times, wash it with 15% ammonium chloride acid solution for 2-3 times to remove sodium, and obtain 2.4g low-sodium Fe-Mn-ZSM5 / 11 molecular sieve by suction filtration and washing;

[0046] S4: Preparation of Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieves with high iron and manganese content

[0047] 0.5 g of inorganic iron salt, 0.25 g of manganese dichloride, 150 g of water and 2.4 g of the low sodium Fe-Mn-ZSM5 / 11 molecular sieve obtained in step S3 are mixed and slurried evenly, exchanged at 80°C for 5 hours, filtered and washed to obtain 2.8 g of low sodium, high iron and high manganese Fe-Mn-ZSM5 / 11 molecular sieve filter cake; then the obtained low sodium, high iron and high manganese Fe-Mn-ZSM5 / 11 molecular sieve filter cake is dried and calcined at 500°C for 3 hours to obtain a low sodium, high iron and high manganese molecular sieve with high iron and high manganese content.

[0048] like Figure 2 As shown, the diffraction peaks of the barium slag-based Fe-Mn-ZSM5 / 11 co-crystallized molecular sieve prepared by the above method can match those of the standard cards ZSM-5 (PDF#42-0003) and ZSM-11 (PDF#42-0022) and have no impurity peaks, which indicates that the barium slag-based Fe-Mn-ZSM5 / 11 co-crystallized molecular sieve prepared by this method has a high purity.

[0049] like Figure 3 As shown, at binding energies of 711.27 eV, 641.84 eV, 532.03 eV, 284.81 eV, 102.87 eV and 74.46 eV, obvious orbitals of Fe 2p, Mn 2p, O 1s, C 1s, Si 2p, and Al 2p were found. Therefore, it can be judged that the barium slag-based Fe-Mn-ZSM5 / 11 co-crystallized molecular sieve prepared by the above method has chemical bonds of Si-Fe-O and Si-Mn-O.

[0050] like Figure 4As shown in Figures (a) and (b), the ZSM-5 / ZSM-11 molecular sieve presents a regular rectangular structure, about 2-5 microns long and about 1-1.5 microns wide. As can be seen from Figures (c) and (d), the surface of the molecular sieve doped with iron and manganese elements becomes very rough, which makes it possible to adsorb gas and subsequently improve catalytic performance.

[0051] like Figure 5 As shown, the barium slag-based Fe-Mn-ZSM5 / ZSM-11 co-crystallized molecular sieve prepared by the above method has a large amount of iron and manganese elements on its surface in addition to the basic silicon and aluminum elements. These elements are evenly distributed on the surface. Figure 3 The XPS spectrum conclusion is consistent with that of

[0052] like Figure 6 As shown in the figure, the desorption of NO by the barium slag-based Fe-Mn-ZSM5 / ZSM-11 co-crystallized molecular sieve prepared by the above method is related to its temperature trend. When the temperature is lower than 300°C, the desorption of Fe-Mn-ZSM5 / ZSM-11 is significantly higher than that of ZSM-5 / ZSM-11. This can also be reflected indirectly, and Fe-Mn-ZSM5 / ZSM-11 has better adsorption of NO.

[0053] In summary, the present invention uses barium slag containing iron compounds, aluminum compounds and manganese compounds as raw materials to prepare Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized 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 pores 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 manganese has a strong acid center, and there is a strong Coulomb field in the crystal pores to play a polarizing role. These characteristics increase the catalytic performance of the Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieve, which not only solves the pollution of barium slag to the environment, but also increases the catalytic performance of the Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieve modified by barium slag, thereby realizing resource recycling.

