Coal gangue-based SAPO-5 molecular sieve and preparation method thereof
By using coal gangue as raw material, the preparation process of molecular sieve is simplified, and the existing methods are solved, the existing methods are cost-effective and low-cost molecular sieve preparation is achieved, and the resource utilization methods of coal gangue are expanded.
Patent Information
- Application Number
- CN202510075466.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-17
- Publication Date
- 2025-05-13
AI Technical Summary
The existing molecular sieve preparation methods are costly and have low synthesis efficiency, resulting in environmental pollution and waste of resources.
Coal gangue is used as the main raw material, and coal gangue-based SAPO-5 molecular sieve is prepared through steps such as roasting, hydrothermal crystallization and multiple roasting, simplifying the process and improving the synthesis efficiency.
The preparation cost of molecular sieve is reduced, the synthesis efficiency is improved, the high value-added resource utilization method of coal gangue is broadened, and the prepared molecular sieve has excellent structural characteristics.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of solid waste recycling and relates to a gangue-based SAPO-5 molecular sieve and a preparation method thereof. Background Art
[0002] Molecular sieves are made of [SiO4] 4- and [AlO4] 5- Tetrahedrons form a three-dimensional skeleton, and the pore structure is arranged in an orderly manner. It can screen molecules according to the pore size and has excellent ion exchange and selective adsorption properties. In addition, it has excellent hydrothermal stability and is currently widely used in environmental and industrial fields, including adsorbents, catalysts, ion exchangers, antibacterial materials and other new frontier fields.
[0003] Existing methods for preparing molecular sieves are mainly based on synthesis using pure chemical reagents. Molecular sieves synthesized using pure chemical reagents have good structures and excellent performance. However, chemical reagent synthesis methods usually require the use of a large amount of chemical reagents, which not only increases production costs, but may also generate a large amount of chemical waste, placing a burden on the environment. Summary of the invention
[0004] In view of the defects and shortcomings in the prior art, the present invention aims to provide a method for preparing a gangue-based SAPO-5 molecular sieve to solve the technical problems of high cost and low synthesis efficiency of the prior art.
[0005] In order to achieve the above technical effects, the technical solution adopted by the present invention is:
[0006] A gangue-based SAPO-5 molecular sieve, the raw materials of which include gangue, aluminum isopropoxide, phosphoric acid, triethylamine, hydrofluoric acid and water.
[0007] Preferably, the molar ratio of silicon to aluminum in the raw material is 0.1-0.2, the molar ratio of aluminum to phosphorus in the raw material is 0.7-1.3, the molar ratio of aluminum to triethylamine in the raw material is 1.0-2.0, the molar ratio of fluorine to aluminum in the raw material is 0.1-0.3, and the molar ratio of water to aluminum in the raw material is 30-40.
[0008] Preferably, the average pore size is 20 to 60 Å.
[0009] Preferably, the BET specific surface area is 150 to 200 m 2 / g.
[0010] Preferably, the pore volume is 0.05 to 0.15 cm 3 / g.
[0011] Preferably, the molar ratio of silicon to aluminum in the raw material is 0.15, the molar ratio of aluminum to phosphorus in the raw material is 1.0, the molar ratio of aluminum to triethylamine in the raw material is 1.5, the molar ratio of fluorine to aluminum in the raw material is 0.2, and the molar ratio of water to aluminum in the raw material is 40.
[0012] A method for preparing a gangue-based SAPO-5 molecular sieve comprises the following steps:
[0013] S1, roasting the coal gangue to obtain pretreated coal gangue;
[0014] S2, mixing the pretreated coal gangue obtained in S1 with aluminum isopropoxide, phosphoric acid, triethylamine, hydrofluoric acid and water, aging the mixture, and then subjecting the mixture to a hydrothermal crystallization reaction to obtain a molecular sieve product;
[0015] S3, washing, drying and grinding the molecular sieve product obtained in S2, and then calcining it again, cooling it to room temperature after calcination to obtain a gangue-based SAPO-5 molecular sieve.
[0016] Preferably, the coal gangue in S1 is calcined at a temperature of 700 to 850° C. and for a time of 4 to 6 hours.
[0017] Preferably, in S2, the pretreated coal gangue is mixed with aluminum isopropoxide, phosphoric acid, triethylamine, hydrofluoric acid and water and stirred at a temperature of 20-25°C for 4-6 hours, and then subjected to a hydrothermal crystallization reaction at a temperature of 190-200°C, and the hydrothermal crystallization reaction time is 22-24 hours.
