Integrated reaction device for iron extraction from steel slag by chlorination and tail gas purification

Abstract

This invention discloses an integrated reaction device for chlorination and iron extraction from steel tailings and tail gas purification, relating to the field of steel tailings treatment technology. The device includes a chlorination reaction mechanism and a tail gas purification mechanism connected thereto. The tail gas purification mechanism sequentially includes a condensation component, a coalescence component, and a collection component. The coalescence component includes a first baffle channel with adjustable channel size and baffle members disposed within the first baffle channel. The baffle members include a first baffle plate and a second baffle plate. The surface of the second baffle plate has a surface structure for enhancing aerosol adhesion and coalescence, and the coalescence intensity of this surface structure changes with the size of the first baffle channel. This invention, through the synergistic effect of staged condensation and the variable baffle coalescence structure, enables metal chloride aerosols to achieve stable coalescence and collection conditions under different tail gas treatment volumes, realizing the integrated operation of the chlorination and iron extraction process from steel tailings and the tail gas purification process.

Description

Technical Field

[0001] This invention belongs to the technical field of steel tailings treatment, and more specifically, it relates to an integrated reaction device for chlorination and iron extraction and tail gas purification of steel tailings. Background Technology

[0002] Steel tailings treatment typically uses calcium chloride as a chlorinating agent to effectively separate metals such as iron and copper. However, this process inevitably produces highly corrosive and toxic waste gases containing chlorine, hydrogen chloride, and potentially heavy metals. The traditional segmented approach of "extracting iron first, then treating the tail gas" suffers from problems such as a long process, high investment, and the risk of leakage.

[0003] The existing technologies for treating steel tailings still have the following drawbacks:

[0004] In existing technologies, due to the lack of precise staged control in the exhaust gas cooling process, metal chlorides often condense disorderly in pipes, heat exchangers, or undesigned areas, resulting in uncontrollable white smoke generation locations. On the one hand, white smoke particles are mostly in the submicron range, with small particle size and weak inertia, making them difficult to effectively intercept through conventional spraying, baffles, or simple mist-catching structures, resulting in low collection efficiency. On the other hand, disordered condensation easily forms crystals and scale on the inner wall of pipes or heat exchange surfaces, leading to channel blockage, rapid increase in pressure drop, and seriously affecting the continuous operation capability of the system.

[0005] In existing technologies, most exhaust gas capture devices adopt fixed structural parameters, and the size of their baffle channels, the shape of their mist-catching elements, and their intensity of action are difficult to dynamically adjust after the design is completed. When the exhaust gas volume is large, in order to ensure capture efficiency, it is usually necessary to reduce the flow channel or increase the number of baffle stages, but this will cause a sharp increase in system pressure drop and accelerate scaling and clogging. On the other hand, when the exhaust gas volume is small, excessively strong baffles and capture effects can easily cause violent disturbances to the already formed liquid film or droplets, resulting in secondary entrainment and a decrease in capture efficiency.

[0006] Therefore, in view of this, we have studied and improved the existing structure and its shortcomings, and provided an integrated reaction device for chlorination and iron extraction from steel tailings and purification of tail gas, in order to achieve a more practical and valuable purpose. Summary of the Invention

[0007] This invention provides an integrated reaction device for chlorination and iron extraction from steel tailings and tail gas purification, which overcomes the above-mentioned defects in the prior art.

[0008] The purpose and effectiveness of this invention, a reaction device for chlorination and iron extraction from steel tailings and purification of tail gas, are achieved by the following specific technical means:

[0009] An integrated reaction device for chlorination and iron extraction from steel tailings and tail gas purification includes a chlorination reaction mechanism and a tail gas purification mechanism connected to the chlorination reaction mechanism. The tail gas purification mechanism includes:

[0010] A condensation assembly is used to stage-cool the tail gas from the chlorination reaction unit to form a metal chloride aerosol at a predetermined location. The condensation assembly includes a first condensation chamber and a second condensation chamber.

[0011] A coalescence assembly is disposed downstream of the condensation assembly. The coalescence assembly includes a first baffle channel and a baffle member disposed within the first baffle channel. The channel size of the first baffle channel is adjustable. The baffle member includes a first baffle plate and a second baffle plate. The surface of the second baffle plate is provided with a surface structure for enhancing aerosol adhesion and coalescence. The coalescence intensity of the surface structure changes with the change of the size of the first baffle channel.

[0012] A collection component, located downstream of the aggregation component, is used to collect and recover the aggregated metal chlorides.

[0013] In this scheme, by setting up a staged condensation component, a baffle coalescence component with variable channel size, and a baffle component surface structure that changes in synergy with it, metal chloride aerosols can obtain stable inertial impaction and surface adhesion conditions under different exhaust gas treatment conditions. This avoids the risks of increased pressure drop, scaling and blockage, and droplet re-entrainment caused by simply narrowing the flow channel, thereby achieving efficient purification of exhaust gas and resource recovery of metal chlorides.

