Iron-manganese-based modified feldspar powder as well as preparation method and application thereof
By preparing iron-manganese-based modified feldspar powder, the problem of remediation of thallium-contaminated soil, water and solid waste has been solved, achieving efficient, stable and low-cost thallium pollution remediation and resource utilization of feldspar powder.
Patent Information
- Application Number
- CN202511848358.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-03-06
AI Technical Summary
Existing technologies are insufficient for efficiently, stably, and cost-effectively remediating thallium-contaminated soil, water, and solid waste, and commonly used methods may cause secondary pollution or are complex to operate.
By preparing iron-manganese-based modified feldspar powder, and reacting it with potassium permanganate and ferrous salts to adjust the pH value, loaded iron-manganese oxides are generated, forming a multifunctional composite material for thallium pollution remediation.
It achieves efficient and stable adsorption of thallium, reduces processing costs, avoids secondary pollution, and realizes the resource utilization of feldspar powder.
Smart Images
Figure CN121607127A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of solid waste resource utilization and heavy metal pollution remediation technology, and in particular to an iron-manganese-based modified feldspar powder, its preparation method and application. Background Technology
[0002] Thallium (Tl) is a highly toxic rare and dispersed metallic element with significant bioaccumulation and environmental persistence. Its toxicity far exceeds that of common heavy metals such as mercury, lead, and cadmium, and it has been included in my country's key prevention and control efforts. Non-ferrous metal and steel smelting industries are the main sources of thallium pollution. Thallium-containing pollutants emitted from these industries enter the natural environment through atmospheric deposition and rainwater leaching, posing a significant threat to soil and water safety. In recent years, with the further development of mining and metallurgical activities and the high-increase demand for thallium from emerging technology industries, the risk of thallium exposure has increased significantly, leading to frequent large-scale thallium pollution incidents. Currently, commonly used methods for thallium pollution treatment, such as leaching, chemical oxidation, and precipitation, can alleviate the current situation to some extent, but they are complex to operate, consume large amounts of chemical reagents or agents, damage the original ecological functions of soil or water bodies, and even cause secondary pollution. Existing thallium passivating agents are expensive to prepare and require cumbersome procedures, making large-scale application difficult.
[0003] Feldspar powder is a byproduct of mineral beneficiation and is commonly used as a raw material for glass and ceramic products. In recent years, with the booming development of the lithium industry, large quantities of feldspar powder have been stockpiled and landfilled as solid waste due to a lack of large-scale resource utilization methods, resulting in high treatment costs. Feldspar powder contains a wide variety of minerals, with rich porosity and oxygen-containing polar functional groups, and contains slow-release nutrients such as potassium, silicon, and magnesium, making it a common raw material for soil conditioners. However, there is still a lack of efficient, stable, and trace-level remediation methods for using feldspar powder for thallium pollution.
[0004] Therefore, we need to develop efficient, stable, green, and inexpensive thallium pollution remediation materials based on feldspar powder to resolve the contradiction between "resource development and utilization" and "ecological environment safety protection" and meet the dual needs of current industrial production and environmental management. Summary of the Invention
[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a method for preparing iron-manganese-based modified feldspar powder. The iron-manganese-based modified feldspar powder prepared by this invention for thallium pollution remediation can achieve trace thallium pollution remediation, exhibiting good stability and adsorption effects on thallium in soil, solid waste, and water. Furthermore, this material not only has readily available raw materials but also enables the disposal of feldspar powder solid waste.
[0006] In a first aspect, the present invention provides a method for preparing iron-manganese-based modified feldspar powder, comprising the following steps:
[0007] S1. Add feldspar powder to potassium permanganate solution and stir to obtain slurry 1;
[0008] S2. Add ferrous salt solution to the slurry and stir to obtain slurry 2;
[0009] S3. Add alkaline solution to adjust the pH of slurry 2 to 7-13, stir to react, and let stand.
[0010] S4. Wash slurry 2 with deionized water, separate solid and liquid to obtain solid product, dry and grind to obtain iron-manganese-based modified feldspar powder.
[0011] The molar ratio of Mn to Fe in the potassium permanganate and the ferrous salt is 1:(0.5~5).
