Process and device for removing heavy metal ions in sludge after comprehensive utilization of power generation slag

Abstract

The invention discloses a process and a device for removing heavy metal ions in sludge after comprehensive utilization of power generation slag, relates to the technical field of removal of heavy metal ions in power generation slag, and aims to solve the problem of non-uniform contact between a chelating agent and the heavy metal ions. A chelating agent is uniformly injected into the middle part of the sludge through the chelating mechanism, then is conveyed to the stirring reaction tank, and is fully stirred in the stirring reaction tank, so that the chelating agent is fully contacted with the heavy metal ions and is subjected to complex reaction to form stable insoluble metal chelate precipitate, and the effect of treating the heavy metal ions is achieved; in this way, the chelating agent is evenly mixed with the sludge to the maximum extent, the complexing reaction effect is improved, and then the heavy metal ion treatment effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of removing heavy metal ions from power generation slag, and in particular to a process and a device for removing heavy metal ions from sludge after comprehensive utilization of power generation slag. Background Art

[0002] Heavy metal ions in sludge produced after comprehensive utilization of power generation slag refer to the metal ions remaining in the sludge after a series of comprehensive utilization treatments of the slag remaining after fuel combustion in the power generation process (such as thermal power generation).

[0003] During the power generation process, some of the heavy metal elements (such as lead, mercury, cadmium, chromium, etc.) in coal and other fuels will be enriched in the slag. When the slag is recycled, such as making building materials, road paving materials and other comprehensive utilization methods, the slag undergoes water leaching, chemical treatment and other processes, and the heavy metal elements in it will enter the generated sludge in the form of ions. These heavy metal ions are toxic and have potential environmental hazards. If they are not handled properly, they will enter the soil and water bodies through rainwater erosion and infiltration, posing a serious threat to the ecological environment and human health, such as causing soil pollution, eutrophication of water bodies, biological toxicity effects and many other problems.

[0004] However, in the prior art, heavy metal ions are reacted into stable compounds through chemical reactions. Most of the prior art uses a method of spraying a chelating agent onto the soil. However, the chelating agent can only be sprayed on the soil surface and mixed by immersing the soil from the upper layer downward. The lower layer of the soil has less contact with the chelating agent, resulting in uneven mixing, uneven heavy metal ion treatment, and a large amount of chelating agent used.

[0005] Therefore, it is necessary to have a process and device for removing heavy metal ions from the sludge after comprehensive utilization of power generation slag. Summary of the invention

[0006] In order to solve all or part of the above problems, the present invention aims to provide a process and device for removing heavy metal ions in sludge after comprehensive utilization of power generation slag, so as to solve the problem of uneven contact between chelating agent and heavy metal ions.

[0007] To achieve the above object, the present invention provides the following technical solution: a process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag, comprising the following steps: S1: Sludge pretreatment: Mechanical dehydration: preliminary dehydration of the original sludge to reduce the sludge moisture content to 60%-70%; Crushing and screening: The dehydrated sludge is crushed to refine its particles, and then screened through a vibrating screen to remove larger impurity particles and incompletely reacted slag fragments; S2: Heavy metal ion leaching test: Take a small amount of pre-treated sludge sample and use the leaching method to determine the leaching concentration of the main heavy metal ions therein; S3: Adding reagents and stirring reaction: According to the leaching test results, the sludge is transported through the transport mechanism, and the chelating agent is uniformly injected into the middle of the sludge through the chelating mechanism, and then transported to the stirring reaction tank, where it is fully stirred to allow the chelating agent to fully contact with the heavy metal ions and undergo a complex reaction to form a stable insoluble metal chelate precipitate; S4: Curing treatment: Solidifying agent materials in chemically stabilized sludge; S5: Forming and curing: The evenly stirred sludge solidified material is poured into a mold to be formed into solidified blocks of a certain shape and size. The formed solidified blocks are cured in a curing site and the treatment is completed.

[0008] Furthermore, in S3, the servo motor drives the middle part of the support frame to rotate and then drives the conveyor belt to rotate, so that the sludge transported to the upper side of the conveyor belt near the end of the support frame can be transported to the chelating mechanism, and the sludge is evenly injected with chelating agent by the chelating mechanism and then transported to the end of the conveyor belt near the support frame two.