[0014] Preferably, the surface structure of the second baffle is a micro-bump structure, a corrugated structure, or a composite structure of concave and convex parts.

[0015] In this scheme, by setting micro-protrusions, corrugations, or a composite structure of concave and convex surfaces on the surface of the second baffle, the effective contact area and roughness of the baffle surface are significantly increased, thereby improving the adhesion probability and initial aggregation efficiency of aerosol particles.

[0016] Preferably, the second baffle plate has a plurality of grooves spaced apart along its extension direction, and a top plate is slidably provided in each groove. One end of the top plate is provided with a V-shaped plate, and the other end of the top plate is fixedly connected to the first baffle plate. The two ends of the V-shaped plate are respectively connected to the two ends of the corresponding groove through elastic elements. The outer walls of the two ends of the V-shaped plate and the elastic elements are provided with a plurality of pairs of protrusions.

[0017] In this scheme, by setting a groove, top plate, V-shaped plate and elastic element to form a variable surface structure on the second baffle plate, the coalescence capability of the second baffle plate surface can be automatically adjusted according to the working conditions of the baffle channel, so as to ensure high coalescence efficiency while avoiding excessive disturbance to the formed liquid film.

[0018] Preferably, the aggregation component further includes a hydraulic telescopic rod for adjusting the size of the first baffle channel. The hydraulic telescopic rod is used to drive the first movable frame to move. The first movable frame is connected to a sliding plate. The sliding plate causes the first baffle and the second baffle to undergo relative displacement, so as to change the aggregation intensity of the surface structure of the second baffle while changing the channel size of the first baffle channel.

[0019] In this scheme, by setting a hydraulic telescopic rod to drive the first movable frame and the slide plate to move, the size of the baffle channel and the surface structure of the baffle plate are coordinated and adjusted, thereby improving the device's adaptability to changes in the amount of exhaust gas treated.

[0020] Preferably, the trapping assembly includes a swirling separation structure, which includes a swirling tube and a drive motor for driving the swirling tube to rotate.

[0021] In this scheme, by setting up a cyclone drum and a drive motor, centrifugal force is used to perform primary separation of the aerosols after aggregation, thereby improving the separation efficiency of large droplets and reducing the burden on the subsequent fog-collecting structure.

[0022] Preferably, the collection assembly further includes a second deflector channel disposed downstream of the cyclone separation structure, and the second deflector channel is provided with a plurality of first mist-collecting elements.

[0023] Preferably, the upper part of the agglomeration component is provided with a first spray component, which is used to rinse the surface of the second baffle plate, and the upper part of the collection component is provided with a second spray component, which is used to rinse the surface of the first mist eliminator.

[0024] Preferably, the condensation assembly is equipped with a first temperature sensor and a second temperature sensor to monitor the temperature of the first condensation chamber and the second condensation chamber, respectively. The first condensation chamber is equipped with a first heat exchanger, and the second condensation chamber is equipped with a second heat exchanger.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention employs a staged condensation structure, consisting of a first condensation chamber and a second condensation chamber, within the exhaust gas purification mechanism to cool the exhaust gas in stages and at different temperature zones. During operation, the exhaust gas is first cooled in the first condensation chamber to a temperature range that does not trigger the large-scale condensation of metal chlorides, preventing premature white smoke formation. Subsequently, it is further cooled in the second condensation chamber, allowing the metal chlorides to condense in a controlled manner within a designated area and form aerosols. This staged condensation process makes the location and state of white smoke formation predictable, preventing disordered condensation of metal chlorides in pipes or heat exchangers, thereby effectively reducing scaling, blockage, and abnormal pressure drop, and providing stable inlet conditions for subsequent aggregation and capture processes.

[0027] The present invention incorporates an adjustable first baffle channel within the coalescing assembly, allowing the baffle channel to adjust its structure according to changes in the exhaust gas throughput. When the exhaust gas throughput increases, a drive mechanism widens the first baffle channel to reduce local airflow velocity and decrease system pressure drop; conversely, when the exhaust gas throughput decreases, the first baffle channel narrows accordingly to ensure adequate airflow deflection strength. This structure and its adjustment mechanism enable the device to maintain a reasonable flow state under both high and low load conditions, avoiding excessive pressure drop or insufficient processing efficiency caused by a fixed channel design, thereby improving the system's adaptability to fluctuations in operating conditions.