[0012] According to some preferred embodiments of the present invention, the molar ratio of Mn to Fe in the potassium permanganate and the ferrous salt is 1:(1.5~5), more preferably, the molar ratio of Mn to Fe is 1:(2~3).
[0013] According to some embodiments of the present invention, the solid-liquid ratio of the feldspar powder to the potassium permanganate solution is 1:(4~20)g / mL.
[0014] According to some embodiments of the present invention, the concentration of the potassium permanganate solution is 0.1~0.4 mol / L.
[0015] According to some embodiments of the present invention, the concentration of the ferrous salt solution is 0.1~1 mol / L.
[0016] According to some embodiments of the present invention, the ferrous salt includes ferrous sulfate and ferrous nitrate.
[0017] According to some embodiments of the present invention, the alkaline solution includes at least one of sodium hydroxide, potassium hydroxide, or sodium carbonate.
[0018] According to some preferred embodiments of the present invention, the alkaline solution is a 3-10 mol / L sodium hydroxide solution.
[0019] According to some embodiments of the present invention, in step S3, the pH of the slurry 2 is adjusted to pH 9-12.
[0020] According to some embodiments of the present invention, in step S3, the stirring reaction time is 4~10h, and the settling time is 3~10h.
[0021] According to some embodiments of the present invention, in step S4, the drying temperature is 50~80°C.
[0022] In a second aspect, the present invention provides a composite material for thallium contamination remediation, comprising iron-manganese-based modified feldspar powder obtained by the preparation method described in the first aspect of the present invention.
[0023] A third aspect of the present invention provides the application of the composite material for thallium contamination remediation as described in the second aspect of the present invention in the remediation of thallium-contaminated wastewater, thallium-contaminated soil or thallium-containing solid waste.
[0024] The beneficial effects of this invention are:
[0025] This invention provides a preparation process for combining iron-manganese-based materials with common solid waste feldspar powder. By optimizing process parameters such as raw material concentration, ratio, and pH, high-quality iron-manganese-based modified feldspar powder is prepared. The prepared iron-manganese-based modified feldspar powder can achieve trace TiL pollution remediation, exhibiting good stabilization and adsorption effects on TiL in soil, solid waste, and water. This invention not only utilizes readily available raw materials, enabling the disposal of feldspar powder solid waste, but also boasts advantages such as low cost, easy industrial production, green environmental protection, and no secondary pollution after application.
[0026] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description
[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:
[0028] Figure 1 This is a flowchart of the preparation process of Example 1 of the present invention;
[0029] Figure 2 The figures show the experimental results of the remediation of polluted wastewater prepared by the products Tl prepared in Examples 1 and 2 and Comparative Examples 3 and 4 of this invention.
[0030] Figure 3 The figures show the experimental results of the remediation of polluted wastewater prepared by the products Tl prepared in Examples 1 and 3 of this invention;
[0031] Figure 4 The figures show the experimental results of the remediation of polluted wastewater prepared by the products Tl prepared in Examples 1 and 4 of this invention;
[0032] Figure 5 The figures show the experimental results of the remediation of polluted wastewater prepared by the product Tl prepared in Examples 1 and 5 of this invention;
[0033] Figure 6 SEM image of unmodified feldspar powder;
[0034] Figure 7 This is a SEM image of the iron-manganese-based modified feldspar powder of Example 1 of the present invention;
[0035] Figure 8 This is an EDS image of the iron-manganese-based modified feldspar powder of Example 1 of the present invention;
[0036] Figure 9 This is an XPS image of the iron-manganese-based modified feldspar powder of Example 1 of the present invention. Detailed Implementation
[0037] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.
[0038] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.
[0039] Example 1
[0040] This embodiment provides iron-manganese-based modified feldspar powder that can be used for thallium contamination remediation. Its preparation process flow diagram is shown below. Figure 1 As shown, the specific preparation steps are as follows:
[0041] 1) Air-dry the feldspar powder under natural conditions (or dry it in a drying oven at 40~60℃), crush the agglomerated feldspar powder, and obtain pretreated dried feldspar powder.
