A system for selective extraction of calcium ions from alkali residue and recovery by carbonation

Abstract

This invention discloses a selective extraction and carbonation recovery system for calcium ions from alkaline residue in the field of calcium ion recovery technology. The system includes a vessel, a stirring shaft, a guide tube, and a combined stirring paddle. The guide tube is fixed in the middle of the vessel's inner cavity, with an upward channel running through its inner side and a downward channel between its outer side and the inner wall of the vessel. A material sedimentation zone is formed between its bottom and the bottom of the vessel. The stirring shaft rotates synchronously with the combined stirring paddle to drive its rotation. The top of the stirring shaft extends outside the vessel and is equipped with a driving component. The combined stirring paddle includes a spiral guide vane and a centrifugal structure. The spiral guide vane is located at the bottom of the guide tube, and the centrifugal structure is located at the top port of the guide tube. Through the coordinated operation of the combined stirring paddle and the guide tube, a stable closed-loop circulating flow field is formed, solving the problem of continuous sedimentation and accumulation of alkaline residue due to poor circulation, and insufficient contact between calcium ions and extraction / carbonation reagents.

Description

Technical Field

[0001] This invention relates to the field of calcium ion recovery technology, specifically to a selective extraction and carbonation recovery system for calcium ions from alkaline residue. Background Technology

[0002] Currently, the industry mainly uses extraction, carbonation, and precipitation methods to recover and treat calcium ions from alkali residue. Among these, the combination of extraction and carbonation has become the mainstream treatment method due to its high recovery efficiency and high resource utilization.

[0003] However, in the existing process of selective extraction and carbonation recovery of calcium ions from alkaline residue, the core reaction equipment is a stirred reactor. Simple stirring can only achieve local material mixing and cannot drive the material to form an up-and-down circulation. As a result, the alkaline residue at the bottom of the reactor continues to settle and accumulate due to poor circulation. The calcium ions do not come into sufficient contact with the extraction and carbonation reagents, which not only greatly reduces the recovery efficiency and causes reagent waste, but also results in extremely poor mass transfer due to insufficient circulation, which cannot meet the reaction requirements of selective extraction and carbonation of calcium ions. Summary of the Invention

[0004] The technical solution of this invention is to provide a selective extraction and carbonation recovery system for calcium ions in alkali residue. Through the coordinated operation of a combined stirring paddle and a guide tube, a stable closed-loop circulating flow field is formed, which solves the problem of continuous precipitation and accumulation of alkali residue due to poor circulation, and insufficient contact between calcium ions and extraction and carbonation reagents.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a selective extraction and carbonation recovery system for calcium ions in alkaline residue, characterized in that it includes a vessel body, a stirring shaft, a guide tube, and a combined stirring paddle; The guide tube is fixed in the middle of the inner cavity of the vessel, with an upward channel forming on its inner side and a downward channel forming between its outer side and the inner wall of the vessel, and a material sedimentation zone forming between its bottom and the bottom of the vessel. The stirring shaft rotates synchronously with the combined stirring paddle to drive the combined stirring paddle to rotate, and the top of the stirring shaft extends out of the vessel body and is equipped with a driving component. The combined agitator includes helical guide blades and a centrifugal structure; The spiral guide vanes are located at the bottom of the guide tube and are used to simultaneously lift the material and liquid in the sedimentation zone at the bottom of the vessel into the rising channel. The centrifugal structure is located at the top port of the guide tube and is used to uniformly throw the material and liquid discharged from the rising channel into the falling channel radially, so that the material and liquid flow from top to bottom along the falling channel and fall back to the sedimentation area, forming a closed-loop circulating flow field.

[0006] As a further embodiment of the present invention, a scraper is also included, which is rotatably disposed in contact with the inner side of the bottom of the vessel body; a speed regulating component and a sensing component are disposed between the scraper and the stirring shaft, the sensing component is used to sense the axial force on the scraper and convert it into axial displacement; the speed regulating component adaptively adjusts the rotation speed of the scraper according to the amount of axial displacement generated by the sensing component.

[0007] As a further embodiment of the present invention, the sensing component includes a pressure sensor and a telescopic rod. The pressure sensor is installed on the side wall of the scraper, and the telescopic rod is installed between the scraper and the speed regulating component to convert the axial force on the scraper into axial displacement.

