Blast furnace slag treatment method

Abstract

The invention discloses a blast furnace slag treatment method, and relates to the technical field of steel smelting, the blast furnace slag treatment method is used for treating blast furnace slag separated from molten iron, and comprises the following steps: carrying out granulation cooling treatment on the blast furnace slag; the granulated and cooled molten slag is conveyed into a stirring cage pool to be subjected to primary slag-water separation; the separated slag flushing water is subjected to secondary slag-water separation through a spiral centrifugal device; and the fluid subjected to secondary slag-water separation is filtered by a filter and then sequentially passes through a horizontal flow sediment tank, a water storage tank and a water absorption well for recycling. According to the technical scheme provided by the invention, the water quality of the whole circulating slag flushing water is improved, sediments in the horizontal flow sediment pool are reduced, the burden of manual cleaning is reduced, and normal operation of equipment is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of steel smelting, and in particular to a blast furnace slag treatment method. Background Art

[0002] The blast furnace slag treatment process is a core technology for rapidly cooling high-temperature molten slag into granular slag. The current mainstream processes include bottom filtration method, Inba method, Tula method, Lhasa method and Minter method. Among them, the Minter method uses a high-speed water flow sprayed from a slag punching box to water-quench, granulate and cool the slag, which meets the needs of smelting large amounts of slag. However, there are problems such as rapid wear of core components, the need to regularly replace core components, high maintenance costs, and scaling or corrosion of pipes. The present invention is mainly aimed at the low grading efficiency of the agitator cage and filter in the Minter method treatment process, and a large amount of slag solids cannot be separated before entering the horizontal sediment, which ultimately leads to excessive sediment in the horizontal sediment pool, requiring a large amount of manual cleaning, which can seriously affect the normal operation of the system.

[0003] Therefore, the present application designs a new treatment method to reduce the sediment in the horizontal flow sedimentation tank, improve the water quality of the overall circulating slag flushing water, reduce the burden of manual cleaning, and ensure the normal operation of the equipment. Summary of the Invention

[0004] The main purpose of the present invention is to propose a blast furnace slag treatment method, which aims to improve the water quality of the overall circulating slag flushing water, reduce the sediment in the horizontal flow slag sedimentation tank, reduce the burden of manual cleaning, and ensure the normal operation of the equipment.

[0005] To achieve the above-mentioned object, the present invention provides a method for treating blast furnace slag, which is used to treat blast furnace slag after separation from molten iron, and comprises the following steps:

[0006] Step 1: granulating and cooling the blast furnace slag;

[0007] Step 2: The granulated and cooled slag is sent to a mixing cage pool for preliminary slag-water separation;

[0008] Step 3: The separated slag flushing water is passed through a spiral centrifugal device for secondary slag-water separation;

[0009] Step 4: The fluid after the secondary slag-water separation is filtered through a filter and then passes through a horizontal sedimentation tank, a water storage tank and a water absorption well in sequence to be recycled.

[0010] In one embodiment, after step 3 and before step 4, the method further includes:

[0011] The solids are dehydrated.

[0012] In one embodiment, after step 3 and before dehydrating the solid, the method further comprises:

[0013] The water slag solids after the secondary slag-water separation are concentrated.

[0014] In one embodiment, the spiral centrifugal device has a cyclone centrifugal separation chamber and an inlet, a slag discharge port and a water outlet connected to the spiral centrifugal separation chamber; the water outlet is located at the upper end of the spiral centrifugal device, the slag discharge port is located at the lower end of the spiral centrifugal device, and the inlet is located below the water outlet.

[0015] In one embodiment, a concentrating device is provided below the spiral centrifugal device, and the concentrating device is used to concentrate the water-slag solids after the secondary slag-water separation.

[0016] In one embodiment, the concentrating device includes a shell, a first pneumatic valve and a second pneumatic valve; the shell is located below the slag discharge port and is connected to the slag discharge port; a concentrating chamber is formed in the shell, and the first pneumatic valve is installed at the upper end of the shell for opening and closing the upper end of the shell; the second pneumatic valve is installed at the lower end of the shell for opening and closing the lower end of the shell.

