Method for synthesizing MOR zeolite

Abstract

The invention belongs to the technical field of industrial solid waste recycling and molecular sieve materials, and particularly discloses a method for synthesizing MOR zeolite. The fluorine-containing silicon slag generated in the fluorine chemical industry is converted into the high-performance MOR zeolite aiming at the dual problems that the traditional zeolite synthesis raw material cost is high and the fluorine-containing industrial waste slag is difficult to treat. The specific method comprises the following steps: mixing fluorine-containing silicon slag with an alkaline solution to obtain aluminosilicate gel; mixing the aluminosilicate gel with a sodium source, performing aging, and then performing crystallization reaction to obtain MOR zeolite; wherein the fluorine-containing silicon slag is waste slag generated in the production process of anhydrous hydrogen fluoride; the alkaline solution is a solution obtained by dissolving sodium metaaluminate in deionized water; the sodium source is sodium hydroxide. According to the invention, the coupling of hazardous waste recycling and high-value material preparation is realized, the process flow is simple, the preparation cost is low, and the synthesized MOR zeolite is suitable for reactions such as catalytic cracking, isomerization, dimethyl ether carbonylation and the like and adsorption of heavy metals and harmful gases.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial solid waste resource utilization and molecular sieve material synthesis, and particularly relates to a method for synthesizing MOR zeolite. Background Art

[0002] MOR zeolite is a multifunctional zeolite material with a unique pore structure, and is widely used in the fields of petrochemical industry, gas separation, adsorption, environmental protection and agriculture.

[0003] The following patents and public literatures disclose and report the synthesis methods of MOR zeolite.

[0004] The public literature "Chemical Engineering Journal. 2023, 476" reports that in the absence of an organic template, using natural halloysite aluminosilicate nanotubes as the precursors of aluminum and silicon, hierarchical MOR-type zeolite can be successfully synthesized by hydrothermal method. Halloysite can also be used as a hard template to introduce mesopores into the obtained material. Adding halloysite nanotubes will result in a decrease in the acidity of the MOR-type zeolite-based catalyst, which helps to process raw materials with a higher ethylbenzene content and provides a high yield of xylene at the same time.

[0005] Patent CN117361555A (application date: September 26, 2023) discloses a method for synthesizing MOR zeolite molecular sieve by converting natural clinoptilolite. The invention mixes natural clinoptilolite powder, an alkali source, a silicon source and water to obtain a synthesis mother liquor; the molar ratio of the effective components in the synthesis mother liquor satisfies: SiO2:Al2O3:M2O:H2O = (10 - 32.5):1:(1.0 - 5.0):(210 - 500); the synthesis mother liquor is crystallized to obtain MOR zeolite molecular sieve.

[0006] The public literature "ChemCatChem. 2019, 11, 2803 - 2811" reports the hydrothermal synthesis of mordenite using a cheap pyrrolidine-based mesoporous precursor. The synthesized mordenite has a very high external surface area of 88.5 m 2 g -1 and a total pore volume of 0.23 cm 3 g -1 , and a total surface area of 379.3 m 2 g -1 . The synthesized material was tested in the hydroisomerization of alkanes and showed good selectivity.

[0007] The open literature "Nanoscale Adv. 2019, 1, 3918 - 3928" reported the synthesis of mordenite by a template - free and solvent - free method. And no seed was added, and high - temperature calcination was not required. The reaction was carried out through a mechanochemical pathway, and mordenite was successfully synthesized by ball - milling method at 50 min.

[0008] The open literature "Journal of Inorganic and Organometallic Polymers and Materials. 2020, 30, 1369 - 1383" reported the use of low - cost mixed organic templates, such as polyethylene glycol and glycerol, polyethylene glycol and ethylene glycol, ethylene glycol and glycerol and ethylene glycol, polyethylene glycol and glycerol, to fabricate mordenite nanoparticles by hydrothermal technology.

[0009] The open literature "Microporous Mesoporous Mater. 2020, 295, 109950" reported the preparation of a series of hierarchically porous mordenites using n - butylamine and polyacrylamide as soft templates. It was used for the carbonylation of dimethyl ether to methyl acetate. Introducing an appropriate amount of soft template improved the porosity of the catalyst and increased the number of acid sites. With the introduction of mesopores, the mass transfer efficiency was improved and coke deposition was reduced.

[0010] The open literature "Journal of Porous Materials. 2023, 31, 365 - 376" reported the synthesis of mordenite by adding different contents of monosodium L - glutamate between 4 and 48 h of stirring at 170 °C. The obtained mordenite had a relatively high crystallinity (83 - 101%). The insertion of monosodium L - glutamate reduced the acidity of the zeolite from 0.788 to 0.612 mmol / g. Thermal analysis showed that monosodium L - glutamate was completely removed from the zeolite structure after washing, eliminating the calcination process, thus reducing the cost.

[0011] The open literature "Chinese Journal of Chemical Engineering. 2014, 66, 216 - 223" reported the synthesis of mordenites with different Si / Al ratios by a solvent - free method for the carbonylation reaction of dimethyl ether, and systematically studied the effect of the Si / Al ratio in the raw materials on the structure, porosity and acid sites.

