Resource utilization method for iron ore tailings

Abstract

The invention provides a method for resource utilization of iron ore tailings. The method comprises the following steps: S1, purifying hematite tailings and preparing superfine powder; s2, oriented modification treatment of the biomass solid waste; s3, accurately proportioning a composite precursor, and performing homogeneous mixing; s4, carrying out sectional type hydrothermal carbonization reduction reaction in an inert atmosphere; s5, carrying out post-treatment activation and classified screening on the catalyst; and S6, catalyst performance detection and quality control. According to the method for resource utilization of the iron ore tailings, collaborative resource utilization of the iron ore tailings and the agriculture and forestry biomass solid waste is achieved, the environmental problem of tailing accumulation and the problem of treatment of the biomass solid waste are solved, a high-performance heterogeneous catalyst is prepared, and the product additional value is high; meanwhile, parameters of each step in the technological process are accurate and controllable, the iron component conversion rate is high, and the catalyst is stable in activity and can be repeatedly utilized.

Description

Technical Field

[0001] This invention relates to the field of iron ore tailings resource utilization, and more particularly to a method for iron ore tailings resource utilization. Background Technology

[0002] Iron ore mining and processing generate a large amount of tailings. These tailings not only occupy a lot of land resources, but also easily cause ecological and environmental problems such as dust and water pollution. At the same time, the valuable components such as iron contained in the tailings are not effectively recovered, resulting in a serious waste of resources.

[0003] Currently, most existing technologies for the resource utilization of iron ore tailings suffer from problems such as low iron recovery rate, low product added value, complex processes, and high costs, making it difficult to achieve efficient and high-value utilization of tailings.

[0004] Therefore, it is necessary to provide a method for the resource utilization of iron ore tailings to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides a method for the resource utilization of iron ore tailings, which solves the problems of environmental pollution caused by iron ore tailings accumulation, inefficient recovery of valuable components, low added value and high cost of existing utilization technologies.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for the resource utilization of iron ore tailings, comprising the following steps:

[0007] S1. Purification and ultrafine powder preparation of hematite tailings;

[0008] S11. The concentrated and filtered hematite tailings are first subjected to high-frequency vibrating screening to remove inert coarse impurities such as quartz and feldspar with a particle size >80μm, and the tailings are then fined.

[0009] S12. Put the tailings fines into the ultrasonic reaction tank, add a 2.5% dilute hydrochloric acid solution, control the liquid-solid ratio to 5:1, and ultrasonically clean for 25 minutes at 45℃ and ultrasonic power of 350W to remove calcium magnesium carbonate and soluble salt impurities attached to the surface of the tailings.

[0010] S13. Rinse the cleaned tailings repeatedly with deionized water until neutral, then put them into a vacuum drying oven and dry them at 108°C to constant weight.

[0011] S14. The dried tailings are fed into an inert atmosphere airflow pulverizer, and high-purity argon is introduced as a protective gas. The pulverizing pressure is controlled at 0.8MPa to prepare highly active hematite tailings ultrafine powder raw materials with a particle size of 8-15μm and a specific surface area ≥18m² / g.

[0012] S2. Targeted modification treatment of biomass solid waste;

[0013] S21. Select agricultural and forestry biomass solid waste as carbon source, first crush it to a particle size ≤5mm, then add a 6% NaOH solution, and alkali hydrolyze it at 85℃ for 1.2h to break the lignin structure and retain the highly active cellulose and hemicellulose components.

[0014] S22. The alkaline hydrolyzed biomass raw material is washed with deionized water until neutral, then sent to a forced-air drying oven and dried at 90°C until the moisture content is ≤8% to obtain modified biomass powder.

[0015] S23. Further pulverize the modified biomass powder to a particle size ≤2mm to obtain a biomass carbon source precursor with high carbon conversion rate.

[0016] S3, precise proportioning and homogeneous mixing of composite precursors;

[0017] S31. Weigh each raw material according to the mass ratio, wherein the porous kaolin additive is used to enhance the pore structure of the catalyst and the dispersibility of the active components.