[0028] This invention incorporates a surface structure with variable coalescence capability on the surface of the second baffle plate, and links this surface structure to changes in the baffle channel dimensions. During operation, when the first baffle channel widens to accommodate high-flow exhaust gas, the protrusion of the second baffle plate surface structure increases synchronously, thereby enhancing the inertial impaction and adhesion capabilities of aerosols on the baffle plate surface. Conversely, when the exhaust gas throughput decreases, the protrusion of the surface structure decreases accordingly to avoid excessive disturbance to the already formed liquid film. This synergistic adjustment method ensures that aerosols achieve matching coalescence conditions under different operating conditions, effectively avoiding fluctuations in coalescence efficiency and secondary entrainment problems caused by a single adjustment method. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] Figure 1 This is a schematic diagram of the first isometric structure of the present invention;

[0032] Figure 2 This is a schematic diagram of the second isometric structure of the present invention;

[0033] Figure 3 This is a schematic diagram of the first isometric structure of the exhaust gas purification mechanism in this invention;

[0034] Figure 4 This is a schematic diagram of the second isometric structure of the exhaust gas purification mechanism in this invention;

[0035] Figure 5 This is a schematic diagram of the third isometric structure of the exhaust gas purification mechanism in this invention;

[0036] Figure 6 This is a schematic diagram of the fourth isometric structure of the exhaust gas purification mechanism in this invention;

[0037] Figure 7 for Figure 3 A front view structural diagram;

[0038] Figure 8 for Figure 7 Schematic diagram of the cross-sectional structure at point AA;

[0039] Figure 9 for Figure 8 A magnified schematic diagram of the local structure at point E;

[0040] Figure 10 for Figure 8 A magnified schematic diagram of the local structure at point F;

[0041] Figure 11 for Figure 3 A top-view structural diagram;

[0042] Figure 12 for Figure 11 Schematic diagram of the cross-sectional structure at point BB;

[0043] Figure 13 This is a front view of the coalescing component in this invention.

[0044] Figure 14 for Figure 13 Schematic diagram of the cross-sectional structure at the CC section;

[0045] Figure 15 for Figure 14 A magnified schematic diagram of the local structure at point G;

[0046] Figure 16 for Figure 13 Schematic diagram of the cross-sectional structure at point DD.

[0047] Explanation of reference numerals in the attached figures:

[0048] 10. Chlorination reaction mechanism; 11. Tail gas purification mechanism; 12. Conveying pipe; 13. Control box; 14. Box body; 15. I-beam plate; 16. Partition plate; 17. First condensing chamber; 18. Second condensing chamber; 19. First mist-catching chamber; 20. Agglomeration chamber; 21. Second mist-catching chamber; 22. First heat exchanger; 23. Second heat exchanger; 24. First mounting plate; 25. First spray assembly; 26. First movable frame; 27. Telescopic pipe; 28. Slide plate; 29. ​​First connecting piece; 30. First baffle plate; 31. Second baffle plate; 32. Groove; 33. Top plate; 34. V-shaped plate; 35. Elastic element; 36. Protrusion; 37. Fixing strip; 38. 39. Second connecting piece; 40. Limiting frame; 41. Slider; 42. Hydraulic telescopic rod; 43. Movable block; 44. First limiting ring; 45. Second limiting ring; 46. Swirl tube; 47. Drive motor; 48. Recovery tank; 49. Recovery pipe; 50. Second mounting plate; 51. Second spray assembly; 52. Fixed frame; 53. Second movable frame; 54. First mist eliminator; 55. Discharge valve; 56. Second mist eliminator; 57. Fixed pipe; 58. First through hole; 59. Second through hole; 60. Sleeve; 61. First baffle channel; 62. Second baffle channel; 63. Third baffle channel; 64. First temperature sensor; 65. Second temperature sensor. Detailed Implementation

[0049] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0050] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0052] As attached Figure 1 To be continued Figure 16 As shown:

[0053] This invention provides an embodiment of an integrated reaction device for chlorination and iron extraction from steel tailings and tail gas purification.

[0054] See attached document Figure 1 To be continued Figure 16 The system includes a chlorination reaction unit 10 and an exhaust gas purification unit 11 connected to the chlorination reaction unit 10. The exhaust gas purification unit 11 includes:

[0055] A condensation assembly is used to stage-cool the tail gas from the chlorination reaction unit 10 and can form metal chloride aerosols at predetermined locations. The condensation assembly includes a first condensation chamber 17 and a second condensation chamber 18.

[0056] A coalescence assembly is located downstream of the condensation assembly. The coalescence assembly includes a first baffle channel 60 and a baffle member disposed within the first baffle channel 60. The channel size of the first baffle channel 60 is adjustable. The baffle member includes a first baffle plate 30 and a second baffle plate 31. The surface of the second baffle plate 31 is provided with a surface structure for enhancing aerosol adhesion and coalescence, and the coalescence intensity of the surface structure changes with the channel size of the first baffle channel 60.

[0057] The capture unit, located downstream of the aggregation unit, is used to capture and recover the aggregated metal chlorides.

