A method of electrochemically activating iron tailings
By using electrochemical activation of iron tailings, combined with mechanical and chemical pretreatment, the problems of high energy consumption, high cost, and high pollution in existing iron tailings activation technologies have been solved. High-performance cementitious materials have been prepared, promoting the large-scale application of iron tailings in the field of building materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENYANG JIANZHU UNIVERSITY
- Filing Date
- 2026-02-12
- Publication Date
- 2026-05-29
AI Technical Summary
Existing iron tailings activation technologies suffer from high energy consumption, high cost, high pollution, and low efficiency, making it difficult to achieve large-scale and high-value applications.
High-performance cementitious materials are prepared by using an electrochemical activation method, which involves mixing iron tailings with activation additives and applying a DC or pulsed electric field in an electrochemical activation device to control the current parameters. Combined with mechanical and chemical pretreatment, these materials are then processed.
It has achieved low-energy consumption, low-cost, and pollution-free activation of iron tailings, and produced high-performance cementitious materials that can replace cement, improving the activity and strength of iron tailings and making them suitable for the field of building materials.
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Figure CN122105415A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of iron tailings activation technology, and relates to a method for electrochemically activating iron tailings. Background Technology
[0002] Iron tailings are the main solid waste generated during the iron ore beneficiation process, with global annual emissions exceeding 1.5 billion tons and my country's stockpile exceeding 6 billion tons. While occupying a large amount of land resources, they also pose environmental and safety hazards such as tailings dam failures, heavy metal leaching and groundwater pollution, and dust pollution. Their large-scale disposal has become a key bottleneck restricting the green development of the steel industry.
[0003] Current approaches to the resource utilization of iron tailings have significant limitations, making it difficult to achieve a synergistic effect of "large quantity, high efficiency, and high value": Valuable metal recovery targets only small amounts of residual iron, titanium, and other elements in the tailings, with complex and costly extraction processes; while the preparation of adsorbent materials utilizes the magnetic adsorption of water pollutants from some iron tailings to achieve a certain level of high value, the annual consumption of a single production line is less than 10,000 tons; backfilling of mining areas is currently the largest consumption method, but iron tailings themselves have extremely low cementitious activity, resulting in insufficient early strength when used directly as backfill material; replacing iron tailings in building materials by using them as cement admixtures or aggregates can achieve large-scale disposal, but the volcanic ash activity index of natural iron tailings is typically <40%, and directly replacing cement would lead to a significant decrease in the strength of building materials.
[0004] Existing iron tailings activation technologies all have insurmountable shortcomings that restrict their industrial application: Mechanical activation increases the specific surface area and breaks down the crystal lattice of iron tailings through high-speed grinding with equipment such as ball mills and impact mills, making them more conducive to hydration reactions, but this method has a high overall cost; Thermal activation requires calcination at high temperatures of 800-1200℃ to enhance reactivity by destroying the stable silicate crystal structure in the tailings, but it is the most energy-intensive of all activation methods, with large investment and long start-up and shutdown cycles, making it unsuitable for intermittent production; Chemical activation uses strong acid and strong alkali solutions to induce ion exchange and redox reactions in iron tailings, destroying the original stable structure and stimulating its activity, but the amount of reagents used must be strictly controlled; Mechanical-chemical activation integrates grinding and chemical soaking functions, using mechanical activation before or simultaneously with chemical activation to increase the specific surface area, making the ion exchange and redox reactions more complete, but the equipment structure is complex, the equipment is difficult to maintain, and the failure and downtime rate is high. Therefore, the industry urgently needs a low-energy, low-cost, low-pollution, and high-efficiency iron tailings activation technology to break through existing technological bottlenecks and promote the large-scale and high-value application of iron tailings in the field of building materials. Summary of the Invention
[0005] The core objective of this invention is to overcome the drawbacks of existing iron tailings activation technologies, which are characterized by "high energy consumption, high cost, high pollution, and low efficiency," and to provide a method for electrochemically activating iron tailings. This method has the advantages of simple structure, convenient operation, good activation uniformity, and green economy.
