Tailing pond slurry in-situ temperature gradient drainage consolidation method

Abstract

The invention discloses a tailing pond slurry in-situ temperature gradient drainage consolidation method. The method comprises the following steps that steel sheet piles are buried in tailing slurry; the solar heat collection plate is installed on the steel sheet pile, and the solar heat collection plate and the steel sheet pile are connected through a heat transfer medium circulating pipeline; the drainage pipeline is buried around the steel sheet pile, and the other end of the drainage pipeline is connected to a drainage structure; wherein a heat transfer medium in the heat transfer medium circulating pipeline is heated by the solar heat collection plate, the heat transfer medium in the circulating pipeline exchanges heat with the steel sheet pile when passing through the steel sheet pile, and the heat transfer medium flows back to the solar heat collection plate to be heated after heat exchange; the steel sheet pile heats surrounding slurry with heat, the slurry is dewatered through the thermal consolidation effect until the water content of the slurry is reduced to a target value, and slurry consolidation is completed; in the process of heating the slurry, water in the slurry is drained to the drainage structure through the drainage pipeline. The method provided by the invention solves the problems of high long-term moisture content of tailings pond slurry and difficulty in natural consolidation of a reservoir area site, and belongs to the technical field of geotechnical engineering.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering technology, and in particular to an in-situ temperature gradient drainage consolidation method for tailings dam mud. Background Technology

[0002] Tailings dams are specialized hydraulic structures used to store tailings slurry left over from mineral processing. The large amount of mixed tailings slurry makes tailings dams a high-potential source of man-made debris flows, threatening the lives and property of downstream residents and the environment. The moisture content of tailings slurry varies greatly depending on the region and the time of accumulation. Newly filled tailings can have a moisture content exceeding 300%, with 65% of the particles ranging from 0.005 to 0.075 mm in diameter, a porosity as high as 2.53, and a moisture content exceeding 180%. The surface is fluid, and the structural strength approaches zero. Under natural accumulation conditions, the drainage and consolidation effect of bauxite tailings slurry is minimal. Even after more than a decade of cessation of discharge, the surface tailings slurry remains in a fluid plastic state, with virtually no load-bearing capacity, making it impossible for personnel and machinery to enter the site, posing significant challenges to the management and utilization of the tailings dam.

[0003] To reduce the moisture content of tailings slurry, mining companies typically employ pressure filtration technology for mechanical dewatering of tailings. This method can significantly reduce the initial moisture content of tailings upon discharge. However, this technology still faces several key challenges. First, fluidity is a constraint. To ensure the transport and discharge of tailings slurry, the dewatered tailings must maintain a certain moisture content, resulting in them remaining in a fluid-plastic state upon entering the tailings dam. Second, secondary environmental water infiltration occurs. Under the influence of rainfall infiltration and capillary action, the moisture content of open-air stored tailings will further increase. Finally, deep consolidation is difficult. Pressure filtration only dewaters the tailings before discharge, while the slurry already deposited in the tailings dam lacks effective in-situ drainage and consolidation, remaining in a high moisture content state for extended periods, severely impacting the stability of the dam.

[0004] Currently, in-situ mud drainage and consolidation technologies for tailings dam environments include physical drainage consolidation methods, chemical solidification methods, and microbial consolidation methods. Physical drainage consolidation methods primarily utilize vacuum preloading, a soft soil foundation treatment method that creates negative pressure within the soil by drawing a vacuum, using atmospheric pressure as a load to accelerate the discharge of pore water and promote soil consolidation. This method mainly includes the following steps: 1) Laying a drainage system: A horizontal drainage layer (such as a sand cushion or drainage board) is laid on the surface of the tailings mud, and vertical drainage bodies (such as plastic drainage boards / PVD or sand wells) are inserted to form drainage channels; 2) Sealing and vacuuming: A sealing membrane (such as a geomembrane or clay layer) is covered, and a vacuum pump is connected to continuously pump air, creating a negative pressure of 60-80 kPa inside the mud; 3) Consolidation and drainage: The negative pressure forces water in the mud to drain along the drainage bodies, increasing the effective stress between particles and achieving compression consolidation. However, the vacuum preloading method has high sealing requirements. When the tailings dam area is large, the sealing membrane is easily damaged, leading to vacuum leakage. The consolidation period is long, requiring several months or even years to reach the target strength. The construction is difficult, and the tailings slurry has low bearing capacity, making it difficult to withstand the operating load of large construction equipment.