[0009] Furthermore, the chelating mechanism is activated by a hydraulic mechanism, driving the pressure plate to move downward, and the pressure plate drives the movable plate to move downward. At this time, the movable plate is preferentially blocked by the second support frame. At this time, the movable plate moves in the opposite direction, and the injection molding tube continues to move downward, and extends the liquid outlet from the movable plate and inserts into the sludge. The chelating agent overflows and merges into the sludge, and then the chelating agent is added to the sludge and then a heavy metal ion complexation reaction is carried out.

[0010] Furthermore, when the movable plate is pressed against the support plate so that the liquid outlet hole extends, the relative extension column pushes the piston plate upward to move upward on the inner side of the pressure plate, thereby compressing the chelating agent on the inner side of the pressure plate, so that the chelating agent is pressed out from the liquid outlet hole, and further the chelating agent has a certain injection force, which facilitates the chelating agent to be immersed in the soil near the liquid outlet hole.

[0011] Furthermore, when the piston plate moves upward, the chelating mechanism preferably drives the sealing member to move the sealing plate upward until the sealing plate blocks the connecting hole between the guide inner tube and the pressure plate. At this time, the piston plate continues to move upward, thereby squeezing the chelating agent out of the liquid outlet. When the pressure plate is reset, the movable plate is reset under the reset effect of the reset spring, and finally the sealing plate moves downward to open the connecting hole between the guide inner tube and the pressure plate. At this time, the chelating agent in the storage tank is replenished to the inner side of the pressure plate to complete automatic liquid replenishment.

[0012] Furthermore, a device for removing heavy metal ions from sludge after comprehensive utilization of power generation slag is provided, which is used to implement a process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag, and includes a conveying mechanism and a chelating mechanism arranged at the upper middle end of the conveying mechanism. The conveying mechanism includes a conveyor belt and support frame one and support frame two installed at the inner ends of the conveyor belt. One end of the conveyor belt is coated on the middle part of support frame one, and the other end of the conveyor belt is coated on the middle part of support frame two. A servo motor is installed on the upper end of one side of support frame one.

[0013] Furthermore, the chelating mechanism includes a support frame 2 and a hydraulic mechanism installed in the middle of the upper end of the support frame 2, the driving end of the hydraulic mechanism passes through the middle of the support frame 2, and the driving end of the hydraulic mechanism located on the inner side of the support frame 2 is provided with a pressure plate, the inner side of the pressure plate is in a cavity state and a chelating agent is stored inside, a movable plate is installed on the lower side of the pressure plate, a plurality of injection molding tubes are fixedly installed on the lower end of the pressure plate, the upper ends of the injection molding tubes are inserted into the inner side of the pressure plate, liquid outlet holes are opened on both sides of the lower end of the injection molding tubes, and the lower end of the injection molding tubes movably passes through the movable plate.

[0014] Furthermore, a support plate is installed on the inner side of the second support frame, a support block is installed on the inner upper end of the support plate, the bottom of the conveyor belt is in contact with the support block, and the upper surface of the support plate is higher than the upper surface of the conveyor belt.

[0015] Furthermore, a return spring is installed at the upper end of the movable plate, and the upper end of the return spring is fixedly connected to the pressure plate. An extension column is installed at the upper end of the movable plate located inside the return spring. The upper end of the extension column movably passes through the pressure plate and is inserted into the inner side of the pressure plate. A piston plate is installed on the inner side of the pressure plate, and the lower side of the piston plate is fixedly connected to the extension column. The upper end of the injection molding tube movably passes through the piston plate.

