A kind of magnetic hectorite and preparation method thereof

Abstract

The invention discloses a magnetic hectorite and a preparation method thereof, relating to the technical field of hectorite preparation processes. The preparation method of the present invention comprises using natural clay as a raw material, depolymerizing it in a solid-phase-like environment using a microwave progressive irradiation method to obtain a clay-based mineral polymer; preparing a magnetic precursor based on a solid-phase-like system and a microwave progressive irradiation method; and preparing the magnetic hectorite using a solid-phase-like method and freeze-drying technology. The method of the present invention has the advantages of low cost, high efficiency, and low pollution. It can simultaneously achieve magnetic functionalization while preparing the hectorite, providing a new approach for the high-value-added development of natural clay resources.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation technology of hectorite, and particularly relates to magnetic hectorite and a preparation method thereof. Background Art

[0002] Hectorite is a synthetic layered silicate material. Its unique nanostructure, high surface area, and adjustable surface charge make it a valuable resource for the treatment of heavy metal, dye, and antibiotic pollution. However, traditional hectorite preparation processes generally rely on chemical raw materials such as high-purity lithium salts, magnesium salts, and silicates. These processes are plagued by high raw material costs and complex synthesis routes (typically using hydrothermal synthesis, which results in low yields due to the low solid-to-liquid ratio per reactor, high wastewater discharge, and low synthesis efficiency). These factors contribute to high costs for large-scale production.

[0003] With the advent of green chemistry, alternative synthesis processes for producing industrial products using natural clays, such as kaolin and montmorillonite, as raw materials have garnered widespread attention. However, while layered clays like montmorillonite and kaolin share structural elements similar to hectorite, their direct use in hectorite preparation faces two major technical bottlenecks. First, natural clays are high in impurities, making traditional flotation processes unable to completely remove associated minerals, making them impractical for direct use in hectorite preparation. Second, while traditional acid-base treatments can enhance reactivity, they require prior high-temperature treatment, resulting in high energy consumption. Furthermore, magnetic functionalization has become an important modification approach to improve the efficiency of adsorption materials. This technology involves chemically combining magnetic particles with adsorbent materials, aiming to enhance their separation and regeneration capabilities. Existing literature indicates that the moderate addition of magnetic particles not only modifies the adsorbent's physicochemical properties, such as its specific surface area and the distribution of surface adsorption sites, significantly improving its adsorption capacity for pollutants, but also imparts magnetic properties, facilitating separation and regeneration. However, the self-aggregation of magnetic particles and the random distribution of functional groups (or defects) on the surface of the adsorbent make it difficult to ensure uniform and efficient loading of the magnetic particles. Furthermore, due to the weak interaction between the magnetic particles and the adsorbent, the magnetic particles are prone to detachment during the regeneration and recycling of the adsorbent, severely reducing the regeneration performance of the magnetic adsorbent. More importantly, the introduction of magnetic components often comes at the expense of the material's specific surface area, resulting in a 20%-40% decrease in adsorption capacity, which restricts its practical application in wastewater treatment scenarios. A prior art method for preparing nano-hectorite using clay as a raw material by microwave irradiation (CN118324153A) discloses a process for preparing nano-hectorite using a clay-based active silicon source obtained by depolymerizing natural clay as a raw material, using a solid-phase technique and microwave progressive irradiation. However, the microwave progressive irradiation technique described in this method results in uneven heating of the magnetic particles and the clay-based active silicon source during the preparation of the magnetic material, and can damage the magnetic properties of the magnetic particles, making it unsuitable for the synthesis of magnetic hectorite. In order to solve the above problems, it is urgent to develop a green method for preparing hectorite using cheap clay as raw material and simultaneously realize its magnetic functionalization. Summary of the Invention