[0005] Chemical solidification primarily relies on quicklime. Quicklime (CaO) solidifies tailings slurry through chemical reactions and physical processes to achieve dehydration and hardening. On one hand, CaO reacts with water to produce calcium hydroxide (Ca(OH)2), consuming free water in the slurry and releasing a large amount of heat, accelerating water evaporation. On the other hand, the generated Ca(OH)2 reacts with clay minerals (such as SiO2 and Al2O3) in the tailings to form volcanic ash, forming cementitious substances (such as CSH gel), enhancing the interparticle bonding strength. However, chemical solidification suffers from poor durability; under long-term exposure, Ca(OH)2 easily carbonizes, leading to strength degradation; and environmental risks, as increased pH may trigger the leaching of heavy metals.

[0006] Microbial consolidation primarily utilizes the metabolic activity of urease-producing microorganisms to generate calcium carbonate (CaCO3) cement between tailings particles, thus consolidating the mud. The microorganisms decompose urea (CO(NH2)2) to produce carbonate ions (CO3²⁻) and ammonium ions (NH4⁺), simultaneously raising the local pH. The CO3²⁻ reacts with the tailings or an external calcium source (such as CaCl2) to form calcite (CaCO3) crystals. However, microbial consolidation is slow, requiring weeks to months to reach the target strength; it is also costly, with high expenses for bacterial culture and calcium source addition; and it has poor environmental adaptability, as extreme pH or high salinity inhibits microbial activity.

[0007] In summary, current in-situ mud drainage consolidation technology for tailings ponds suffers from problems such as long fixation periods, heavy metal leaching, and high costs. Summary of the Invention

[0008] To address the above shortcomings, this invention provides an in-situ temperature gradient drainage consolidation method for tailings slurry. This method has a short consolidation cycle and low cost, and can ensure uniform consolidation of tailings slurry, avoiding the risk of heavy metal leaching caused by quicklime solidification.

[0009] The specific technical solution is as follows: A method for in-situ temperature gradient drainage consolidation of tailings dam slurry includes the following steps: Steel sheet piles are embedded in the tailings slurry so that the bottom of the steel sheet piles reaches the bottom layer of the tailings slurry. Solar collectors are installed on steel sheet piles, and the solar collectors and steel sheet piles are connected by a heat transfer medium circulation pipe. Drainage pipes are laid around the sheet piles, with one end of the drainage pipe flush with the bottom of the sheet piles and the other end connected to the drainage structure. The process involves using solar collectors to heat the heat transfer medium in the heat transfer medium circulation pipe. When the heat transfer medium in the heat transfer medium circulation pipe passes through the steel sheet pile, it exchanges heat with the steel sheet pile. After the heat exchange, it flows back to the heat transfer medium circulation pipe located at the solar collector for further heating. Sheet piles use heat transferred by the heat transfer medium to heat the surrounding mud, and use the thermal consolidation effect to dehydrate the mud until the mud moisture content drops to the target value, thus completing mud consolidation. During the heating process of the mud, the water in the mud is discharged to the drainage structure through the drainage pipe.

[0010] Preferably, the heat transfer medium circulation pipeline is made of stainless steel or copper pipe, and the heat transfer medium is heat transfer oil or ethylene glycol solution.

[0011] Preferably, the sheet piles are made of Q345B steel, and the surface of the sheet piles is provided with spiral grooves. The heat transfer medium circulation pipes connected to the sheet piles are installed in the spiral grooves.

[0012] Preferably, the surface of the solar collector is coated with an absorption coating to improve the photothermal conversion efficiency.

[0013] Preferably, the drainage pipes are made of PVC or metal corrugated pipes.

[0014] Preferably, the drainage pipe is inclined relative to the sheet pile.

[0015] Preferably, the sheet pile is equipped with a solar collector plate clip, and the solar collector plate is fastened to the sheet pile through the solar collector plate clip.

[0016] Preferably, the method analyzes the consolidation effect of tailings mud using a numerical model of tailings mud heat-water migration. The numerical model of tailings mud heat-water migration includes a water-vapor conversion efficiency model and a heat transfer efficiency model. The temperature and circulation flow rate of the heat transfer medium are optimized based on the calculation results of the water-vapor conversion efficiency model and the heat transfer efficiency model.

