Method for preparing multiple high-crystallinity molecular sieves by regulating and controlling multi-element ratio of tungsten tailings / aluminum tailings and high-crystallinity molecular sieves
By performing specific treatment of tungsten tailings and aluminum tailings, high crystallinity molecular sieve was prepared, which solved the problem that tungsten tailings was difficult to prepare high crystallinity molecular sieve, and achieved resource utilization and cost reduction, meeting various application needs.
Patent Information
- Application Number
- CN202411234226.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-04
- Publication Date
- 2024-12-10
AI Technical Summary
The prior art is difficult to effectively prepare high crystallinity molecular sieve through solid waste such as tungsten tailings, resulting in poor preparation effect, high cost and difficult to achieve industrialization.
By washing and removing impurities, removing iron, drying, ball milling, and sieving the tungsten tailings and aluminum tailings, adding alkali flux to alkali melting, forming metastable clinker, adding water to aging, and finally The polytetrafluoroethylene lining reactor was subjected to crystallization treatment to prepare molecular sieves such as LTA, FUA, FUA/LTA with high crystallinity.
The efficient resource utilization of tungsten tailings is achieved, and molecular sieves with relatively high crystallinity are prepared, which reduces the preparation cost and realizes the production of a variety of molecular sieves to meet different application needs.
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Figure CN119100413A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of resource utilization of various tailings, and specifically relates to a method for preparing various high-crystallinity molecular sieves by regulating the multi-component ratio of tungsten tailings / aluminum tailings, and a high-crystallinity molecular sieve. Background Art
[0002] Molecular sieve refers to an inorganic crystal material with a regular pore structure formed by connecting TO4 tetrahedrons through common vertices. Due to its uniform pore structure and large specific surface area, it is widely used in ion exchange, chemical industry, environmental protection and other fields.
[0003] Type (FAU) and Lynde type (LTA) are the two most widely used molecular sieves in commercial applications. At the same time, studies have also found that the calcium ion exchange capacity of FAU / LTA composite molecular sieve is equivalent to that of 4A, and the magnesium ion exchange capacity is significantly better than that of commercial 4A molecular sieve, and it has more comprehensive application performance in the fields of chemical industry and environmental protection.
[0004] At present, the industrial production of molecular sieves mainly adopts silicon source and aluminum source pure reagents for preparation. For example, the silicon source mainly adopts white carbon black, porous silicon, sodium silicate, etc., and the aluminum source mainly adopts reagents such as aluminum oxide and sodium aluminate. The raw material consumption is large and the preparation cost is high. Therefore, the use of solid wastes such as rare earth tailings and lithium tailings to prepare molecular sieves has become a hot spot, which can not only reduce the cost of raw materials but also realize waste resource utilization. However, when using solid wastes such as tailings to prepare molecular sieves, due to the difference of silicon source and aluminum source and the complex components, the preparation effect is poor, and the relative crystallinity is low, it is difficult to realize industrialization. In the tailings, the silicon source and aluminum source are often amorphous SiO2, crystalline aluminate phase or amorphous aluminosilicate phase. The different structures lead to different crystal nuclei produced by crystallization polycondensation reaction during the crystallization process, thereby growing into different types of zeolites. Therefore, it is difficult to stably prepare molecular sieves with high relative crystallinity.
[0005] Tungsten is known as "industrial salt" and is one of the strategic materials in high-tech fields such as national defense and aviation. Due to its excellent properties such as stable chemical properties, excellent high-temperature mechanical properties, and high compression modulus and elastic modulus, it is mainly used in electronics, metallurgy, aerospace, and military industries. However, for every ton of tungsten concentrate produced, about 8 tons of tungsten tailings are produced. The amount of tungsten tailings increases year by year. The use of open-air stacking will occupy a large amount of land resources and pose certain potential hazards to the environment. The resource utilization of tungsten tailings has always been a research hotspot, but it is currently mainly used to prepare microcrystalline glass, cement materials, geopolymers, etc. Due to its complex composition, uneven distribution, and many impurities, it has not yet been studied for the preparation of molecular sieves.