[0018] S32. Put the above raw materials into a planetary ball mill, add anhydrous ethanol as a dispersion medium, control the ball-to-material ratio to be 8:1, the rotation speed to be 220 r / min, and ball mill for 40 min.

[0019] S33. After ball milling, the mixture is fed into a rotary evaporator and anhydrous ethanol is removed at 60°C to obtain a composite precursor with uniform mixing and excellent component dispersibility.

[0020] S4. Segmented hydrothermal carbonization and reduction reaction under an inert atmosphere;

[0021] S41. Mix the composite precursor with deionized water at a mass ratio of 4:1 and transfer it into a hydrothermal reactor lined with polytetrafluoroethylene.

[0022] S42. Perform nitrogen purging operation three times on the hydrothermal reactor. Each time, high-purity nitrogen is introduced until the pressure inside the reactor is 0.2 MPa and then the pressure is released to ensure that the atmosphere inside the reactor is completely inert and to prevent the low-valent iron to be reduced later from being oxidized.

[0023] S43. A stepped heating process is used for hydrothermal carbonization reaction.

[0024] S44. During the reaction, the concentration of reducing gas inside the reactor is monitored in real time by an online gas monitoring module. When the concentration stabilizes below 500 ppm, the reduction reaction is considered complete. Heating is then stopped, and the reactor is allowed to cool naturally to room temperature.

[0025] S5. Post-treatment activation and classification screening of catalysts;

[0026] S6. Catalyst performance testing and quality control;

[0027] The performance of the finished heterogeneous catalyst was characterized by: detecting the Fe phase composition by X-ray diffraction to ensure that the total proportion of Fe² and zero-valent Fe is ≥65%; detecting its specific surface area by a specific surface area analyzer to ensure that it reaches 38-45 m² / g; and testing the catalytic activity by simulating a Fenton-like reaction to ensure that the degradation rate of the target organic pollutant is ≥90% and the activity retention rate is ≥85% after 5 reuses.

[0028] Preferably, step-by-step heating is used in step S43 for the hydrothermal carbonization reaction:

[0029] First stage: The temperature is increased to 175℃ at a rate of 4℃ / min and held at a constant temperature for 2.5h to achieve the initial hydrolysis and precarbonization of biomass and generate small molecule reduced hydrocarbons.

[0030] The second stage involves heating to 250℃ at a rate of 2℃ / min and reacting at this temperature for 5 hours. During this stage, the biomass undergoes deep carbonization, continuously producing... Reducing gases such as CO are used to purify the hematite tailings under an inert atmosphere. Directional restoration to And some zero-valent Fe, while the porous carbon framework formed by biomass carbonization will load and anchor the reduced Fe active components in situ.

[0031] Preferably, step S5 includes the following steps:

[0032] S51. Take out the product after hydrothermal reaction, wash it with deionized water 3-4 times to remove soluble impurities, then dehydrate it with anhydrous ethanol, and then put it into a vacuum drying oven and dry it at 75°C to constant weight to obtain crude catalyst.

[0033] S52. The crude catalyst is transferred into a tube furnace, and argon is introduced as a protective gas. The temperature is increased to 320°C at a rate of 3°C / min, and the catalyst is activated at a constant temperature for 2 hours to optimize the pore structure of the carbon support and enhance the bonding strength between the Fe active component and the carbon skeleton.

[0034] S53. After activation, cool to room temperature and classify the catalyst by sieving. Select particles with a particle size of 5-20μm as the finished heterogeneous catalyst. Particles that do not meet the size requirements can be returned to S3 for re-mixing.

[0035] Preferably, in step S12, an ultrasonic reaction device is used when processing the tailings fines. The ultrasonic reaction device includes a housing, a first filter box, a second filter box, and multiple mounting components. The first filter box is disposed inside the housing, and the second filter box is disposed inside the housing and above the first filter box. The multiple mounting components are respectively disposed between the housing and the second filter box.

[0036] Preferably, the installation assembly includes an installation groove and an installation block. The installation groove is formed on one side of the inner wall of the housing, and the installation block is pluggable into the interior of the installation groove and connected to the second filter box.