[0016] Furthermore, a sealing piece is installed at the upper end of the piston plate, a sealing plate is installed on the inner side of the upper end of the sealing piece, a movable column is installed in the middle part of the lower end of the sealing plate, an extrusion spring is installed at the lower end of the movable column, and the lower end of the extrusion spring is fixedly connected to the inner side of the upper end of the sealing piece, a storage tank is installed at the upper end of the support frame 2, and a guide outer tube is installed at the four corners of the storage tank, the guide outer tube passes through the support frame 2, and a guide inner tube is installed on the inner side of the guide outer tube located at the lower end of the support frame 2, and the lower end of the guide inner tube is fixedly connected to the upper end of the pressure plate and is connected to the inside of the pressure plate.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The process and device for removing heavy metal ions in sludge after comprehensive utilization of power generation sludge proposed in the present invention transport the sludge through a conveying mechanism according to the results of leaching tests, and inject a chelating agent evenly into the middle of the sludge through a chelating mechanism, and then transport it to a stirred reaction tank, where it is fully stirred so that the chelating agent and heavy metal ions are fully in contact and complexed to form a stable insoluble metal chelate precipitate, thereby achieving the effect of treating heavy metal ions. This method maximizes the uniform mixing of the chelating agent with the sludge, improves the complexing reaction effect, and further improves the heavy metal ion treatment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The process flow chart of the process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag according to the present invention; Figure 2 This is a schematic diagram of the overall three-dimensional structure of the device for removing heavy metal ions in sludge after comprehensive utilization of power generation slag according to the present invention; Figure 3 It is a schematic diagram of the three-dimensional structure of the conveying mechanism of the device for removing heavy metal ions in the sludge after comprehensive utilization of power generation slag according to the present invention; Figure 4 It is a schematic diagram of the planar structure of the chelating mechanism of the device for removing heavy metal ions in the sludge after comprehensive utilization of power generation slag according to the present invention; Figure 5 This is a schematic diagram of the support frame 2, hydraulic mechanism, pressing plate and movable plate structure of the device for removing heavy metal ions in sludge after comprehensive utilization of power generation slag according to the present invention; Figure 6 It is a schematic diagram of the internal planar structure of the hydraulic mechanism, the pressing plate and the movable plate of the device for removing heavy metal ions in the sludge after comprehensive utilization of power generation furnace slag according to the present invention; Figure 7 The device for removing heavy metal ions in sludge after comprehensive utilization of power generation slag according to the present invention Figure 2 A is an enlarged structural diagram of FIG.

[0019] In the figure: 1. Conveyor belt; 11. Baffle; 12. Scraper; 13. Insert plate; 14. Spring; 2. Support frame 1; 21. Servo motor; 3. Support frame 2; 4. Support frame 2; 41. Support plate; 42. Support block; 5. Hydraulic mechanism; 6. Press plate; 61. Injection tube; 611. Liquid outlet; 62. Piston plate; 63. Sealing piece; 64. Sealing plate; 641. Movable column; 642. Extrusion spring; 7. Movable plate; 71. Reset spring; 72. Extension column; 8. Storage tank; 81. Outer guide tube; 82. Inner guide tube. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] like Figure 1-Figure 2 As shown, the process for removing heavy metal ions in sludge after comprehensive utilization of power generation slag includes the following steps: Step 1: Sludge pretreatment: Mechanical dehydration: Use a plate and frame filter press or a centrifugal dehydrator to preliminarily dehydrate the original sludge, reducing the sludge moisture content to 60%-70%, facilitating subsequent treatment operations and reducing the amount of treatment agents and treatment volume; Crushing and screening: The dehydrated sludge is crushed to refine its particles, and then screened through a vibrating screen to remove larger impurity particles and incompletely reacted slag fragments to ensure the uniformity of the sludge material.

[0022] Step 2: Heavy metal ion leaching test: Take a small amount of pretreated sludge sample and use leaching methods, such as the toxicity characteristic leaching procedure (TCLP), to determine the leaching concentration of major heavy metal ions, including lead, cadmium, chromium, mercury, arsenic, etc., to provide a basis for determining the subsequent dosage of reagents.

[0023] Step 3: Adding reagents and stirring reaction: According to the results of the leaching test, the sludge is transported through the conveying mechanism, and the chelating agent is evenly injected into the middle of the sludge through the chelating mechanism. The chelating agent can be selected from organic sulfides, phosphates and other agents with strong complexing ability for specific heavy metals. Then it is transported to the stirring reaction tank and fully stirred in the stirring reaction tank. The reaction time is controlled at 30-60 minutes to allow the chelating agent to fully contact with the heavy metal ions and undergo complexing reaction to form a stable insoluble metal chelate precipitate.

[0024] Step 4: Curing treatment: Add cement, fly ash and other curing agent materials to the sludge after chemical stabilization. Ordinary Portland cement can be used for cement, and its dosage is determined according to the properties of the sludge and the treatment requirements, generally accounting for 10%-30% of the dry weight of the sludge. Fly ash can be used as an auxiliary curing agent, and the dosage is about 20%-50% of the cement dosage. After adding the curing agent, stir and mix again to make it even.