[0004] To address the problems existing in the preparation of magnetic hectorite in the prior art, the present invention provides a magnetic hectorite and a method for its preparation. This method uses geopolymers produced by the depolymerization of natural clay as raw material, utilizes surface defects remaining after the depolymerization of the natural clay to immobilize magnetic particles, and uses microwave progressive irradiation technology to identify whether the magnetic particles are chemically loaded. Furthermore, the hectorite is prepared using the topological structure remaining after the depolymerization of the natural clay in the magnetic precursor. During this process, the magnetic particles are incorporated into the crystals of the synthesized product along with the crystallization of the raw material, thereby imparting magnetism to the product.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for preparing magnetic hectorite specifically comprises the following steps:

[0007] A1. The lithium source, magnesium source and magnetic precursor were mixed in a molar ratio of 1.0:3.0:1.7-3.0 and stirred thoroughly. The resulting mixture was designated as mixture I.

[0008] A2. The mixture Ⅰ was transferred to a polytetrafluoroethylene-lined hydrothermal reactor tank, and 3-5 ml of ammonia solution was added to the bottom of the polytetrafluoroethylene-lined hydrothermal reactor tank;

[0009] A3. Place the loaded polytetrafluoroethylene-lined tank into a stainless steel reactor, place it in a constant temperature oven, and react at a temperature of 110-200°C for 24-72h.

[0010] A4. After the reaction is complete, remove the polytetrafluoroethylene-lined tank from the hydrothermal reactor, centrifuge and wash the solid product until neutral, transfer the solid product with deionized water, and freeze-dry the resulting material. The resulting solid powder is magnetic hectorite.

[0011] Furthermore, in step A1, the lithium source is one of lithium fluoride, lithium carbonate, and lithium hydroxide monohydrate, or a mixture of two of them; the magnesium source is one of magnesium chloride, magnesium carbonate, and magnesium hydroxide, or a mixture of two of them.

[0012] Furthermore, in step A2, the ammonia water used is a laboratory-labeled concentrated ammonia water with a concentration of 25%; the mixture I and the ammonia solution are separated by a polytetrafluoroethylene mesh, that is, during the reaction process, only the alkaline vapor formed by the heating of the ammonia water serves as the reaction medium.

[0013] Furthermore, in step A4, the freeze-drying conditions are: freezing temperature -80°C, and freeze-drying time is 1-3 days.

[0014] Furthermore, in step A1, the magnetic precursor is prepared by the following method, specifically comprising:

[0015] B1. The clay-based mineral polymer and the magnetic particles were mixed uniformly in a mass ratio of 1:0.05-1, and the resulting mixture was referred to as mixture II;

[0016] B2. The mixture II was transferred to a polytetrafluoroethylene-lined hydrothermal reactor tank, and 3-5 ml of ammonia solution was added to the bottom of the polytetrafluoroethylene-lined hydrothermal reactor tank;

[0017] B3. The polytetrafluoroethylene-lined tank in step B2 of the hydrothermal reactor was loaded into a stainless steel reactor, placed in a constant temperature oven, and reacted at a temperature of 150-170 ° C for 3-6h;

[0018] B4. After the reaction is complete, the polytetrafluoroethylene-lined hydrothermal reactor tank is removed, and the solid product in the reactor tank is removed. The resulting mixture is referred to as mixture III.

[0019] B5. The mixture obtained in step B4 is loaded into a microwave digestion vessel, and 3-5 ml of ammonia solution is added to the bottom of the microwave digestion vessel;

[0020] B6. Place the prepared microwave digestion vessel into a microwave digestion instrument and irradiate at a certain temperature according to specific irradiation conditions: irradiation temperature 120-150°C, irradiation cycles 3-8 times;

[0021] B7. After the reaction is completed, remove the microwave digestion vessel after microwave irradiation, filter the solid product until it is neutral, and place it in a vacuum oven at 90°C for 12 hours. The vacuum degree of the vacuum oven is 0.07 MPa. The resulting solid powder is the magnetic precursor.

[0022] Furthermore, in step B1, the magnetic particles are one or a combination of Fe2O3, Fe3O4, FeCl2, Co3O4, CoCl2, and NiCl2.