[0037] Preferably, a drain device is connected to one side of the bottom of the box, and handles are symmetrically installed on both sides of the inner wall of the second filter box.

[0038] Preferably, movable components are provided on both sides of the top of the box. Each movable component includes a movable plate, two movable blocks, and two movable slots. The two movable blocks are respectively connected to the two sides of the bottom of the movable plate, and the two movable slots are respectively opened on the two sides of the top of the box.

[0039] Compared with related technologies, the method for resource utilization of iron ore tailings provided by this invention has the following beneficial effects:

[0040] This invention provides a method for the resource utilization of iron ore tailings, realizing the synergistic resource utilization of iron ore tailings and agricultural and forestry biomass solid waste. It not only solves the environmental problems of tailings accumulation and the treatment problems of biomass solid waste, but also prepares a high-performance heterogeneous catalyst with high added value. At the same time, the parameters of each step in the process are precisely controllable, the iron component conversion rate is high, the catalyst activity is stable and reusable, and it has both environmental and economic benefits. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of a second embodiment of a method for resource utilization of iron ore tailings provided by the present invention;

[0042] Figure 2 for Figure 1 The diagram shows a three-dimensional structure of the ultrasonic reaction device from a first-view perspective.

[0043] Figure 3 for Figure 2 The enlarged schematic diagram of part A shown below;

[0044] Figure 4 for Figure 1 A three-dimensional structural schematic diagram of the ultrasonic reaction device from a second perspective;

[0045] Figure 5 A schematic diagram of the structure of a third embodiment of a method for the resource utilization of iron ore tailings provided by the present invention;

[0046] Figure 6 for Figure 5 The enlarged schematic diagram of part B is shown.

[0047] The diagram is labeled: 1. Filter housing, 2. First filter box, 3. Second filter box.

[0048] 4. Installation components, 41. Installation slot, 42. Installation block.

[0049] 5. Handle, 6. Drainage parts,

[0050] 7. Activity components, 71. Activity board, 72. Activity block, 73. Activity slot. Detailed Implementation

[0051] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0052] First Embodiment

[0053] A method for the resource utilization of iron ore tailings includes the following steps:

[0054] S1. Purification and ultrafine powder preparation of hematite tailings;

[0055] S11. The concentrated and filtered hematite tailings are first subjected to high-frequency vibrating screening to remove inert coarse impurities such as quartz and feldspar with a particle size >80μm, and the tailings are then fined.

[0056] S12. Put the tailings fines into the ultrasonic reaction tank, add a 2.5% dilute hydrochloric acid solution, control the liquid-solid ratio to 5:1, and ultrasonically clean for 25 minutes at 45℃ and ultrasonic power of 350W to remove calcium magnesium carbonate and soluble salt impurities attached to the surface of the tailings.

[0057] S13. Rinse the cleaned tailings repeatedly with deionized water until neutral, then put them into a vacuum drying oven and dry them at 108°C to constant weight.

[0058] S14. The dried tailings are fed into an inert atmosphere airflow pulverizer, and high-purity argon is introduced as a protective gas. The pulverizing pressure is controlled at 0.8MPa to prepare highly active hematite tailings ultrafine powder raw materials with a particle size of 8-15μm and a specific surface area ≥18m² / g.

[0059] S2. Targeted modification treatment of biomass solid waste;

[0060] S21. Select agricultural and forestry biomass solid waste as carbon source, first crush it to a particle size ≤5mm, then add a 6% NaOH solution, and alkali hydrolyze it at 85℃ for 1.2h to break the lignin structure and retain the highly active cellulose and hemicellulose components.

[0061] S22. The alkaline hydrolyzed biomass raw material is washed with deionized water until neutral, then sent to a forced-air drying oven and dried at 90°C until the moisture content is ≤8% to obtain modified biomass powder.

[0062] S23. Further pulverize the modified biomass powder to a particle size ≤2mm to obtain a biomass carbon source precursor with high carbon conversion rate.

[0063] S3, precise proportioning and homogeneous mixing of composite precursors;

[0064] S31. Weigh each raw material according to the mass ratio, wherein the porous kaolin additive is used to enhance the pore structure of the catalyst and the dispersibility of the active components.