[0006] In view of this, the present invention proposes a method for multi-element regulation of tungsten tailings and other composite tailings, which can improve the relative crystallinity of FAU, LTA, and FAU / LTA composite molecular sieves prepared from tungsten tailings. It has high value for industrial production, can achieve the disposal of tungsten tailings solid waste, and can also obtain molecular sieve products, realizing "turning waste into treasure". Summary of the invention
[0007] The present disclosure aims to solve at least one of the technical problems existing in the prior art, and provides a method for preparing a variety of high-crystallinity molecular sieves by regulating the multi-component ratio of tungsten tailings / aluminum tailings, and a high-crystallinity molecular sieve.
[0008] In one aspect of the present disclosure, a method for preparing a variety of high crystallinity molecular sieves by regulating the multi-component ratio of tungsten tailings / aluminum tailings is provided, the method comprising:
[0009] The tungsten tailings and aluminum tailings are sequentially washed to remove impurities, iron, dried, ball-milled, and sieved to obtain tungsten tailings raw materials and aluminum tailings raw materials respectively;
[0010] According to the composite Si / Al ratio of the tungsten tailings raw material and the aluminum tailings raw material being 1:(1-2.5) and the mass ratio of the raw materials being 1:(0.2-0.9), the tungsten tailings raw material and the aluminum tailings raw material are weighed respectively, and the raw materials are mixed evenly to form a composite tailings masterbatch;
[0011] Adding an alkali flux to the composite tailings masterbatch for alkali melting treatment to obtain a metastable clinker;
[0012] Grinding the metastable clinker into powder, adding water for aging treatment, and obtaining a crystallization mother solution;
[0013] The crystallization mother liquid is placed in a polytetrafluoroethylene-lined reactor for crystallization to obtain a molecular sieve sample;
[0014] The molecular sieve sample is washed and neutralized to obtain a molecular sieve, wherein the molecular sieve is any one of LTA molecular sieve, FUA molecular sieve, FUA / LTA composite molecular sieve, and FUA and SOD coexisting molecular sieve.
[0015] Optionally, when the composite Si / Al ratio of the tungsten tailings raw material and the aluminum tailings raw material is 1:1 and the mass ratio is 1:0.9, the obtained molecular sieve is an LTA molecular sieve, and the relative crystallinity of the LTA molecular sieve is 95.1%.
[0016] Optionally, when the composite Si / Al ratio of the tungsten tailings raw material and the aluminum tailings raw material is 1:1.2 and the mass ratio is 1:0.7, the obtained molecular sieve is a FUA / LTA composite molecular sieve, and the relative crystallinity of the FUA / LTA composite molecular sieve is 97.6%.
[0017] Optionally, when the composite Si / Al ratio of the tungsten tailings raw material and the aluminum tailings raw material is 1:1.5 and the mass ratio is 1:0.42, the obtained molecular sieve is a FUA molecular sieve, and the relative crystallinity of the FUA molecular sieve is 98.2%.
[0018] Optionally, when the composite Si / Al ratio of the tungsten tailings raw material and the aluminum tailings raw material is 1:2.5 and the mass ratio is 1:0.2, the obtained molecular sieve is a FUA and SOD coexistence state molecular sieve, the relative crystallinity of the FUA molecular sieve is 48.6%, and the relative crystallinity of the SOD molecular sieve is 21.2%.
[0019] Optionally, the molar ratio of the alkali flux to SiO2 in the tungsten tailings raw material is (2-2.2):1.
[0020] Optionally, the alkali fusion treatment is carried out at a temperature of 400-550° C. and for a time of 5-7 hours.
[0021] Optionally, the crystallization treatment is performed at a temperature of 80-95° C. and for a time of 7-9 hours.
[0022] Another aspect of the present disclosure provides a high crystallinity molecular sieve, which is prepared by the method described above.
[0023] Optionally, the specific surface area of the high crystallinity molecular sieve is 62.8-178m 2 / g, pore size: The structure size is 0.8-2μm.