[0023] Furthermore, in step B2, the ammonia solution used is an ammonia solution obtained by uniformly mixing ammonia solution with a laboratory-labeled concentration of 25% and deionized water in a volume ratio of 1:1; the mixture II and the ammonia solution are separated by a polytetrafluoroethylene mesh, that is, the reaction in step B3 relies solely on the alkaline vapor generated by the heating of the ammonia solution as the reaction medium;

[0024] In step B5, the ammonia water used is a laboratory-labeled concentrated ammonia water with a concentration of 25%; the mixture III is separated from the ammonia solution by a polytetrafluoroethylene mesh, that is, the reaction in step B6 relies solely on the alkaline vapor formed by the heating of the ammonia water as the reaction medium.

[0025] Furthermore, in step B6, the irradiation cycle is specifically each cycle of 100W irradiation for 10s, 150W irradiation for 10s, 200W irradiation for 10s, 250W irradiation for 10s, 300W irradiation for 10s, and rest for 10s.

[0026] Furthermore, in step B1, the clay-based mineral polymer is prepared by the following method, specifically comprising:

[0027] C1. Select natural clay ore, flotate and remove impurities, grind to powder, and sieve through an 80-mesh sieve to obtain natural clay powder;

[0028] C2. natural clay powder and acid solution are loaded into a microwave digestion tank according to a certain solid-liquid ratio, wherein the mass volume ratio of natural clay to acid solution is in the range of 1:2.5-5 g / ml;

[0029] C3. Place the microwave digestion vessel prepared in step C2 into a microwave digestion instrument and irradiate at a certain temperature according to specific irradiation conditions, specifically, an irradiation temperature of 150-200° C. and 30-60 irradiation cycles;

[0030] C4. Take out the microwave digestion tank after microwave irradiation, filter the solid product until it is neutral, and place it in a constant temperature oven at 80-90°C to dry for 12 hours. The obtained solid powder is the clay-based mineral polymer.

[0031] Furthermore, in step C1, the natural clay is a mixture of one or more of kaolin, montmorillonite, rectorite, illite, and halloysite;

[0032] In step C2, the acid solution is hydrochloric acid with a concentration of 2-4 mol / L;

[0033] In step C2, the natural clay and the acid solution are isolated by a polytetrafluoroethylene mesh, that is, during the microwave irradiation process, only the acid solution is heated to form acidic vapor as the reaction medium;

[0034] In step C3, the irradiation cycle is specifically each cycle of 200W irradiation for 10s, 230W irradiation for 10s, 270W irradiation for 10s, 330W irradiation for 10s, 350W irradiation for 10s, and rest for 10s.

[0035] Compared with the prior art, the advantages of the present invention are as follows:

[0036] 1. In terms of synthetic raw materials, the present invention uses geopolymers produced by acid steam depolymerization of natural clay as synthetic raw materials, which to a certain extent alleviates the pollution problem of synthetic raw materials caused by the use of silicon-containing chemicals (such as silica gel).

[0037] 2. In the process of obtaining geopolymers, the present invention adopts a superimposed composite process of a solid-phase method and a microwave progressive irradiation method, so that low-concentration acid liquid can achieve the effect of high-concentration acid liquid, effectively improving the utilization rate of the acid liquid, and can achieve multiple recycling by adding a small amount of acid liquid, thereby reducing costs; at the same time, a large amount of high-value elements, such as aluminum and potassium, can also be present in the acid liquid.

[0038] 3. The present invention uses natural clay powder directly irradiated with microwaves. Because different chemical bonds react differently to microwaves, they are directly activated, resulting in consistent activation and cleavage locations. This allows the natural clay to depolymerize without the need for a high-temperature activation step. Furthermore, the broken chemical bonds can better bind firmly and uniformly to the magnetic particles through chemical interactions.

[0039] 4. In the process of preparing magnetic precursors, the present invention adopts a solid-phase preparation method and a microwave progressive irradiation identification method, which can minimize the impact of the synthesis process on the magnetic properties of magnetic particles, while using microwave irradiation technology to quickly identify the chemical loading behavior between magnetic particles and geopolymers.