[0012] The open literature "RSC advances. 2024, 14, 4734 - 4741" reported that a series of hierarchical mordenite catalysts were synthesized by adding a soft template via a solvent-free method. Adding the soft template can successfully introduce a hierarchical structure into the system while maintaining good crystallinity, with an increased specific surface area and pore volume. The surfactant also affects the number and distribution of acid sites.

[0013] The open literature "Microporous Mesoporous Mater. 2020, 299, 110117" reported that hierarchical mordenite zeolite molecular sieves were prepared by alkaline treatment with the assistance of microwave radiation. After alkaline treatment, the relative crystallinity decreased by about 20%, and mesopores were introduced into the mordenite zeolite molecular sieves, with good mesopore dispersion. Compared with the traditional heating method, microwave-assisted alkaline treatment showed selective etching of silicon atoms in the zeolite. The aluminum atoms adjacent to the silicon atoms were extracted to form Al-OH hydroxyl groups. These extracted aluminum atoms were reconnected to the silicon atoms in the zeolite. In the 12-membered ring of mordenite zeolite after microwave-assisted alkali treatment The retention rate of acid sites was relatively high, and the concentration of Lewis acid sites was relatively low.

[0014] Patent CN105366689B (application date: November 14, 2015) disclosed a new method for microwave-assisted synthesis of MOR zeolite molecular sieve membranes for dilute solutions. The MOR zeolite molecular sieve membranes synthesized by this method used a dilute solution as the synthesis solution, reducing the usage amount of chemical reagents, saving the growth cost, and at the same time eliminating the problem of easy gel caking during the preparation of the traditional MOR zeolite molecular sieve membrane synthesis solution.

[0015] The open literature "Catalysis Letters. 2018, 148, 1870 - 1878" reported that mesoporous mordenite samples were prepared by a vapor-phase transport method using soft templates (Brij 58, Pluronic P123, Pluronic F127, and CTABr). Almost all samples had a mordenite structure and maintained the total acidity. The sample using CTABr showed significant mesoporosity, but when a large amount of CTABr was used, a loss of crystallinity was observed.

[0016] The open literature "Microporous and Mesoporous Materials. 2019, 274, 227 - 235" reported the synthesis of a series of hierarchical MOR zeolites using polyethylene glycol as a template. After adding polyethylene glycol, the crystallinity of MOR zeolites almost doubled, the specific surface area and total pore volume also increased, and it showed a strong dependence on polyethylene glycol. Due to the combined effect of the hierarchical structure and the increase in the number of strong acid sites, the number of strong acid sites increased slightly, and the dimethyl ether adsorption capacity also increased. After introducing mesopores, the mass transfer efficiency in hierarchical MOR zeolites was greatly improved. The catalytic activity and stability of hierarchical MOR zeolites gradually increased with the increase in the molecular weight of polyethylene glycol.

[0017] Patent CN105363352A (application date: November 14, 2015) discloses a new method for synthesizing highly acid - resistant MOR zeolite molecular sieve membranes using a dilute fluorine - containing solution. The MOR zeolite molecular sieve membrane synthesized by this method uses a dilute fluorine - containing solution as the synthesis solution, reducing the usage amount of chemical reagents, saving the growth cost, and eliminating the problem of easy gel caking during the preparation of the traditional MOR zeolite molecular sieve membrane synthesis solution. In addition, fluoride ions added as mineralizing agents to the synthesis solution can effectively promote crystal growth and optimize the framework structure of MOR zeolite molecular sieves.

[0018] Honeywell produces MOR zeolites by hydrothermal synthesis. The main raw materials are sodium silicate, sodium aluminate, and sodium hydroxide. The synthesis temperature is usually 150 - 180 °C, and the reaction time is 24 - 72 h. Honeywell's MOR zeolite products have high purity and are mainly used in the fields of petrochemical industry and gas separation.

[0019] BASF also uses hydrothermal synthesis to produce MOR zeolites. The raw materials include sodium silicate, sodium aluminate, and sodium hydroxide. Its synthesis conditions are a temperature of 160 - 180 °C and a time of 48 - 96 h. BASF improves the crystallinity and performance stability of MOR zeolites by optimizing the crystallization process and adding seeding technology. The products are widely used in the fields of catalysis, adsorption, and environmental protection.

[0020] Tosoh Corporation produces MOR zeolites by hydrothermal synthesis. The raw materials are high - purity sodium silicate and aluminum hydroxide. Its synthesis conditions are a temperature of 170 - 190 °C and a time of 72 - 120 h. Tosoh further improves the product performance through secondary growth technology and post - treatment processes (such as ion exchange). Its MOR zeolites are mainly used in high - end gas separation and catalytic fields.

[0021] Zeochem produces MOR zeolites by hydrothermal synthesis. The raw materials are sodium silicate and sodium aluminate. Its synthesis conditions are a temperature of 160 - 180 °C and a time of 72 - 120 h. Zeochem produces high - purity MOR zeolites by optimizing process parameters and post - treatment technologies. The products are mainly used in the fields of gas separation and environmental protection.