[0006] This invention provides a method for electrochemically activating iron tailings, comprising:
[0007] Step 1: Mix the iron tailings with the activation additives to obtain a mixture;
[0008] Step 2: Add water to the mixture and stir until the activating additives dissolve to obtain a fluidized slurry;
[0009] Step 3: Pour the fluidized slurry into the tank of the electrochemical activation device, apply a DC or pulsed electric field to the slurry, and adjust the current parameters to carry out electrochemical activation treatment.
[0010] Furthermore, the activating auxiliary material is red mud, and the mass percentage of each component in the mixture is: 80%~90% iron tailings and 10%~20% red mud.
[0011] Furthermore, the activating additives are phosphogypsum and red mud, and the mass percentage of each component in the mixture is: iron tailings 45%~80%, phosphogypsum 10%~15% and red mud 10%~40%.
[0012] Furthermore, the iron tailings, phosphogypsum, and red mud need to be pretreated separately before preparing the mixture:
[0013] The iron tailings undergo short-term mechanical activation pretreatment: they are placed in a ball mill and milled at a speed of 250-350 rpm for 15-30 minutes.
[0014] The phosphogypsum underwent a water washing and purification pretreatment: it was mixed with room temperature water at a mass ratio of 1:2 to 4:1 and stirred for 15 to 30 minutes, followed by solid-liquid separation. The resulting solid was then dried at 60 to 80°C until the moisture content was below 5%.
[0015] The red mud undergoes a drying and dispersion pretreatment: it is dried at 100~110℃ until the moisture content is less than 3%, and then deagglomerated and sieved to obtain a dispersible powder with an angle of repose of less than 40°.
[0016] Furthermore, in step 3, applying a DC or pulsed electric field to the slurry and adjusting the current parameters for electrochemical activation specifically involves:
[0017] Step 3.1: Treat the slurry with a potential gradient of 3~5V / cm for 10~30 minutes;
[0018] Step 3.2: Adjust the potential gradient to 1.5~2.5V / cm and continue the treatment for 2~10 hours;
[0019] Step 3.3: Reduce the potential gradient to 0.5~1V / cm and continue processing for 1~4 hours.
[0020] Furthermore, the water content of the fluidized slurry is 30% to 40%.
[0021] Furthermore, the electrochemical activation device includes: a power supply, a tank, an annular cathode plate, an anode electrode assembly, and a heat dissipation support;
[0022] The heat dissipation support is located at the bottom of the tank; the anode electrode assembly is inserted into the slurry and arranged in the central area of the tank, with each anode electrode connected in series to form a core electric field source; the annular cathode plate is located on the inner wall of the tank and forms an annular electric field around the anode electrode assembly; the two ends of the anode electrode are provided with anode terminals, and a fixed annular sleeve is fitted on the anode terminals, which is screwed into the anode terminal bolt, and copper wires are used to connect the terminal bolt and the power supply; the annular cathode plate is provided with cathode terminals, and the cathode terminals are connected to the power supply using copper wires; the copper wires are wrapped with a 1.5mm thick polyvinyl chloride insulation layer.
[0023] Furthermore, the tank body is made of steel; the inner wall of the tank is coated with a double-layer insulating coating, the bottom layer is an epoxy resin primer with a thickness of 0.3~0.5mm, and the top layer is a polytetrafluoroethylene topcoat with a thickness of 0.2~0.3mm; the breakdown voltage is ≥5kV, which can effectively isolate the electric field and prevent the tank body from participating in the electrode reaction.
[0024] Furthermore, the anode electrode is a titanium-based lead dioxide coated electrode with a titanium substrate purity of ≥99.5% and a lead dioxide coating thickness of 50~80μm; the annular cathode plate is made of 316L stainless steel with a nickel content of 16%~18%.
[0025] Furthermore, the cementitious material obtained by electrochemically activating iron tailings can replace 30%-50% of cement in mortar.
[0026] The present invention provides a method for electrochemically activating iron tailings, which has the following beneficial effects:
[0027] (1) This invention employs electrochemical activation technology, which uses an external electric field to induce a redox reaction on the surface of iron tailings. Simultaneously, active free radicals (OH-) are generated during the electrochemical process. - and O 2-These active free radicals attack the crystal lattice of the tailings, generating a large number of vacancies and accelerating subsequent chemical reactions. Under the action of the electric field, they will induce a micro-dissolution effect on the surface of the tailings, forming a large number of micropores and mesopores inside or on the surface of the particles. Under multiple effects, the activity of the tailings is enhanced, realizing the efficient activation of iron tailings and providing a new technical path for the resource utilization of iron tailings.