[0017] In one embodiment, a screw pressing device is provided below the spiral centrifugal device, and the screw pressing device is used to achieve dehydration of the solid.

[0018] In one embodiment, the solid concentration of the water-slag solid after the secondary slag-water separation comprises:

[0019] Close the first pneumatic valve and open the second pneumatic valve;

[0020] When the solids in the housing accumulate to a preset height, the second pneumatic valve is closed and the first pneumatic valve is opened to discharge the accumulated solids;

[0021] Fill with compressed air to force out the remaining deposits;

[0022] After the deposits are fed into the screw pressing device, the first pneumatic valve is closed again and the second pneumatic valve is opened.

[0023] In one embodiment, the spiral centrifugal device is provided with an exhaust port, and the exhaust port is used to adjust the negative pressure generated by the discharge of the screw pressing device.

[0024] In one embodiment, in step three, the flow rate of the separated slag flushing water entering the spiral centrifugal device is at least 1 m / s.

[0025] The technical solution of the present invention involves granulating and cooling blast furnace slag; transferring the granulated and cooled slag to a mixing cage for initial slag-water separation; and passing the separated slag-washing water through a spiral centrifugal device 10 for secondary slag-water separation. The fluid after secondary slag-water separation is filtered through a filter and then sequentially passes through a horizontal slag settling tank, a water storage tank, and a water absorption well for recycling. This new process achieves higher classification efficiency, significantly improving the solid removal rate in the slag-washing water and enabling better slag-washing water recycling, making the blast furnace slag-water treatment process more environmentally friendly and economical. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0027] Figure 1 A schematic flow chart of an embodiment of a blast furnace slag treatment method provided by the present invention;

[0028] Figure 2 A schematic flow chart of another embodiment of the blast furnace slag treatment method provided by the present invention;

[0029] Figure 3 A schematic diagram of a cyclonic centrifugal separation flow field for a blast furnace slag treatment method provided by the present invention;

[0030] Figure 4 A schematic structural diagram of a spiral centrifugal device for a blast furnace slag treatment method provided by the present invention from one perspective;

[0031] Figure 5 A schematic structural diagram of another perspective of the spiral centrifugal device for the blast furnace slag treatment method provided by the present invention;

[0032] Figure 6 A schematic diagram of the internal structure of a spiral centrifugal device for a blast furnace slag treatment method provided by the present invention;

[0033] Figure 7 A schematic diagram of the internal structure of a screw pressing device for a blast furnace slag treatment method provided by the present invention.

[0034] Description of Figure Numbers:

[0035] 10. Spiral centrifugal device; 11. Cyclone centrifugal separation chamber; 12. Inlet; 13. Slag discharge port; 14. Drain port; 15. Exhaust port; 16. Pressure regulating port; 20. Concentration device; 21. Shell; 211. Concentration chamber; 22. First pneumatic valve; 23. Second pneumatic valve; 30. Screw pressing device; 31. Motor; 32. Screw shaft; 33. Screw blades; 34. Pressing cylinder; 35. Discharge port; 36. Water outlet; 37. Emergency exit.

[0036] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making any creative efforts shall fall within the scope of protection of the present invention.

[0038] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0039] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0040] In the Minter process of treating blast furnace slag, the grading efficiency of the agitator cage and filter is not high. A large amount of water slag solids cannot be separated before entering the horizontal flow sedimentation tank, which eventually leads to excessive sediment in the horizontal flow sedimentation tank, requiring a lot of manual cleaning. In serious cases, it will affect the normal operation of the system.

[0041] Therefore, the present invention provides a blast furnace slag treatment method.

[0042] See also Figure 1 In one embodiment of the present invention, the blast furnace slag treatment method is used to treat blast furnace slag after separation from molten iron, and includes steps S101 to S104.

[0043] S101, granulating and cooling the blast furnace slag.