[0018] Preferably, the calcination temperature in S3 is 550-600° C., and the calcination time is 5-6 hours.
[0019] The above technical solution has the following beneficial effects:
[0020] (1) The gangue-based SAPO-5 molecular sieve and its preparation method of the present invention simplify the preparation process of the molecular sieve, improve the synthesis efficiency of the molecular sieve, replace all silicon sources and most aluminum sources with gangue, greatly reduce the preparation cost compared with traditional chemical reagent synthesis, and broaden the high value-added resource utilization of gangue.
[0021] (2) A gangue-based SAPO-5 molecular sieve of the present invention has an average pore size of 20 to 60 6 and a BET specific surface area of 150 to 200 m 2 / g ， Pore volume is 0.05~0.15cm 3 / g, has excellent structural characteristics and has broad promotion prospects in practical applications.
[0022] (3) The gangue-based SAPO-5 molecular sieve and its preparation method of the present invention use gangue as the main raw material, which not only reduces the synthesis cost of the molecular sieve, but also realizes the efficient resource utilization of gangue. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 1 to 3. The XRD patterns of the gangue-based molecular sieves in Examples 1 to 3.
[0024] Figure 2 This is the XRD spectrum of the gangue-based molecular sieve in Examples 4 and 5.
[0025] Figure 3 1 is the XRD spectrum of the gangue-based molecular sieve in Examples 7 to 8 and the comparative example.
[0026] Figure 4 This is an electron microscope image of the gangue-based molecular sieve in Example 1.
[0027] Figure 5 This is the energy spectrum of the gangue-based molecular sieve in Example 1.
[0028] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION
[0029] The "BET" in the BET specific surface area is specifically Brunauer-Emmett-Teller.
[0030] It should be noted that, unless otherwise specified, all raw materials in the present invention are raw materials known in the prior art.
[0031] In accordance with the above technical scheme, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical scheme of this application fall within the protection scope of the present invention.
[0032] Embodiment 1:
[0033] This embodiment provides a hydrothermal preparation method of coal gangue-based SAPO-5 molecular sieve, which specifically includes the following steps:
[0034] Step 1, preparing pretreated coal gangue;
[0035] The pretreated gangue was prepared by calcining the gangue powder at 800°C for 6 hours.
[0036] In this embodiment, the particle size of the gangue powder is 200 meshes. The gangue powder contains oxide components, which are composed of the following oxides by mass percentage: SiO2 is 64.58%, CaO is 1.47%, Al2O3 is 22.01%, Na2O is 1.01%, MgO is 0.06%, K2O is 3.29%, Fe2O3 is 1.15%, TiO2 is 5.58%, MnO is 0.10%, and LiO is 0.75%.
[0037] Step 2, preparing a crude molecular sieve product;
[0038] Aluminum isopropoxide is pre-hydrolyzed for 10 hours, and the pre-treated coal gangue obtained in step 1 and aluminum isopropoxide are mixed according to n(Si / Al)=0.1 to obtain a solid mixture, and then phosphoric acid, triethylamine and hydrofluoric acid are added in sequence according to the ratio of n(Al / P)=0.7, n(Al / M)=1.0, and n(F / Al)=0.1, with an interval of two hours between each step. Stir evenly at 25°C to obtain a premixed reactant.
[0039] Step 3, preparing gangue-based SAPO-5 molecular sieve;
[0040] The premixed reactants obtained in step 2 are subjected to a hydrothermal reaction at 200° C. for 24 hours to obtain a molecular sieve crude product. The molecular sieve crude product is filtered, washed to a pH of 7 to 8, and dried to obtain a gangue-based SAPO-5 molecular sieve coarse powder.
[0041] The gangue-based SAPO-5 molecular sieve coarse powder obtained in step 3 was placed in the muffle furnace again, calcined at 550° C. for 6 h, and then cooled to room temperature to obtain the gangue-based SAPO-5 molecular sieve.
[0042] In this embodiment, the characterization data of the gangue-based molecular sieve are as follows:
[0043] The XRD spectrum of gangue-based molecular sieve is as follows: Figure 1 As shown by Figure 1 It can be seen that the XRD spectrum of the gangue-based molecular sieve is highly consistent with the PDF standard card. Figure 4 As shown, the energy spectrum of coal gangue-based molecular sieve is as follows Figure 5 shown.