[0028] (2) This invention enhances ion migration and stimulates the activity of minerals in iron tailings through a special electrode layout of “anode array + ring cathode”. Combined with the synergistic stimulation effect of auxiliary materials such as phosphogypsum and red mud, it promotes the breaking of Si-O bonds and Al-O bonds and surface hydroxylation of silicate and aluminosilicate minerals in iron tailings, significantly improving their pozzolanic activity, and finally preparing a high-performance cementitious material that can replace cement. Attached Figure Description
[0029] Figure 1 This is a schematic diagram of the electrochemical activation device used in the embodiments of the present invention. Detailed Implementation
[0030] This invention provides a method for electrochemically activating iron tailings, specifically comprising the following steps:
[0031] Step 1: Mix the iron tailings with the activation additives to obtain a mixture.
[0032] Preferably, the activating additive is red mud, and the mass percentage of each component in the mixture is: 80%~90% iron tailings and 10%~20% red mud.
[0033] Preferably, the activating additives are phosphogypsum and red mud, and the mass percentage of each component in the mixture is: 45%~80% iron tailings, 10%~15% phosphogypsum and 10%~40% red mud.
[0034] In practice, the iron tailings, phosphogypsum, and red mud need to be pretreated separately before the mixture is prepared.
[0035] Short-term mechanical activation pretreatment of iron tailings: A laboratory or industrial planetary ball mill is used, with a mixture of large and small balls in a mass ratio of 3:1 to 5:1. The mass ratio of grinding balls to iron tailings is controlled at 2:1 to 4:1. The iron tailings are placed in the ball mill and milled at 250-350 rpm for 15-30 minutes. After treatment, the specific surface area increases from 150 m² / kg to 550 m² / kg, and the tailings are then passed through a 100-mesh sieve for later use.
[0036] Pretreatment of phosphogypsum by water washing and purification: Phosphogypsum and water are mixed in a stirring tank at a mass ratio of 1:2 to 4:1. The mixture is mechanically stirred at a speed of 200 to 400 rpm for 15 to 30 minutes. Solid-liquid separation is then performed to fully dissolve soluble impurities (phosphorus and fluorine). The resulting solid is then dried at 60 to 80°C until the moisture content is less than 5%.
[0037] Red mud is pretreated by drying and dispersing: The red mud is placed in a drying oven and dried at 100~110℃ for 2~4 hours. After drying, the moisture content of the red mud is less than 3%. Then it is lightly treated by a vibrating mill for 3 minutes and passed through an 80-mesh sieve to obtain a dispersible powder with an angle of repose of less than 40°.
[0038] Step 2: Add water to the mixture and stir until the activating additives dissolve to obtain a fluidized slurry. Preferably, the water content of the fluidized slurry is 30%~40%.
[0039] Step 3: Pour the fluidized slurry into the tank of the electrochemical activation device, apply a DC or pulsed electric field to the slurry, and adjust the current parameters to carry out electrochemical activation treatment, specifically as follows:
[0040] Step 3.1: Treat the slurry with a potential gradient of 3~5V / cm for 10~30 minutes.
[0041] Step 3.2: Adjust the potential gradient to 1.5~2.5V / cm and continue the treatment for 2~10 hours.
[0042] Step 3.3: Reduce the potential gradient to 0.5~1V / cm and continue processing for 1~4 hours.
[0043] During the main reaction stage (step 3.2), the current value of the reaction system is monitored in real time; when the rate of change of the current value within 30 consecutive minutes is less than ±5%, the main reaction stage is determined to be over, and the system automatically enters the weak field curing stage (step 3.3).
[0044] like Figure 1 As shown, the electrochemical activation device includes: a power source 1, a tank 2, an annular cathode plate 3, an anode electrode assembly, and a heat dissipation support 5.