[0024] The present invention discloses a method for preparing a variety of high-crystallinity molecular sieves by regulating the multi-component ratio of tungsten tailings / aluminum tailings and a high-crystallinity molecular sieve. The preparation method comprises: washing and removing impurities, removing iron, drying, ball milling and sieving tungsten tailings and aluminum tailings in sequence to obtain tungsten tailings raw materials and aluminum tailings raw materials respectively; weighing the tungsten tailings raw materials and the aluminum tailings raw materials according to the Si / Al ratio of 1:(1-2.5) and the mass ratio of 1:(0.2-0.9) in the tungsten tailings raw materials and the aluminum tailings raw materials respectively, and mixing them to form a composite tailings masterbatch; adding an alkali flux to the composite tailings masterbatch for alkali melting treatment to obtain a metastable clinker; grinding the metastable clinker into powder, adding water for aging treatment to obtain a crystallization mother liquor; placing the crystallization mother liquor into a reactor for crystallization treatment to obtain a molecular sieve sample; washing and neutralizing the molecular sieve sample to obtain a molecular sieve, wherein the molecular sieve is any one of LTA molecular sieve, FUA molecular sieve, FUA / LTA composite molecular sieve, FUA and SOD coexistence molecular sieve. The present invention prepares different types of molecular sieves by adjusting the ratio of tungsten tailings and aluminum tailings, and simultaneously achieves the effect of coordinated disposal of the two tailings, effectively reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 A flowchart of a method for preparing a variety of high-crystallinity molecular sieves by adjusting the multi-component ratio of tungsten tailings / aluminum tailings according to an embodiment of the present disclosure;
[0026] Figure 2 is the XRD diagram of the molecular sieve obtained in Examples 1-4 of the present disclosure;
[0027] Figure 3 is a SEM image of the molecular sieve obtained in Example 1 of the present disclosure;
[0028] Figure 4 is a SEM image of the molecular sieve obtained in Example 2 of the present disclosure;
[0029] Figure 5 is a SEM image of the molecular sieve obtained in Example 3 of the present disclosure;
[0030] Figure 6 This is a SEM image of the molecular sieve obtained in Example 4 of the present disclosure. DETAILED DESCRIPTION
[0031] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific embodiments described herein are only used to explain the present disclosure and are not used to limit the disclosure. The described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present disclosure.
[0032] like Figure 1 As shown, in one aspect of the present disclosure, a method S100 for preparing a variety of high crystallinity molecular sieves by regulating the multi-component ratio of tungsten tailings / aluminum tailings composite slag is provided, which specifically includes the following steps S110 to S160:
[0033] S110, washing and removing impurities, removing iron, drying, ball milling and screening the tungsten tailings and aluminum tailings in sequence to obtain tungsten tailings raw materials and aluminum tailings raw materials respectively.
[0034] It should be noted that in this embodiment, tungsten tailings and aluminum tailings are cleaned only with deionized water, and traditional acid washing is not used to remove impurities, thereby reducing material consumption and wastewater generation in the production process, improving the purity of raw materials involved in subsequent reactions, and avoiding the introduction of impurities.
[0035] It should be further explained that the main components of tungsten tailings are SiO2: 63.315%, Al2O3: 14.73%, WO3: 0.24%, CaO: 2.15%, Na2O: 0.742%, K2O: 3.697%. The Si content in the main components is high, which is similar to the components of molecular sieves. This embodiment innovatively uses the tungsten tailings to prepare molecular sieves.
[0036] It should be further explained that the low Al content in tungsten tailings makes it difficult to prepare molecular sieves. Therefore, this embodiment also introduces aluminum tailings, the main components of which are SiO2: 1.71%, Al2O3: 63.06%, CaO: 2.15%, Na2O: 3.03%, MgO: 8.91%, K2O: 1.164%. The introduction of aluminum source not only realizes the resource utilization of solid waste, but also further reduces the preparation cost.
[0037] In this embodiment, tungsten tailings and aluminum tailings are utilized in a coordinated manner. Based on the fact that both tailings contain aluminum and silicon sources and the complementary advantages of their silicon and aluminum contents, the reaction effect can be increased and a high value-added utilization rate of solid waste can be achieved. At the same time, based on the fact that the compositions of the two slags are relatively similar, the introduction of other impurities can be avoided and the purity of the product can be improved.
[0038] S120, according to the mass ratio of tungsten tailings raw material to aluminum tailings raw material being 1:(0.2-0.9), weigh the tungsten tailings raw material and the aluminum tailings raw material respectively, and mix them to form a composite tailings masterbatch.
[0039] In some preferred embodiments, when the mass ratio of the tailings raw material to the aluminum tailings raw material is 1:0.9, the corresponding molar ratio of SiO2 to Al2O3 is 1:1.