[0042] 2) Using high-purity potassium permanganate, prepare 100 mL of 0.2 mol / L potassium permanganate solution, add 20 g of dry feldspar powder, stir evenly, and obtain manganese feldspar powder slurry;
[0043] 3) Using high-purity ferrous sulfate, prepare 100 mL of 0.4 mol / L ferrous sulfate solution, add it to the manganese feldspar powder slurry, and stir continuously during the addition process to obtain the iron-manganese feldspar powder slurry;
[0044] 4) Use high-purity sodium hydroxide to prepare a 5 mol / L sodium hydroxide solution, and slowly add it to the iron-manganese feldspar powder slurry while stirring continuously. Adjust the pH of the slurry to 10; then continue stirring for 5 hours, and let it stand for 5 hours.
[0045] 5) Wash the slurry obtained in step 4) twice with deionized water, separate the solid product, dry it in a drying oven at 60°C, and then grind it into powder to obtain iron-manganese-based modified feldspar powder S1.
[0046] Example 2
[0047] This embodiment provides iron-manganese-based modified feldspar powder that can be used for the remediation of thallium contamination.
[0048] The iron-manganese-based modified feldspar powder in this embodiment is basically the same as that in Example 1. The difference is that in this embodiment, the concentration of the ferrous sulfate solution in step 3) is adjusted to 1.0 mol / L, 0.8 mol / L, 0.6 mol / L, 0.2 mol / L, 0.1 mol / L, 0.067 mol / L, and 0.05 mol / L to prepare iron-manganese-based modified feldspar powder with different manganese-iron ratios, which are denoted as S2, S3, S4, S5, S6, S7, and S8, respectively.
[0049] Example 3
[0050] This embodiment provides iron-manganese-based modified feldspar powder that can be used for the remediation of thallium contamination.
[0051] The iron-manganese-based modified feldspar powder in this embodiment is basically the same as that in Example 1. The difference is that in this embodiment, the amount of sodium hydroxide solution added in step 4) is adjusted to adjust the pH of the slurry to 3, 7 and 12 respectively, so as to obtain iron-manganese-based modified feldspar powder prepared under different pH conditions, which are denoted as S9, S10 and S11 respectively.
[0052] Example 4
[0053] This embodiment provides iron-manganese-based modified feldspar powder that can be used for the remediation of thallium contamination.
[0054] The iron-manganese-based modified feldspar powder in this embodiment is basically the same as that in Example 1. The difference is that in this embodiment, the stirring time after adjusting the pH in step 4) is 0, 1, 3, 7 and 10 h respectively, to obtain iron-manganese-based modified feldspar powder prepared under different stirring time conditions, which are denoted as S12, S13, S14, S15 and S16 respectively.
[0055] Example 5
[0056] This embodiment provides iron-manganese-based modified feldspar powder that can be used for the remediation of thallium contamination.
[0057] The iron-manganese-based modified feldspar powder in this embodiment is basically the same as that in Example 1. The difference is that the iron-manganese-based modified feldspar powder prepared under different standing time conditions is obtained by adjusting the standing time after stirring in step 4) to 0, 1, 3, 7 and 10 hours, respectively, and is denoted as S17, S18, S19, S20 and S21.
[0058] Comparative Example 1
[0059] This comparative example provides iron-manganese-based modified feldspar powder. The specific preparation steps are as follows:
[0060] 1) Air-dry the feldspar powder under natural conditions (or dry it in a drying oven at 40~60℃), crush the agglomerated feldspar powder, and obtain pretreated dried feldspar powder.
[0061] 2) Using high-purity ferrous sulfate, prepare 100 mL of 0.4 mol / L ferrous sulfate solution, add 20 g of dry feldspar powder, stir evenly, and obtain an iron feldspar powder slurry;
[0062] 3) Using high-purity potassium permanganate, prepare 100 mL of 0.2 mol / L potassium permanganate solution, add it to the iron feldspar powder slurry, and stir continuously during the addition process to obtain the iron manganese feldspar powder slurry;
[0063] 4) Use high-purity sodium hydroxide to prepare a 5 mol / L sodium hydroxide solution, and slowly add it to the iron-manganese feldspar powder slurry while stirring continuously. Adjust the pH of the slurry to 10; then continue stirring for 5 hours, and let it stand for 5 hours.