[0025] Step 5: Forming and maintenance The evenly stirred sludge solidified material is poured into a mold to form solidified blocks of a certain shape and size. The formed solidified blocks are cured at a curing site for no less than 7 days, during which appropriate temperature and humidity conditions are maintained to gradually increase the strength of the solidified blocks and further stabilize the heavy metal ions therein to prevent them from leaching again.

[0026] The safety and stability of the product after molding are improved as follows: The solidified sludge blocks formed after chelation reaction and solidification treatment are essentially different from untreated sludge. During the chelation process, heavy metal ions have formed stable insoluble metal chelate precipitation with chelating agents. This precipitation form allows heavy metal ions to be fixed in a relatively stable chemical structure, greatly reducing their mobility and leaching in the environment.

[0027] However, the heavy metal ions in the sludge formed directly without chelation are easily dissolved again under the conditions of rainwater erosion, acid-base environment changes, etc., causing serious pollution to the soil, water and other environments. For example, in the natural environment, acid rain may cause a large amount of heavy metal ions in the untreated sludge to leach into the groundwater system, endangering the ecological environment and human health.

[0028] The use and safety considerations after curing are as follows: The treated sludge solidified blocks can be used as building materials for resource utilization. Under appropriate formulation and treatment conditions, the strength and stability of the solidified blocks can meet the requirements of some low-strength building materials such as paving bricks and building blocks. Since heavy metal ions are stably fixed inside the solidified blocks, they will not be easily released during normal use, so they can be safely used in the construction field.

[0029] On the contrary, if chelation treatment is not carried out, the heavy metal ions in the sludge are high in content and highly active, and cannot be used in areas such as building materials, because heavy metals will continue to be released during use, causing environmental pollution and safety hazards. For example, if the materials used for paving continue to release heavy metal ions, they will spread with rainwater runoff and pollute the surrounding soil and water.

[0030] The long-term environmental risk reduction effect is explained as follows: The solidified sludge can better maintain the stability of heavy metal ions even in the long-term environmental changes. During the curing process, the solidifying agents such as cement and fly ash will further undergo chemical processes such as hydration reactions to form a denser structure, encapsulating the heavy metal ions.

[0031] This structure can resist a certain degree of physical, chemical and biological erosion. Compared with untreated sludge, it greatly reduces the potential harm of heavy metal ions to the environment over decades or even longer time scales, and achieves long-term stabilization control of heavy metal ions in sludge.

[0032] like Figure 2-Figure 3 As shown, another technical solution proposed by the present invention is to provide a device for removing heavy metal ions in sludge after comprehensive utilization of power generation slag, including a conveying mechanism and a chelating mechanism arranged at the upper end of the middle part of the conveying mechanism. The conveying mechanism includes a conveyor belt 1 and a support frame 2 and a support frame 3 installed at both ends of the inner side of the conveyor belt 1. The conveyor belt 1 is made of a flexible material, such as hard rubber or hard silicone. One end of the conveyor belt 1 is covered with a middle part of the support frame 2, and the other end of the conveyor belt 1 is covered with a middle part of the support frame 3. A servo motor 21 is installed on the upper end of one side of the support frame 2. The servo motor 21 drives the middle part of the support frame 2 to rotate and then drives the conveyor belt 1 to rotate. The sludge transported to the upper side of the conveyor belt 1 near one end of the support frame 2 can be transported to the chelating mechanism. After the chelating agent is evenly injected into the sludge by the chelating mechanism, it is transported to the end of the conveyor belt 1 near the support frame 2 3 and finally transported away. A stirring reaction tank is set at the end of the conveyor belt 1. The mixed sludge output by the conveyor belt 1 is stirred by the stirring reaction tank and then output, thereby improving the mixing effect.