[0022] Sinopec produces MOR zeolite by hydrothermal synthesis method. The raw materials include sodium silicate, sodium aluminate and industrial waste (such as fly ash). The synthesis conditions are temperature 150 - 170 °C and time 48 - 96 h. Sinopec reduces production costs through resource utilization technology, and the products are mainly used in the fields of petrochemical industry and environmental protection.

[0023] Luoyang Jianlong Micro-Nano New Materials Co., Ltd. produces MOR zeolite by hydrothermal synthesis method. The raw materials are sodium silicate and sodium aluminate. The synthesis conditions are temperature 160 - 180 °C and time 72 - 96 h. Jianlong Micro-Nano produces high-performance MOR zeolite by optimizing the crystallization conditions and adding seed crystal technology, and the products are mainly used in the fields of gas separation and catalysis.

[0024] Shanghai Hengye Molecular Sieve Co., Ltd. uses hydrothermal synthesis method to produce MOR zeolite. The raw materials are sodium silicate and sodium aluminate. The synthesis conditions are temperature 150 - 170 °C and time 48 - 72 h. Hengye Molecular Sieve improves efficiency through continuous production process, and the products are widely used in the fields of petrochemical industry and adsorption.

[0025] The reported methods for synthesizing MOR zeolite from solid waste include synthesizing MOR zeolite from fly ash, rice husk ash, silica fume, bamboo leaf ash, FCCR, and FCC waste catalyst.

[0026] The open literature "Chemical Synthesis. 2024, 4, 3" reports that under solvent-free conditions, iron-containing mordenite (Fe-MOR) zeolite can be sustainably synthesized from fly ash waste. This zeolite is an effective capturer of CO2 in the CO2 / N2 mixture, with an adsorption capacity of 2.07 mmol / g at 298 K and a separation factor of 58.9.

[0027] The open literature "ChemistrySelect. 2020, 5, 1193 - 1198" reports the synthesis by using fly ash as a source of silica and alumina through hydrothermal synthesis method. The adsorption properties of Pb 2+ and Cd 2+ on commercial mordenite and synthetic mordenite were studied and compared, and it was found that the absorption percentages obtained using synthetic and commercially available mordenite adsorbents were very similar.

[0028] The published literature "Microporous and Mesoporous Materials. 2021, 314" reported the successful synthesis of high-purity mordenite from fly ash without the use of an organic template. Al and Si used for MOR synthesis were simultaneously extracted from fly ash, converted into aluminosilicate gel by coprecipitation, and then coupled with MOR seeds for MOR synthesis. The extraction efficiencies of Al and Si were as high as 82.18% and 93.15% respectively.

[0029] The published literature "Chemical Papers. 2020, 74, 8" reported the use of rice husk ash from a thermal power plant as a silicon source and metakaolin obtained from construction as an aluminum source, and alkaline treatment was carried out with sodium hydroxide and deionized water. The relationship between the textural properties and specific surface area of the synthesized MOR zeolite ranged from 314 to 347 m 2 / g, the micropore volume was 0.198 - 0.279 cm 3 / g, and the average pore diameter ranged from 5.9 to The average cation exchange capacity value ranged from 1.10 to 1.78 meq / g.

[0030] The published literature "Ferroelectrics. 2019, 547, 44 - 50" reported the synthesis of monolithic mordenite was assisted by hydrothermal treatment of silica fume and metakaolin-based polymers at 180 °C for 24 hours to convert them into nanostructured monolithic mordenite. XRD and FESEM results confirmed that the synthesized nanostructured monolithic mordenite had high crystallinity, mainly with prismatic and layered morphologies, and an average size of 2 μm. The N2 adsorption-desorption isotherm results showed that the BET surface area of the nanostructured monolithic mordenite was 30.16 m 2 / g.

[0031] Patent CN108383134B (application date: February 8, 2018) disclosed a method for synthesizing a solid waste multi-porous monolithic mordenite molecular sieve. Silica fume, metakaolin, mordenite seeds, solid sodium hydroxide, and deionized water were stirred and mixed, formed, aged, and hydrothermally reacted according to a mass ratio of 4 - 4.25:1:0.3:0.75:2.35 - 2.5 to synthesize the monolithic mordenite molecular sieve. This method directly used untreated solid waste silica fume as a silicon source and adjusted the Si / Al ratio with metakaolin to obtain the solid waste monolithic mordenite molecular sieve; no template agent needed to be added during the preparation process, avoiding the high energy consumption and environmental pollution caused by high-temperature calcination to decompose the template agent; at the same time, the synthesized monolithic molecular sieve overcame the many problems of filtration and separation during the application of powder particles and had the characteristics of multi-level pores.

[0032] The open document "Journal of the Taiwan Institute of Chemical Engineers. 2024, 159, 105507" reports the hydrothermal synthesis of mordenite with various forms from bamboo ash, and the synthesis steps only involve the mixing of silicate and aluminate solutions.