[0017] Preferably, the water-vapor conversion efficiency model includes liquid water flux. and water vapor flux , (1); (2); In the formula —The hydraulic conductivity of liquid water generated by the head gradient; —The hydraulic conductivity of liquid water caused by the temperature gradient; —The hydraulic conductivity of the gas-phase flux generated by the head gradient; —The hydraulic conductivity of the gas-phase flux generated by the temperature gradient; —Pressure head, taken as a negative value; —Elevation above the reference horizontal plane; --temperature; The changes in water content are obtained from equations (1) and (2): (3); (4); In the formula —Total volumetric water content; —Liquid water content by volume; —Volume water vapor content; --time; By rearranging equations (1) and (4), we can obtain the equilibrium equation for water vapor changes in the mud as temperature changes: (5).

[0018] The preferred heat transfer efficiency model is as follows: (6); In the formula —Effective volumetric heat capacity; —Effective thermal conductivity; —The heat capacity of liquid water; —The heat capacity of water vapor; —Latent heat generated by the evaporation of liquid water.

[0019] Compared with the prior art, the beneficial effects of the present invention are: 1. The method of this invention utilizes solar collectors to convert light energy into heat energy, which is then circulated to the sheet piles via a heat transfer medium (such as ethylene glycol solution) to drive the discharge of mud moisture. The entire process requires no fossil fuels, resulting in near-zero carbon emissions. Compared to traditional pressure filtration or chemical solidification technologies, energy consumption is reduced by more than 60%, lowering costs, improving consolidation efficiency, and avoiding the risk of heavy metal leaching caused by quicklime solidification, thus meeting the requirements of green development.

[0020] 2. The method of this invention uses Q345B high thermal conductivity steel to make steel sheet piles, with spiral grooves on the surface to enhance the heat exchange area. Combined with a high-boiling-point heat transfer medium (ethylene glycol solution), the heat conduction efficiency is high. Driven by a temperature gradient, the evaporation rate of the mud moisture is significantly increased compared to natural consolidation, and the water content of the mud in the deep tailings dam is rapidly reduced, significantly shortening the consolidation period.

[0021] 3. The method of this invention allows steel sheet piles to be directly driven into fluid plastic slurry without the need for foundation pretreatment, solving the problem of equipment inaccessibility due to the low bearing capacity of slurry in traditional vacuum preloading methods. Furthermore, the steel sheet piles can be repeatedly driven in and out, with a single sheet pile having a lifespan of over 5 years. Equipment costs are reduced by 40% compared to microbial consolidation technology, making it suitable for large-area tailings dam projects.

[0022] 4. The method of the present invention, by using a ring-shaped enclosure structure made of steel sheet piles, has high support strength. During the flow of tailings water, it can effectively prevent the tailings dam from collapsing due to factors such as water flow impact and soil instability, providing a solid guarantee for the safety of the surrounding environment and personnel of the tailings dam and reducing the risk of safety accidents. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0024] Figure 1 This is a top view of the method of the present invention during drainage consolidation.

[0025] Figure 2 This is a longitudinal sectional view of the method of the present invention during drainage consolidation.

[0026] Figure 3 This is a schematic diagram of a steel sheet pile.

[0027] Among them, 1 is a steel sheet pile, 2 is a heat collector plate clip, 3 is a heat transfer medium circulation pipe, 4 is a solar heat collector plate, 5 is a drainage pipe, 6 is a drainage outlet, and 7 is a spiral groove. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0030] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. Where the terms "first," "second," and "third" are used for descriptive purposes and to distinguish technical features, they should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the sequential relationship of the indicated technical features.