[0008] As a further aspect of the present invention, the sensing component includes an upper shaft, a lower shaft, a driving member, and a driven member; The bottom of the upper shaft is fixedly provided with a rotating sleeve, and the inner wall of the rotating sleeve is fixedly provided with a protrusion. The top of the upper shaft is connected to the output end of the speed regulating component and rotates accordingly. The bottom of the lower shaft is fixedly connected to the scraper, and a connecting column is fixedly provided at the top of the lower shaft. The outer wall of the connecting column is provided with a spiral groove that slides with the protrusion. The drive component is rotatably mounted on the upper shaft and has a slide rail at the bottom. The outer wall of the rotating sleeve is axially slidingly engaged with the slide rail via a flat key. The driven member is fixedly mounted on the top of the lower shaft, and a vertical support is provided on the top of the driven member. An elastic element is provided between the support and the slide rail.

[0009] As a further embodiment of the present invention, the speed regulating component includes a speed regulating gear ring, a plurality of speed regulating gears, a plurality of idler wheels, and an elastic connecting member; The speed regulating gear ring is coaxially fixed on the stirring shaft; Several speed-regulating gears are coaxial with the speed-regulating gear ring and arranged vertically. Each speed-regulating gear has a slot on its inner side, and the diameter of the speed-regulating gear decreases sequentially from top to bottom. The idler wheel is positioned between the speed regulating gear ring and the speed regulating gear to transmit power to the stirring shaft. The elastic connector is divided into upper and lower parts, which slide together axially. A return spring is provided between the two parts. A snap-fit ​​block that can engage with the slot is installed on the outer side of the upper part of the elastic connector. Both ends of the snap-fit ​​block are provided with chamfers. The bottom of the elastic connector is connected to the sensing component to receive the axial displacement of the sensing component and drive the snap-fit ​​block to engage with different slots to achieve speed adjustment.

[0010] As a further embodiment of the present invention, the spiral guide blades and the centrifugal structure are both fixedly connected to the stirring shaft and rotate synchronously with the stirring shaft.

[0011] As a further embodiment of the present invention, the centrifugal structure is a centrifugal impeller, a transmission shaft sleeve is provided between the centrifugal impeller and the spiral guide blades, a drive gear is installed on the top of the centrifugal impeller, and a transmission gear is provided between the drive gear and the speed regulating gear ring to realize power transmission.

[0012] As a further embodiment of the present invention, a temperature regulating sleeve is provided on the outer side of the vessel body, and an inlet pipe and an outlet pipe are installed on the side wall of the temperature regulating sleeve to realize the circulation of the temperature regulating medium.