[0033] The public document "Chemical Engineering Science.2023, 281" reports a method for treating catalytic cracking waste slag by microwave radiation to synthesize zeolite molecular sieve from catalytic cracking waste slag. The aging temperature and time, crystallization temperature and time, and the amount of water and silica sol have all been systematically optimized, and the obtained zeolite molecular sieve is of high purity and highly crystallized.

[0034] Patent CN115650251B (application date: 2022.11.02) discloses a MOR zeolite molecular sieve monolith and its preparation method and application. The invention mixes an alkali source, water, catalytic cracking waste catalyst and a silicon source to obtain a mixed liquid; the mixed liquid is hydrothermally zeolized to obtain a MOR zeolite molecular sieve monolith; the hydrothermal temperature is 140-200°C.

[0035] Fluorine-containing silicon slag is a solid waste produced during the production of anhydrous hydrogen fluoride, containing high concentrations of fluorine. If not properly handled, fluoride will seep into the soil and water sources, causing fluorine pollution, affecting agriculture and plant growth, and endangering human and animal health through the food chain, and may lead to chronic fluoride poisoning (such as bone damage and fluorosis). In addition, its acidic components (such as calcium fluoride) may destroy the acid-base balance of the soil and cause land degradation; random dumping will also pollute water bodies through rainwater erosion, destroy the ecological balance, and threaten drinking water safety.

[0036] The following patents and documents disclose and report the synthesis of 4A molecular sieve, Beta molecular sieve, SBA-15 molecular sieve and TS-1 zeolite molecular sieve materials using fluorine-containing silicon slag as raw materials.

[0037] Patent CN103121693B (application date: 2013.03.19) discloses a method for preparing 4A zeolite by one-step crystallization using fluorine-containing silicon slag. The specific steps are as follows: for the fluorine-containing silicon slag produced in the process of producing fluoride salts in the aluminum-fluorine chemical industry, sodium aluminate solution, NaOH solution and 4A zeolite crystallization directing agent are added at the same time in a certain proportion, mixed in a reactor, and crystallized at a constant temperature of 75-85°C and a stirring speed of 240-300r / min for 3.0-3.5h. After aging for 12-14h, the washing 4A zeolite that meets the "QB / T1768-2003" standard is obtained after filtering, washing and drying.

[0038] Patent CN117735569A (application date: December 21, 2023) discloses a method for preparing silicon-aluminum molecular sieve and cryolite from fluorosilicate slag. Mix the fluorosilicate slag with caustic soda solution for reaction, then add aluminum source, carry out crystallization reaction, and filter to obtain filtrate and solid product; the solid product is dried to obtain silicon-aluminum molecular sieve; supplement aluminum source to the filtrate, introduce CO2 to adjust pH, form solid cryolite product, after liquid-solid separation, the remaining solution is causticized for recycling. The treatment process of this invention method is clean, does not produce secondary waste residue, is environmentally friendly, makes full use of Si and F elements in the fluorosilicate slag, and recovers them in the forms of silicon-aluminum molecular sieve (4A molecular sieve) and cryolite products respectively.

[0039] The public literature "ChemCatChem. 2024, 16, e202401381-e202401381" uses fluorosilicate slag as silicon source and tetraethylammonium hydroxide as structure-directing agent, and successfully prepares Hβ molecular sieve by green dry gel conversion crystallization method.

[0040] Patent CN118529744A (application date: May 23, 2024) discloses a method for preparing Beta molecular sieve using fluorosilicate slag as silicon source. Its typical feature is using fluorosilicate slag by-product from cheap phosphate fertilizer as silicon source and preparing high-value-added Beta molecular sieve by dry gel method.

[0041] Patent CN112939003B (application date: February 11, 2021) discloses a method for preparing SBA-15 molecular sieve from fluorosilicate slag and recovering fluorine, which includes the following steps: 1) Dissolve the fluorosilicate slag in sodium hydroxide solution to obtain solution A; 2) Mix the template agent, concentrated hydrochloric acid and water in a certain proportion and mix evenly to obtain solution B; 3) Under stirring condition, add solution A to solution B, continue stirring, and then transfer to a hydrothermal reaction kettle for crystallization; 4) After crystallization, carry out liquid-solid separation to obtain solid C and filtrate D, after washing and drying solid C, calcine for a certain time to obtain SBA-15 molecular sieve; 5) Add metal salt to filtrate D for reaction, and carry out liquid-solid separation to obtain metal fluoride and sodium salt solution.

[0042] Patent CN116947062A (application date: June 8, 2023) discloses a method for preparing titanium-silicon molecular sieve TS-1 using fluorosilicate slag. Its typical feature is using fluorosilicate slag as silicon source to prepare high-value-added titanium-silicon molecular sieve TS-1, turning waste into treasure, and using the fluorine contained in the silicon slag to promote the introduction of heteroatoms. The raw materials are cheap and beneficial to industrial application. The prepared modified titanium-silicon molecular sieve TS-1 catalyst shows excellent catalytic performance in the reaction of cyclohexanone ammoxidation to prepare cyclohexanone oxime.