[0045] The heat dissipation support 5 is located at the bottom of the tank 2; the anode electrode assembly is inserted into the slurry and arranged in the central area of the tank, with each anode electrode 4 connected in series to form a core electric field source; the annular cathode plate 3 is located on the inner wall of the tank, forming an annular electric field around the anode electrode assembly. Anode terminals 41 are provided at both ends of the anode electrode 4, and a fixing annular sleeve 42 is fitted onto the anode terminal. The annular sleeve 42 is screwed onto the anode terminal bolt 43, and a copper wire is used to connect the terminal bolt 43 and the power supply 1. The annular cathode plate 3 is provided with cathode terminals 31, which are connected to the power supply using copper wires. The copper wires are wrapped with a 1.5mm thick polyvinyl chloride insulation layer to prevent short circuits with the tank or cathode.
[0046] The electrode system adopts a layout of "central anode group + annular cathode plate" to ensure that the electric field is evenly distributed in the tank and realize the activation of materials in all directions without dead angles.
[0047] In practice, the tank is a cubic steel box, primarily used to hold the iron tailings ore to be activated and to provide a mounting platform for the electrodes. The main body of the tank is welded from Q235 steel plates, with a thickness of 8-12mm, ensuring structural strength. The inner wall of the tank is coated with a double-layer insulating coating: the bottom layer is an epoxy resin primer with a thickness of 0.3-0.5mm and an adhesion strength ≥5MPa; the top layer is a polytetrafluoroethylene topcoat with a thickness of 0.2-0.3mm, resistant to acid and alkali corrosion. The breakdown voltage is ≥5kV, effectively isolating the electric field and preventing the tank from participating in the electrode reaction. Simultaneously, raised heat dissipation supports are installed at the bottom of the tank to lift it off the ground for better heat dissipation.
[0048] In specific implementation, the anode electrode is a titanium-based lead dioxide coated electrode with a titanium substrate purity ≥99.5% and a lead dioxide coating thickness of 50~80μm. It exhibits excellent conductivity, corrosion resistance, and electrochemical stability, with a service life ≥800h. The annular cathode plate is made of 316L stainless steel with a nickel content of 16%~18%, demonstrating excellent resistance to electrochemical corrosion and a service life ≥1000h.
[0049] The power supply output voltage is adjustable from 0 to 220V, and the current is adjustable from 0 to 10A. The electric field strength can be flexibly adjusted according to the material characteristics.
[0050] After activation, turn off the power and wait for the slurry to cool to room temperature (20~25℃). The cementitious material obtained by electrochemically activating iron tailings can then be taken out. This cementitious material can be used directly to prepare building materials such as mortar and unfired bricks, or it can be dried, ground, and stored for later use.
[0051] In practice, the amount of cementitious material obtained by electrochemically activating iron tailings is used to replace cement in mortar at a rate of 30% to 50%.
[0052] Example 1
[0053] This embodiment provides a method for electrochemically activating iron tailings, specifically including the following steps:
[0054] Step 1: Mix the iron tailings and red mud to obtain a mixture. The mass percentage of each component in the mixture is: 85% iron tailings and 15% red mud.
[0055] Before preparing the mixture, the iron tailings and red mud need to be pretreated separately:
[0056] Short-term mechanical activation pretreatment of iron tailings: A laboratory or industrial planetary ball mill was used, with a mixture of large and small balls (mass ratio of large to small balls 4:1) and a ball-to-tailings mass ratio of 3:1. The iron tailings were placed in the ball mill and milled at 300 rpm for 20 minutes. After treatment, the specific surface area increased from 150 m² / kg to 550 m² / kg, and the tailings were passed through a 100-mesh sieve for later use.
[0057] Red mud was pretreated by drying and dispersing: the red mud was placed in a drying oven and dried at 105°C for 3 hours. After drying, the moisture content of the red mud was less than 3%. Then it was lightly treated by a vibrating mill for 3 minutes and passed through an 80-mesh sieve to obtain a dispersible powder with an angle of repose of less than 40°.
[0058] Step 2: Add water to the mixture and stir until the activating additives are dissolved to obtain a fluidized slurry.
[0059] Step 3: Pour the fluidized slurry into the tank of the electrochemical activation device and treat the slurry with a potential gradient of 4V / cm for 25 minutes; adjust the potential gradient to 2V / cm and continue treatment for 8 hours; reduce the potential gradient to 0.8V / cm and continue treatment for 3 hours.