[0013] Compared with the prior art, the beneficial effects of the present invention are: In this invention, a stable closed-loop circulating flow field is formed through the synergistic cooperation of a combined stirring paddle and a guide tube, utilizing the lifting effect of the spiral guide vanes and the dispersing effect of the centrifugal structure. This completely changes the shortcomings of simple stirring without effective circulation in existing technologies, enabling the alkaline slag material in the material sedimentation zone at the bottom of the reactor to be continuously lifted and circulated, preventing material accumulation that would prevent it from participating in the reaction. The closed-loop circulating flow field achieves comprehensive and thorough mixing of the material with the extractant and carbonation reagent, significantly increasing the contact area and contact time between calcium ions and reagents. This effectively solves the problem of poor mass transfer in existing technologies, significantly improving the selective extraction rate of calcium ions and the carbonation recovery efficiency in alkaline slag, and reducing reagent waste. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the overall cross-sectional structure of the present invention; Figure 3 For the present invention Figure 2 Enlarged structural diagram at point A in the middle; Figure 4 This is a schematic cross-sectional view of the speed regulating component of the present invention; Figure 5 For the present invention Figure 4 Enlarged structural diagram at point B; Figure 6 This is a schematic cross-sectional view of the sensing component of the present invention; Figure 7 For the present invention Figure 6 Enlarged structural diagram at point C; Figure 8 This is a schematic diagram of the connecting column and its connection relationship structure according to the present invention; Figure 9 This is a schematic diagram of the telescopic rod and its connection structure according to the present invention; The attached diagram lists the components represented by each number as follows: 1. Kettle body; 11. Stirring shaft; 12. Flow guide tube; 13. Temperature regulating sleeve; 14. Water inlet pipe; 15. Water outlet pipe; 21. Rising channel; 22. Falling channel; 23. Sedimentation zone; 24. Spiral guide vane; 25. Centrifugal structure; 26. Drive gear; 27. Transmission gear; 28. Transmission shaft sleeve; 3. Scraper; 4. Speed ​​regulating component; 41. Speed ​​regulating gear ring; 42. Speed ​​regulating gear; 43. Idler wheel; 44. Elastic connecting part; 45. Slot; 46. Return spring; 47. Snap-fit ​​block; 5. Sensing component; 51. Upper shaft; 52. Lower shaft; 53. Driven part; 54. Rotating sleeve; 55. Protrusion; 56. Connecting column; 57. Spiral groove; 59. Telescopic rod; 6. Driving component; 61. Slide rail; 62. Flat key; 63. Vertical rod; 64. Elastic part; 7. Driving component. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figures 1-9 The present invention provides a technical solution comprising a vessel body 1, a stirring shaft 11, a guide tube 12, and a combined stirring paddle, the specific structure, connection relationship, and working principle of which are as follows: The vessel body 1 is a cylindrical sealed structure used to contain alkaline residue, extractant and carbonation reagent to achieve selective extraction and carbonation reaction of calcium ions; The guide tube 12 is fixed in the middle of the inner cavity of the vessel body 1 by a bracket. The guide tube 12 is a cylindrical hollow structure. An upward channel 21 is formed on its inner side, and an annular downward channel 22 is formed between its outer side and the inner wall of the vessel body 1. A space is reserved between the bottom of the guide tube 12 and the bottom of the vessel body 1 to form a material sedimentation zone 23, which is used to accommodate the alkaline residue material that precipitates during the reaction process, so as to avoid the material from directly accumulating at the bottom of the vessel body 1 and being unable to participate in the reaction. The stirring shaft 11 is coaxially arranged at the central axis of the vessel body 1. The bottom of the stirring shaft 11 extends to the vicinity of the bottom of the guide tube 12, and the top of the stirring shaft 11 passes through the sealing cover at the top of the vessel body 1 and extends to the outside of the vessel body 1. A driving component 7 is installed on the top of the stirring shaft 11. In this embodiment, the driving component 7 is preferably a geared motor. The output end of the geared motor is fixedly connected to the top of the stirring shaft 11 and is used to drive the stirring shaft 11 to rotate at a uniform speed, providing power for the stirring and circulation of the entire system. The combined stirring paddle is coaxially arranged with the stirring shaft 11 and rotates synchronously. The combined stirring paddle includes a spiral guide blade 24 and a centrifugal structure 25. The spiral guide blade 24 is located at the bottom of the guide tube 12 and above the material sedimentation zone 23. The outer diameter of the spiral guide blade 24 is adapted to the inner diameter of the bottom of the guide tube 12, and its edge is in clearance fit with the inner wall of the guide tube 12. It is used to synchronously lift the material and liquid in the sedimentation zone 23 at the bottom of the vessel 1 into the rising channel 21 to avoid the problem of material sedimentation and accumulation, which prevents it from participating in the reaction. Centrifugal structure 25 is located at the top port of guide tube 12 and is used to uniformly throw the material and liquid discharged from the rising channel 21 radially into the falling channel 22, so that the material and liquid flow from top to bottom along the falling channel 22 and fall back to the material sedimentation area 23, forming a closed-loop circulating flow field; realizing the comprehensive circulation and mixing of materials, solving the problem that simple stirring in the existing technology cannot form an effective circulation, and ensuring that calcium ions and reagents are in full contact.

[0018] In summary, through the coordinated operation of the combined stirring paddle and the guide tube 12, and with the lifting effect of the spiral guide vane 24 and the dispersing effect of the centrifugal structure 25, a stable closed-loop circulating flow field is formed. This completely changes the shortcomings of the existing technology where simple stirring does not result in effective circulation. It allows the alkaline residue material in the material sedimentation zone 23 at the bottom of the vessel 1 to be continuously lifted and circulated, preventing material accumulation that would prevent it from participating in the reaction. The closed-loop circulating flow field achieves comprehensive and thorough mixing of the material with the extractant and carbonation reagent, significantly increasing the contact area and contact time between calcium ions and reagents. This effectively solves the problem of poor mass transfer in the existing technology, significantly improves the selective extraction rate of calcium ions in the alkaline residue and the carbonation recovery efficiency, and reduces reagent waste.