[0033] like Figure 3-Figure 6 As shown, the chelating mechanism includes a support frame 2 4 and a hydraulic mechanism 5 installed in the middle of the upper end of the support frame 2 4, the driving end of the hydraulic mechanism 5 passes through the middle of the support frame 2 4, and the driving end of the hydraulic mechanism 5 located on the inner side of the support frame 2 4 is provided with a pressing plate 6, the inner side of the pressing plate 6 is in a cavity state and a chelating agent is stored inside, a movable plate 7 is installed on the lower side of the pressing plate 6, and a plurality of injection molding tubes 61 are fixedly installed on the lower end of the pressing plate 6, the injection molding tube 61 is open at the upper end and closed at the lower end, the upper end of the injection molding tube 61 is inserted into the inner side of the pressing plate 6, and liquid outlet holes 611 are opened on both sides of the lower end of the injection molding tube 61, and the lower end of the injection molding tube 61 movably passes through the movable plate 7; When the hydraulic mechanism 5 is not started, the liquid outlet 611 is retracted into the movable plate 7, and the liquid outlet 611 will not overflow. When the hydraulic mechanism 5 is started, it drives the pressure plate 6 to move downward, and the pressure plate 6 drives the movable plate 7 to move downward. At this time, the movable plate 7 is preferentially blocked by the support frame 2 4. At this time, the movable plate 7 moves in the opposite direction, and the injection tube 61 continues to move downward, and extends the liquid outlet 611 from the movable plate 7 and inserts it into the sludge. The chelating agent overflows and merges into the sludge, and then the chelating agent is added to the sludge and then a heavy metal ion complexation reaction is carried out to achieve the effect of treating heavy metal ions. This method maximizes the uniform mixing of the chelating agent with the sludge, improves the complexation reaction effect, and thus improves the heavy metal ion treatment effect.

[0034] like Figure 3-Figure 4 As shown, a support plate 41 is installed on the inner side of the support frame 2 4, and a support block 42 is installed on the inner upper end of the support plate 41. The bottom of the conveyor belt 1 is in contact with the support block 42, and the upper surface of the support plate 41 is higher than the upper surface of the conveyor belt 1. When soil is transported on the conveyor belt 1, the movable plate 7 moves downward, and the bottom of the movable plate 7 preferentially fits with the soil to flatten the soil, thereby making the soil evenly compressed. As the movable plate 7 continues to move, the two ends of the movable plate 7 are supported by the support plate 41, and the liquid outlet 611 extends out and is inserted into the soil for injection.

[0035] like Figure 3-Figure 6 As shown, a return spring 71 is installed at the upper end of the movable plate 7, and the upper end of the return spring 71 is fixedly connected to the pressure plate 6. An extension column 72 is installed at the upper end of the movable plate 7 located inside the return spring 71. The upper end of the extension column 72 movably penetrates the pressure plate 6 and is inserted into the inner side of the pressure plate 6. A piston plate 62 is installed on the inner side of the pressure plate 6, and the lower side of the piston plate 62 is fixedly connected to the extension column 72. The upper end of the injection tube 61 movably penetrates the piston plate 62. When the movable plate 7 is supported by the support plate 41 so that the liquid outlet 611 extends, the relative extension column 72 pushes the piston plate 62 upward to move upward on the inner side of the pressure plate 6, thereby compressing the chelating agent on the inner side of the pressure plate 6, thereby causing the chelating agent to be pressed out from the liquid outlet 611, further allowing the chelating agent to have a certain injection force, which is convenient for the chelating agent to be immersed in the soil near the liquid outlet 611, and to be immersed from the upper and lower sides of the middle of the soil, further improving the chelating agent addition effect.

[0036] like Figure 3-Figure 6 As shown, a plugging member 63 is also installed at the upper end of the piston plate 62, a plugging plate 64 is installed on the inner side of the upper end of the plugging member 63, a movable column 641 is installed at the middle part of the lower end of the plugging plate 64, a squeezing spring 642 is installed at the lower end of the movable column 641, and the lower end of the squeezing spring 642 is fixedly connected to the inner side of the upper end of the plugging member 63, a storage tank 8 is installed at the upper end of the support frame 4, and a guide outer tube 81 is installed at the four corners of the storage tank 8, the guide outer tube 81 passes through the support frame 4, and a guide inner tube 82 is installed on the inner side of the guide outer tube 81 located at the lower end of the support frame 4, and the lower end of the guide inner tube 82 is fixedly connected to the upper end of the pressure plate 6 and is connected to the pressure plate 6. The interior of the pressure plate 6 is connected. When the piston plate 62 moves upward, it preferably drives the sealing member 63 to move the sealing plate 64 upward until the sealing plate 64 blocks the connecting hole between the upper guide inner tube 82 and the pressure plate 6. At this time, the piston plate 62 continues to move upward, thereby squeezing the chelating agent out from the liquid outlet 611. When the pressure plate 6 is reset, the movable plate 7 is reset under the reset effect of the reset spring 71, and finally the sealing plate 64 moves downward to open the connecting hole between the guide inner tube 82 and the pressure plate 6. At this time, the chelating agent in the storage tank 8 is supplemented to the inner side of the pressure plate 6 to complete automatic liquid replenishment. The structure is simple, liquid discharge and liquid supply are automatic, and the degree of automation is high.