[0054] 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 Fe-Mn-ZSM5 / 11 barium slag-based cocrystallized molecular sieve, characterized in that: The following steps are involved: S1, preparing barium slag acidification separation solution A containing trivalent iron ions, aluminum ions, and divalent manganese ions The silicon-barium slag is washed to neutrality, then an acid solution is added to acidify it, and 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, manganese tetrachloride powder and aluminum sulfate reagent are added to dilute to obtain solution A; S2, using silicon-barium slag residue to prepare reaction solution B The barium slag residue in step S1 is washed to neutrality and dried, and then the barium slag residue is crushed by ball milling to obtain barium slag residue particles, which are then soaked in a strong alkaline solution. After the aging reaction is completed, the supernatant is taken to obtain a reaction solution B; S3. Preparation of low sodium Fe-Mn-ZSM5 / 11 barium slag based co-crystallized molecular sieve Dispersing ZSM5 / 11 molecular sieve into solution A, heating to accelerate ion exchange, and obtaining mixed system C; after the reaction is completed, dripping the reaction solution B obtained in step S2 into the mixed system C under stirring, heating for pre-crystallization, and transferring to a reactor for reaction after cooling to obtain a mixed system D; filtering the mixed system D, and after washing, obtaining a low-sodium Fe-Mn-ZSM5 / 11 barium slag-based cocrystallized molecular sieve; S4. Preparation of high iron and high manganese Fe-Mn-ZSM5 / 11 barium slag based co-crystallized molecular sieve Add iron-containing and manganese-containing solutions to the low-sodium Fe-Mn-ZSM5 / 11 barium slag-based eutectic molecular sieve obtained in step S3, heat it to carry out ion exchange, and then wash, dry and calcine it to prepare a high-iron and high-manganese Fe-Mn-ZSM5 / 11 barium slag-based eutectic molecular sieve.

2. The method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based cocrystallized molecular sieve according to claim 1, characterized in that: In S1, the acid solution has a concentration of 0.25 mol·L -1 of sulfuric acid, and the volume of sulfuric acid and the mass of barium slag are based on 100ml of sulfuric acid for 10g of barium slag; 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 5h.

3. The method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieve according to claim 2, characterized in that: The molar ratio of each component in the prepared solution A is Fe 3+ :Mn 2+ :Al 3+ It is 2:1:2~20.

4. The method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based cocrystallized molecular sieve according to claim 1, characterized in that: In S2, the ball milling time is 5-8h, and the ball-to-material ratio is 1:

10. The particle size of the barium slag residue after ball milling is 5-20μm. The concentration of the strong alkali solution is 0.25mol·L -1 of sodium hydroxide.

5. The method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based cocrystallized molecular sieve according to claim 4, characterized in that: In the prepared reaction solution B, each component and the solution A in step S1 are Al 3+ The molar ratio is SiO2:NaOH:Al 3+ :H2O is 10~30:5~15:0.2~1:100~600.

6. The method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based cocrystallized molecular sieve according to claim 1, characterized in that: In S3, after the mixed system D is filtered, it is washed with water and an acidic solution in sequence by suction filtration to remove sodium.

7. The method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieve according to claim 6, characterized in that: The acidic solution is an ammonium sulfate solution or an ammonium chloride solution with a mass fraction of 10 to 15%.

8. The method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based co-crystallized molecular sieve according to claim 1, characterized in that: In S3, the temperature for accelerating ion exchange and pre-crystallization is 75-85° C., and the pre-crystallization time is 5 hours.

9. The method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based cocrystallized molecular sieve according to claim 1, characterized in that: In S3, during the process of dispersing the ZSM5 / 11 molecular sieve into solution A, the mass of the ZSM5 / 11 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.

10. The method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based cocrystallized molecular sieve according to claim 1, characterized in that: In S4, before adding the iron-containing and manganese-containing solution to the low-sodium Fe-Mn-ZSM5 / 11 barium slag-based eutectic molecular sieve, an inorganic iron salt, manganese tetrachloride, water and the low-sodium Fe-Mn-ZSM5 / 11 obtained in step S3 in a mass ratio of 0.3-1:0.3-1:4-10:1 are mixed and slurried, and exchanged at 75-85°C for 1-10 hours, filtered and washed to obtain a low-sodium high-iron, high-manganese Fe-Mn-ZSM5 / 11 molecular sieve filter cake.

11. The method for preparing a Fe-Mn-ZSM5 / 11 barium slag-based cocrystallized molecular sieve according to claim 1, characterized in that: In S4, the temperature for ion exchange is raised to 75-85°C, and the solution containing iron and manganese is a mixed solution of inorganic iron salt, manganese tetrachloride and water.

12. The Fe-Mn-ZSM5 / 11 barium slag based eutectic molecular sieve prepared according to the method for preparing a Fe-Mn-ZSM5 / 11 barium slag based eutectic molecular sieve according to any one of claims 1 to 11.

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