[0065] S32. Put the above raw materials into a planetary ball mill, add anhydrous ethanol as a dispersion medium, control the ball-to-material ratio to be 8:1, the rotation speed to be 220 r / min, and ball mill for 40 min.

[0066] S33. After ball milling, the mixture is fed into a rotary evaporator and anhydrous ethanol is removed at 60°C to obtain a composite precursor with uniform mixing and excellent component dispersibility.

[0067] S4. Segmented hydrothermal carbonization and reduction reaction under an inert atmosphere;

[0068] S41. Mix the composite precursor with deionized water at a mass ratio of 4:1 and transfer it into a hydrothermal reactor lined with polytetrafluoroethylene.

[0069] S42. Perform nitrogen purging operation three times on the hydrothermal reactor. Each time, high-purity nitrogen is introduced until the pressure inside the reactor is 0.2 MPa and then the pressure is released to ensure that the atmosphere inside the reactor is completely inert and to prevent the low-valent iron to be reduced later from being oxidized.

[0070] S43. A stepped heating process is used for hydrothermal carbonization reaction.

[0071] S44. During the reaction, the concentration of reducing gas inside the reactor is monitored in real time by an online gas monitoring module. When the concentration stabilizes below 500 ppm, the reduction reaction is considered complete. Heating is then stopped, and the reactor is allowed to cool naturally to room temperature.

[0072] S5. Post-treatment activation and classification screening of catalysts;

[0073] S6. Catalyst performance testing and quality control;

[0074] The performance of the finished heterogeneous catalyst was characterized by: detecting the Fe phase composition by X-ray diffraction to ensure that the total proportion of Fe² and zero-valent Fe is ≥65%; detecting its specific surface area by a specific surface area analyzer to ensure that it reaches 38-45 m² / g; and testing the catalytic activity by simulating a Fenton-like reaction to ensure that the degradation rate of the target organic pollutant is ≥90% and the activity retention rate is ≥85% after 5 reuses.

[0075] The S43 employs a stepped heating process for the hydrothermal carbonization reaction.

[0076] First stage: The temperature is increased to 175℃ at a rate of 4℃ / min and held at a constant temperature for 2.5h to achieve the initial hydrolysis and precarbonization of biomass and generate small molecule reduced hydrocarbons.

[0077] The second stage involves heating to 250℃ at a rate of 2℃ / min and reacting at this temperature for 5 hours. During this stage, the biomass undergoes deep carbonization, continuously producing... Reducing gases such as CO are used to purify the hematite tailings under an inert atmosphere. Directional restoration to And some zero-valent Fe, while the porous carbon framework formed by biomass carbonization will load and anchor the reduced Fe active components in situ.

[0078] S5 includes the following steps:

[0079] S51. Take out the product after hydrothermal reaction, wash it with deionized water 3-4 times to remove soluble impurities, then dehydrate it with anhydrous ethanol, and then put it into a vacuum drying oven and dry it at 75°C to constant weight to obtain crude catalyst.

[0080] S52. The crude catalyst is transferred into a tube furnace, and argon is introduced as a protective gas. The temperature is increased to 320°C at a rate of 3°C / min, and the catalyst is activated at a constant temperature for 2 hours to optimize the pore structure of the carbon support and enhance the bonding strength between the Fe active component and the carbon skeleton.

[0081] S53. After activation, cool to room temperature and classify the catalyst by sieving. Select particles with a particle size of 5-20μm as the finished heterogeneous catalyst. Particles that do not meet the size requirements can be returned to S3 for re-mixing.

[0082] First, hematite tailings are purified and prepared into ultrafine powder to remove impurities and enhance their activity. Then, agricultural and forestry biomass solid waste is directionally modified to obtain a carbon source precursor with high carbon conversion rate. Subsequently, the raw materials are precisely proportioned and homogenized to form a composite precursor. Under an inert atmosphere, a segmented hydrothermal carbonization reduction reaction is carried out to reduce the high-valence iron in the tailings to low-valence iron and load it onto the carbon framework formed by biomass carbonization. Finally, after post-treatment activation, classification screening and performance testing, a high-quality heterogeneous catalyst is obtained, realizing the synergistic resource utilization of iron ore tailings and biomass solid waste.