[0031] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0032] Example 1 like Figures 1-3 As shown in this embodiment, an in-situ temperature gradient drainage consolidation method for tailings dam slurry is provided, comprising the following steps: Steel sheet pile 1 is embedded in the tailings slurry so that the bottom of steel sheet pile 1 reaches the bottom layer of the tailings slurry. Specifically, multiple sheet piles are vertically buried into the bottom layer of tailings mud in an equilateral triangular grid with a spacing of 3-5m. The top of the sheet piles is 0.5-1m above the mud surface, forming a ring-shaped enclosure and heat transfer matrix. Adjacent sheet piles are connected by interlocking to form a closed or semi-closed reinforcement area, improving structural stability. Solar collector 4 is installed on steel sheet pile 1, and solar collector 4 and steel sheet pile 1 are connected by heat transfer medium circulation pipe 3. Specifically, the solar collector panel adopts a hyperboloid concentrating structure and is coated with a nano-level selective absorption coating. The solar collector panel is connected to the steel sheet pile through a heat transfer medium circulation pipe. The pipe is made of stainless steel corrugated pipe, and the connection section with the steel sheet pile is embedded in a pre-set spiral groove on the surface. The spiral groove is filled with thermally conductive silicone grease to enhance the heat conduction effect. Drainage pipe 5 is buried around sheet pile 1, with one end of drainage pipe 5 flush with the bottom of sheet pile 1 and the other end of drainage pipe 5 connected to drainage structure. Specifically, drainage pipes are laid at an angle of 15°-30° around the steel sheet piles; the drainage pipes are made of reinforced PVC pipes with micron-level permeable holes with a diameter of 50-100μm in the pipe wall, and geotextile mesh is wrapped around the holes to prevent mud particles from clogging the pipes; a submersible pump is installed in the drainage structure, and a water level sensor is provided to realize automatic drainage. The heat transfer medium in the heat transfer medium circulation pipe 3 is heated by the solar collector plate 4. When the heat transfer medium in the heat transfer medium circulation pipe 3 passes through the steel sheet pile 1, it exchanges heat with the steel sheet pile 1. After the heat exchange, it flows back to the heat transfer medium circulation pipe 3 located at the solar collector plate 4 for heating. The sheet pile 1 heats the surrounding mud with the heat transferred by the heat transfer medium, and uses the thermal consolidation effect to dehydrate the mud until the water content of the mud drops to the target value, thus completing the mud consolidation. During the heating process of the mud, the water in the mud is discharged to the drainage structure through the drainage pipe 5.

[0033] The drainage structure is a drainage ditch.

[0034] The method in this embodiment uses a heat transfer medium circulation pipeline 3 to deliver heat transfer medium over a wider area to heat the steel sheet piles 1, thereby improving heat conduction efficiency and shortening the consolidation cycle. The heat transfer medium is heated by a solar collector plate 4, and the temperature of the heat transfer medium is detected by a corresponding temperature sensor to achieve precise temperature control, avoiding localized overheating or uneven heating, and ensuring uniform consolidation of the tailings slurry. The use of the steel sheet piles 1, solar collector plate 4, and corresponding pipelines reduces equipment complexity and maintenance costs, making it suitable for large-scale tailings dam projects. It utilizes solar energy to convert into thermal energy, reducing consolidation costs. The steel sheet piles 1 are suitable for soils with high water content, solving the problem of low bearing capacity and difficulty in equipment operation during tailings dam construction.

[0035] The working principle of this embodiment is as follows: Solar energy is converted into thermal energy by solar collector plate 4, which heats the heat transfer medium (such as ethylene glycol solution) in heat transfer medium circulation pipe 3. The high-temperature medium flows into steel sheet pile 1 made of high thermal conductivity steel (such as Q345B) with pre-set spiral grooves 7 on the surface through heat transfer medium circulation pipe 3. The steel sheet pile 1 evenly conducts heat to the surrounding tailings slurry, forming a temperature gradient in the slurry. After the slurry is heated, the water evaporates into gaseous water. The liquid water and gaseous water are discharged through the pre-buried drainage pipe 5 under the action of the temperature gradient. The liquid water flows faster due to the increased permeability coefficient caused by the temperature increase, and the gaseous water is discharged through the vapor pressure gradient, finally realizing the drainage and consolidation of the tailings slurry. By controlling the temperature and circulation flow of the heat transfer medium, the temperature of the slurry can be ensured to be uniform and maintained within a reasonable range. At the same time, the temperature field and water migration law can be analyzed by the tailings slurry heat-water migration numerical model to optimize the heating parameters and improve the consolidation efficiency.

[0036] The heat transfer medium circulation pipe 3 is made of stainless steel or copper pipe. The heat transfer medium is a nano-modified ethylene glycol solution with 5%-8% carbon nanotubes added, which increases the thermal conductivity by more than 40%. It is driven by a circulation pump to flow in the pipe. The solar collector is equipped with a temperature control sensor and an automatic shading device. When the temperature of the heat transfer medium exceeds 60°C, the shading device will automatically open to avoid local overheating. At the same time, temperature sensors are deployed at different depths of the mud to monitor the temperature field distribution in real time.