[0019] See Figure 2 The specific operating procedure is as follows: Open the top sealing cover of the vessel body 1, and slowly add the alkaline residue, extractant and carbonation reagent into the vessel body 1. The amount of material added should not exceed the top of the guide tube 12 and should not be lower than the bottom of the guide tube 12 to avoid the formation of the circulating flow field due to too much or too little material. After filling, close the sealing cover and lock it.

[0020] Start the drive component 7 (in this embodiment, it is a geared motor). The output end of the drive component 7 drives the stirring shaft 11 to rotate at a constant speed. The stirring shaft 11 synchronously drives the combined stirring paddle to ensure that the spiral guide blade 24, the centrifugal structure 25 and the stirring shaft 11 rotate synchronously.

[0021] The spiral guide vane 24 rotates, and using the lifting force of its spiral structure, it simultaneously lifts the alkaline residue and mixed liquid in the material sedimentation zone 23 at the bottom of the vessel 1 to the rising channel 21 inside the guide tube 12. The liquid level in the rising channel 21 gradually rises until it is discharged from the top port of the guide tube 12. The centrifugal structure 25 at the top port of the guide tube 12 rotates synchronously, and the discharged material and liquid are evenly thrown radially into the annular descending channel 22 between the outer side of the guide tube 12 and the inner wall of the vessel 1. Under the influence of gravity, the materials and liquids flow from top to bottom along the descending channel 22, eventually falling back to the material settling zone 23 at the bottom of the vessel 1, completing one cycle. After continuous operation, a stable closed-loop circulating flow field is formed, and the alkaline residue material in the material settling zone 23 is continuously lifted to the ascending channel 21, where it is fully mixed and contacted with the extractant and carbonation reagent, ensuring the efficient selective extraction and carbonation reaction of calcium ions. During the process, the flow state of the materials is observed to avoid channel blockage. After the calcium ion extraction and carbonation reaction is completed, first turn off the drive component 7, stop the rotation of the stirring shaft 11 and the combined stirring paddle, and after the material in the vessel 1 has settled, open the sealing cover and discharge the reaction product and remaining material; clean the residual material on the surface of the vessel 1, the guide tube 12 and the combined stirring paddle to prepare for the next use.

[0022] As a further embodiment of the present invention, the system also includes a scraper 3, which is rotatably mounted to fit the inner side of the bottom of the vessel body 1. The scraper 3 is preferably made of wear-resistant rubber to avoid scratching the inner wall of the vessel body 1 and to improve the fit. It is used to clean the material in the material sedimentation area 23. A speed regulating component 4 and a sensing component 5 are provided between the scraper 3 and the stirring shaft 11. The sensing component 5 is used to sense the axial force on the scraper 3 and convert the axial force into axial displacement. The speed regulating component 4 receives the axial displacement generated by the sensing component 5 and adaptively adjusts the rotation speed of the scraper 3. The high-speed rotating scraper 3 is prone to breaking up agglomerated materials, which may produce fine impurities that affect the purity of the extraction reaction, or cause agglomerated materials to get stuck on the scraper 3. After reducing the rotation speed, the scraper 3 can slowly and steadily push the agglomerated materials, allowing them to gradually enter the rising channel 21 to participate in the circulation. This not only avoids the agglomerated materials getting stuck and damaging the scraper 3, but also allows the agglomerated materials to be fully dispersed and in contact with the reagent, taking into account both the cleaning effect and the reaction purity, and indirectly improving the calcium ion recovery efficiency.

[0023] As a further embodiment of the present invention, the sensing component 5 includes a pressure sensor and a telescopic rod 59; the pressure sensor is installed on the side wall of the scraper 3 and faces the side of the scraper 3 in the direction of rotation, and is used to sense in real time the axial resistance that the scraper 3 experiences when it rotates, i.e. the resistance generated by material sedimentation. The telescopic rod 59 is installed between the scraper 3 and the speed regulating component 4 to convert the axial force on the scraper 3 into axial displacement and transmit the displacement to the speed regulating component 4, providing a signal for adjusting the speed of the speed regulating component 4.