[0040] 5. In the process of preparing magnetic hectorite, the present invention adopts a solid-phase preparation method combined with a freeze-drying process to avoid the complex operation of traditional hydrothermal synthesis of hectorite. At the same time, it greatly reduces the loss of magnetic particles, that is, the magnetic hectorite is prepared with maximum efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the specific implementation or the description of the prior art.

[0042] Figure 1 is the XRD pattern of the geopolymer of Example 1;

[0043] Figure 2 is the XRD pattern of the magnetic precursor of Example 1;

[0044] Figure 3 The XRD pattern of the magnetic hectorite prepared in Example 1-3;

[0045] Figure 4 This is the SEM image of the magnetic hectorite prepared in Example 1. DETAILED DESCRIPTION

[0046] In order to clearly and completely describe the technical solution and specific working process of the present invention, the specific implementation methods of the present invention are as follows in conjunction with the accompanying drawings:

[0047] Example 1

[0048] This embodiment provides a method for preparing magnetic hectorite, and the specific steps are as follows:

[0049] A1. The lithium source, magnesium source, and magnetic precursor were mixed in a molar ratio of 1.0:3.0:3.0 and stirred thoroughly. The resulting mixture was referred to as mixture I.

[0050] A2. Transfer the above mixture I to a 100 ml polytetrafluoroethylene-lined hydrothermal reactor tank and add 5 ml of ammonia solution to the bottom of the polytetrafluoroethylene hydrothermal reactor tank;

[0051] A3. The polytetrafluoroethylene-lined tank in step A2 was loaded into a stainless steel reactor and placed in a constant temperature oven at 200°C for 24h.

[0052] A4. After the reaction is complete, remove the polytetrafluoroethylene-lined tank from the hydrothermal reactor, centrifuge and wash the solid product until neutral, transfer the solid product with deionized water, and freeze-dry the resulting material to obtain a solid powder; this is magnetic hectorite.

[0053] In this embodiment, in step A1, the lithium source is lithium hydroxide monohydrate; and the magnesium source is magnesium hydroxide.

[0054] In this embodiment, the aqueous ammonia used in step A2 is concentrated aqueous ammonia with a laboratory labeled concentration of 25%; the mixture I and the aqueous ammonia solution are separated by a polytetrafluoroethylene mesh, that is, during the reaction, only the alkaline vapor formed by the heating of the aqueous ammonia serves as the reaction medium.

[0055] In this embodiment, in step A4, the freeze-drying conditions are: freezing temperature -80°C, and freeze-drying time is 3 days.

[0056] In this embodiment, in step A1, the magnetic precursor is prepared by the following method, specifically comprising:

[0057] B1. The clay-based mineral polymer and magnetic particles were mixed uniformly in a mass ratio of 1:0.05. The resulting mixture was designated as mixture II.

[0058] B2. Transfer the mixture II to a 100 ml polytetrafluoroethylene-lined hydrothermal reactor and add 5 ml of ammonia solution to the bottom of the polytetrafluoroethylene-lined hydrothermal reactor.

[0059] B3. The polytetrafluoroethylene-lined tank in step B2 was loaded into a stainless steel reactor and placed in a constant temperature oven at a temperature of 150°C for 6h;

[0060] B4. After the reaction is complete, the polytetrafluoroethylene-lined hydrothermal reactor tank is removed, and the solid product in the reactor tank is removed. The resulting mixture is referred to as mixture III.

[0061] B5. The mixture obtained in step B4 was loaded into a microwave digestion vessel, and 5 ml of ammonia solution was added to the bottom of the microwave digestion vessel;

[0062] B6. Place the microwave digestion vessel into a microwave digestion instrument and irradiate at a certain temperature according to specific irradiation conditions, specifically, the irradiation temperature is 150°C and the irradiation cycle is 3;

[0063] B7. After the reaction is completed, remove the microwave digestion vessel after microwave irradiation, filter the solid product until it is neutral, and place it in a vacuum oven at 90°C for 12 hours (vacuum degree is 0.07 MPa). The resulting solid powder is the magnetic precursor.