[0043] There is no process for synthesizing MOR zeolite using fluorosilicate slag in the above-mentioned patents and published literature. The present invention will disclose a green method for synthesizing MOR zeolite using fluorosilicate slag as a silicon source without using a template agent. As a cheap industrial waste, using fluorosilicate slag as a raw material to synthesize MOR zeolite not only reduces the production cost compared with using traditional raw materials (such as bauxite, silicate minerals, etc.), but also realizes the resource utilization of solid waste, reduces environmental pollution, and improves the resource utilization efficiency. This technology has significant economic, environmental and social benefits, provides a new way for the high-value utilization of industrial waste and the development of green chemical industry, and has remarkable economic and environmental benefits. Summary of the Invention

[0044] According to the above problems, the object of the present invention is to provide a method for preparing synthetic MOR zeolite using fluorosilicate slag, and converting the fluorosilicate slag (SiO2≥90%, F - content 8-10%) generated in the fluorochemical industry into high-performance MOR zeolite.

[0045] The technical solution of the present invention is as follows:

[0046] A method for synthesizing MOR zeolite, the steps are as follows:

[0047] Mix the fluorosilicate slag with an alkaline solution to obtain a silicoaluminate gel; mix the silicoaluminate gel with a sodium source, age it, and then carry out a crystallization reaction to obtain MOR zeolite.

[0048] The fluorosilicate slag is the waste residue generated by the hydrolysis of silicon tetrafluoride during the production of anhydrous hydrogen fluoride, and includes silicon dioxide, fluosilicic acid and water.

[0049] The alkaline solution is a solution obtained by dissolving sodium aluminate in deionized water.

[0050] The sodium source is sodium hydroxide.

[0051] The molar ratio of silicon dioxide in the fluorosilicate slag to aluminum oxide in sodium aluminate is 15-50.

[0052] The total molar amount of sodium oxide in sodium aluminate and sodium oxide in sodium hydroxide and silicon dioxide in the fluorosilicate slag is 0.12-0.32.

[0053] The molar ratio of deionized water in the alkaline solution to the total molar amount of sodium oxide in sodium aluminate and sodium oxide in sodium hydroxide is 100.

[0054] The aging is constant temperature stirring.

[0055] The temperature of the aging reaction is 20-80°C, and the time is 1-5 hours.

[0056] The temperature of the crystallization reaction is 140 - 180 °C, and the time is 6 - 36 hours.

[0057] Application of the MOR zeolite prepared by the above method in adsorption, catalysis, petrochemical industry or molecular sieves.

[0058] Compared with the prior art, the beneficial effects of the present invention are:

[0059] The present invention uses industrial solid waste fluorine-containing silicon slag to prepare synthetic MOR zeolite, realizing the coupling of hazardous waste resource utilization and high-value material preparation. The process flow is simple, the preparation cost is low, and no organic template agent is used. The synthesized MOR zeolite is applicable to reactions such as catalytic cracking, isomerization, dimethyl ether carbonylation, etc., and adsorption of heavy metals and harmful gases. Description of the Drawings

[0060] Figure 1 It is the SEM scanning electron microscope picture of fluorine-containing silicon slag.

[0061] Figure 2 It is the process route of synthesizing MOR zeolite from fluorine-containing silicon slag.

[0062] Figure 3 It is the XRD spectrum of the samples of Examples 1 - 6.

[0063] Figure 4 It is the SEM scanning electron microscope picture of Example 1.

[0064] Figure 5 It is the SEM scanning electron microscope picture of Example 2.

[0065] Figure 6 It is the SEM scanning electron microscope picture of Example 3.

[0066] Figure 7 It is the SEM scanning electron microscope picture of Example 4.

[0067] Figure 8 It is the SEM scanning electron microscope picture of Example 5.

[0068] Figure 9 It is the SEM scanning electron microscope picture of Example 6.

[0069] Figure 10 It is the XRD spectrum of the samples of Examples 7 - 11.

[0070] Figure 11 It is the SEM scanning electron microscope picture of Example 7.

[0071] Figure 12 It is the SEM scanning electron microscope picture of Example 8.

[0072] Figure 13 It is the SEM (Scanning Electron Microscope) picture of Example 9.

[0073] Figure 14 It is the SEM (Scanning Electron Microscope) picture of Example 10.

[0074] Figure 15 It is the SEM (Scanning Electron Microscope) picture of Example 11.

[0075] Figure 16 It is the XRD (X-Ray Diffraction) pattern of the samples of Examples 12 - 14.

[0076] Figure 17 It is the SEM (Scanning Electron Microscope) picture of Example 12.

[0077] Figure 18 It is the SEM (Scanning Electron Microscope) picture of Example 13.

[0078] Figure 19 It is the SEM (Scanning Electron Microscope) picture of Example 14.

[0079] Figure 20 It is the XRD (X-Ray Diffraction) pattern of the samples of Examples 15 - 20.

[0080] Figure 21 It is the SEM (Scanning Electron Microscope) picture of Example 15.

[0081] Figure 22 It is the SEM (Scanning Electron Microscope) picture of Example 16.

[0082] Figure 23 It is the SEM (Scanning Electron Microscope) picture of Example 17.