[0083] Compared with related technologies, the method for resource utilization of iron ore tailings provided by this invention has the following beneficial effects:

[0084] This invention provides a method for the resource utilization of iron ore tailings, realizing the synergistic resource utilization of iron ore tailings and agricultural and forestry biomass solid waste. It not only solves the environmental problems of tailings accumulation and the treatment problems of biomass solid waste, but also prepares a high-performance heterogeneous catalyst with high added value. At the same time, the parameters of each step in the process are precisely controllable, the iron component conversion rate is high, the catalyst activity is stable and reusable, and it has both environmental and economic benefits.

[0085] Second Embodiment

[0086] Please refer to the following: Figure 1 , Figure 2 , Figure 3 and Figure 4 Based on the method for resource utilization of iron ore tailings provided in the first embodiment of this application, the second embodiment of this application proposes another method for resource utilization of iron ore tailings. The second embodiment is merely a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the separate implementation of the first embodiment.

[0087] Specifically, the second embodiment of this application provides a method for the resource utilization of iron ore tailings, which differs in that an ultrasonic reaction device is used when processing the tailings fines in step S12. The ultrasonic reaction device includes a housing 1, a first filter box 2, a second filter box 3, and multiple installation components 4. The first filter box 2 is disposed inside the housing 1, and the second filter box 3 is disposed inside the housing 1 and above the first filter box 2. The multiple installation components 4 are respectively disposed between the housing 1 and the second filter box 3.

[0088] The installation component 4 includes an installation groove 41 and an installation block 42. The installation groove 41 is opened on one side of the inner wall of the housing 1, and the installation block 42 is plugged into the interior of the installation groove 41 and connected to the second filter box 3.

[0089] A draining device 6 is connected to one side of the bottom of the box 1, and handles 5 are symmetrically installed on both sides of the inner wall of the second filter box 3.

[0090] The drain component 6 can promptly discharge the waste liquid after ultrasonic cleaning, and the handle 5 facilitates the operator to pick up and put down the second filter box. The second filter box 3 can be quickly disassembled and assembled through the cooperation of the mounting groove 41 and the mounting block 42, which facilitates the feeding and removal of tailings fine materials.

[0091] The working principle of the method for resource utilization of iron ore tailings provided by this invention is as follows:

[0092] The tailings fines are placed in the second filter box 3, and then the second filter box is installed into the box body 1 through the cooperation of the mounting block 42 and the mounting groove 41. A dilute hydrochloric acid solution of a specified concentration and liquid-solid ratio is added into the box body, and the ultrasonic equipment is turned on for cleaning.

[0093] After cleaning, the waste liquid is discharged through the drain 6, and then the second filter box 3 is taken out through the handle 5 for subsequent rinsing of the tailings. The first filter box 2 can intercept the fine tailings particles in the waste liquid, reducing raw material waste.

[0094] Compared with related technologies, the method for resource utilization of iron ore tailings provided by this invention has the following beneficial effects:

[0095] This invention provides a method for the resource utilization of iron ore tailings. Inside the housing 1, a first filter box 2, a second filter box 3, and multiple installation components 4 are arranged in coordination to achieve efficient ultrasonic cleaning of fine tailings and to trap small tailings particles in the waste liquid, reducing raw material loss. At the same time, the design of the installation components enables quick assembly and disassembly of the filter boxes, and the configuration of the drain and handle improves the ease of operation, ensuring the cleaning efficiency and raw material utilization rate in S12.

[0096] Third Embodiment

[0097] Please refer to the following: Figure 5 and Figure 6 Based on the method for resource utilization of iron ore tailings provided in the first embodiment of this application, the third embodiment of this application proposes another method for resource utilization of iron ore tailings. The third embodiment is merely a preferred embodiment of the first embodiment, and the implementation of the third embodiment will not affect the separate implementation of the first embodiment.