[0040] In other preferred embodiments, when the mass ratio of the tailings raw material to the aluminum tailings raw material is 1:0.7, the corresponding molar ratio of SiO2 to Al2O3 is 1:1.2.
[0041] In other preferred embodiments, when the mass ratio of the tailings raw material to the aluminum tailings raw material is 1:0.42, the corresponding molar ratio of SiO2 to Al2O3 is 1:1.5.
[0042] In other preferred embodiments, when the mass ratio of the tailings raw material to the aluminum tailings raw material is 1:0.2, the corresponding molar ratio of SiO2 to Al2O3 is 1:2.5.
[0043] S130, adding the composite tailings masterbatch into a crucible, adding an alkali flux to perform alkali melting treatment to extract Si and Al components to obtain a metastable clinker.
[0044] In some preferred embodiments, the molar ratio of the alkali flux to SiO2 in the tungsten tailings raw material is (2-2.2): 1. For example, 2:1, 2.1:1, 2.2:1.
[0045] In other preferred embodiments, the alkali flux may preferably be NaOH. It should be understood that those skilled in the art may also select other alkali fluxes, such as KOH, Mg(OH)2, etc., without specific limitation.
[0046] In other preferred embodiments, the temperature of the alkali fusion treatment is 450-550°C, for example, 450°C, 470°C, 500°C, 530°C, 550°C, and the time is 5-7h, for example, 5h, 6h, 7h.
[0047] S140, grinding the metastable clinker into powder, adding water for aging treatment, and obtaining a crystallization mother liquor.
[0048] In some preferred embodiments, the aging treatment time is 5-7 hours, for example, 5 hours, 6 hours, 7 hours.
[0049] S150, placing the crystallization mother liquor into a reactor for crystallization treatment to obtain a molecular sieve initial sample.
[0050] In some preferred embodiments, the crystallization treatment temperature is 90-100°C, for example, 90°C, 92°C, 95°C, 97°C, 100°C, and the time is 7-9h, for example, 7h, 8h, 9h.
[0051] S160, washing and neutralizing the molecular sieve sample to obtain a molecular sieve.
[0052] It should be noted that one of the key points of the present embodiment is that different molecular sieves can be obtained by adjusting the ratio of tungsten tailings to aluminum tailings. That is to say, a variety of molecular sieve products can be produced based on the same preparation process. For example, the molecular sieve obtained in the present embodiment is any one of the LTA molecular sieve, FUA molecular sieve, FUA / LTA composite molecular sieve, FUA, and SOD coexistence molecular sieve.
[0053] In some preferred embodiments, when the mass ratio of the tungsten tailings raw material to the aluminum tailings raw material is 1:0.9 and the molar ratio of SiO2 to Al2O3 is 1:1, the obtained molecular sieve is an LTA molecular sieve, and the relative crystallinity of the LTA molecular sieve is 95.1%.
[0054] In other preferred embodiments, when the mass ratio of the tungsten tailings raw material to the aluminum tailings raw material is 1:0.7 and the molar ratio of SiO2 to Al2O3 is 1:1.2, the obtained molecular sieve is a FUA / LTA composite molecular sieve, and the relative crystallinity of the FUA / LTA composite molecular sieve is 97.6%.
[0055] Of course, it should be understood that when the molar ratio of SiO2 to Al2O3 is 1:1.3 or 1:1.4, a FUA / LTA composite molecular sieve is obtained.
[0056] In other preferred embodiments, when the mass ratio of the tungsten tailings raw material to the aluminum tailings raw material is 1:0.42, and the molar ratio of SiO2 to Al2O3 is 1:1.5, the obtained molecular sieve is a FUA molecular sieve, and the relative crystallinity of the FUA molecular sieve is 98.2%.
[0057] It should also be understood that when the molar ratio of SiO2 to Al2O3 is 1:(1.6-2.4), the FAU molecular sieve is converted to the SOD molecular sieve.
[0058] In other preferred embodiments, when the mass ratio of the tungsten tailings raw material to the aluminum tailings raw material is 1:0.2 and the molar ratio of SiO2 to Al2O3 is 1:2.5, the obtained molecular sieve is a FUA and SOD coexistence state molecular sieve, wherein the relative crystallinity of the FUA molecular sieve is 48.6%, and the relative crystallinity of the SOD molecular sieve is 21.2%.