[0064] In this embodiment, the ammonia solution used in step B2 is an ammonia solution obtained by uniformly mixing ammonia solution with a laboratory-labeled concentration of 25% and deionized water in a volume ratio of 1:1. Mixture II and the ammonia solution are separated by a polytetrafluoroethylene mesh, that is, the reaction in step B3 relies solely on the alkaline vapor formed by heating the ammonia solution as the reaction medium.

[0065] In this embodiment, the ammonia water used in step B5 is a laboratory-labeled concentrated ammonia water with a concentration of 25%; the mixture III and the ammonia solution are separated by a polytetrafluoroethylene mesh, that is, the reaction in step B6 relies solely on the alkaline vapor formed by the heating of the ammonia water as the reaction medium.

[0066] In this embodiment, in step B6, the irradiation cycles mentioned are as follows: 100W irradiation for 10s, 150W irradiation for 10s, 200W irradiation for 10s, 250W irradiation for 10s, 300W irradiation for 10s, and rest for 10s.

[0067] In this embodiment, in step B1, the magnetic particles are Fe3O4.

[0068] In this embodiment, in step B1, the clay-based mineral polymer is prepared by the following method, specifically comprising:

[0069] C1. Select natural clay ore, flotate and remove impurities, grind it into powder, and sieve it through an 80-mesh sieve to obtain natural clay powder;

[0070] C2. Load natural clay powder and acid solution into a microwave digestion tank at a certain solid-liquid ratio, with the ratio range of natural clay: acid solution = 1:2.5 g / ml;

[0071] C3. Place the microwave digestion vessel prepared in step C2 into a microwave digestion instrument and irradiate at a certain temperature according to specific irradiation conditions, specifically, an irradiation temperature of 150-200° C. and irradiation cycles of 30-60;

[0072] C4. Take out the microwave digestion tank after microwave irradiation, filter the solid product until it is neutral, and place it in a constant temperature oven at 80°C to dry for 12 hours. The obtained solid powder is the clay-based mineral polymer.

[0073] In this embodiment, in step C1, the natural clay is halloysite;

[0074] In step C2, the acid solution is hydrochloric acid with a concentration of 4 mol / L;

[0075] In step C2, the natural clay and the acid solution are isolated by a polytetrafluoroethylene mesh, that is, during the microwave irradiation process, only the acid solution is heated to form acidic vapor as the reaction medium;

[0076] In step C3, the irradiation cycle is specifically each cycle of 200W irradiation for 10s, 230W irradiation for 10s, 270W irradiation for 10s, 330W irradiation for 10s, 350W irradiation for 10s, and rest for 10s.

[0077] from Figure 1 It can be seen that the clay-based mineral polymer presents an amorphous structure, indicating that its inherent crystal structure has been completely depolymerized.

[0078] from Figure 3 It can be seen from the figure that the products synthesized in Examples 1-3 are all magnetic hectorite according to the diffraction peaks.

[0079] from Figure 4 As can be seen in the figure, the synthesized sample is a block formed by stacking flakes, with nanoparticles protruding on the surface. This confirms that it is formed by stacking flakes of hectorite, and the nanoparticles are the morphological characteristics of the magnetic particles after loading.

[0080] The rest of Example 2 is the same as Example 1, except that the natural clay in step C1 is kaolin.

[0081] The rest of Example 3 is the same as Example 1, except that the natural clay in step C1 is illite.

[0082] The rest of Example 4 is the same as Example 1, except that in step B1

[0083] The magnetic particles used were FeCl2.

[0084] The rest of Example 5 is the same as Example 1, except that in step A1, the molar ratio of the lithium source, magnesium source, and magnetic precursor is 1.0:3.0:1.7.

[0085] The rest of Example 6 is the same as Example 1, except that in step A1, the lithium source is lithium fluoride and the magnesium source is magnesium chloride.