[0044] Specifically, after blast furnace slag is separated from molten iron, it flows through a slag ditch to the granulation zone. Here, a high-speed water jet from a slag blasting box sprays water, which fully contacts the high-temperature slag, rapidly quenching and granulating the slag. During this process, the water flow from the slag blasting box uniformly and rapidly cools the slag into a suitable granular shape, laying the foundation for subsequent processing.

[0045] It should be noted that the water flow ejected from the slag flushing box causes the slag to be initially granulated, but the slag particles at this time are not uniform in size. The slag ditch provides space for further granulation of the slag. In the slag ditch, the slag flows with the water flow, and the particles constantly collide and rub against each other, and the larger particles will gradually break into smaller particles. After further granulation and buffering, the slag particles are more uniform and fine, and can better adapt to the work of the mixing cage when entering the mixing cage pool for slag-water separation. Smaller particles are more easily separated from water under the stirring of the mixing cage, thereby improving the slag-water separation effect. Uniform particle distribution can also reduce the problem of incomplete separation caused by differences in particle size, making the water content of the dry slag lower, improving the quality of the dry slag, and facilitating subsequent transportation and reuse.

[0046] The slag after granulation and cooling contains a large amount of water, which requires slag-water separation. In order to achieve efficient resource utilization, ensure the circulation of slag-flushing water, and maintain stable system operation, a series of subsequent treatments are required.

[0047] S102: The granulated and cooled slag is sent to a mixing cage pool for preliminary slag-water separation.

[0048] Specifically, the granulated slag contains a significant amount of water and is then transported to the mixing cage. This equipment is used for the initial separation of slag and water. The mixing cage consists of a main shaft and blades with varying pitches. When the mixing cage begins to rotate, it generates a specific mechanical force. On the one hand, the rotating blades propel the slag upward; on the other hand, the water, under the dual effects of gravity and the mechanical agitation of the mixing cage, overcomes its adhesion to the slag and automatically flows back downward. This gradually separates the water and solid slag in the slag, achieving a preliminary separation effect. During this process, parameters such as the mixing cage speed and blade pitch are carefully designed and adjusted to ensure optimal separation efficiency. If the mixing cage speed is too fast, uneven mixing of slag and water may occur, resulting in incomplete separation; if the speed is too slow, production efficiency may be affected. The design of the blade pitch is also closely related to the slag-water separation effect. The appropriate pitch ensures that the water and slag are fully separated during the upward conveyance of the slag.

[0049] After the initial separation of slag and water, the resulting dry slag has considerable economic value and can be reused as building materials, cement raw materials, and other applications. Therefore, this dry slag needs to be transported to a designated external location, such as a storage yard or processing plant, using a conveyor. A commonly used conveyor is a belt conveyor, which offers advantages such as high transport capacity, long transport distances, and stable operation. The dry slag is transported smoothly to the external environment along the conveyor belt.

[0050] S103, the separated slag flushing water passes through the spiral centrifugal device 10 for secondary slag-water separation.

[0051] Specifically, the slag-washing water separated from the mixing cage tank still contains a lot of solid particles of slag. If these particles are not further separated, they will affect the recycling of the slag-washing water and subsequent processes. The slag-washing water enters the spiral centrifugal device 10 at a preset flow rate by pumping. A spiral centrifugal flow field is formed inside the spiral centrifugal device 10. When the slag-washing water enters, a centrifugal force field (such as the acceleration of gravity) is formed. Figure 3 As shown). Under the action of centrifugal force, the slag solids and water have different movement trajectories due to the difference in density, so the solids and water can be separated, further reducing the solid content in the slag flushing water and reducing the risk of wear of subsequent equipment. After processing in this step, the impurities in the slag flushing water that subsequently enters the filter are greatly reduced, which reduces the workload of the filter, extends the service life of the filter, and reduces maintenance costs. The high-purity slag flushing water enters the water storage tank and the water absorption well for recycling, which improves the quality and efficiency of the slag flushing water circulation, ensures the continuous and stable operation of the blast furnace slag flushing process, and promotes the green, environmental protection and economic efficiency of the entire blast furnace slag flushing process. Among them, the preset flow rate is at least 1m / s.