[0059] It should be noted that since the structure of the aluminum source and silicon source in the tailings is different from that of the pure aluminum source and pure silicon source reagents, the nucleation mechanism of the crystallization reaction will also be different. This is also the main difficult technology and core technology for preparing molecular sieves from tailings. To this end, the present embodiment first uses alkali melting excitation to encapsulate the insoluble minerals in the tailings in aluminosilicate gel, and then uses a method of growing molecular sieve crystal nuclei on the surface of the insoluble minerals to grow into a molecular sieve with a "core-shell" structure.
[0060] In this embodiment, in the absence of inducer seed crystals, tungsten tailings and aluminum tailings are pretreated to allow a synergistic reaction between the two, and different types of molecular sieves are obtained by adjusting the ratio of the two. This process is simple and easy to operate, and it also achieves effective synergistic utilization of the tailings, thereby reducing the preparation cost of the molecular sieve.
[0061] Another aspect of the present disclosure provides a high crystallinity molecular sieve, which is prepared by the method described above.
[0062] In this embodiment, the specific surface area of the high crystallinity molecular sieve obtained by the method described above is 62.8-178m 2 / g, pore size: The structural size is 0.8-2μm, and the larger specific surface area helps to improve the adsorption capacity of the molecular sieve.
[0063] The preparation method of high crystallinity molecular sieve will be further described below in conjunction with specific examples:
[0064] Example 1
[0065] The preparation method of the high crystallinity molecular sieve in this example comprises the following steps:
[0066] S1. The tungsten tailings and aluminum tailings are sequentially washed to remove impurities, iron, dried, ball-milled and sieved to obtain tungsten tailings raw materials and aluminum tailings raw materials.
[0067] S2. A composite tailings masterbatch is prepared with an n(SiO2) / n(Al2O3) ratio of 1:1 and a mass ratio of tungsten tailings raw material to aluminum tailings raw material of 1:0.9 for standby use.
[0068] S3, adding the composite tailings masterbatch into a crucible, adding an alkali flux according to an alkali / silicon molar ratio of 2.1:1, wherein the alkali flux is NaOH, and performing alkali melting treatment at a temperature of 500° C. for 6 hours to obtain a metastable clinker.
[0069] S4. Grind the metastable clinker into powder, add water and age for 6 hours to obtain a crystallization mother liquor.
[0070] S5. Put the crystallization mother liquor into a reactor and crystallize it at 95° C. and normal pressure for 8 hours to obtain a molecular sieve sample.
[0071] S6. Wash and neutralize the initial sample of molecular sieve to obtain LTA molecular sieve.
[0072] like Figure 2 As shown, according to the XRD results, it can be seen that the molecular sieve obtained in this Example 1 is a pure phase LTA molecular sieve.
[0073] like Figure 3 As shown in (A, B), the LTA molecular sieve obtained in Example 1 has a cubic crystal structure, a single morphology, a structure size of about 1 μm, and a uniform size. In addition, the relative crystallinity is calculated to be 95.1% by the "peak fitting" algorithm of JADE 6.5 software, and the specific surface area is: 62.8 m 2 / g, pore size:
[0074] Example 2
[0075] The preparation method of the high crystallinity molecular sieve in this example comprises the following steps:
[0076] S1. The tungsten tailings and aluminum tailings are sequentially washed to remove impurities, iron, dried, ball-milled and sieved to obtain tungsten tailings raw materials and aluminum tailings raw materials.
[0077] S2. A composite tailings masterbatch is prepared with an n(SiO2) / n(Al2O3) ratio of 1:1.2 and a mass ratio of tungsten tailings raw material to aluminum tailings raw material of 1:0.7 for standby use.
[0078] S3, adding the composite tailings masterbatch into a crucible, adding an alkali flux according to an alkali / silicon molar ratio of 2.2:1, wherein the alkali flux is NaOH, and performing alkali melting treatment at a temperature of 500° C. for 6 hours to obtain a metastable clinker.
[0079] S4. Grind the metastable clinker into powder, add water and age for 6 hours to obtain a crystallization mother liquor.
[0080] S5. Put the crystallization mother liquor into a reactor and crystallize it at 95° C. and normal pressure for 8 hours to obtain a molecular sieve sample.