[0098] Specifically, the method for resource utilization of iron ore tailings provided in the third embodiment of this application differs in that it further includes two movable components 7. Both movable components 7 are disposed on both sides of the top of the box 1. Each movable component 7 includes a movable plate 71, two movable blocks 72 and two movable slots 73. The two movable blocks 72 are respectively connected to both sides of the bottom of the movable plate 71, and the two movable slots 73 are respectively opened on both sides of the top of the box 1.

[0099] The movable block 72 can slide within the movable groove 73, thereby driving the movable plate 71 to move on the top of the box.

[0100] The working principle of the method for resource utilization of iron ore tailings provided by this invention is as follows:

[0101] During ultrasonic cleaning, slide the movable plate 71 to move the movable block 72 within the movable tank 73, covering the top of the chamber 1 with the movable plate 71. This reduces the emission of acid mist and splashing of solution during ultrasonic cleaning. After the operation is completed, slide the movable plate to remove it without affecting the subsequent removal and placement of the filter box.

[0102] Compared with related technologies, the method for resource utilization of iron ore tailings provided by this invention has the following beneficial effects:

[0103] This invention provides a method for the resource utilization of iron ore tailings. By setting an movable component 7 on the top of the box 1, the box 1 can be partially sealed during the ultrasonic cleaning process, reducing acid mist emission and solution splashing. This not only protects the operating environment and the health of the operators, but also reduces the loss of raw materials and reagents, further optimizing the operating conditions of the tailings cleaning process.

[0104] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for the resource utilization of iron ore tailings, characterized in that, Includes the following steps: S1. Purification and ultrafine powder preparation of hematite tailings; S11. The concentrated and filtered hematite tailings are first subjected to high-frequency vibrating screening to remove inert coarse impurities such as quartz and feldspar with a particle size >80μm, and the tailings are then fined. S12. Put the tailings fines into the ultrasonic reaction tank, add a 2.5% dilute hydrochloric acid solution, control the liquid-solid ratio to 5:1, and ultrasonically clean for 25 minutes at 45℃ and ultrasonic power of 350W to remove calcium magnesium carbonate and soluble salt impurities attached to the surface of the tailings. S13. Rinse the cleaned tailings repeatedly with deionized water until neutral, then put them into a vacuum drying oven and dry them at 108°C to constant weight. S14. The dried tailings are fed into an inert atmosphere airflow pulverizer, and high-purity argon is introduced as a protective gas. The pulverizing pressure is controlled at 0.8MPa to prepare highly active hematite tailings ultrafine powder raw materials with a particle size of 8-15μm and a specific surface area ≥18m² / g. S2. Targeted modification treatment of biomass solid waste; S21. Select agricultural and forestry biomass solid waste as carbon source, first crush it to a particle size ≤5mm, then add a 6% NaOH solution, and alkali hydrolyze it at 85℃ for 1.2h to break the lignin structure and retain the highly active cellulose and hemicellulose components. S22. The alkaline hydrolyzed biomass raw material is washed with deionized water until neutral, then sent to a forced-air drying oven and dried at 90°C until the moisture content is ≤8% to obtain modified biomass powder. S23. Further pulverize the modified biomass powder to a particle size ≤2mm to obtain a biomass carbon source precursor with high carbon conversion rate. S3, precise proportioning and homogeneous mixing of composite precursors; S31. Weigh each raw material according to the mass ratio, wherein the porous kaolin additive is used to enhance the pore structure of the catalyst and the dispersibility of the active components. S32. Put the above raw materials into a planetary ball mill, add anhydrous ethanol as a dispersion medium, control the ball-to-material ratio to be 8:1, the rotation speed to be 220 r / min, and ball mill for 40 min. S33. After ball milling, the mixture is fed into a rotary evaporator and anhydrous ethanol is removed at 60°C to obtain a composite precursor with uniform mixing and excellent component dispersibility. S4. Segmented hydrothermal carbonization and reduction reaction under an inert atmosphere; S41. Mix the composite precursor with deionized water at a mass ratio of 4:1 and transfer it into a hydrothermal reactor lined with polytetrafluoroethylene. S42. Perform nitrogen purging operation three times on the hydrothermal reactor. Each time, high-purity nitrogen is introduced until the pressure inside the reactor is 0.2 MPa and then the pressure is released to ensure that the inside of the reactor is a completely inert atmosphere and to prevent the low-valent iron to be reduced in the subsequent process from being oxidized. S43. A stepped heating process is used for hydrothermal carbonization reaction. S44. During the reaction, the concentration of reducing gas inside the reactor is monitored in real time by an online gas monitoring module. When the concentration stabilizes below 500 ppm, the reduction reaction is considered complete. Heating is then stopped, and the reactor is allowed to cool naturally to room temperature. S5. Post-treatment activation and classification screening of catalysts; S6. Catalyst performance testing and quality control; The performance of the finished heterogeneous catalyst was characterized by: detecting the Fe phase composition by X-ray diffraction to ensure that the total proportion of Fe² and zero-valent Fe is ≥65%; detecting its specific surface area by a specific surface area analyzer to ensure that it reaches 38-45 m² / g; and testing the catalytic activity by simulating a Fenton-like reaction to ensure that the degradation rate of the target organic pollutant is ≥90% and the activity retention rate is ≥85% after 5 reuses.