[0024] When the amount of sediment increases and the resistance sensed by the pressure sensor exceeds the preset threshold, the axial force on scraper 3 increases synchronously, pushing the telescopic rod 59 to extend and retract axially. This precisely converts the axial force on scraper 3 into axial displacement, which is then directly transmitted to the bottom of the elastic connector 44 of the speed regulating component 4. After receiving the axial displacement transmitted by the telescopic rod 59, the speed regulating component 4 reduces the speed of scraper 3. In addition, by setting the resistance threshold of the pressure sensor, it can adapt to the sedimentation of alkaline residue with different concentrations and agglomeration degrees, flexibly adjusting the extension and retraction of the telescopic rod 59, thereby precisely controlling the speed adjustment range of the speed regulating component 4. This ensures the cleaning effect of scraper 3 while maximizing equipment protection, balancing practicality and safety.

[0025] As a further embodiment of the present invention, the sensing component 5 includes an upper shaft 51, a lower shaft 52, a driving member 6, and a driven member 53; A rotating sleeve 54 is fixedly provided at the bottom of the upper shaft 51, and a protrusion 55 is fixedly provided on the inner wall of the rotating sleeve 54. The top of the upper shaft 51 is connected to the output end of the speed regulating component 4 and rotates accordingly. The bottom of the lower shaft 52 is fixedly connected to the scraper 3, and the top of the lower shaft 52 is fixedly provided with a connecting post 56. The outer wall of the connecting post 56 is provided with a spiral groove 57 that slides with the protrusion 55. The drive component 6 is rotatably mounted on the upper shaft 51 via a bearing, and a slide rail 61 is provided at the bottom. The outer wall of the rotating sleeve 54 is axially slidingly engaged with the slide rail 61 via a flat key 62. The follower 53 is fixedly mounted on the top of the lower shaft 52. A vertical rod 63 is provided on the top of the follower 53. An elastic element 64 is provided between the rod 63 and the slide 61. The elastic element 64 is preferably a compression spring. The geared motor drives the upper shaft 51 to rotate through the speed regulating component 4. The upper shaft 51 drives the rotating sleeve 54 fixed thereto to rotate. The rotating sleeve 54 drives the slide rail 61 to rotate synchronously through the flat key 62 on the side wall. The slide rail 61 drives the upright rod 63 to rotate through the elastic element 64. The upright rod 63 drives the driven element 53 to rotate. The driven element 53 drives the scraper 3 to rotate through the lower shaft 52. Since the slide rail 61 drives the upright rod 63 to rotate through the elastic element 64, the two can generate relative rotation through the extension and contraction of the elastic element 64, which reserves buffer space for subsequent force displacement adjustment and avoids component wear caused by rigid connection. Simultaneously, the protrusion 55 on the inner wall of the rotating sleeve 54 rotates synchronously with the rotating sleeve 54. Since the connecting column 56 is fixedly connected to the driven member 53, the connecting column 56 rotates synchronously with the driven member 53. When the axial resistance of the scraper 3 increases, the resistance of the slide 61 driving the upright 63 to rotate through the elastic member 64 increases synchronously. The elastic member 64 is stretched, and relative rotation occurs between the rotating sleeve 54 and the connecting column 56. This causes relative displacement between the protrusion 55 and the spiral groove 57 on the outer wall of the connecting column 56. Under the guidance of the spiral groove 57, the protrusion 55 is driven to move upward. The protrusion 55 drives the upper shaft 51 to rise synchronously through the rotating sleeve 54, realizing the linkage between force and displacement.

[0026] As a further embodiment of the present invention, the speed regulating component 4 includes a speed regulating gear ring 41, a plurality of speed regulating gears 42, a plurality of idler gears 43 and an elastic connecting member 44. The speed regulating gear ring 41 is coaxially fixed on the stirring shaft 11 and rotates synchronously with the stirring shaft 11. As the power input component of the speed regulating assembly 4, it transmits the power of the stirring shaft 11 to the subsequent components. Several speed regulating gears 42 are coaxial with the speed regulating gear ring 41 and arranged vertically. Each speed regulating gear 42 has a slot 45 on its inner side, and the diameter of the speed regulating gears 42 decreases from top to bottom. Different diameter speed regulating gears 42 correspond to different rotation speeds, that is, the larger the diameter, the lower the speed, providing different speed levels for the adaptive speed regulation of the scraper 3.