[0086] The rest of Example 7 is the same as Example 1, except that in step A2, 3 ml of ammonia solution is added to the bottom of the polytetrafluoroethylene hydrothermal reactor; in step A3, the reaction is carried out at a temperature of 110° C. for 72 hours.

[0087] Experimental data

[0088] Table 1 shows the adsorption performance test results of the magnetic hectorite in the first and after 7 regenerations of Examples 1-7.

[0089] serial number Adsorption efficiency (first time) Adsorption efficiency (8th time) Example 1 99% 93% Example 2 99% 91% Example 3 99% 92% Example 4 99% 91% Example 5 99% 90% Example 6 98% 90% Example 7 99% 92%

[0090] Adsorption experiments

[0091] Each time, a certain mass of magnetic hectorite (0.2 g) was weighed and placed in a conical flask. A certain volume of wastewater containing methylene blue (100 mL) was then added and shaken at 30 °C for 2 h. After the adsorption was completed, the supernatant was taken and centrifuged at 8000 r / min for 15 min. The concentration of methylene blue in the wastewater before and after adsorption was determined by ultraviolet spectrophotometry (the initial concentration C0 was 700 mg·L -1 , C t is the concentration of methylene blue in the solution after adsorption), and then calculate the removal rate of methylene blue (R, %) according to the following formula.

[0092]

[0093] The adsorbed material is collected under the action of an external magnetic field, and then a regeneration adsorption experiment is carried out. Before each regeneration adsorption, it needs to be ultrasonically treated at room temperature (20-30°C) (the ultrasonic frequency used is 40KHz, and the ultrasonic time is 15min). After the ultrasonic treatment is completed, the adsorption experiment is carried out.

[0094] It can be seen from the methylene blue dye adsorption experimental results in Table 1 that the magnetic hectorite prepared in each example has relatively excellent adsorption performance and regeneration performance.

[0095] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0096] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0097] In addition, the various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing magnetic hectorite, characterized in that: The specific steps include: A1. The lithium source, magnesium source and magnetic precursor were mixed in a molar ratio of 1.0:3.0:1.7-3.0 and stirred thoroughly. The resulting mixture was designated as mixture I. A2. The mixture Ⅰ was transferred to a polytetrafluoroethylene-lined hydrothermal reactor tank, and 3-5 ml of ammonia solution was added to the bottom of the polytetrafluoroethylene-lined hydrothermal reactor tank; A3. Place the loaded polytetrafluoroethylene-lined tank into a stainless steel reactor, place it in a constant temperature oven, and react at a temperature of 110-200°C for 24-72h. A4. After the reaction is completed, the polytetrafluoroethylene-lined hydrothermal reactor tank is removed, the solid product is centrifuged and washed to neutrality, the solid product is transferred to deionized water, and the resulting material is freeze-dried to obtain a solid powder that is magnetic hectorite; In step A1, the magnetic precursor is prepared by the following method, specifically comprising: B1. The clay-based mineral polymer and magnetic particles were mixed uniformly in a mass ratio of 1:0.05-1, and the resulting mixture was referred to as mixture II; B2. The mixture II was transferred to a polytetrafluoroethylene-lined hydrothermal reactor tank, and 3-5 ml of ammonia solution was added to the bottom of the polytetrafluoroethylene-lined hydrothermal reactor tank; B3. The polytetrafluoroethylene-lined tank in step B2 of the hydrothermal reactor was loaded into a stainless steel reactor, placed in a constant temperature oven, and reacted at a temperature of 150-170 ° C for 3-6h; B4. After the reaction is complete, the polytetrafluoroethylene-lined hydrothermal reactor tank is removed, and the solid product in the reactor tank is removed. The resulting mixture is referred to as mixture III. B5. The mixture obtained in step B4 is loaded into a microwave digestion vessel, and 3-5 ml of ammonia solution is added to the bottom of the microwave digestion vessel; B6. Place the prepared microwave digestion vessel into a microwave digestion instrument and irradiate at a certain temperature according to specific irradiation conditions: irradiation temperature 120-150°C, irradiation cycles 3-8 times; B7. After the reaction is complete, remove the microwave digestion vessel from the microwave irradiation chamber, filter the solid product until it is neutral, and place it in a vacuum oven at 90°C for 12 hours at a vacuum level of 0.07 MPa. The resulting solid powder is the magnetic precursor. In step B1, the clay-based mineral polymer is prepared by the following method, specifically comprising: C1. Select natural clay ore, flotate and remove impurities, grind to powder, and sieve through an 80-mesh sieve to obtain natural clay powder; C2. natural clay powder and acid solution are loaded into a microwave digestion tank according to a certain solid-liquid ratio, wherein the mass volume ratio of natural clay to acid solution is in the range of 1:2.5-5g / ml; C3. Place the microwave digestion vessel prepared in step C2 into a microwave digestion instrument and irradiate at a certain temperature according to specific irradiation conditions, specifically, an irradiation temperature of 150-200° C. and 30-60 irradiation cycles; C4. Take out the microwave digestion tank after microwave irradiation, filter the solid product until it is neutral, and place it in a constant temperature oven at 80-90°C to dry for 12 hours. The obtained solid powder is the clay-based mineral polymer.