2. The method for resource utilization of iron ore tailings according to claim 1, characterized in that, The S43 employs a stepped heating process for the hydrothermal carbonization reaction. First stage: The temperature is increased to 175℃ at a rate of 4℃ / min and held at a constant temperature for 2.5h to achieve the initial hydrolysis and precarbonization of biomass and generate small molecule reduced hydrocarbons. The second stage involves heating to 250℃ at a rate of 2℃ / min and reacting at this temperature for 5 hours. During this stage, the biomass undergoes deep carbonization, continuously producing... Reducing gases such as CO are used to purify the hematite tailings under an inert atmosphere. Directional restoration to And some zero-valent Fe, while the porous carbon framework formed by biomass carbonization will load and anchor the reduced Fe active components in situ.

3. The method for resource utilization of iron ore tailings according to claim 1, characterized in that, S5 includes the following steps: S51. Take out the product after hydrothermal reaction, wash it with deionized water 3-4 times to remove soluble impurities, then dehydrate it with anhydrous ethanol, and then put it into a vacuum drying oven and dry it at 75°C to constant weight to obtain crude catalyst. S52. The crude catalyst is transferred into a tube furnace, argon is introduced as a protective gas, and the temperature is increased to 320℃ at a rate of 3℃ / min. The temperature is kept constant for 2 hours to optimize the pore structure of the carbon support and enhance the bonding strength between the Fe active component and the carbon skeleton. S53. After activation, cool to room temperature and classify the catalyst by sieving. Select particles with a particle size of 5-20μm as the finished heterogeneous catalyst. Particles that do not meet the size requirements can be returned to S3 for re-mixing.

4. The method for resource utilization of iron ore tailings according to claim 1, characterized in that, In step S12, an ultrasonic reaction device is used when processing tailings fines. The ultrasonic reaction device includes a housing, a first filter box, a second filter box, and multiple mounting components. The first filter box is located inside the housing, and the second filter box is located inside the housing and above the first filter box. The multiple mounting components are respectively located between the housing and the second filter box.

5. The method for resource utilization of iron ore tailings according to claim 4, characterized in that, The installation assembly includes an installation slot and an installation block. The installation slot is located on one side of the inner wall of the housing, and the installation block is pluggable into the interior of the installation slot and connected to the second filter box.

6. The method for resource utilization of iron ore tailings according to claim 4, characterized in that, A drain device is connected to one side of the bottom of the box, and handles are symmetrically installed on both sides of the inner wall of the second filter box.

7. The method for resource utilization of iron ore tailings according to claim 1, characterized in that, Movable components are provided on both sides of the top of the box. Each movable component includes a movable plate, two movable blocks, and two movable slots. The two movable blocks are respectively connected to the two sides of the bottom of the movable plate, and the two movable slots are respectively opened on the two sides of the top of the box.

Images