[0058] Specifically, the tail gas containing metal chlorides generated by the chlorination reaction unit 10 enters the tail gas purification unit 11. First, it undergoes staged cooling through the first condensation chamber 17 and the second condensation chamber 18 in the condensation assembly, causing the metal chlorides to form an aerosol state at a predetermined location. Subsequently, the tail gas enters the agglomeration assembly, where the airflow is forced to change direction multiple times by the baffle members in the first baffle channel 60, causing the aerosol particles to collide with and adhere to the surface of the baffle members under inertial action. When the tail gas treatment volume changes, the channel size of the first baffle channel 60 is adjusted, and the agglomeration intensity of the surface structure of the baffle members is changed simultaneously, so that the aerosols always remain in agglomerable state. The agglomerated aerosols further enter the capture assembly, are captured and recovered, thereby achieving stable purification of the tail gas.

[0059] By setting up a staged condensation component, a baffle coalescence component with variable channel size, and a baffle component surface structure that changes in synergy with it, it is possible to achieve stable inertial impaction and surface adhesion conditions for metal chloride aerosols under different exhaust gas treatment conditions. This avoids the risks of increased pressure drop, scaling and blockage, and droplet re-entrainment caused by simply narrowing the flow channel, thereby achieving efficient purification of exhaust gas and resource recovery of metal chlorides.

[0060] Preferably, refer to the appendix Figure 1 To be continued Figure 4 A control box 13 is provided on the outer side of the chlorination reaction mechanism 10. The chlorination reaction mechanism 10 is connected to the tail gas purification mechanism 11 by a conveying pipe 12, and a regulating valve is installed inside the conveying pipe 12. The tail gas purification mechanism 11 includes a box body 14. The two ends of the box body 14 are provided with a condensation chamber and a first mist-catching chamber 19. The condensation chamber is separated into a first condensation chamber 17 and a second condensation chamber 18 by a partition plate 16. The middle part of the box body 14 is separated into a coalescence chamber 20 and a second mist-catching chamber 21 by an I-shaped plate 15. The interior of the coalescence chamber 20 is separated into an upper part, a middle part, and a lower part by two symmetrical first mounting plates 24.

[0061] Preferably, refer to the appendix Figure 14 To be continued Figure 16 A first movable frame 26 is slidably provided in the middle of the aggregation cavity 20. Two slide plates 28 are symmetrically slidably provided inside the first movable frame 26. Several pairs of first baffles 30 are provided on the side of the two slide plates 28 that are close to each other. A limiting frame 39 is fixed on both sides of each first baffle 30. A slider 40 is slidably provided inside the two limiting frames 39. A second baffle 31 is fixed on the side of the two sliders 40 that are far apart from each other. The surface of the second baffle 31 is provided with a surface structure for enhancing aerosol adhesion and aggregation.

[0062] Preferably, refer to the appendix Figure 14 To be continued Figure 16 The surface structure of the second baffle 31 is a micro-protrusion structure, a corrugated structure, or a composite structure of concave and convex.

[0063] Preferably, refer to the appendix Figure 14 To be continued Figure 16 The second baffle plate 31 has a number of grooves 32 spaced apart along its extension direction. A top plate 33 is slidably provided in each groove 32. A V-shaped plate 34 is provided at one end of the top plate 33. The other end of the top plate 33 is fixedly connected to the first baffle plate 30. The two ends of the V-shaped plate 34 are respectively connected to the two ends of the corresponding groove 32 through elastic members 35.

[0064] Specifically, the top plate 33, located within the groove 32 on the surface of the second baffle 31, forms a structural linkage with the first baffle 30. When the channel size of the first baffle channel 60 changes, the top plate 33 moves relative to the first baffle 30. The top plate 33 causes the V-shaped plate 34 on it to change position relative to the groove 32, resulting in deformation of the elastic elements 35 connected to both ends of the V-shaped plate 34. The deformation of the elastic elements 35 causes the V-shaped plate 34 and its outer protrusions 36 to form different degrees of protrusion on the surface of the second baffle 31, thereby changing the aerosol adhesion and coalescence capabilities of the baffle surface. Thus, a matching coalescence strength can be obtained under different exhaust gas flow conditions. By providing a variable surface structure formed by the groove 32, top plate 33, V-shaped plate 34, and elastic elements 35 on the second baffle 31, the coalescence capability of the surface of the second baffle 31 can be automatically adjusted according to the changes in the baffle channel operating conditions, ensuring high coalescence efficiency while avoiding excessive disturbance to the formed liquid film.

[0065] Preferably, refer to the appendix Figure 15 Several pairs of protrusions 36 are provided on the outer walls of both ends of the V-shaped plate 34 and on the elastic element 35.

[0066] Preferably, refer to the appendix Figure 6 Appendix Figure 8 A first deflection channel 60 is formed between the two slide plates 28 by a number of first deflection plates 30, and a telescopic tube 27 is provided between the two ends of the first movable frame 26 and the two ends of the middle part of the aggregation cavity 20.

[0067] Preferably, refer to the appendix Figure 14 Appendix Figure 16 A first connector 29 is provided between the two sliding plates 28 on opposite sides and the middle two side walls of the merging cavity 20. One end of the first connector 29 is rotatably connected to the middle side wall of the merging cavity 20, and the other end of the first connector 29 is rotatably connected to the sliding plate 28.