[0064] 5) Wash the slurry obtained in step 4) twice with deionized water, separate the solid product, dry it in a drying oven at 60°C, and then grind it into powder to obtain iron-manganese-based modified feldspar powder D1.
[0065] Comparative Example 2
[0066] This comparative example provides iron-manganese-based modified feldspar powder. The specific preparation steps are as follows:
[0067] 1) Air-dry the feldspar powder under natural conditions (or dry it in a drying oven at 40~60℃), crush the agglomerated feldspar powder, and obtain pretreated dried feldspar powder.
[0068] 2) Using high-purity potassium permanganate and ferrous sulfate, prepare 200 mL of a mixed solution containing 0.2 mol / L potassium permanganate and 0.4 mol / L ferrous sulfate, add 20 g of dry feldspar powder, stir evenly, and obtain an iron feldspar powder slurry;
[0069] 3) Use high-purity sodium hydroxide to prepare a 5 mol / L sodium hydroxide solution, and slowly add it to the iron-manganese feldspar powder slurry while stirring continuously. Adjust the pH of the slurry to 10; then continue stirring for 5 hours, and let it stand for 5 hours.
[0070] 4) Wash the slurry obtained in step 3) twice with deionized water, separate the solid product, dry it in a drying oven at 60°C, and then grind it into powder to obtain iron-manganese-based modified feldspar powder D2.
[0071] Comparative Example 3
[0072] This embodiment provides iron-manganese oxide particles. The specific preparation steps are as follows:
[0073] 1) Prepare 100 mL of 0.2 mol / L potassium permanganate solution using analytical grade potassium permanganate;
[0074] 2) Using high-purity ferrous sulfate, prepare 100 mL of 0.4 mol / L ferrous sulfate solution and add it to potassium permanganate solution while stirring continuously.
[0075] 3) Using analytical grade sodium hydroxide, prepare a 5 mol / L sodium hydroxide solution, slowly add it to the mixed solution while stirring continuously, and adjust the pH to 10; then continue stirring for 5 hours, and let it stand for 5 hours.
[0076] 4) Wash the product obtained in step 3) twice with deionized water to separate the solid particles, dry them in a drying oven at 60°C, and then grind them into powder to obtain iron manganese oxide particles D3.
[0077] Comparative Example 4
[0078] This comparative example provides iron-manganese-based modified biochar. The specific preparation steps are as follows:
[0079] 1) Weigh corn stalks and place them in a crucible. Pyrolyze them in a muffle furnace at 250°C for 2 hours. After cooling, grind them into powder to obtain biochar.
[0080] 2) Using high-purity potassium permanganate, prepare 100 mL of 0.2 mol / L potassium permanganate solution, add 20 g of biochar, stir well to obtain manganese biochar slurry;
[0081] 3) Using high-purity ferrous sulfate, prepare 100 mL of 0.4 mol / L ferrous sulfate solution and add it to the manganese biochar slurry. Stir continuously during the addition process to obtain an iron-manganese biochar slurry.
[0082] 4) Prepare a 5 mol / L sodium hydroxide solution using high-purity sodium hydroxide and slowly add it to the iron-manganese biochar slurry while stirring continuously. Adjust the pH of the slurry to 10. Then continue stirring for 5 hours and let it stand for another 5 hours.
[0083] 5) Wash the slurry obtained in step 4) twice with deionized water, separate the solid product, dry it in a drying oven at 60°C, and then grind it into powder to obtain iron-manganese-based modified biochar D4.
[0084] Thallium contamination remediation performance test:
[0085] 1. Prepare simulated wastewater contaminated with Tl using a Tl standard solution for Tl-contaminated wastewater remediation experiment: Weigh 0.05g of the products obtained in Examples 1, 2, 3, and 4 above, and add them to 20ml of wastewater contaminated with a Tl concentration of 300μg / L. Shake at 25℃ for 8h, take the supernatant, filter it, and measure the Tl concentration of the solution using ICP-MS.
[0086] Test results as follows Figure 2 As shown, the Mn / Fe ratio refers to the iron-manganese-based modified feldspar powder prepared under different Mn / Fe molar ratios in Examples 1 and 2.