[0052] S104. The fluid after the secondary slag-water separation is filtered through a filter and then passes through a horizontal sedimentation tank, a water storage tank and a water absorption well in sequence to be recycled.

[0053] Specifically, this step is an important link in ensuring the cleanliness of slag flushing water and realizing the recycling of water resources. It further removes impurities in the fluid, stores and allocates slag flushing water, and provides a stable water source for blast furnace slag flushing. Although most of the water-slag solids in the fluid have been removed after the secondary slag-water separation, a small amount of fine particles may still remain. The fluid can be deeply purified by filtering through the filter. The filter usually uses a fine filter mesh, and its pore size is precisely designed to effectively intercept these tiny impurities and further improve the purity of the fluid. Different types of filters, such as filter mesh type, filter element type, etc., can be selected according to actual needs to ensure the best filtration effect and provide a better quality water source for subsequent recycling.

[0054] After filtering, the fluid enters the advection sedimentation tank. This tank utilizes gravity to allow the remaining extremely fine solid particles to slowly settle to the bottom. The design of the advection sedimentation tank prioritizes the smooth flow of water. Through rational design, the fluid flows evenly and slowly within the tank, allowing solid particles ample time to settle. This sedimentation process further reduces the solids content in the fluid, improves water clarity, and provides better conditions for subsequent storage and recycling.

[0055] After treatment in the horizontal slag settling tank, the fluid enters the water storage tank. This storage tank serves as a reservoir for slag flushing water, regulating its supply to meet the varying water demands of the blast furnace during slag flushing. The capacity of the water storage tank is designed based on the blast furnace's production scale and water usage patterns, ensuring sufficient water reserves to cope with emergencies or production fluctuations. The suction well is connected to the water storage tank, providing stable water intake for the slag flushing pump. The slag flushing pump draws the water from the suction well, pressurizes it, and returns it to the slag flushing tank for recycling.

[0056] The blast furnace slag treatment method of the present application is to granulate and cool the blast furnace slag; send the granulated and cooled slag to the stirring cage pool for preliminary slag-water separation; the separated slag-washing water passes through the spiral centrifugal device 10 for secondary slag-water separation; the fluid after the secondary slag-water separation is filtered through a filter, and then passes through the horizontal sedimentation tank, the water storage tank and the water absorption well in sequence to be recycled. Through the new process, a higher classification efficiency is achieved, which significantly improves the solid removal rate in the slag-washing water, realizes better slag-washing water recycling, reduces the energy consumption and water consumption of the Minter process, and makes the blast furnace slag treatment process more green, economical and environmentally friendly. It also reduces the problems of wear and scaling caused by excessive solid concentration in the slag-washing water, increases the service life of related equipment in the system, reduces the replacement frequency of related wearing parts in the system, reduces the downtime caused by inspection and maintenance, reduces the overall operation and maintenance costs, and improves the production efficiency of the blast furnace.

[0057] Please refer to Figure 2 As shown, in an optional embodiment, the blast furnace slag processing method of the present application includes steps S101-S104.

[0058] S101, granulating and cooling the slag.

[0059] S102: The granulated and cooled slag is sent to a mixing cage pool for preliminary slag-water separation.

[0060] S103: The separated slag-washing water passes through a spiral centrifugal flow field for secondary slag-water separation.

[0061] S1031. Concentrate the water slag solids after the secondary slag-water separation.

[0062] S1032. Dehydrate the separated solid.

[0063] S104. The fluid after the secondary slag-water separation is filtered through a filter and then passes through a horizontal sedimentation tank, a water storage tank and a water absorption well in sequence to be recycled.

[0064] For S101-S103 in this embodiment, please refer to the detailed steps of the previous embodiment. The following focuses on S1031 and S1032 in this embodiment.

[0065] S1031. Concentrate the water slag solids after the secondary slag-water separation.