[0060] The strength of mortar prepared from activated iron tailings can reach 23.58 MPa, which is 120.6% higher than that prepared from undisturbed iron tailings.
[0061] Example 2
[0062] This embodiment provides a method for electrochemically activating iron tailings. The specific steps are the same as in Embodiment 1, except that the mass percentage of each component in the mixture is: 80% iron tailings and 20% red mud.
[0063] The strength of mortar prepared from activated iron tailings can reach 21.3 MPa.
[0064] Example 3
[0065] This embodiment provides a method for electrochemically activating iron tailings. The specific steps are the same as in Embodiment 1, except that the mass percentage of each component in the mixture is: 90% iron tailings and 10% red mud.
[0066] The strength of mortar prepared from activated iron tailings can reach 20.9 MPa.
[0067] In the above embodiments 1-3, an electric field is used as the driving force to cause soluble ions (such as...) in the system to... , , , , (etc.) undergo directional migration. Compared to systems that rely solely on concentration gradient diffusion, this migration accelerates the contact and interaction between reactants. On the other hand, the electric field and the resulting basic ions ( The electric field causes partial breakage of the silicon-oxygen bonds (Si-O-Si) and aluminum-oxygen bonds (Al-O-Al) on the surfaces of minerals such as quartz and feldspar, forming surface hydroxylation and amorphous aluminosilicate gel precursors. This alters their low surface energy and reactivity in their natural state. The electric field drives the originally slow reaction between the mixtures to be completed efficiently in a short time. Based on the above-mentioned electric field effect, the addition of red mud increases the pH value of the system. The strongly alkaline electrolyte environment promotes the depolymerization of aluminosilicate glass in iron tailings, providing conditions for the formation of subsequent gel products. Furthermore, the local redox reaction of iron oxides in red mud under the electric field can further stimulate the chemical activity of the mineral surface.
[0068] Example 4
[0069] This embodiment provides a method for electrochemically activating iron tailings, specifically including the following steps:
[0070] Step 1: Mix iron tailings, phosphogypsum and red mud to obtain a mixture. The mass percentage of each component in the mixture is: iron tailings 60%, phosphogypsum 10% and red mud 30%.
[0071] Before preparing the mixture, the iron tailings, phosphogypsum, and red mud need to be pretreated separately:
[0072] Short-term mechanical activation pretreatment of iron tailings: A laboratory or industrial planetary ball mill was used, with a mixture of large and small balls (mass ratio of large to small balls 5:1) and a ball-to-tailings mass ratio of 4:1. The iron tailings were placed in the ball mill and milled at 350 rpm for 30 minutes. After treatment, the specific surface area increased from 138 m² / kg to 500 m² / kg, and the tailings were then passed through a 100-mesh sieve for later use.
[0073] Pretreatment of phosphogypsum by water washing and purification: Phosphogypsum and water are mixed in a stirring tank at a mass ratio of 1:1 and mechanically stirred at 300 rpm for 20 minutes. Solid-liquid separation is then carried out to fully dissolve soluble impurities (phosphorus and fluorine). The resulting solid is then dried at 70°C until the moisture content is less than 5%.
[0074] Red mud was pretreated by drying and dispersing: the red mud was placed in a drying oven and dried at 105°C for 3 hours. After drying, the moisture content of the red mud was less than 3%. Then it was lightly treated by a vibrating mill for 3 minutes and passed through an 80-mesh sieve to obtain a dispersible powder with an angle of repose of less than 40°.
[0075] Step 2: Add water to the mixture and stir until the activating additives are dissolved to obtain a fluidized slurry.
[0076] Step 3: Pour the fluidized slurry into the tank of the electrochemical activation device and treat the slurry with a potential gradient of 5V / cm for 20 minutes; adjust the potential gradient to 1.5V / cm and continue treatment for 7 hours; reduce the potential gradient to 1V / cm and continue treatment for 4 hours.
[0077] The strength of mortar prepared from activated iron tailings can reach 25.22 MPa, which is 135.9% higher than that of mortar prepared from untreated iron tailings.