[0083] Figure 24 It is the SEM (Scanning Electron Microscope) picture of Example 18.

[0084] Figure 25 It is the SEM (Scanning Electron Microscope) picture of Example 19.

[0085] Figure 26 It is the SEM (Scanning Electron Microscope) picture of Example 20.

[0086] Figure 27 It is the XRD (X-Ray Diffraction) pattern of the samples of Examples 21 - 23.

[0087] Figure 28 It is the SEM (Scanning Electron Microscope) picture of Example 21.

[0088] Figure 29 It is the SEM (Scanning Electron Microscope) picture of Example 22.

[0089] Figure 30 It is the SEM (Scanning Electron Microscope) picture of Example 23.

[0090] Figure 31 It is the XRD (X-ray Diffraction) pattern of the samples of Examples 24 - 26.

[0091] Figure 32 It is the SEM (Scanning Electron Microscope) picture of Example 24.

[0092] Figure 33 It is the SEM (Scanning Electron Microscope) picture of Example 25.

[0093] Figure 34 It is the SEM (Scanning Electron Microscope) picture of Example 26. Detailed implementation manners

[0094] The following further illustrates the detailed implementation manners of the present invention in combination with the attached drawings and technical solutions.

[0095] The component analysis of the fluorine-containing silicon slag used in the embodiments of the present invention is as follows: the content of silicon dioxide is 90%, the content of fluorine is 8%, and the content of water is 2%. Figure 1 It is the SEM (Scanning Electron Microscope) picture of the fluorine-containing silicon slag.

[0096] The following are the examples for exploring the optimal silicon-aluminum ratio for synthesizing MOR zeolite.

[0097]

[0098] Example 1: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0099] Dissolve 1.91 g of sodium hydroxide in 54.06 ml of ultrapure water; then add 0.91 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals and continuously stir to form a homogeneous gel. Perform homogenization treatment on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7, put it into a blast drying oven at 110 °C for drying after rinsing, grind it into powder and store it sealed, which is the pure-phase MOR zeolite product.

[0100] Figure 2 It is the process route for synthesizing MOR zeolite from fluorine-containing silicon slag.

[0101] Example 2: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0102] Dissolve 1.43 g of sodium hydroxide in 40.5 ml of ultrapure water; then add 0.68 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Homogenize at a stirring speed of 150 rpm on a magnetic stirrer for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it sealed, which is the MOR zeolite product.

[0103] Example 3: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0104] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Homogenize at a stirring speed of 150 rpm on a magnetic stirrer for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it sealed, which is the MOR zeolite product.

[0105] Example 4: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0106] Dissolve 0.95 g of sodium hydroxide in 27 ml of ultrapure water; then add 0.45 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Homogenize at a stirring speed of 150 rpm on a magnetic stirrer for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it sealed, which is the MOR zeolite product.

[0107] Example 5: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0108] Dissolve 0.71 g of sodium hydroxide in 20.3 ml of ultrapure water; then add 0.34 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystal, and continuously stir to form a homogeneous gel. Homogenize on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7, then put it into a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0109] Example 6: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0110] Dissolve 0.57 g of sodium hydroxide in 16.2 ml of ultrapure water; then add 0.27 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystal, and continuously stir to form a homogeneous gel. Homogenize on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7, then put it into a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0111] The XRD patterns of the samples in Examples 1-6 are shown in Figure 3 , and diffraction peaks consistent with the MOR standard card (PDF#80-0644 Mordenite) appear in the patterns of all six samples, indicating that all the synthesized samples have the MOR structure. Among them, when n(SiO2) / n(Al2O3) is 25, the synthesized MOR zeolite has high crystallinity and no impurity peaks. Therefore, the optimal n(SiO2) / n(Al2O3) is selected as 25. Figure 4 、 5 Figures 6, 7, 8, 9 are the SEM photos of Examples 1, 2, 3, 4, 5, 6 respectively. It can be seen from the figures that all six samples show clear flaky or columnar MOR zeolite morphologies.

[0112] The following are examples of exploring the optimal sodium-silicon ratio for synthesizing MOR zeolite on the basis of the optimal silicon-aluminum ratio of 25.

[0113]

[0114] Example 7: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0115] Dissolve 0.42 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorosilicate slag; add 0.23 g of MOR seed crystals and continuously stir to form a homogeneous gel. Perform homogenization treatment on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0116] Example 8: Hydrothermal synthesis of MOR zeolite from fluorosilicate slag

[0117] Dissolve 0.66 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorosilicate slag; add 0.23 g of MOR seed crystals and continuously stir to form a homogeneous gel. Perform homogenization treatment on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0118] Example 9: Hydrothermal synthesis of MOR zeolite from fluorosilicate slag

[0119] Dissolve 0.9 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorosilicate slag; add 0.23 g of MOR seed crystals and continuously stir to form a homogeneous gel. Perform homogenization treatment on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0120] Example 10: Hydrothermal synthesis of MOR zeolite from fluorosilicate slag

[0121] Dissolve 1.38 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystal, and continuously stir to form a homogeneous gel. Homogenize on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it sealed, which is the MOR zeolite product.