[0066] Specifically, the slag solids after secondary slag-water separation are concentrated. This process reduces their volume and increases their concentration. When they subsequently enter the screw press system, the material processed by the equipment is more concentrated, reducing the operating pressure of the screw press system. Furthermore, the concentration process not only reduces the volume of the slag solids, facilitating subsequent transportation and handling, but also increases their concentration, increasing their economic value, laying the foundation for subsequent dehydration and resource recycling.

[0067] S1032. Dehydrate the solid.

[0068] Specifically, after secondary slag-water separation and solid concentration, the water slag solid still contains a certain amount of water, which cannot directly meet the needs of subsequent efficient utilization. After further compression and dehydration, the moisture content of the water slag solid is reduced to less than 30%.

[0069] It should be noted that the separated water is filtered through a filter, and then passes through a horizontal sedimentation tank, a water storage tank and a water absorption well in sequence to participate in recycling.

[0070] The technical solution of the present invention utilizes a spiral centrifugal flow field for secondary slag-water separation, followed by solids concentration and dehydration. This separation efficiency is significantly improved compared to the traditional Minter method, which uses a mixing cage and filter for grading. This efficient separation ensures the high purity of the subsequent slag-water treatment, reduces sediment in the horizontal sedimentation tank, reduces manual cleaning workload, and prevents excessive sediment from affecting the normal operation of the system. After secondary slag-water separation, solids concentration, dehydration, and filtration through a filter, more than 70% of the liquid is purified and recycled into a water storage tank and a suction well. This process improves the recycling efficiency of the slag-water treatment, reduces the amount of new water added, reduces water consumption, and achieves efficient utilization of water resources. Furthermore, the improved quality of the recycled slag-water treatment water helps stabilize the slag-water granulation effect and ensures the continuity and stability of the blast furnace slag-water treatment process. Since the solids concentration in the slag-water treatment water is significantly reduced, the wear and tear of solids on system equipment such as pipes and pumps is reduced. At the same time, it reduces scaling problems caused by excessive solids concentration, extends the service life of the equipment, reduces the frequency of replacement of related vulnerable parts within the system, and thus reduces downtime caused by maintenance and repairs, thereby improving the production efficiency of the blast furnace. It also reduces manual operation and maintenance costs and avoids the safety risks caused by manual operation in high-temperature environments on site.

[0071] Please refer to Figures 4 to 7As shown, the present application also relates to a spiral centrifugal device 10 for a blast furnace slag treatment method. The spiral centrifugal device 10 has a cyclonic centrifugal separation chamber 11, an inlet 12, a slag discharge port 13, and a water outlet 14. The inlet 12, the slag discharge port 13, and the water outlet 14 are all connected to the cyclonic centrifugal separation chamber 11. The water outlet 14 is located at the upper end of the spiral centrifugal device 10, the slag discharge port 13 is located at the lower end of the spiral centrifugal device 10, and the inlet 12 is located below the water outlet 14.

[0072] Specifically, the spiral centrifugal device 10 is cylindrical in shape, and has a cyclonic centrifugal separation chamber 11 inside thereof and forms a spiral centrifugal flow field. The inlet 12 is located on the circumferential side of the spiral centrifugal device 10, the drain port 14 is provided at the upper end of the spiral centrifugal device 10, and the slag discharge port 13 is located at the lower end of the spiral centrifugal device 10. The slag flushing water enters the spiral centrifugal flow field from the inlet 12 at a flow rate of at least 1 m / s, forming a spiral centrifugal flow field. Figure 3 The spiral flow state shown in the figure. This spiral motion generates a centrifugal force field far greater than the acceleration due to gravity, enhancing the separation of the slag-water mixture. Under the action of centrifugal force, the water-slag solids and liquid in the slag-water mixture are subjected to different forces, causing them to move along different trajectories, achieving separation.