[0027] The idler wheel 43 is fixedly mounted between the speed regulating gear ring 41 and the speed regulating gear 42 by a bracket, and is used to transmit the power of the stirring shaft 11 so that the speed regulating gear 42 rotates synchronously with the speed regulating gear ring 41. The elastic connector 44 is divided into upper and lower parts, which are axially slidingly fitted together, and a return spring 46 is provided between them. A snap-fit ​​block 47 that can snap into the slot 45 is installed on the outer side of the upper part of the elastic connector 44. The snap-fit ​​block 47 is adapted to the slot 45 to realize the synchronous rotation of the elastic connector 44 and the speed regulating gear 42. The bottom of the elastic connector 44 is connected to the sensing component 5 to receive the axial displacement transmitted by the sensing component 5, thereby driving the snap-fit ​​block 47 to snap into the slot 45 of different speed regulating gears 42 to realize the adaptive adjustment of the scraper 3 speed. For details, see Figure 2, Figure 4 , Figure 5 and Figure 8 , The stirring shaft 11 drives the speed regulating gear ring 41 fixed thereto to rotate synchronously; the speed regulating gear ring 41 drives the speed regulating gear 42 to rotate through the idler wheel 43 meshing with it. At this time, the snap-fit ​​block 47 above the elastic connector 44 snaps into the snap-fit ​​groove 45 of the corresponding speed regulating gear 42. The speed regulating gear 42 drives the snap-fit ​​block 47 to rotate synchronously through the internal snap-fit ​​groove 45. The snap-fit ​​block 47 drives the elastic connector 44 to rotate as a whole. When the elastic connector 44 rotates, it drives the upper shaft 51 in the sensing component 5 to rotate synchronously; the upper shaft 51 drives the rotating sleeve 54, the flat key 62, and the slide rail 61 to rotate in sequence; the slide rail 61 drives the upright rod 63 to rotate through the elastic connector 64; the upright rod 63 drives the driven component 53 to rotate; and the driven component 53 drives the scraper 3 to rotate through the lower shaft 52. When the axial resistance of the scraper 3 increases, the sensing component 5 converts the force into axial displacement, which drives the upper shaft 51 to rise. When the upper shaft 51 rises, it drives the lower half of the elastic connector 44 to rise synchronously. The lower half of the elastic connector 44 generates axial displacement relative to the upper half, thereby compressing the reset spring 46 between the two. The reset spring 46 generates elastic restoring force. When the upper part pushes against the locking block 47, overcoming the resistance of the slot 45 to the locking block 47, the elastic connector 44 bends slightly, and the locking block 47 disengages from the slot 45 of the current speed regulating gear 42; under the elastic restoring force of the return spring 46, the elastic connector 44 quickly returns to its original position, and the locking block 47 rises synchronously and quickly engages in the slot 45 of the adjacent, larger diameter speed regulating gear 42, thereby achieving synchronous rotation of the elastic connector 44 and different speed regulating gears 42; Since the diameter of the speed regulating gear 42 decreases sequentially from top to bottom, when the locking block 47 is locked onto the speed regulating gear 42 with a larger diameter, the rotational speed of the elastic connecting piece 44 decreases. This, in turn, drives the scraper 3 to reduce its speed synchronously through the sensing component 5, thus achieving adaptive adjustment of the scraper 3's speed. This can adapt to the sedimentation of alkaline slag materials with different concentrations and different degrees of agglomeration, flexibly adjust the scraper 3's speed, and take into account equipment protection, cleaning effect, and reaction efficiency, which is consistent with the overall closed-loop circulation flow field design concept of the system.

[0028] The stirring shaft 11 directly drives the combined stirring paddle, ensuring direct and lossless power transmission and synergistic operation of all functions of the combined stirring paddle. The specific structure is as follows: As a further embodiment of the present invention, the spiral guide blade 24 and the centrifugal structure 25 are both fixedly connected to the stirring shaft 11 and rotate synchronously with the stirring shaft 11, so as to ensure that the stirring, lifting and centrifugal dispersion functions of the combined stirring paddle are realized simultaneously, and to ensure the stable formation of the closed-loop circulating flow field.