[0068] Preferably, refer to the appendix Figure 14 To be continued Figure 16 Several pairs of fixing strips 37 are fixedly provided on both sides of the inner side wall of the first movable frame 26. Each pair of fixing strips 37 slides in the first baffle 30 and slides in contact with the slide plate 28. A second connector 38 is provided between one end of the fixing strip 37 and the two second baffles 31 respectively. One end of the second connector 38 is rotatably connected to the fixing strip 37, and the other end of the second connector 38 is rotatably connected to the second baffle 31.

[0069] Preferably, refer to the appendix Figure 4 The upper part of the coalescence chamber 20 is equipped with a first spray assembly 25, which is used to rinse the surface of the second baffle plate 31. The lower part of the coalescence chamber 20 is used to collect liquid.

[0070] Specifically, during device operation, the first spray assembly 25 periodically sprays and washes the surface of the second baffle plate 31, flushing away and guiding the attached solid or liquid deposits to the lower recovery area, thereby keeping the baffle plate surface clean. By setting up the first spray assembly 25, scaling is concentrated and controlled, reducing the impact of scaling on the baffle plate surface on channel resistance and coalescence efficiency.

[0071] Preferably, refer to the appendix Figure 3 To be continued Figure 5 Appendix Figure 8 The collection assembly includes a swirling separation structure, which includes a swirling cylinder 45 and a drive motor 46 for driving the swirling cylinder 45 to rotate. A first limiting ring 43 and a second limiting ring 44 are symmetrically fixed inside the first mist-collecting chamber 19. The outer walls at both ends of the swirling cylinder 45 are rotatably connected to the inner wall of the first limiting ring 43 and the second limiting ring 44, respectively.

[0072] Specifically, the exhaust gas, after being processed by the agglomeration component, enters the cyclone separator 45. The drive motor 46 rotates the cyclone separator 45, causing the exhaust gas to form a rotating airflow. Under the action of centrifugal force, aerosol droplets migrate towards the inner wall of the cyclone separator 45 and aggregate. After forming larger droplets, they are released from the airflow under the action of gravity and collected, thus achieving preliminary separation. By setting up the cyclone separator 45 and the drive motor 46, centrifugal force is used to perform primary separation of the agglomerated aerosols, improving the separation efficiency of large droplets and reducing the burden on the subsequent mist-collecting structure.

[0073] Preferably, refer to the appendix Figure 3 To be continued Figure 8 Appendix Figure 12 The second condensation chamber 18 is connected to one end of the first baffle channel 60 via one of the telescopic tubes 27, and the first limiting ring 43 is connected to the other end of the first baffle channel 60 via the other telescopic tube 27. One end of the interior of the vortex tube 45 is connected to the first limiting ring 43, and the other end of the interior of the vortex tube 45 is connected to the second limiting ring 44. A recovery tank 47 is provided on the lower side of the first mist-collecting chamber 19, and the recovery tank 47 is connected to the second limiting ring 44.

[0074] Specifically, the exhaust gas, after being treated by the cyclone separator 45, enters the second deflection channel 61, where it changes direction multiple times. Aerosol droplets, under inertia, collide with the first mist-catching element 53, attaching and coalescing to form droplets that can detach under gravity, thus achieving further collection. By setting the second deflection channel 61 and the first mist-catching element 53 downstream of the cyclone separation structure, the exhaust gas flow path is extended, enhancing the interception and collection capability of fine droplets.

[0075] Preferably, refer to the appendix Figure 5 Appendix Figure 12The interior of the second mist-catching chamber 21 is divided into an upper part, a middle part, and a lower part by two symmetrical second mounting plates 49. The upper part of the second mist-catching chamber 21 is equipped with a second spray assembly 50, the lower part of the second mist-catching chamber 21 is used to collect chloride, and the lower part of the second mist-catching chamber 21 is connected to the recovery tank 47 by a recovery pipe 48.

[0076] Specifically, after the second spray assembly 50 rinses the internal structure of the collection assembly, the rinsing liquid carrying the collected metal chlorides flows into the recovery tank 47 through the recovery channel, achieving resource collection. The lower part of the second mist-catching chamber 21 is connected to the recovery tank 47, enabling centralized recovery of the spray liquid and agglomeration products, preventing metal chlorides from entering the waste liquid system.

[0077] Preferably, refer to the appendix Figure 5 To be continued Figure 10 A fixed frame 51 is fixedly provided at one end of the middle of the second mist-catching chamber 21, and a fixed pipe 56 is fixedly provided at the other end of the middle of the second mist-catching chamber 21. Several pairs of first mist-catching elements 53 are provided on the inner side walls of the fixed frame 51. A second baffle channel 61 is formed inside the fixed frame 51 through several pairs of first mist-catching elements 53. One end of the second baffle channel 61 is connected to the middle of the second mist-catching chamber 21, and the other end of the second baffle channel 61 is connected to the outside of the box 14 and is provided with a discharge valve 54.