[0078] Example 5
[0079] This embodiment provides a method for electrochemically activating iron tailings. The specific steps are the same as in embodiment 4, except that the mass percentage of each component in the mixture is: iron tailings 45%, phosphogypsum 15%, and red mud 40%.
[0080] The strength of mortar prepared from activated iron tailings can reach 20.6 MPa.
[0081] Example 6
[0082] This embodiment provides a method for electrochemically activating iron tailings. The specific steps are the same as in Embodiment 4, except that the mass percentage of each component in the mixture is: 80% iron tailings, 10% phosphogypsum and 10% red mud.
[0083] The strength of mortar prepared from activated iron tailings can reach 21.8 MPa.
[0084] In Examples 4-6 above, compared to Example 1, phosphogypsum was added. The alkaline environment generated by the electric field and red mud caused the phosphogypsum to be continuously released. and The silicate and aluminate ions produced by the depolymerization of iron tailings, along with those provided by red mud... Phosphogypsum provided and A rapid reaction occurs, generating a large amount of hydrated calcium silicate (CSH) gel and ettringite (AFt) crystals, which improves strength. The electric field has the unique advantage of directional drainage, which can reduce the development of harmful pores and promote the continuous development of strength.
[0085] Compared with existing iron tailings activation technologies, this invention has significant technical and economic advantages, specifically in the following three aspects:
[0086] 1. Economic and environmental benefits: low energy consumption, low cost, and no pollution.
[0087] Low energy consumption: It adopts room temperature electrochemical activation, without the need for high temperature heating or high speed grinding. The energy consumption per ton of iron tailings is only 80~150 kWh, which is 70%~80% lower than thermal activation (800 kWh / t) and 27.8%~55.6% lower than mechanical activation (250 kWh / t).
[0088] Cost controllable: The electrodes have a long service life (anode ≥800h, cathode ≥1000h), with no consumption of consumables such as steel balls and large amounts of chemical reagents, and the maintenance cost per ton is ≤10 yuan; the amount of auxiliary materials used is small, with solid waste such as phosphogypsum and red mud as auxiliary materials, further reducing the cost of raw materials.
[0089] Green and pollution-free: No strong acid or high-concentration strong alkali is required. Only a small amount of activation additives are used. The activation process produces no wastewater or exhaust gas emissions, reducing pollution control costs by 100% compared to chemical activation, and meeting environmental protection requirements.
[0090] 2. Activation performance: good uniformity, high efficiency, and strong activity.
[0091] Excellent activation uniformity: The "anode + plate cathode ring distribution" layout achieves no dead angle coverage of the electric field, with activation uniformity ≥90% and activity index difference ≤5% in different regions of the material; the fluidized slurry design accelerates ion migration, and the diffusion rate is 3 to 5 times higher than that of dry materials, further ensuring uniformity.
[0092] High activation efficiency: The energizing time of 3~14.5h can fully break the Si-O bond and Al-O bond in the iron tailings, and the number of active sites increases by 3~5 times compared with the existing short-time activation device (≤4h).
[0093] Significantly enhanced activity: The 7-day activity index of the activated product is ≥86%, and the specific surface area reaches 500-550m² / kg, far exceeding that of natural iron tailings (activity index <40%) and traditional activated products (7-day activity index <70%).
[0094] 3. Product applicability: Performance meets standards, cost is low, and applications are wide-ranging.
[0095] Excellent mechanical properties: The mortar prepared by replacing 30% cement with the activated product has a 7-day compressive strength ≥20MPa, which meets the M20 mortar standard in the "Masonry Mortar Mix Proportion Design Code" (JGJ / T 98-2010). The strength is 90%-130% higher than that of the products of existing activation devices.
[0096] Good application compatibility: The activated product has a pH value of 7.5~8.5, with no free alkali residue, and is highly compatible with building materials such as cement and sand, requiring no additional neutralization treatment.
[0097] Low application cost: The cost of preparing the activated product is about 80-120 yuan / ton, which is much lower than that of cement (about 400 yuan / ton). Replacing 30% of cement in the preparation of building materials can reduce the raw material cost by 30%-50%. It can be widely used in mortar, non-fired bricks, roadbed fillers, concrete admixtures and other fields.