[0029] The stirring shaft 11 indirectly drives the combined stirring paddle, and its specific structure is as follows: As a further embodiment of the present invention, the centrifugal structure 25 adopts a centrifugal impeller with an arc-shaped blade design to meet the material dispersion requirements. It can uniformly throw the material and liquid discharged from the rising channel 21 into the falling channel 22 radially to improve the dispersion uniformity. The drive shaft sleeve 28 is coaxially sleeved on the outside of the stirring shaft 11. Its top is fixedly connected to the bottom of the centrifugal impeller and its bottom is fixedly connected to the top of the spiral guide blade 24, ensuring that the centrifugal impeller and the spiral guide blade 24 rotate synchronously through the drive shaft sleeve 28, further enhancing the coordination of their actions. A drive gear 26 is mounted on the top of the centrifugal impeller. The drive gear 26 meshes with a transmission gear 27, which is fixedly mounted by a bracket and meshes with the speed regulating ring 41 of the speed regulating component 4, forming a complete power transmission link to achieve linkage between the centrifugal impeller and the speed regulating component 4; see also Figure 4 The characteristic that the diameter of the drive gear 26 is smaller than that of the speed regulating gear 42 makes the rotation speed of the combined stirring paddle higher than that of the scraper 3. This speed difference design fits the overall working requirements of the system. The combined stirring paddle needs to have a higher speed to achieve efficient lifting and uniform dispersion of materials, ensuring sufficient power for the closed-loop circulation flow field. The scraper 3 only needs to be adapted to the speed required for material cleaning, without the need for excessive speed. This speed ratio not only ensures the efficiency of material circulation and dispersion, but also avoids problems such as excessive resistance and component wear caused by the high-speed rotation of the scraper 3. It further optimizes the rationality of the system's power distribution, so that the centrifugal dispersion function of the combined stirring paddle and the cleaning function of the scraper 3 form a synergistic complement, improving the overall operating efficiency of the system.

[0030] As a further embodiment of the present invention, a temperature regulating sleeve 13 is fixedly sleeved on the outside of the vessel body 1. A water inlet pipe 14 and a water outlet pipe 15 are respectively installed on the side wall of the temperature regulating sleeve 13. The water inlet pipe 14 is used to introduce a temperature regulating medium such as warm water or cold water, and the water outlet pipe 15 is used to discharge the temperature regulating medium. Through the circulation of the temperature regulating medium, the reaction temperature inside the vessel body 1 is precisely controlled, which is adapted to the optimal temperature requirements of calcium ion extraction and carbonation reaction, and solves the problem of insufficient temperature control accuracy in the prior art.

Claims

1. A selective extraction and carbonation recovery system for calcium ions in alkaline residue, characterized in that: Includes a vessel body (1), a stirring shaft (11), a guide tube (12), and a combined stirring paddle; The guide tube (12) is fixed in the middle of the inner cavity of the vessel body (1), and an upward channel (21) is formed on its inner side, and a downward channel (22) is formed between its outer side and the inner wall of the vessel body (1). A material sedimentation zone (23) is formed between its bottom and the bottom of the vessel body (1). The stirring shaft (11) rotates synchronously with the combined stirring paddle to drive the combined stirring paddle to rotate, and the top of the stirring shaft (11) extends to the outside of the vessel body (1) and is equipped with a driving component (7). The combined impeller includes a spiral guide blade (24) and a centrifugal structure (25). The spiral guide vane (24) is located at the bottom of the guide tube (12) and is used to simultaneously lift the material and liquid in the sedimentation zone (23) at the bottom of the vessel (1) into the rising channel (21); The centrifugal structure (25) is set at the top port of the guide tube (12) to uniformly throw the material and liquid out of the rising channel (21) into the falling channel (22) radially, so that the material and liquid flow from top to bottom along the falling channel (22) and fall back to the sedimentation zone (23), forming a closed loop circulation flow field.