[0087] The test results show that when preparing iron-manganese-based modified feldspar powder according to the present invention, controlling the Mn / Fe ratio between 1:5 and 2:1 results in excellent adsorption performance of thallium, enabling efficient adsorption of thallium-containing wastewater. Specifically, the adsorption effect of the iron-manganese-based modified feldspar powder on thallium is best when the Mn / Fe ratio is 1:3 and 1:2, achieving remediation of trace Tl pollution. This is because when the ferrous ion concentration is too low, it cannot effectively reduce permanganate to generate sufficient manganese oxide, reducing the adsorption effect on thallium. Conversely, when the ferrous ion concentration is too high, its reducing properties cause the manganese oxide to be further reduced to Mn(II), destroying the manganese oxide structure loaded on the feldspar powder surface and reducing the adsorption effect on thallium. Therefore, in the present invention, when the Mn / Fe molar ratio is within the range of 1:(1.5~3.5), iron-manganese-based modified feldspar powder with superior thallium adsorption performance can be prepared.
[0088] In Comparative Example 3, the method without feldspar powder directly generates dense iron-manganese oxide particles with limited specific surface area and few pore channels, resulting in limited adsorption capacity for thallium. Comparative Example 4 uses biochar instead of feldspar powder, producing a thallium remediation agent with some adsorption capacity, but it struggles to achieve higher remediation performance. Analysis suggests that the abundant silicon-oxygen and aluminum-oxygen bonds in feldspar powder enable more uniform and stable dispersion of the modified iron-manganese particles, providing more surface complexation sites. Furthermore, the silica-alumina framework of feldspar powder itself exhibits better compatibility with the supported iron-manganese particles, forming a multifunctional composite material. This material captures thallium through multiple mechanisms, including ion exchange, surface complexation, and redox reactions, with the two working synergistically to achieve better adsorption.
[0089] 2. Solid waste and soil remediation experiments: Lithium smelting slag was selected as the solid waste remediation experimental material, and Ti-contaminated soil was used as the soil remediation experimental material.
[0090] Weigh 50g of solid waste (lithium smelting slag, Tl leaching: 72.3μg / kg) and soil (Tl leaching: 32.21μg / kg) into beakers, add 1g of iron-manganese-based modified feldspar powder S1 prepared in the example to each, stir evenly, add 30ml of water, and age for 7 days, keeping the mixture moist during the aging process. After completion, take samples and extract the leachate according to the horizontal oscillation method of leaching toxicity of solid waste (HJ557-2010), and then measure the Tl content using ICP-MS.
[0091] The results showed that the Tl content in the leachate after solid waste treatment was only 0.013 μg / L, and the Tl content in the leachate after soil treatment was only 0.009 μg / L. These results indicate that the iron-manganese-based modified feldspar powder prepared in this invention has excellent effects in the remediation of thallium-contaminated solid waste and soil, and can be widely applied.
[0092] Furthermore, the solid waste leachate without modified feldspar powder had Fe: 1.344 μg / L, Mn: 0.430 μg / L, and pH: 8.23. After adding the modified feldspar powder, the Fe: 2.219 μg / L, Mn: 0.766 μg / L, and pH: 8.25. Therefore, after using the iron-manganese-based modified feldspar powder of this invention for thallium pollution remediation, the Fe and Mn contents of the solid waste leachate remained essentially unchanged, indicating that the modified feldspar powder of this invention has high stability, will not produce secondary pollution, and is a green remediation material.
[0093] 3. The iron-manganese-based modified feldspar powder S1 prepared in Example 1 was compared with the iron-manganese-based modified feldspar powders S9~S21 prepared in Examples 3, 4 and 5, respectively, in a wastewater remediation experiment for Tl-polluted wastewater. The experimental results are as follows: Figure 3 , Figure 4 and Figure 5 As shown.