[0081] S6. Wash and neutralize the initial molecular sieve sample to obtain the FUA / LTA composite molecular sieve.
[0082] like Figure 2 As shown, according to the XRD results, it can be known that the molecular sieve obtained in Example 2 is a FAU / LTA composite molecular sieve, that is, it includes both the characteristic peaks of the FAU molecular sieve and the characteristic peaks of the LTA molecular sieve.
[0083] like Figure 4 As shown in (A, B), the FUA / LTA molecular sieve obtained in Example 2 is a combination of cube and octahedron crystal structure, showing that the LTA phase is dominant, and the structure size is about 1 μm. In addition, the relative crystallinity is calculated to be 97.6% by the "peak fitting" algorithm of JADE 6.5 software, and the specific surface area is: 77.5m 2 / g, pore size:
[0084] Example 3
[0085] The preparation method of the high crystallinity molecular sieve in this example comprises the following steps:
[0086] S1. The tungsten tailings and aluminum tailings are sequentially washed to remove impurities, iron, dried, ball-milled and sieved to obtain tungsten tailings raw materials and aluminum tailings raw materials.
[0087] S2. A composite tailings masterbatch is prepared with an n(SiO2) / n(Al2O3) ratio of 1:1.5 and a mass ratio of tungsten tailings raw material to aluminum tailings raw material of 1:0.42 for standby use.
[0088] S3, adding the composite tailings masterbatch into a crucible, adding an alkali flux according to an alkali / silicon molar ratio of 2.2:1, wherein the alkali flux is NaOH, and performing alkali melting treatment at a temperature of 500° C. for 6 hours to obtain a metastable clinker.
[0089] S4. Grind the metastable clinker into powder, add water and age for 6 hours to obtain a crystallization mother liquor.
[0090] S5. Put the crystallization mother liquor into a reactor and crystallize it at 95° C. and normal pressure for 8 hours to obtain a molecular sieve sample.
[0091] S6. Wash and neutralize the initial molecular sieve sample to obtain the FUA molecular sieve.
[0092] like Figure 2 As shown, according to the XRD results, it can be seen that the molecular sieve obtained in Example 3 is a FAU pure phase molecular sieve.
[0093] like Figure 5 As shown in (A, B), the FUA molecular sieve obtained in Example 3 is a conical octahedral combined crystal structure with a single morphology, a structure size of about 0.8 μm, and a uniform size. In addition, the relative crystallinity is calculated to be 98.2% by the "peak fitting" algorithm of JADE 6.5 software, and the specific surface area is: 178m 2 / g, pore size:
[0094] Example 4
[0095] The preparation method of the high crystallinity molecular sieve in this example comprises the following steps:
[0096] S1. The tungsten tailings and aluminum tailings are sequentially washed to remove impurities, iron, dried, ball-milled and sieved to obtain tungsten tailings raw materials and aluminum tailings raw materials.
[0097] S2. A composite tailings masterbatch is prepared with an n(SiO2) / n(Al2O3) ratio of 1:2.5 and a mass ratio of tungsten tailings raw material to aluminum tailings raw material of 1:0.2 for standby use.
[0098] S3, adding the composite tailings masterbatch into a crucible, adding an alkali flux according to an alkali / silicon molar ratio of 2.2:1, wherein the alkali flux is NaOH, and performing alkali melting treatment at a temperature of 500° C. for 6 hours to obtain a metastable clinker.
[0099] S4. Grind the metastable clinker into powder, add water and age for 6 hours to obtain a crystallization mother liquor.
[0100] S5. Put the crystallization mother liquor into a reactor and crystallize it at 95° C. and normal pressure for 8 hours to obtain a molecular sieve sample.
[0101] S6. Wash and neutralize the initial sample of molecular sieve to obtain a coexistence state of FUA and SOD molecular sieve.
[0102] like Figure 2 As shown, according to the XRD results, it can be known that the molecular sieve obtained in Example 4 is a FAU / SOD composite molecular sieve, that is, it includes both the characteristic peaks of the FAU molecular sieve and the characteristic peaks of the SOD molecular sieve.
[0103] like Figure 6As shown in (A, B), the FUA molecular sieve obtained in Example 4 is a conical octahedral combined crystal structure with a structure size of about 2 μm. The SOD molecular sieve is a layered molecular sieve alternately stacked in a morphology, composed of a plate-like structure arranged in spherical clusters, with a structure size of 1 μm. The relative crystallinity of FUA and SOD calculated by the "peak fitting" algorithm of JADE 6.5 software is 48.6%, and the relative crystallinity of SOD is 21.2%.