[0122] Example 11: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0123] Dissolve 1.62 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystal, and continuously stir to form a homogeneous gel. Homogenize on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it sealed, which is the MOR zeolite product.

[0124] The XRD patterns of Examples 7 - 11 and Example 3 are shown in Figure 10 , and diffraction peaks consistent with the MOR standard card (PDF#80 - 0644 Mordenite) appear in the patterns of all six samples, indicating that all the synthesized samples have the MOR structure. Among them, when n(Na2O) / n(SiO2) is 0.24, the synthesized MOR zeolite has a stable baseline, high crystallinity and no impurity peaks. Therefore, the optimal n(Na2O) / n(SiO2) is selected as 0.24. Figure 11 , 12 , 13, 6, 14, 15 are the SEM photos of Examples 7, 8, 9, 3, 10, 11 respectively. It can be seen from the figures that all six samples show clear flaky or columnar MOR zeolite morphologies.

[0125] The following are examples of exploring the optimal crystallization temperature for synthesizing MOR zeolite on the basis of the optimal silicon-aluminum ratio of 25 and the optimal sodium-silicon ratio of 0.24.

[0126]

[0127] Example 12: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0128] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Perform homogenization treatment on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 150 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0129] Example 13: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0130] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Perform homogenization treatment on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 160 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0131] Example 14: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0132] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Perform homogenization treatment on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 180 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0133] The XRD patterns of Examples 12 - 14 and Example 3 are shown in Figure 16, diffraction peaks consistent with the MOR standard card (PDF#80 - 0644 Mordenite) appeared in the spectra of all four samples, indicating that all the synthesized samples had the MOR structure. Among them, when the crystallization temperature was 170 °C, the synthesized MOR zeolite had a high crystallinity and no impurity peaks. Therefore, the optimal crystallization temperature was selected as 170 °C. Figure 17 、 18 、6, and 19 are SEM photos of Examples 12, 13, 3, and 14 respectively. It can be seen from the figures that the samples all showed clear flaky or columnar MOR zeolite morphologies.

[0134] The following are examples of exploring the optimal crystallization time for synthesizing MOR zeolite based on the optimal silica - alumina ratio of 25, the optimal sodium - silica ratio of 0.24, and the optimal crystallization temperature of 170 °C.

[0135]

[0136] Example 15: Hydrothermal synthesis of MOR zeolite from fluorine - containing silicon slag

[0137] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine - containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Homogenize at a stirring speed of 150 rpm on a magnetic stirrer for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene and carry out hydrothermal crystallization at 170 °C for 6 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner to obtain the MOR zeolite product.

[0138] Example 16: Hydrothermal synthesis of MOR zeolite from fluorine - containing silicon slag

[0139] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine - containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Homogenize at a stirring speed of 150 rpm on a magnetic stirrer for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene and carry out hydrothermal crystallization at 170 °C for 9 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner to obtain the MOR zeolite product.

[0140] Example 17: Hydrothermal synthesis of MOR zeolite from fluorine - containing silicon slag

[0141] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Perform homogenization treatment on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 15 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0142] Example 18: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0143] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Perform homogenization treatment on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 18 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0144] Example 19: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0145] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Perform homogenization treatment on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 24 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0146] Example 20: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0147] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Homogenize on a magnetic stirrer at a stirring speed of 150 rpm for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene and carry out hydrothermal crystallization at 170 °C for 36 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7, then put it into a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product. Figure 24 It is the SEM photograph of Example 20, and clear columnar mordenite morphology can be seen.

[0148] The XRD patterns of Examples 15 - 20 and Example 3 are shown in Figure 20 , and diffraction peaks consistent with the MOR standard card (PDF#80 - 0644 Mordenite) appear in the spectra of all seven samples, indicating that all the synthesized samples have the MOR structure. Among them, when the crystallization time is 12 h, the synthesized MOR zeolite has high crystallinity and no impurity peaks. Therefore, the optimal crystallization time is selected as 12 h. Figure 21 , 22 6, 23, 24, 25, 26 are the SEM photographs of Examples 15, 16, 3, 17, 18, 19, 20 respectively. It can be seen from the figures that all the samples show clear columnar MOR zeolite morphology.

[0149] The following are examples for exploring the optimal aging time for synthesizing MOR zeolite based on the optimal silica-alumina ratio of 25, the optimal sodium-silica ratio of 0.24, the optimal crystallization temperature of 180 °C, and the optimal crystallization time of 12 h.

[0150]

[0151] Example 21: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0152] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7, then put it into a blast drying oven at 110 °C for drying, grind it into powder and store it in a sealed manner, which is the MOR zeolite product.

[0153] Example 22: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0154] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Homogenize at a stirring speed of 150 rpm on a magnetic stirrer for 1 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it sealed, which is the MOR zeolite product.

[0155] Example 23: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0156] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Homogenize at a stirring speed of 150 rpm on a magnetic stirrer for 3 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it sealed, which is the MOR zeolite product.