[0078] Preferably, refer to the appendix Figure 8 To be continued Figure 12 One end of the fixed tube 56 is connected to the second limiting ring 44, and the other end of the fixed tube 56 is connected to the middle of the second mist-catching chamber 21 and has a first through hole 57. A second movable frame 52 is slidably provided on the outer wall of the fixed tube 56. Several pairs of second mist-catching elements 55 are provided on the inner two side walls of the second movable frame 52. A third baffle channel 62 is formed inside the second movable frame 52 through the several pairs of second mist-catching elements 55. One end of the third baffle channel 62 is connected to the middle of the second mist-catching chamber 21. A second through hole 58 is provided on one side of the middle of the fixed tube 56. A sleeve 59 is provided at one end of the inner wall of the second movable frame 52. The outer wall of the fixed tube 56 and the inner wall of the sleeve 59 are in sliding contact.

[0079] Preferably, refer to the appendix Figure 9 A hydraulic telescopic rod 41 is installed at one end of the middle of the coalescence cavity 20. The extended end of the hydraulic telescopic rod 41 is provided with a movable block 42. The first movable frame 26 and the second movable frame 52 are fixedly connected by the movable block 42. The movable block 42 slides in contact with the middle of the I-shaped plate 15.

[0080] Preferably, refer to the appendix Figure 11The condensing assembly is equipped with a first temperature sensor 63 and a second temperature sensor 64 to monitor the temperature of the first condensing chamber 17 and the second condensing chamber 18. The first condensing chamber 17 is equipped with a first heat exchanger 22, and the second condensing chamber 18 is equipped with a second heat exchanger 23.

[0081] Specifically, the first temperature sensor 63 and the second temperature sensor 64 monitor the temperature status of the first condensing chamber 17 and the second condensing chamber 18, respectively. Based on the monitoring results, the cooling conditions are adjusted so that the exhaust gas sequentially undergoes a process of non-condensation and controlled condensation, thereby improving the system's operational stability. By setting the first temperature sensor 63 and the second temperature sensor 64, real-time monitoring of the condensation temperature zone is achieved, ensuring that metal chlorides are generated in a controlled manner within the designated area.

[0082] Specific usage of this invention:

[0083] Calcium chloride is typically used as a chlorinating agent in the treatment of steel tailings to achieve selective separation of metals such as iron and copper. However, the high-temperature chlorination reaction inevitably produces highly corrosive and toxic tail gases containing chlorine, hydrogen chloride, and potentially heavy metal chlorides. Traditional processes often employ a segmented treatment method of "extracting iron first, then treating the tail gas," which is not only lengthy and requires significant equipment investment, but also poses a risk of leakage during tail gas transportation and switching, making it difficult to meet safety and stability requirements.

[0084] I. Pretreatment and Chlorination Reaction

[0085] First, steel tailings and calcium chloride are mixed in a predetermined ratio and then granulated.

[0086] Subsequently, the granulated material is fed into the chlorination reaction unit 10, where a chlorination reaction is carried out at a high temperature of about 1000 to 1250°C. During this process, gaseous chlorides of the target metal are generated, along with unreacted chlorine gas (Cl2) and hydrogen chloride (HCl) as tail gases.

[0087] II. Staged condensation and controlled white smoke generation

[0088] The exhaust gas generated in the chlorination reaction unit 10 enters the exhaust gas purification unit 11 through the delivery pipe 12, and then enters the first condensation chamber 17 and the second condensation chamber 18 in sequence to achieve graded condensation control.

[0089] Within the first condensation chamber 17, the exhaust gas is cooled by heat exchange through the first heat exchanger 22, reducing its temperature to below the reaction temperature but still above the temperature threshold for the large-scale condensation of metal chlorides. Within this temperature range, the metal chlorides mainly remain in a gaseous state or undergo only minimal nucleation, without significant condensation or crystallization, thus achieving cooling without triggering the generation of white smoke.

[0090] The exhaust gas, after being processed by the first condensation chamber 17, further enters the second condensation chamber 18, where it is further cooled by the second heat exchanger 23. This brings the exhaust gas temperature into the condensation temperature zone of metal chlorides, where the metal chloride vapor undergoes controlled condensation to form submicron-sized metal chloride aerosols, i.e., white smoke precursors. This staged condensation method ensures that white smoke is generated at a designated location, preventing its disorderly generation in pipelines or undesigned areas, and providing stable and predictable inlet conditions for subsequent aerosol shaping and capture.

[0091] III. Aerosol Shaping and Aggregation Enhancement

[0092] The metal chloride aerosol generated in the second condensation chamber 18 is transported to one end of the first baffle channel 60 via one of the telescopic pipes 27. After the exhaust gas enters the first baffle channel 60, it is forced to change its flow direction multiple times under the guidance of the baffle structure.