[0037] like Figure 2 as well as Figure 6 As shown, multiple baffles 11 are installed at both ends of the outer side of the conveyor belt 1 to prevent sludge from falling from the surface of the conveyor belt 1. A slot is opened at one end of the baffle 11, and a plug plate 13 is inserted into the slot. A scraper 12 is fixedly installed at one end of the plug plate 13, and a spring 14 is fixedly installed at the other end of the plug plate 13. The spring 14 is located inside the slot, and one end of the spring 14 is fixedly connected to the baffle 11. The lower end of the scraper 12 is on the same horizontal line as the lower side of the middle part of the non-working movable plate 7. When the movable plate 7 moves downward to inject the chelating agent into the sludge, in order to ensure the sludge processing speed, the conveyor belt 1 does not stop at this time. At this time, the plug plate 13 contacts the movable plate 7 and moves in the opposite direction under the conveyance of the conveyor belt 1, ensuring the normal operation of the conveyor belt 1 while blocking the sludge transported by the conveyor belt 1 on one side of the plug plate 13 with the side facing away from the movable plate 7. When the movable plate 7 is reset, the plug plate 13 is reset by the spring 14, and under the conveyance of the conveyor belt 1, the upper side of the plug plate 13 can scrape off the sludge adsorbed on the lower side of the movable plate 7 to avoid accumulation caused by sludge adhesion.

[0038] It should be noted that, in the description of the present application, it should be understood that the terms "length", "thickness", "inside", "outside", "axial", "radial", etc., indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0039] In addition, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises", or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article, or apparatus.

[0040] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag, characterized in that: The steps include: S1: Sludge pretreatment: Mechanical dehydration: preliminary dehydration of the original sludge to reduce the sludge moisture content to 60%-70%; Crushing and screening: The dehydrated sludge is crushed to refine its particles, and then screened through a vibrating screen to remove larger impurity particles and incompletely reacted slag fragments; S2: Heavy metal ion leaching test: Take a small amount of pre-treated sludge sample and use the leaching method to determine the leaching concentration of the main heavy metal ions therein; S3: Adding reagents and stirring reaction: According to the leaching test results, the sludge is transported through the transport mechanism, and the chelating agent is uniformly injected into the middle of the sludge through the chelating mechanism, and then transported to the stirring reaction tank, where it is fully stirred to allow the chelating agent to fully contact with the heavy metal ions and undergo a complex reaction to form a stable insoluble metal chelate precipitate; S4: Curing treatment: Solidifying agent materials in chemically stabilized sludge; S5: Forming and curing: The evenly stirred sludge solidified material is poured into a mold to be formed into solidified blocks of a certain shape and size. The formed solidified blocks are cured in a curing site and the treatment is completed.

2. The process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag according to claim 1, characterized in that: In the S3, the servo motor (21) drives the middle part of the support frame (2) to rotate, thereby driving the conveyor belt (1) to rotate, so that the sludge transported to the upper side of the conveyor belt (1) near one end of the support frame (2) can be transported to the chelating mechanism, and the sludge is evenly injected with a chelating agent by the chelating mechanism and then transported to the end of the conveyor belt (1) near the support frame (3).

3. The process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag according to claim 2, characterized in that: The chelating mechanism is activated by the hydraulic mechanism (5), driving the pressure plate (6) to move downward, and the pressure plate (6) drives the movable plate (7) to move downward. At this time, the movable plate (7) is preferentially blocked by the second support frame (4). At this time, the movable plate (7) moves in the opposite direction, and the injection tube (61) continues to move downward, and extends the liquid outlet hole (611) from the movable plate (7) and inserts into the sludge. The chelating agent overflows and merges into the sludge, and then the chelating agent is added to the sludge and then a heavy metal ion complexation reaction is carried out.

4. The process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag according to claim 2, characterized in that: The chelating mechanism is such that when the movable plate (7) is pressed against the support plate (41) so that the liquid outlet hole (611) extends, the relative extension column (72) pushes the piston plate (62) upward to move upward on the inner side of the pressure plate (6), thereby compressing the chelating agent on the inner side of the pressure plate (6), so that the chelating agent is pressed out from the liquid outlet hole (611), further giving the chelating agent a certain injection force, thereby facilitating the chelating agent to be immersed in the soil near the liquid outlet hole (611).