[0157] The XRD patterns of Examples 21-23 and Example 3 are shown in Figure 27 , and diffraction peaks consistent with the MOR standard card (PDF#80-0644 Mordenite) appear in the patterns of all four samples, indicating that all the synthesized samples have the MOR structure. Among them, when the aging time is 5 h, the synthesized MOR zeolite has high crystallinity and no impurity peaks. Therefore, the optimal crystallization time is selected as 5 h. Figure 28 , 29 , 30, 6 are the SEM photos of Examples 21, 22, 23, and 3 respectively. It can be seen from the figures that the samples all show clear flaky or columnar MOR zeolite morphologies.

[0158] The following are examples for exploring the optimal aging temperature for synthesizing MOR zeolite on the basis of the optimal silicon-aluminum ratio of 25, the optimal sodium-silicon ratio of 0.24, the optimal crystallization temperature of 180 °C, the optimal crystallization time of 12 h, and the aging time of 5 h.

[0159]

[0160] Example 24: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0161] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Homogenize at a stirring speed of 150 rpm and a temperature of 40 °C on a magnetic stirrer for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it sealed, which is the MOR zeolite product.

[0162] Example 25: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0163] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Homogenize at a stirring speed of 150 rpm and a temperature of 60 °C on a magnetic stirrer for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it sealed, which is the MOR zeolite product.

[0164] Example 26: Hydrothermal synthesis of MOR zeolite from fluorine-containing silicon slag

[0165] Dissolve 1.14 g of sodium hydroxide in 32.4 ml of ultrapure water; then add 0.54 g of sodium aluminate and mix; slowly add 5 g of fluorine-containing silicon slag; add 0.23 g of MOR seed crystals, and continuously stir to form a homogeneous gel. Homogenize at a stirring speed of 150 rpm and a temperature of 80 °C on a magnetic stirrer for 5 h to obtain a reaction precursor. Transfer the stirred solution into a reaction kettle lined with polytetrafluoroethylene, and carry out hydrothermal crystallization at 170 °C for 12 h. Wash the hydrothermal crystallization reaction product with ultrapure water until the pH of the rinsing filtrate is about 7. After rinsing, place it in a blast drying oven at 110 °C for drying, grind it into powder and store it sealed, which is the MOR zeolite product.

[0166] The XRD patterns of Examples 24 - 26 and Example 3 are shown in Figure 31, diffraction peaks consistent with the MOR standard card (PDF#80-0644 Mordenite) appeared in the spectra of all four samples, indicating that all the synthesized samples had the MOR structure. Among them, when the aging temperature was 20 °C, the synthesized MOR zeolite had high crystallinity and no impurity peaks. Therefore, the optimal aging temperature was selected as 20 °C. Figure 6 , 32 , 33, 34 are the SEM photos of Examples 3, 24, 25, and 26 respectively. It can be seen from the figure that the samples all show clear flaky or columnar MOR zeolite morphologies.

[0167] In summary, the optimal silica-alumina ratio for synthesizing MOR zeolite is 25, the optimal sodium-silica ratio is 0.24, the optimal crystallization temperature is 180 °C, the optimal crystallization time is 12 h, the optimal aging time is 5 h, and the optimal aging temperature is 20 °C.

Claims

1. A method for synthesizing MOR zeolite, characterized in that: Here are the steps: Mixing fluorine-containing silicon slag with an alkaline solution to obtain an aluminosilicate gel; mixing the aluminosilicate gel with a sodium source, aging it, and then performing a crystallization reaction to obtain MOR zeolite; The fluorine-containing silicon slag is waste residue produced by hydrolysis of silicon tetrafluoride in the production process of anhydrous hydrogen fluoride, and its main components are silicon dioxide, fluorosilicic acid and water; The alkaline solution is a solution obtained by dissolving sodium aluminate in deionized water; The sodium source is sodium hydroxide.

2. A method for synthesizing MOR zeolite according to claim 1, characterized in that: The molar ratio of silicon dioxide in the fluorine-containing silicon slag to aluminum oxide in the sodium metaaluminate is 15-50.

3. A method for synthesizing MOR zeolite according to claim 1, characterized in that: The molar ratio of the sum of the sodium oxide in the sodium aluminate and the sodium oxide in the sodium hydroxide to the silicon dioxide in the fluorine-containing silicon slag is 0.12 to 0.

32.

4. A method for synthesizing MOR zeolite according to claim 1, characterized in that: The molar ratio of the deionized water in the alkaline solution to the total of the sodium oxide in the sodium aluminate and the sodium oxide in the sodium hydroxide is 100.

5. A method for synthesizing MOR zeolite according to claim 1, characterized in that: The aging process is performed by stirring at a constant temperature.

6. A method for synthesizing MOR zeolite according to claim 1, characterized in that: The aging reaction is carried out at a temperature of 20 to 80° C. and for a time of 1 to 5 hours.

7. A method for synthesizing MOR zeolite according to claim 1, characterized in that: The temperature of the crystallization reaction is 140-180° C., and the time is 6-36 hours.

8. The MOR zeolite prepared by the method described in any one of claims 1 to 7 is used in the fields of adsorption, catalysis and petrochemical industry.

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