2. The method for preparing a magnetic hectorite according to claim 1, wherein In step A1, the lithium source is one of lithium fluoride, lithium carbonate, and lithium hydroxide monohydrate, or a mixture of two of them; the magnesium source is one of magnesium chloride, magnesium carbonate, and magnesium hydroxide, or a mixture of two of them.

3. The method for preparing a magnetic hectorite according to claim 1, wherein In step A2, the aqueous ammonia used is a laboratory-labeled 25% concentrated aqueous ammonia solution; the mixture I is separated from the aqueous ammonia solution by a polytetrafluoroethylene mesh, that is, during the reaction, only the alkaline vapor formed by the heating of the aqueous ammonia solution serves as the reaction medium.

4. The method for preparing a magnetic hectorite according to claim 1, wherein In step A4, the freeze-drying conditions are: freezing temperature -80°C, and freeze-drying time is 1-3 days.

5. The method for preparing a magnetic hectorite according to claim 1, wherein In step B1, the magnetic particles are one or a combination of Fe2O3, Fe3O4, FeCl2, Co3O4, CoCl2, and NiCl2.

6. The method for preparing a magnetic hectorite according to claim 1, wherein In step B2, the ammonia solution used is a mixture of 25% concentrated ammonia solution with deionized water in a volume ratio of 1:

1. Mixture II is separated from the ammonia solution by a polytetrafluoroethylene mesh, meaning that the reaction in step B3 relies solely on the alkaline vapor generated by the heating of the ammonia solution as the reaction medium. In step B5, the ammonia solution used is a laboratory-labeled 25% concentrated ammonia solution; mixture III and the ammonia solution are separated by a polytetrafluoroethylene mesh, that is, the reaction in step B6 relies solely on the alkaline vapor formed by the heating of the ammonia solution as the reaction medium; In step B6, the irradiation cycle is specifically each cycle of 100W irradiation for 10s, 150W irradiation for 10s, 200W irradiation for 10s, 250W irradiation for 10s, 300W irradiation for 10s, and stop for 10s.

7. The method for preparing a magnetic hectorite according to claim 1, wherein In step C1, the natural clay is a mixture of one or more of kaolin, montmorillonite, rectorite, illite, and halloysite; In step C2, the acid solution is hydrochloric acid with a concentration of 2-4 mol / L; In step C2, the natural clay and the acid solution are isolated by a polytetrafluoroethylene mesh, that is, during the microwave irradiation process, only the acid solution is heated to form acidic vapor as the reaction medium; In step C3, the irradiation cycle is specifically each cycle of 200W irradiation for 10s, 230W irradiation for 10s, 270W irradiation for 10s, 330W irradiation for 10s, 350W irradiation for 10s, and rest for 10s.

8. A magnetic hectorite, characterized in that The method is prepared by any one of claims 1 to 7.

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