[0044] In this embodiment, the structural characteristic parameters of the gangue-based molecular sieve are shown in Table 1.
[0045] Embodiment 2:
[0046] This embodiment provides a hydrothermal preparation method of coal gangue-based SAPO-5 molecular sieve. The specific steps of the method are basically the same as those in Example 1, except that in step 2, the ratios are n(A l / P)=1.0, n(A l / M)=2.0, and n(F / A l)=0.2.
[0047] In this embodiment, the XRD spectrum of the gangue-based molecular sieve is as follows: Figure 1 shown.
[0048] Embodiment 3:
[0049] This embodiment provides a hydrothermal preparation method of coal gangue-based SAPO-5 molecular sieve. The specific steps of the method are basically the same as those in Example 1, except that in step 2, the ratios are n(A l / P)=1.3, n(A l / M)=1.5, and n(F / A l)=0.3.
[0050] In this embodiment, the XRD spectrum of the gangue-based molecular sieve is as follows: Figure 1 shown.
[0051] Embodiment 4:
[0052] This embodiment provides a hydrothermal preparation method of coal gangue-based SAPO-5 molecular sieve. The specific steps of the method are basically the same as those of Example 1, except that in step 2, the ratios are n(Si / Al)=0.15, n(Al / M)=2.0, and n(F / Al)=0.3.
[0053] In this embodiment, the XRD spectrum of the gangue-based molecular sieve is as follows: Figure 2 shown.
[0054] Embodiment 5:
[0055] This embodiment provides a hydrothermal preparation method of coal gangue-based SAPO-5 molecular sieve. The specific steps of the method are basically the same as those of Example 1, except that in step 2, the ratios are n(Si / Al)=0.15, n(Al / P)=1.0, and n(Al / M)=1.5.
[0056] In this embodiment, the XRD spectrum of the gangue-based molecular sieve is as follows: Figure 2 shown.
[0057] Embodiment 6:
[0058] This embodiment provides a hydrothermal preparation method of coal gangue-based SAPO-5 molecular sieve. The specific steps of the method are basically the same as those of Example 1, except that in step 2, the ratios are n(Si / Al)=0.15, n(Al / P)=1.3, and n(F / Al)=0.2.
[0059] In this embodiment, the XRD spectrum of the gangue-based molecular sieve is as follows: Figure 2 shown.
[0060] Embodiment 7:
[0061] This embodiment provides a hydrothermal preparation method of coal gangue-based SAPO-5 molecular sieve. The specific steps of the method are basically the same as those of Example 1, except that in step 2, the ratios are n(Si / Al)=0.2, n(Al / P)=1.0, and n(F / Al)=0.3.
[0062] In this embodiment, the XRD spectrum of the gangue-based molecular sieve is as follows: Figure 3 shown.
[0063] Embodiment 8:
[0064] This embodiment provides a hydrothermal preparation method of coal gangue-based SAPO-5 molecular sieve. The specific steps of the method are basically the same as those of Example 1, except that in step 2, the ratios are n(Si / Al)=0.2, n(Al / P)=1.3, and n(Al / M)=2.0.
[0065] In this embodiment, the XRD spectrum of the gangue-based molecular sieve is as follows: Figure 3 shown.
[0066] Comparative Example 1:
[0067] This embodiment provides a hydrothermal preparation method of coal gangue-based SAPO-5 molecular sieve. The specific steps of the method are basically the same as those of Example 1, except that in step 2, the ratios are n(Si / Al)=0.2, n(Al / M)=1.5, and n(F / Al)=0.2.
[0068] The method specifically comprises the following steps:
[0069] In this comparative example, step 1 is exactly the same as step 1 in Example 1.
[0070] Step 2: Aluminum isopropoxide is pre-hydrolyzed for 10 hours, and the pre-treated gangue obtained in step 1 and aluminum isopropoxide are mixed according to n(Si / A l) of 0.2 to obtain a solid mixture, and then phosphoric acid, triethylamine and hydrofluoric acid are added in sequence according to the ratio of n(A l / P) = 0.7, n(A l / M) = 1.5, and n(F / A l) = 0.2, with an interval of two hours between each step. Stir evenly at 25°C to obtain a premixed reactant.