[0073] When the slag-flushing water is in the spiral centrifugal field, the solid density of the water-slag is relatively high, and it will be thrown toward the inner wall of the cyclonic centrifugal separation chamber 11. Under the combined action of gravity and centrifugal force, it moves downward along the inner wall and is eventually discharged through the drain port 14 at the bottom. Meanwhile, the water is concentrated toward the center under the action of centrifugal force. Since the pressure near the central axis is lower, the water flows upward due to the pressure difference and is discharged from the drain port 14 at the top, thus achieving efficient secondary slag-water separation. The discharged water is then sent to the horizontal sedimentation tank for further treatment.

[0074] Furthermore, a concentrator 20 is disposed below the spiral centrifugal device 10. This concentrator 20 is used to concentrate the water-slag solids after the secondary slag-water separation. The concentrator 20 comprises a housing 21, a first pneumatic valve 22, and a second pneumatic valve 23. The housing 21 is located below and connected to the slag discharge port 13. A concentrating chamber 211 is formed within the housing 21. The first pneumatic valve 22 is mounted at the upper end of the housing 21 for opening and closing the upper end of the housing 21. The second pneumatic valve 23 is mounted at the lower end of the housing 21 for opening and closing the lower end of the housing 21. A screw press 30 is disposed below the concentrator 20 for dehydrating the separated solids.

[0075] Specifically, in this embodiment, the concentrator 20 is disposed below the spiral centrifuge 10 and includes a housing 21 and a first pneumatic valve 22 and a second pneumatic valve 23 disposed at the upper and lower ends of the housing 21. The housing 21 is directly connected to the discharge port 13 of the spiral centrifuge 10. This arrangement ensures that the water-slag solids separated from the spiral centrifuge 10 can fall directly and smoothly into the concentrator 20, preventing the scattering and loss of solids during transportation and ensuring the continuity of the processing flow. The first pneumatic valve 22 is mounted at the upper end of the housing 21 and is responsible for opening and closing the upper end opening of the housing 21 to connect or isolate the discharge port 13 from the housing 21. When the spiral centrifuge 10 is discharging slag, the first pneumatic valve 22 opens, allowing the water-slag solids to enter the concentrating chamber 211. During the concentration process, the first pneumatic valve 22 closes to prevent solid leakage and the ingress of external impurities. The second pneumatic valve 23 is mounted at the lower end of the housing 21 to control the discharge of the water-slag solids after concentration. When the solids in the concentrating chamber 211 reach a preset level or the concentration time reaches the required level, the second pneumatic valve 23 opens, allowing the concentrated water slag solids to be discharged for subsequent processing. It should be noted that a level detector can be provided within the concentrating device 20 to detect the solids level within the housing 21. Alternatively, a timer can be set, such as automatically closing the first pneumatic valve 22 after opening for 30 seconds, or the opening time of the first pneumatic valve 22 can be set based on the volume of the housing 21.

[0076] It should be noted that in this embodiment, as the water slag solids continue to fall into the housing 21 of the concentrator 20, as the solids continue to accumulate, the gaps between the solids are gradually compressed under the influence of gravity, and some water naturally seeps out. This is because gravity causes the denser water slag solids to continuously sink, squeezing the upper solids, causing the water to move upward or outward, and be discharged from the gaps between the solids, achieving initial concentration. This initial concentration method based on gravity requires no additional power, is low-cost, simple and effective, and lays the foundation for subsequent more efficient concentration operations.