2. The selective extraction and carbonation recovery system for calcium ions in alkaline residue according to claim 1, characterized in that: It also includes a scraper (3), which is rotatably mounted to fit the inner bottom of the vessel body (1); a speed regulating component (4) and a sensing component (5) are provided between the scraper (3) and the stirring shaft (11), the sensing component (5) is used to sense the axial force on the scraper (3) and convert it into axial displacement; the speed regulating component (4) adaptively adjusts the rotation speed of the scraper (3) according to the amount of axial displacement generated by the sensing component (5).

3. The selective extraction and carbonation recovery system for calcium ions in alkaline residue according to claim 2, characterized in that: The sensing component (5) includes a pressure sensor and a telescopic rod (59). The pressure sensor is installed on the side wall of the scraper (3), and the telescopic rod (59) is installed between the scraper (3) and the speed regulating component (4) to convert the axial force of the scraper (3) into axial displacement.

4. The selective extraction and carbonation recovery system for calcium ions in alkaline residue according to claim 2, characterized in that: The sensing component (5) includes an upper shaft (51), a lower shaft (52), a driving element (6), and a driven element (53). The bottom of the upper shaft (51) is fixedly provided with a rotating sleeve (54), and the inner wall of the rotating sleeve (54) is fixedly provided with a protrusion (55). The top of the upper shaft (51) is connected to the output end of the speed regulating component (4) and rotates accordingly. The bottom of the lower shaft (52) is fixedly connected to the scraper (3), and the top of the lower shaft (52) is fixedly provided with a connecting post (56). The outer wall of the connecting post (56) is provided with a spiral groove (57) that slides with the protrusion (55). The drive component (6) is rotatably mounted on the upper shaft (51) and has a slide rail (61) at the bottom. The outer wall of the rotating sleeve (54) is axially slidingly engaged with the slide rail (61) via a flat key (62). The driven member (53) is fixedly mounted on the top of the lower shaft (52), and a vertical rod (63) is provided on the top of the driven member (53). An elastic member (64) is provided between the vertical rod (63) and the slide (61).

5. The selective extraction and carbonation recovery system for calcium ions in alkaline residue according to claim 2, characterized in that: The speed regulating component (4) includes a speed regulating gear ring (41), a plurality of speed regulating gears (42), a plurality of idler gears (43) and an elastic connecting member (44). The speed regulating gear ring (41) is coaxially fixed on the stirring shaft (11); Several speed-regulating gears (42) are coaxial with the speed-regulating gear ring (41) and arranged vertically. Each speed-regulating gear (42) has a slot (45) on its inner side, and the diameter of the speed-regulating gear (42) decreases from top to bottom. The idler wheel (43) is disposed between the speed regulating gear ring (41) and the speed regulating gear (42) to transmit the power of the stirring shaft (11); The elastic connector (44) is divided into upper and lower parts. The upper and lower parts of the elastic connector (44) are axially slidingly fitted, and a return spring (46) is provided between them. A snap-fit ​​block (47) that can snap into the slot (45) is installed on the outer side of the upper part of the elastic connector (44). Both ends of the snap-fit ​​block (47) are provided with bevels. The bottom of the elastic connector (44) is connected to the sensing component (5) to receive the axial displacement of the sensing component (5) and drive the snap-fit ​​block (47) to snap into different slots (45) to realize speed adjustment.

6. The selective extraction and carbonation recovery system for calcium ions in alkaline residue according to claim 1, characterized in that: The spiral guide blade (24) and centrifugal structure (25) are fixedly connected to the stirring shaft (11) and rotate synchronously with the stirring shaft (11).

7. The selective extraction and carbonation recovery system for calcium ions in alkaline residue according to claim 5, characterized in that: The centrifugal structure (25) is a centrifugal impeller. A transmission shaft sleeve (28) is provided between the centrifugal impeller and the spiral guide blade (24). A drive gear (26) is installed on the top of the centrifugal impeller. A transmission gear (27) is provided between the drive gear (26) and the speed regulating gear ring (41) to realize power transmission.

8. The selective extraction and carbonation recovery system for calcium ions in alkaline residue according to claim 1, characterized in that: A temperature regulating sleeve (13) is provided on the outside of the vessel body (1). A water inlet pipe (14) and a water outlet pipe (15) are installed on the side wall of the temperature regulating sleeve (13) to realize the circulation of the temperature regulating medium.

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