[0037] The solar collectors convert solar energy into thermal energy, heating the heat transfer medium. The high-temperature medium exchanges heat with the steel sheet piles through pipes, raising the temperature of the steel sheet piles to 45-60℃ and creating a radial temperature gradient in the mud. The thermal consolidation effect accelerates the evaporation and infiltration of liquid water in the mud. The liquid water flows by gravity along the drainage pipes to the drainage structure, while the gaseous water diffuses through the vapor pressure gradient to the drainage pipes and is discharged. The consolidation effect is analyzed in real time using a numerical model of heat and water migration in the tailings mud, and the temperature and circulation flow of the heat transfer medium are dynamically optimized.

[0038] When the mud moisture content drops below 60%, monitor continuously for 3-5 days. If the moisture content is stable, stop heating. After the sheet pile temperature drops to ambient temperature, remove the solar collector and circulation pipe in sequence, and use a pile extractor to pull out and recycle the sheet pile to complete the mud consolidation.

[0039] The sheet pile 1 is made of Q345B steel. The surface of the sheet pile 1 has spiral grooves 7, and a portion of the heat transfer medium circulation pipe 3 connected to the sheet pile 1 is installed in the spiral grooves 7. The sheet pile 1 acts as a heat transfer medium, uniformly transferring the heat generated by the heat exchange medium to the tailings slurry. It also provides structural support to prevent deformation of the slurry during flow.

[0040] The surface of the solar collector panel 4 is coated with an absorption coating to improve the photothermal conversion efficiency. The solar collector panel 4 converts solar energy into heat energy to heat the heat transfer medium (ethylene glycol solution).

[0041] The drainage pipe 5 is made of PVC or corrugated metal pipe. The drainage pipe 5 is pre-embedded around the steel sheet piles 1, and the drainage outlet 6 of the drainage pipe connects to the drainage ditch outside the tailings dam. This discharges the gaseous water that evaporates from the heated mud, accelerating dehydration and consolidation. It also prevents water backflow and maintains the consolidation effect.

[0042] The drainage pipe 5 is inclined relative to the sheet pile 1.

[0043] The sheet pile 1 is equipped with a heat collection plate buckle 2, and the solar heat collection plate 4 is fastened to the sheet pile 1 through the heat collection plate buckle 2.

[0044] It should be noted that there are multiple sheet piles 1. The sheet piles 1 are driven into the tailings mud at the designed spacing to ensure that they penetrate deep into the bottom of the mud.

[0045] The solar collector panel 4 can utilize existing flat-plate collectors, resembling a flat box. It consists of a transparent cover (glass), an absorber plate (usually a metal plate coated with a selective absorption coating), an insulation layer, and an outer shell. The absorber plate contains flow channels, which circulate with the heat transfer medium 3. Sunlight passes through the cover, is absorbed by the absorber plate, and converted into heat energy, heating the heat transfer medium in the flow channels. The cover reduces heat loss, and the insulation layer prevents heat loss from the back and sides.

[0046] The method analyzes the consolidation effect of tailings mud using a numerical model of heat-water migration. The numerical model of heat-water migration of tailings mud includes a water-vapor conversion efficiency model and a heat transfer efficiency model. Based on the calculation results of the water-vapor conversion efficiency model and the heat transfer efficiency model, the temperature and circulation flow rate of the heat transfer medium are optimized.

[0047] The water-vapor conversion efficiency model includes liquid water flux. and water vapor flux , (1); (2); In the formula —The hydraulic conductivity of liquid water generated by the head gradient; —The hydraulic conductivity of liquid water caused by the temperature gradient; —The hydraulic conductivity of the gas-phase flux generated by the head gradient; —The hydraulic conductivity of the gas-phase flux generated by the temperature gradient; —Pressure head, taken as a negative value; —Elevation above the reference horizontal plane; --temperature; The changes in water content are obtained from equations (1) and (2): (3); (4); In the formula —Total volumetric water content; —Liquid water content by volume; —Volume water vapor content; --time; By rearranging equations (1) and (4), we can obtain the equilibrium equation for water vapor changes in the mud as temperature changes: (5).

[0048] The heat transfer efficiency model is as follows: (6); In the formula —Effective volumetric heat capacity; —Effective thermal conductivity; —The heat capacity of liquid water; —The heat capacity of water vapor; —Latent heat generated by the evaporation of liquid water.