[0093] During multiple sharp turns, aerosol particles cannot turn synchronously with the airflow due to inertia, resulting in inertial impacts and adhesion to the surface of the second baffle plate 31. The attached aerosol particles continue to aggregate and grow on the liquid film or droplets formed on the surface of the second baffle plate 31, gradually forming larger droplets that can flow stably downwards under gravity. The droplets flow along the surface of the second baffle plate 31 into the lower part of the aggregation cavity 20 and are discharged in a concentrated manner.

[0094] The surface of the second baffle 31 is provided with a surface structure to enhance the adhesion and aggregation of aerosols. Under the synergistic effect of multiple airflow reversals and impacts, the collision frequency between submicron-sized aerosols is increased, transforming fine particles that are difficult to capture directly into micron-sized droplets that can be captured.

[0095] Meanwhile, the first spray assembly 25 periodically sprays the second baffle plate 31 in the first baffle channel 60. The spray medium washes away and diverts the impurities and deposits attached to the surface of the second baffle plate 31, thereby solving the problem that the white smoke particles are small and difficult to capture with conventional washing. This creates good physical capture conditions for the subsequent fog-catching structure and reduces the dependence on spray volume and chemical agents.

[0096] IV. Multi-stage collection and resource recovery

[0097] After agglomeration treatment, the exhaust gas enters the cyclone cylinder 45, where it forms a rotating airflow driven by the drive motor 46. Under the action of centrifugal force and inertial collision, the aerosol droplets migrate towards the inner wall of the cyclone cylinder 45 and further agglomerate with the liquid film on the wall. After the particle size increases, they are collected by gravity and fall into the second limiting ring 44 and into the recovery tank 47.

[0098] The exhaust gas after cyclone separation enters the second mist-catching chamber 21 through the fixed pipe 56. The exhaust gas then passes sequentially through the second baffle channel 61 and the first mist-catching element 53. Droplets continue to be intercepted, adhered to, and coalesced on the surface of the mist-catching element. Once they reach a certain size, they detach and enter the lower part of the second mist-catching chamber 21, and are then transported to the recovery tank 47 via the recovery pipe 48. The second spray assembly 50 periodically rinses the first mist-catching element 53, and the rinsing liquid is also recovered to the recovery tank 47, achieving centralized recovery of the spray liquid and coalescing products, and preventing metal chlorides from entering the alkaline washing waste liquid system.

[0099] After being captured, the exhaust gas eventually enters the alkaline washing system through the discharge valve 54 for treatment, and the purified exhaust gas meets the emission standards.

[0100] V. Synergistic Adjustment Process under Different Exhaust Gas Treatment Capacities

[0101] The amount of exhaust gas entering the exhaust gas purification mechanism 11 is adjusted by a regulating valve installed in the delivery pipe 12. When the exhaust gas treatment volume increases, the system controls the hydraulic telescopic rod 41 to extend, driving the movable block 42 to move, thereby driving the first movable frame 26 and the second movable frame 52 to move synchronously.

[0102] The first movable frame 26 moves towards the second condensing chamber 18 within the middle of the coalescing chamber 20, pulling the sliding plates 28 apart via the first connecting member 29. This increases the distance between the two sliding plates 28, widening the first baffle channel 60 to accommodate a larger exhaust gas flow. Simultaneously, the telescopic tube 27 ensures that the first baffle channel 60 remains in communication with the second condensing chamber 18 and the first limiting ring 43.

[0103] As the first baffle channel 60 widens, the second baffle plates 31 are brought closer together by the second connector 38, causing the top plate 33 on the surface of the second baffle plate 31 to push the V-shaped plate 34 and stretch the elastic member 35, thereby increasing the protrusion of the surface structure of the second baffle plate 31 to compensate for the insufficient inertial impact caused by the widening of the channel and ensure that it still has stable coalescence efficiency under high exhaust gas volume conditions.

[0104] When the exhaust gas treatment volume decreases, the first baffle channel 60 shrinks accordingly, and the protrusion of the surface structure of the second baffle plate 31 decreases synchronously, so that the formed droplets can flow stably down the surface of the baffle plate and avoid excessive disturbance causing droplet re-entrainment.

[0105] By coordinating the channel size of the first baffle channel 60 and the aggregation capacity of the surface structure of the second baffle plate 31, the metal chloride aerosol can obtain matching inertial impaction and surface adhesion conditions under different exhaust gas treatment conditions, thereby avoiding large fluctuations in aggregation efficiency with changes in operating conditions and effectively reducing the risk of pressure drop increase and crystallization blockage.