[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the ideas of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for electrochemically activating iron tailings, characterized in that, include: Step 1: Mix the iron tailings with the activation additives to obtain a mixture; Step 2: Add water to the mixture and stir until the activating additives dissolve to obtain a fluidized slurry; Step 3: Pour the fluidized slurry into the tank of the electrochemical activation device, apply a DC or pulsed electric field to the slurry, and adjust the current parameters to carry out electrochemical activation treatment.
2. The method for electrochemically activating iron tailings according to claim 1, characterized in that, The activating additive is red mud, and the mass percentage of each component in the mixture is: 80%~90% iron tailings and 10%~20% red mud.
3. The method for electrochemically activating iron tailings according to claim 1, characterized in that, The activating additives are phosphogypsum and red mud, and the mass percentages of each component in the mixture are: iron tailings 45%~80%, phosphogypsum 10%~15%, and red mud 10%~40%.
4. The method for electrochemically activating iron tailings according to claim 2 or 3, characterized in that, Before preparing the mixture, the iron tailings, phosphogypsum, and red mud need to be pretreated separately: The iron tailings undergo short-term mechanical activation pretreatment: they are placed in a ball mill and milled at a speed of 250-350 rpm for 15-30 minutes. The phosphogypsum underwent a water washing and purification pretreatment: it was mixed with room temperature water at a mass ratio of 1:2 to 4:1 and stirred for 15 to 30 minutes, followed by solid-liquid separation. The resulting solid was then dried at 60 to 80°C until the moisture content was below 5%. The red mud undergoes a drying and dispersion pretreatment: it is dried at 100~110℃ until the moisture content is less than 3%, and then deagglomerated and sieved to obtain a dispersible powder with an angle of repose of less than 40°.
5. The method for electrochemically activating iron tailings according to claim 1, characterized in that, In step 3, applying a DC or pulsed electric field to the slurry and adjusting the current parameters for electrochemical activation specifically involves: Step 3.1: Treat the slurry with a potential gradient of 3~5V / cm for 10~30 minutes; Step 3.2: Adjust the potential gradient to 1.5~2.5V / cm and continue the treatment for 2~10 hours; Step 3.3: Reduce the potential gradient to 0.5~1V / cm and continue processing for 1~4 hours.
6. The method for electrochemically activating iron tailings according to claim 1, characterized in that, The water content of the fluidized slurry is 30%~40%.
7. The method for electrochemically activating iron tailings according to claim 1, characterized in that, The electrochemical activation device includes: a power source, a tank, an annular cathode plate, an anode electrode assembly, and a heat dissipation support; The heat dissipation support is located at the bottom of the tank; the anode electrode assembly is inserted into the slurry and arranged in the central area of the tank, with each anode electrode connected in series to form a core electric field source; the annular cathode plate is located on the inner wall of the tank and forms an annular electric field around the anode electrode assembly; the two ends of the anode electrode are provided with anode terminals, and a fixed annular sleeve is fitted on the anode terminals, which is screwed into the anode terminal bolt, and copper wires are used to connect the terminal bolt and the power supply; the annular cathode plate is provided with cathode terminals, and the cathode terminals are connected to the power supply using copper wires; the copper wires are wrapped with a 1.5mm thick polyvinyl chloride insulation layer.
8. The method for electrochemically activating iron tailings according to claim 7, characterized in that, The tank is made of steel; the inner wall of the tank is coated with a double layer of insulating coating, the bottom layer is an epoxy resin primer with a thickness of 0.3~0.5mm, and the top layer is a polytetrafluoroethylene topcoat with a thickness of 0.2~0.3mm; the breakdown voltage is ≥5kV, which can effectively isolate the electric field and prevent the tank from participating in the electrode reaction.
9. The method for electrochemically activating iron tailings according to claim 7, characterized in that, The anode electrode is a titanium-based lead dioxide coated electrode with a titanium substrate purity of ≥99.5% and a lead dioxide coating thickness of 50~80μm; the annular cathode plate is made of 316L stainless steel with a nickel content of 16%~18%.
10. The method for electrochemically activating iron tailings according to claim 1, characterized in that, The cementitious material obtained by electrochemically activating iron tailings can replace 30%-50% of cement in mortar.