[0077] See also Figure 5 and Figure 7As shown, the screw press 30 is located below the concentrator 20 and is a key device for achieving deep concentration and dehydration of solid slag materials and increasing their utilization value. It is used to squeeze and dehydrate the water slag solids that have undergone preliminary concentration, so that the slag materials meet the requirements for subsequent direct transportation and disposal. The screw press 30 mainly consists of a motor 31, a screw shaft 32, spiral blades 33, a pressing barrel 34, a discharge port 35, a water outlet 36, and an emergency outlet 37. The motor 31 serves as a power source, driving the screw shaft 32 to rotate at high speed. The spiral blades 33 are tightly mounted on the screw shaft 32, and when the screw shaft 32 rotates, the spiral blades 33 rotate accordingly. The water slag solids discharged from the concentrator 20 enter the pressing barrel 34 and, driven by the spiral blades 33, move along the pressing barrel 34 toward the discharge port 35. During this process, the water-slag solids are further compressed under the powerful extrusion force. At the same time, the water in the water-slag solids is continuously squeezed out and discharged through the water outlet holes in the squeezing cylinder 34. The dehydrated water-slag solids are then discharged from the discharge port 35, completing the dehydration process. Emergency outlet 37 is opened for emergency drainage in the event of a large drainage volume or abnormal system operation. It is understood that the water discharged from both emergency outlet 37 and water outlet 36 can be sent to the agitation cage tank or to subsequent circulation.

[0078] The concentrator 20 and the screw press 30 work closely together to form a coherent processing flow. The concentrator 20 performs preliminary concentration on the water-slag solids after the secondary slag-water separation, increasing the concentration of the solids, reducing the processing capacity of the subsequent screw press 30, and lowering energy consumption. The water-slag solids that have undergone preliminary concentration fall into the screw press 30 in a relatively concentrated state. The screw press 30 then vigorously squeezes the preliminarily concentrated solids for further compression and dehydration. The collaborative work of the two not only improves overall processing efficiency but also ensures the final dehydration effect, reducing the volume of the water-slag solids and reducing the moisture content to less than 30%, meeting the standards for direct transportation and disposal.

[0079] Furthermore, the solid slag solids after the secondary slag-water separation are concentrated, including the following steps: closing the first pneumatic valve 22 and opening the second pneumatic valve 23; when the solids in the shell 21 accumulate to a preset height, closing the second pneumatic valve 23 and opening the first pneumatic valve 22 to discharge the deposits; filling with compressed air to forcibly discharge the remaining deposits; after the deposits are sent into the screw pressing device 30, closing the first pneumatic valve 22 again and opening the second pneumatic valve.

[0080] Specifically, after the spiral centrifugal device 10 completes the secondary slag-water separation, the slag solids enter the concentrating device 20 below through the slag discharge port 13. At this point, the first pneumatic valve 22 of the concentrating device 20 is closed. The second pneumatic valve 23 is opened, allowing the slag solids discharged from the spiral centrifugal device 10 to fall smoothly into the housing 21 of the concentrating device 20. Over time, the slag solids accumulate within the housing 21, gradually filling the concentrating chamber 211. A level detector is provided within the concentrating device 20 to monitor the accumulation height of the slag solids within the housing 21 in real time. When the solids accumulate to a preset height, indicating that the amount of solids in the concentrating chamber 211 has reached an appropriate processing capacity, the second pneumatic valve 23 is closed, preventing the entry of new slag solids. The first pneumatic valve 22 is then opened. This operation creates conditions for the subsequent discharge of the accumulated solids, allowing them to exit the concentrating device 20 smoothly under the action of gravity. After the first pneumatic valve 22 is opened, most of the accumulated slag solids are discharged from the concentrating device 20 by gravity. However, due to the presence of certain friction and adhesion between the water slag solids, some solids may remain. In order to ensure that the solids in the concentration device 20 can be discharged as completely as possible, compressed air is filled into the shell 21 at this time. The compressed air forms pressure in the shell 21, forcing the remaining deposits to be discharged. This process can effectively reduce solid residues, improve the processing efficiency of the concentration device 20, and avoid the residual solids from affecting the next concentration process. The discharged deposits are sent to the screw pressing device 30 for further dehydration. After the deposits are successfully sent to the screw pressing device 30, in order to prepare for the next solid concentration cycle, it is necessary to close the first pneumatic valve 22 again to prevent external impurities from entering the concentration chamber 211, and at the same time open the second pneumatic valve 23 so that a new batch of water slag solids separated by the spiral centrifugal device 10 can enter the concentration device 20 again to start a new round of solid concentration process. Through such a continuous cycle of operation, continuous and efficient concentration treatment of the water slag solids after the secondary slag-water separation is achieved.