[0106] Simultaneously, the first movable frame 26 and the second movable frame 52 move synchronously. The second movable frame 52 moves towards the fixed frame 51 in the middle of the second mist-catching chamber 21. The movement of the second movable frame 52 drives the sleeve 59 to move. Since the sleeve 59 is fitted on the outer wall of the fixed tube 56, the sleeve 59 slides on the outer wall of the fixed tube 56, thereby blocking the first through hole 57 and connecting the second through hole 58 with the third baffle channel 62. At this time, the exhaust gas after coalescence in the vortex tube 45 is transported to the fixed tube 56 through the second limiting ring 44. The exhaust gas in the fixed tube 56 is transported to the third baffle channel 62 through the second through hole 58. Several second mist-catching elements 55 intercept and adhere the droplets and promote their continued coalescence to form drainable droplets. The exhaust gas in the third deflection channel 62 is transported to the second deflection channel 61 through the middle of the second mist-catching chamber 21, thereby using a number of first mist-catching elements 53 to intercept and adhere the droplets and promote their continued aggregation to form drainable droplets, so as to extend the channel for intercepting droplets.

[0107] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

Claims

1. An integrated reaction device for chlorination and iron extraction from steel tailings and tail gas purification, comprising a chlorination reaction mechanism (10) and a tail gas purification mechanism (11) connected to the chlorination reaction mechanism (10), characterized in that, The exhaust gas purification mechanism (11) includes: A condensation assembly is used to stage-cool the tail gas from the chlorination reaction unit (10) to form a metal chloride aerosol at a predetermined location. The condensation assembly includes a first condensation chamber (17) and a second condensation chamber (18). A coalescence assembly is disposed downstream of the condensation assembly. The coalescence assembly includes a first baffle channel (60) and a baffle member disposed within the first baffle channel (60). The channel size of the first baffle channel (60) is adjustable. The baffle member includes a first baffle plate (30) and a second baffle plate (31). The surface of the second baffle plate (31) is provided with a surface structure for enhancing aerosol adhesion and coalescence. The coalescence intensity of the surface structure changes with the channel size of the first baffle channel (60). A collection component, located downstream of the aggregation component, is used to collect and recover the aggregated metal chlorides.

2. The integrated reaction device for chlorination and iron extraction from steel tailings and purification of tail gas according to claim 1, characterized in that: The surface structure of the second baffle (31) is a micro-bump structure, a corrugated structure, or a concave-convex composite structure.

3. The integrated reaction device for chlorination and iron extraction from steel tailings and purification of tail gas according to claim 1, characterized in that: The second baffle plate (31) has a plurality of grooves (32) spaced apart along its extension direction. A top plate (33) is slidably provided in each groove (32). One end of the top plate (33) is provided with a V-shaped plate (34). The other end of the top plate (33) is fixedly connected to the first baffle plate (30). The two ends of the V-shaped plate (34) are respectively connected to the two ends of the corresponding groove (32) through elastic members (35).

4. The integrated reaction device for chlorination and iron extraction from steel tailings and purification of tail gas according to claim 3, characterized in that: The outer walls at both ends of the V-shaped plate (34) and the elastic element (35) are provided with several pairs of protrusions (36).

5. The integrated reaction device for chlorination and iron extraction from steel tailings and purification of tail gas according to claim 1, characterized in that: The aggregation assembly also includes a hydraulic telescopic rod (41) for adjusting the channel size of the first deflector channel (60), the hydraulic telescopic rod (41) for driving the first movable frame (26) to move.

6. The integrated reaction device for chlorination and iron extraction from steel tailings and purification of tail gas according to claim 5, characterized in that: The first movable frame (26) is connected to the slide plate (28), and the slide plate (28) causes the first baffle plate (30) and the second baffle plate (31) to move relative to each other, so as to change the aggregation intensity of the surface structure of the second baffle plate (31) while changing the channel size of the first baffle channel (60).

7. The integrated reaction device for chlorination and iron extraction from steel tailings and purification of tail gas according to claim 1, characterized in that: The trapping assembly includes a swirling separation structure, which includes a swirling tube (45) and a drive motor (46) for driving the swirling tube (45) to rotate.

8. The integrated reaction device for chlorination and iron extraction from steel tailings and purification of tail gas according to claim 7, characterized in that: The collection assembly also includes a second deflector channel (61) disposed downstream of the cyclone separation structure, and the second deflector channel (61) is provided with a plurality of first mist-catching elements (53).

9. The integrated reaction device for chlorination and iron extraction from steel tailings and purification of tail gas according to claim 8, characterized in that: The upper part of the agglomeration component is provided with a first spray component (25), which is used to rinse the surface of the second baffle (31). The upper part of the collection component is provided with a second spray component (50), which is used to rinse the surface of the first mist collector (53).

10. The integrated reaction device for chlorination and iron extraction from steel tailings and purification of tail gas according to claim 1, characterized in that: The condensation assembly is equipped with a first temperature sensor (63) and a second temperature sensor (64) to monitor the temperature of the first condensation chamber (17) and the second condensation chamber (18). The first condensation chamber (17) is equipped with a first heat exchanger (22), and the second condensation chamber (18) is equipped with a second heat exchanger (23).

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