5. The process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag according to claim 2, characterized in that: When the piston plate (62) moves upward, the chelating mechanism preferably drives the sealing member (63) to move the sealing plate (64) upward until the sealing plate (64) blocks the connecting hole between the upper guide inner tube (82) and the pressure plate (6). At this time, the piston plate (62) continues to move upward, thereby causing the chelating agent to be squeezed out from the liquid outlet (611). When the pressure plate (6) is reset, the movable plate (7) is reset under the reset effect of the reset spring (71), and finally the sealing plate (64) moves downward to open the connecting hole between the guide inner tube (82) and the pressure plate (6). At this time, the chelating agent in the storage tank (8) is replenished to the inner side of the pressure plate (6), completing the automatic liquid replenishment.

6. A device for removing heavy metal ions from sludge after comprehensive utilization of power generation slag, used for implementing the process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag as claimed in any one of claims 1 to 5, characterized in that: The invention comprises a conveying mechanism and a chelating mechanism arranged at the middle upper end of the conveying mechanism. The conveying mechanism comprises a conveying belt (1) and a support frame 1 (2) and a support frame 2 (3) installed at both ends of the inner side of the conveying belt (1). One end of the conveying belt (1) is sheathed in the middle of the support frame 1 (2), and the other end of the conveying belt (1) is sheathed in the middle of the support frame 2 (3). A servo motor (21) is installed at the upper end of one side of the support frame 1 (2).

7. The process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag according to claim 6, characterized in that: The chelating mechanism comprises a support frame 2 (4) and a hydraulic mechanism (5) installed at the middle part of the upper end of the support frame 2 (4), the driving end of the hydraulic mechanism (5) passes through the middle part of the support frame 2 (4), and the driving end of the hydraulic mechanism (5) located inside the support frame 2 (4) is provided with a pressing plate (6), the inner side of the pressing plate (6) is in a hollow state and a chelating agent is stored inside, a movable plate (7) is installed at the lower side of the pressing plate (6), a plurality of injection molding tubes (61) are fixedly installed at the lower end of the pressing plate (6), the upper ends of the injection molding tubes (61) are inserted into the inner side of the pressing plate (6), liquid outlet holes (611) are opened on both sides of the lower end of the injection molding tubes (61), and the lower ends of the injection molding tubes (61) movably pass through the movable plate (7).

8. The process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag according to claim 7, characterized in that: A support plate (41) is installed on the inner side of the second support frame (4), a support block (42) is installed on the inner upper end of the support plate (41), the bottom of the conveyor belt (1) is in contact with the support block (42), and the upper surface of the support plate (41) is higher than the upper surface of the conveyor belt (1).

9. The process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag according to claim 7, characterized in that: A return spring (71) is installed at the upper end of the movable plate (7), and the upper end of the return spring (71) is fixedly connected to the pressure plate (6). An extension column (72) is installed at the upper end of the movable plate (7) located inside the return spring (71), and the upper end of the extension column (72) movably penetrates the pressure plate (6) and is inserted into the inner side of the pressure plate (6). A piston plate (62) is installed inside the pressure plate (6), and the lower side of the piston plate (62) is fixedly connected to the extension column (72). The upper end of the injection tube (61) movably penetrates the piston plate (62).

10. The process for removing heavy metal ions from sludge after comprehensive utilization of power generation slag according to claim 9, characterized in that: A blocking member (63) is also mounted on the upper end of the piston plate (62), a blocking plate (64) is mounted on the inner side of the upper end of the blocking member (63), a movable column (641) is mounted on the middle part of the lower end of the blocking plate (64), a pressing spring (642) is mounted on the lower end of the movable column (641), the lower end of the pressing spring (642) is fixedly connected to the inner side of the upper end of the blocking member (63), a storage tank (8) is mounted on the upper end of the second support frame (4), a flow guide outer tube (81) is mounted at the four corners of the storage tank (8), the flow guide outer tube (81) passes through the second support frame (4), and a flow guide inner tube (82) is mounted on the inner side of the flow guide outer tube (81) located at the lower end of the second support frame (4), the lower end of the flow guide inner tube (82) is fixedly connected to the upper end of the pressure plate (6) and communicates with the inside of the pressure plate (6).

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