[0104] The present invention discloses a method for preparing a variety of high-crystallinity molecular sieves by adjusting the ratio of tungsten tailings to aluminum tailings and a high-crystallinity molecular sieve. Compared with the prior art, the following advantages are achieved:
[0105] Beneficial effects:
[0106] First, in view of the fact that most of the current molecular sieves are prepared using reagents and the high preparation cost, the present invention uses tungsten tailings and aluminum tailings to collaboratively prepare molecular sieves, effectively reducing costs, while achieving collaborative treatment of tailings and improving resource utilization.
[0107] Second, in order to address the problems of single and complex tungsten tailings, difficulty in preparing molecular sieves and low crystallinity, the present invention can produce different types of molecular sieve products by adjusting the ratio of tungsten tailings to aluminum tailings, and each type of molecular sieve has high crystallinity to meet various application needs.
[0108] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.
Claims
1. A method for preparing a variety of high crystallinity molecular sieves by regulating the multi-component ratio of tungsten tailings / aluminum tailings, characterized in that: The method comprises: The tungsten tailings and aluminum tailings are sequentially washed to remove impurities, iron, dried, ball-milled, and sieved to obtain tungsten tailings raw materials and aluminum tailings raw materials respectively; According to the mass ratio of tungsten tailings raw material to aluminum tailings raw material being 1:(0.2-0.9), the tungsten tailings raw material and the aluminum tailings raw material are weighed respectively, and the raw materials are mixed to form a composite tailings masterbatch; Adding an alkali flux to the composite tailings masterbatch for alkali melting treatment to obtain a metastable clinker; Grinding the metastable clinker into powder, adding water for aging treatment, and obtaining a crystallization mother solution; The crystallization mother solution is placed in a reaction kettle for crystallization treatment to obtain a molecular sieve primary sample; The molecular sieve sample is washed and neutralized to obtain a molecular sieve, wherein the molecular sieve is any one of LTA molecular sieve, FUA molecular sieve, FUA / LTA composite molecular sieve, and FUA and SOD coexisting molecular sieve.
2. The method according to claim 1, characterized in that When the mass ratio of the tungsten tailings raw material to the aluminum tailings raw material is 1:0.9, the obtained molecular sieve is an LTA molecular sieve, and the relative crystallinity of the LTA molecular sieve is 95.1%.
3. The method according to claim 1, characterized in that When the mass ratio of the tungsten tailings raw material to the aluminum tailings raw material is 1:0.7, the obtained molecular sieve is a FUA / LTA composite molecular sieve, and the relative crystallinity of the FUA / LTA composite molecular sieve is 97.6%.
4. The method according to claim 1, characterized in that: When the mass ratio of the tungsten tailings raw material to the aluminum tailings raw material is 1:0.42, the obtained molecular sieve is a FUA molecular sieve, and the relative crystallinity of the FUA molecular sieve is 98.2%.
5. The method according to claim 1, characterized in that When the mass ratio of the tungsten tailings raw material to the aluminum tailings raw material is 1:0.2, the obtained molecular sieve is a FUA and SOD coexisting molecular sieve, the relative crystallinity of the FUA molecular sieve is 48.6%, and the relative crystallinity of the SOD molecular sieve is 21.2%.
6. The method according to any one of claims 1 to 5, characterized in that: The molar ratio of the alkali flux to SiO2 in the tungsten tailings raw material is (2-2.2):
1.
7. The method according to any one of claims 1 to 5, characterized in that: The alkali fusion treatment is carried out at a temperature of 400-550° C. and for a time of 5-7 hours.
8. The method according to any one of claims 1 to 5, characterized in that: The temperature of the crystallization treatment is 80-95° C. and the time is 7-9 hours.
9. A high crystallinity molecular sieve, characterized in that: The high crystallinity molecular sieve is prepared by the method according to any one of claims 1 to 8.
10. The high crystallinity molecular sieve according to claim 9, characterized in that: The specific surface area of the high crystallinity molecular sieve is 62.8-178m 2 / g, pore size: The structure size is 0.8-2μm.