[0081] Furthermore, the spiral centrifugal device 10 is provided with an exhaust port 15 and a pressure regulating port 16. The exhaust port 15 discharges the gas generated by the injection of compressed air into the cyclonic centrifugal separation chamber 11, thereby preventing the backflow of the slag flushing water due to excessive air pressure. The pressure regulating port 16 is used to regulate the negative pressure generated by the discharge of material in the cyclonic centrifugal separation chamber 11, thereby preventing the occurrence of vacuum siphoning, in which the material cannot fall naturally due to gravity.

[0082] It should be noted that this method can be configured for automated operation, and can be automatically controlled through electrical components PLC, in conjunction with touch screens, pneumatic solenoid valves and other devices to achieve full automated operation, reduce manual operation costs, and avoid the risks of manual operation in high-temperature environments on site, thereby ensuring safe production.

[0083] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformation made by using the contents of the present invention description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the scope of protection of the present invention.

Claims

1. A method for treating blast furnace slag, for treating blast furnace slag after separation from molten iron, characterized in that: include: Step 1: granulating and cooling the blast furnace slag; Step 2: The granulated and cooled slag is sent to a mixing cage pool for preliminary slag-water separation; Step 3: The separated slag flushing water is passed through a spiral centrifugal device for secondary slag-water separation; Step 4: The fluid after the secondary slag-water separation is filtered through a filter and then passes through a horizontal sedimentation tank, a water storage tank and a water absorption well in sequence to be recycled.

2. The blast furnace slag treatment method according to claim 1, wherein: After step 3 and before step 4, the method further includes: The solids are dehydrated.

3. The method for treating blast furnace slag according to claim 2, wherein: After step 3 and before dehydrating the solid, the method further comprises: The water slag solids after the secondary slag-water separation are concentrated.

4. The method for treating blast furnace slag according to claim 3, wherein: The spiral centrifugal device comprises a cyclonic centrifugal separation chamber and an inlet, a slag discharge port and a water outlet connected to the spiral centrifugal separation chamber; the water outlet is located at the upper end of the spiral centrifugal device, the slag discharge port is located at the lower end of the spiral centrifugal device, and the inlet is located below the water outlet.

5. The blast furnace slag treatment method according to claim 4, characterized in that: A concentrating device is provided below the spiral centrifugal device, and the concentrating device is used to concentrate the water-slag solids after the secondary slag-water separation.

6. The method for treating blast furnace slag according to claim 5, wherein: The concentrating device includes a shell, a first pneumatic valve and a second pneumatic valve; the shell is located below the slag discharge port and is connected to the slag discharge port; a concentrating chamber is formed in the shell, the first pneumatic valve is installed at the upper end of the shell, and is used to open and close the upper end of the shell; the second pneumatic valve is installed at the lower end of the shell, and is used to open and close the lower end of the shell.

7. The method for treating blast furnace slag according to claim 6, wherein: A screw pressing device is provided below the spiral centrifugal device, and the screw pressing device is used to achieve dehydration treatment of the solid.

8. The method for treating blast furnace slag according to claim 7, wherein: The solid concentration of the water slag solid after the secondary slag-water separation comprises: Close the first pneumatic valve and open the second pneumatic valve; When the solids in the housing accumulate to a preset height, the second pneumatic valve is closed and the first pneumatic valve is opened to discharge the accumulated solids; Fill with compressed air to force out the remaining deposits; After the deposits are fed into the screw pressing device, the first pneumatic valve is closed again and the second pneumatic valve is opened.

9. The method for treating blast furnace slag according to claim 8, wherein: The spiral centrifugal device is provided with an exhaust port, and the exhaust port is used to adjust the negative pressure generated by the discharge of the spiral pressing device.

10. The method for treating blast furnace slag according to claim 1, wherein: In the step 3, the flow rate of the separated slag flushing water entering the spiral centrifugal device is at least 1 m / s.

Images