[0094] The test results above show that alkaline conditions are more conducive to the formation of products with good thallium adsorption capacity, such as loaded iron-manganese oxides and hydroxides. In this invention, controlling the pH of the preparation conditions to 9-12 can produce iron-manganese-based modified feldspar powder with better Tl pollution remediation effect. Meanwhile, the stirring and settling time after pH adjustment in this invention also have a crucial impact on the remediation performance of the product. Sufficient stirring and settling time help the iron-manganese material to be uniformly and stably loaded on the surface and pores of the feldspar powder, and to be deeply compatible with the chemical bonds of the feldspar powder, thereby improving its adsorption performance. Considering production costs and industrial production efficiency, the stirring time in this invention is preferably controlled at 4-10 hours, and the settling time is preferably controlled at 3-15 hours.
[0095] 4. The iron-manganese-based modified feldspar powder S1 prepared in Example 1 and the iron-manganese-based modified feldspar powders D1 and D2 prepared in comparative documents 1 and 2 were used in a wastewater remediation experiment for Tl-contaminated wastewater. The test results showed that the Tl concentrations in the wastewater after remediation by D1 and D2 were still as high as 15.13 μg / L and 20.28 μg / L, respectively.
[0096] Analysis suggests that the adsorption of thallium (Tl) by the composite material is largely provided by the manganese oxide material. The preferential addition of ferrous salt solution creates a reducing atmosphere in the solution system. Adding potassium permanganate solution at this point causes it to react directly in the solution system to form manganese oxide, which is difficult to load onto feldspar powder. Furthermore, the manganese oxide further reacts with ferrous ions, causing the solid thallium structure to fail. Similarly, after mixing iron and manganese solutions, manganese oxide is already formed and precipitated, making it difficult to load onto feldspar powder. In addition, the method of this invention utilizes the reducing property of ferrous salt to reduce permanganate ions to form manganese oxide, a property that ferric salt does not possess.
[0097] 5. The iron-manganese-based modified feldspar powder S1 prepared in Example 1 was characterized using surface analysis techniques (SEM-EDS and XPS), and the results are as follows: Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown.
[0098] Figure 6 SEM images of feldspar powder without iron-manganese modification. Figure 7 The image shows an SEM image of iron-manganese-based modified feldspar powder S1. It can be seen that iron-manganese oxides were successfully loaded onto the surface of the feldspar powder, resulting in a rough surface and further increased porosity.
[0099] Figure 8 The elemental distribution of iron-manganese-based modified feldspar powder after adsorption of Tl is shown in the EDS image.
[0100] Figure 9 XPS characterization of Fe, Mn and Tl loading on the surface of modified feldspar powder.
[0101] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.
Claims
1. A method for preparing an iron-manganese-based modified feldspar powder, characterized by, The method comprises the following steps: S1, adding feldspar powder into potassium permanganate solution, and stirring to obtain slurry 1; S2, adding ferrous salt solution into the slurry, and stirring to obtain slurry 2; S3, adding alkali solution, adjusting the pH of the slurry 2 to 7-13, stirring and reacting, and standing; S4, cleaning the slurry 2 with deionized water, solid-liquid separation to obtain solid product, drying, and grinding to obtain iron-manganese-based modified feldspar powder. The molar ratio of Mn and Fe in the potassium permanganate and the ferrous salt is 1: (0.5-5).
2. The production method according to claim 1, characterized by, The solid-liquid ratio of the feldspar powder and the potassium permanganate solution is 1: (4-20) g / mL.
3. The preparation method according to claim 1, characterized in that, The concentration of the potassium permanganate solution is 0.1-0.4 mol / L.
4. The method of claim 1, wherein, The concentration of the ferrous salt solution is 0.1-1 mol / L.
5. The preparation method according to claim 1, characterized in that, The alkali solution comprises at least one of sodium hydroxide, potassium hydroxide or sodium carbonate.
6. The method of claim 1, wherein, In step S3, the pH of the slurry 2 is adjusted to pH 9-12.
7. The preparation method according to claim 1, characterized in that, In step S3, the stirring reaction time is 4-10 h, and the standing time is 3-15 h.
8. The method of claim 1, wherein, In step S4, the drying temperature is 50-80℃.
9. A composite material for thallium contamination remediation, characterized by, The iron-manganese-based modified feldspar powder obtained by the preparation method of any one of claims 1-8.
10. The application of the composite material for thallium pollution remediation in the remediation of thallium-polluted wastewater, thallium-polluted soil or thallium-containing solid waste according to claim 9.