[0071] In this comparative example, step three is substantially the same as step three of embodiment 1, except that the different premixed reactants obtained in step two are subjected to a hydrothermal reaction.
[0072] In this comparative example, the XRD spectrum of the gangue-based molecular sieve is as follows: Figure 3 shown.
[0073] In this comparative example, the structural characteristic parameters of the gangue-based molecular sieve are shown in Table 1.
[0074] Table 1 Structural characteristic parameters of gangue-based molecular sieves in Example 1 and Comparative Example 1
[0075]
[0076] The following conclusions can be drawn from Example 1 and Comparative Example 1:
[0077] (A) The BET specific surface areas of Example 1 and Comparative Example 1 were 166.35 m 2 / g and 2.04m 2 / g, and the pore volume is 0.08cm 3 / g and negligible, the larger the specific surface area and pore volume, the stronger the adsorption capacity. From the above analysis, it can be seen that the BET specific surface area and pore volume of Example 1 are much larger than those of Comparative Example 1, indicating that the molecular sieve prepared in Example 1 has better adsorption capacity than that of Comparative Example 1.
[0078] (B) The average pore sizes of Example 1 and Comparative Example 1 are 20.3 6 and 0.1 6, respectively. The pore size of the comparative example is almost negligible, indicating that there is not much adsorption effect. From the above analysis, it can be seen that Example 1 can adsorb molecules better than Comparative Example 1.
Claims
1. A gangue-based SAPO-5 molecular sieve, characterized in that: The raw materials include coal gangue, aluminum isopropoxide, phosphoric acid, triethylamine, hydrofluoric acid and water.
2. The gangue-based SAPO-5 molecular sieve according to claim 1, characterized in that: The molar ratio of silicon to aluminum in the raw material is 0.1-0.2, the molar ratio of aluminum to phosphorus in the raw material is 0.7-1.3, the molar ratio of aluminum to triethylamine in the raw material is 1.0-2.0, the molar ratio of fluorine to aluminum in the raw material is 0.1-0.3, and the molar ratio of water to aluminum in the raw material is 30-40.
3. The gangue-based SAPO-5 molecular sieve according to claim 2, characterized in that: The average pore size is 20~60 6.
4. The gangue-based SAPO-5 molecular sieve according to claim 2, characterized in that: BET specific surface area is 150~200m 2 / g.
5. The gangue-based SAPO-5 molecular sieve according to claim 2, characterized in that: Pore volume is 0.05~0.15cm 3 / g.
6. The gangue-based SAPO-5 molecular sieve according to any one of claims 1 to 5, characterized in that: The molar ratio of silicon to aluminum in the raw material is 0.15, the molar ratio of aluminum to phosphorus in the raw material is 1.0, the molar ratio of aluminum to triethylamine in the raw material is 1.5, the molar ratio of fluorine to aluminum in the raw material is 0.2, and the molar ratio of water to aluminum in the raw material is 40.
7. A method for preparing a gangue-based SAPO-5 molecular sieve, characterized in that: The specific steps include: S1, roasting the coal gangue to obtain pretreated coal gangue; S2, mixing the pretreated coal gangue obtained in S1 with aluminum isopropoxide, phosphoric acid, triethylamine, hydrofluoric acid and water, aging the mixture, and then subjecting the mixture to a hydrothermal crystallization reaction to obtain a molecular sieve product; S3, washing, drying and grinding the molecular sieve product obtained in S2, and then calcining it again, cooling it to room temperature after calcination to obtain a gangue-based SAPO-5 molecular sieve.
8. The method for preparing the gangue-based SAPO-5 molecular sieve according to claim 7, characterized in that: The coal gangue in S1 is calcined at a temperature of 700 to 850° C. and for a time of 4 to 6 hours.
9. The method for preparing the gangue-based SAPO-5 molecular sieve according to claim 7, characterized in that: In S2, the pretreated coal gangue is mixed with aluminum isopropoxide, phosphoric acid, triethylamine, hydrofluoric acid and water, stirred at a temperature of 20-25° C. for 4-6 hours, and then subjected to a hydrothermal crystallization reaction at a temperature of 190-200° C. The hydrothermal crystallization reaction time is 22-24 hours.
10. The method for preparing the gangue-based SAPO-5 molecular sieve according to claim 7, characterized in that: The calcination temperature in S3 is 550-600° C., and the calcination time is 5-6 hours.