[0049] Specifically, temperature sensors and flow meters can be installed on the outer wall of the sheet pile 1 and the drainage pipe to detect relevant data. The data can then be input into the model to adjust the heating time of the heat transfer medium in the solar collector plate 4 and the power of the circulation pump, thereby adjusting the flow rate of the heat transfer medium.

[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for in-situ temperature gradient drainage consolidation of tailings dam slurry, characterized in that, Includes the following steps: Steel sheet piles are embedded in the tailings slurry so that the bottom of the steel sheet piles reaches the bottom layer of the tailings slurry. Solar collectors are installed on steel sheet piles, and the solar collectors and steel sheet piles are connected by heat transfer medium circulation pipes. Drainage pipes are laid around the sheet piles, with one end of the drainage pipe flush with the bottom of the sheet piles and the other end connected to the drainage structure. The process involves using solar collectors to heat the heat transfer medium in the heat transfer medium circulation pipe. When the heat transfer medium in the heat transfer medium circulation pipe passes through the steel sheet pile, it exchanges heat with the steel sheet pile. After the heat exchange, it flows back to the heat transfer medium circulation pipe located at the solar collector for further heating. Sheet piles use heat transferred by the heat transfer medium to heat the surrounding mud, and use the thermal consolidation effect to dehydrate the mud until the water content of the mud drops to the target value, thus completing the mud consolidation. During the heating process of the mud, the water in the mud is discharged to the drainage structure through the drainage pipe.

2. The method for in-situ temperature gradient drainage and consolidation of tailings dam slurry according to claim 1, characterized in that, The heat transfer medium circulation pipeline is made of stainless steel or copper pipe, and the heat transfer medium is heat transfer oil or ethylene glycol solution.

3. The method for in-situ temperature gradient drainage and consolidation of tailings dam slurry according to claim 1, characterized in that, The sheet piles are made of Q345B steel. The surface of the sheet piles is provided with spiral grooves, and the heat transfer medium circulation pipes connected to the sheet piles are installed in the spiral grooves.

4. The method for in-situ temperature gradient drainage and consolidation of tailings dam slurry according to claim 1, characterized in that, The surface of the solar collector is coated with an absorption coating to improve the photothermal conversion efficiency.

5. The method for in-situ temperature gradient drainage consolidation of tailings dam slurry according to claim 1, characterized in that, The drainage pipes are made of PVC or metal corrugated pipes.

6. The method for in-situ temperature gradient drainage consolidation of tailings dam slurry according to claim 1, characterized in that, The drainage pipes are installed at an angle relative to the sheet piles.

7. The method for in-situ temperature gradient drainage consolidation of tailings dam slurry according to claim 1, characterized in that, The sheet piles are equipped with solar collector clips, and the solar collectors are fastened to the sheet piles through the solar collector clips.

8. The method for in-situ temperature gradient drainage consolidation of tailings dam slurry according to claim 1, characterized in that, The method analyzes the consolidation effect of tailings mud using a numerical model of heat-water migration. The numerical model of heat-water migration of tailings mud includes a water-vapor conversion efficiency model and a heat transfer efficiency model. Based on the calculation results of the water-vapor conversion efficiency model and the heat transfer efficiency model, the temperature and circulation flow rate of the heat transfer medium are optimized.

9. The method for in-situ temperature gradient drainage consolidation of tailings dam slurry according to claim 8, characterized in that, The water-vapor conversion efficiency model includes liquid water flux. and water vapor flux , (1)； (2)； In the formula —The hydraulic conductivity of liquid water generated by the head gradient; —The hydraulic conductivity of liquid water caused by the temperature gradient; —The hydraulic conductivity of the gas-phase flux generated by the head gradient; —Hydraulic conductivity of gas-phase flux generated by temperature gradient; —Pressure head, taken as a negative value; —Elevation above the reference horizontal plane; --temperature; The changes in water content are obtained from equations (1) and (2): (3)； (4)； In the formula —Total volumetric water content; —Liquid water content by volume; —Volume water vapor content; --time; By rearranging equations (1) and (4), we can obtain the equilibrium equation for water vapor changes in the mud as temperature changes: （5）。 10. The method for in-situ temperature gradient drainage and consolidation of tailings dam slurry according to claim 8, characterized in that, The heat transfer efficiency model is as follows: （6）； In the formula —Effective volumetric heat capacity; —Effective thermal conductivity; —The heat capacity of liquid water; —The heat capacity of water vapor; —Latent heat generated by the evaporation of liquid water.

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