A rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device with easy maintenance

Abstract

The present application relates to the technical field of rare earth industry, and discloses a rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation equipment easy to maintain, which comprises a gas conveying pipeline, one end of the gas conveying pipeline is fixedly connected to an evaporator, and the other end is fixedly connected to a gas separation tower, the gas separation tower is provided with a first fluorine removal cavity, a second fluorine removal cavity and a desulfurization cavity, a fluorine removal unit is arranged in the first fluorine removal cavity, the fluorine removal unit comprises a first fixed column, an adsorption coating is fixedly connected to the outer side of the first fixed column, and a scraper assembly is abutted to the outer side of the adsorption coating; the scraper assembly comprises a scraper, and the scraper is slidingly connected in a sliding base. In the present application, the scraper assembly and the clamping assembly are connected through structures such as protrusions, compression springs and ball head clamping pieces, so that the scraper can realize the action switching of "sticking to the adsorption coating when removing slag and opening to avoid when descending", which can completely remove the calcium fluoride solid particles and avoid scratching the coating during the descending process, thereby prolonging the service life of the adsorption medium.

Description

Technical Field

[0001] This invention relates to the field of rare earth industry technology, and in particular to an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device. Background Technology

[0002] In the rare earth production process, "sulfuric acid concentration and purification" and "fluorine-containing mixed acid waste gas treatment" are two key steps. The former directly determines the processing purity and efficiency of the rare earth solution, while the latter relates to environmental compliance and resource utilization. The treatment of pollutants from the rare earth industry has become one of the core needs of the rare earth sector.

[0003] The existing equipment mainly uses ordinary spray towers for direct spraying. This method is prone to uneven contact between waste gas and absorbent liquid, and the residue generated by the reaction needs to be cleaned manually at regular intervals. It is inefficient and requires shutdown for maintenance, which reduces production efficiency and wastes resources significantly.

[0004] To address these issues, an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device is proposed. Summary of the Invention

[0005] To overcome the above shortcomings, the present invention provides an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device, which aims to improve the problems of manual slag removal and uneven contact between waste gas and absorbent liquid in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device, comprising a gas conveying pipeline, one end of which is fixedly connected to an evaporator and the other end of which is fixedly connected to a gas separation tower. The gas separation tower is provided with a first defluorination chamber, a second defluorination chamber, and a desulfurization chamber. The first defluorination chamber is provided with a defluorination unit, which includes a first fixed column. An adsorption coating is fixedly connected to the outside of the first fixed column, and a scraper assembly abuts against the outside of the adsorption coating.

[0007] The scraper assembly includes a scraper that is slidably connected to a sliding base. An arc-shaped recycling groove is fixedly connected to the outer wall of the sliding base, and a fixed end of a positioning assembly is fixedly connected to the sliding base.

[0008] Preferably, the positioning assembly includes a second fixed post, a rotating block is rotatably connected to the top of the second fixed post, a ball head clamp is fixedly connected to the rotating block, and a crank is rotatably connected to the rotating block, the other end of the crank being rotatably connected to the scraper; a spherical positioning groove is provided in the scraper corresponding to the middle position of the ball head clamp.

[0009] Preferably, the defluorination unit further includes an outer wall, and a fixing block is fixedly connected to the inner side of the outer wall near the top and bottom ends, and a wedge-shaped surface is provided in the fixing block; a V-shaped block that matches the wedge-shaped surface is fixedly connected to the scraper.

[0010] Preferably, the scraper is semi-conical, and the top of the scraper is slidably connected to the fixed ring through a connecting column. A rotating ring is slidably connected inside the fixed ring, and a rotating component is rotatably connected to the bottom of the rotating ring. The rotating component is provided with spikes facing the adsorption coating.

[0011] Preferably, the top of the rotating ring is fixedly connected to a sliding block by a fixing rod, the sliding block is slidably connected in a spiral groove, the spiral groove is opened in the first fixing column and the dripping column, the top of the dripping column is provided with a spray ring, and the bottom of the dripping column and the bottom of the spray ring are both provided with nozzles.

[0012] Preferably, a gas diversion plate is fixedly connected to the bottom of the desulfurization chamber, an adsorption element is provided inside the desulfurization chamber, and a demister is provided on the top of both the desulfurization chamber and the top of the second defluorination chamber.

[0013] Preferably, the bottom end of the sliding base is fixedly connected to the output end of the driving component, the driving component is fixedly connected to the outer wall of the slag collection part, and the slag collection part is located at the bottom of the gas separation tower.

[0014] Preferably, a partition is fixedly connected between the first defluorination chamber, the second defluorination chamber, and the desulfurization chamber, and an inspection door is provided on the outer wall of each of the first defluorination chamber, the second defluorination chamber, and the desulfurization chamber.

[0015] Preferably, the bottom of the arc-shaped recovery tank is fixedly connected to a slag discharge pipe, which passes through the partition at the bottom of the first defluorination chamber and is slidably connected to the slag collection section.

[0016] Preferably, the outer diameter of the scraper is the same as the outer diameter of the sliding base, and the maximum distance between the scrapers when the scrapers are in the open state does not exceed the inner diameter of the arc-shaped recycling trough.

[0017] The present invention has the following beneficial effects:

[0018] 1. In this invention, the scraper assembly and the locking assembly use structures such as protrusions, compression springs, and ball head locking parts to achieve the action switching of the scraper "adhering to the adsorption coating when cleaning slag and opening to avoid it when descending". This can not only thoroughly remove calcium fluoride solid particles, but also avoid scratching the coating during the descent, extend the service life of the adsorption medium, and ensure stable defluorination efficiency.

[0019] 2. In this invention, the spiral slider and spiral groove work together to rotate the rotating part when the spiral slider is raised, and the spikes puncture the unreacted bubbles to ensure that the hydrogen fluoride reacts fully; the demister at the top of the second defluorination chamber can capture the absorbent droplets in the exhaust gas, and the demister at the top of the gas separation tower performs final treatment on the desulfurized gas to prevent the droplets from carrying pollutants for emission. The dual demisting design further improves the environmental compliance rate.

[0020] 3. In this invention, the arc-shaped recovery tank of the defluorination unit, together with the slag discharge pipe and the slag collection part, can collect the scraped solid particles in a concentrated manner. The solid particles are recycled as industrial by-products, and the residual solution is returned to the defluorination unit for circulation, which further improves resource utilization and maintenance convenience. Attached Figure Description

[0021] Figure 1 This is a three-dimensional schematic diagram of an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device proposed in this invention.

[0022] Figure 2 This is a schematic diagram of the defluorination unit of an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device proposed in this invention.

[0023] Figure 3 This is a schematic diagram of the scraper assembly of an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device proposed in this invention.

[0024] Figure 4 This is a schematic diagram showing the connection relationship of the first fixed column in an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device proposed in this invention.

[0025] Figure 5 This is a schematic diagram of the second defluorination chamber of an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device proposed in this invention;

[0026] Figure 6 This is a schematic diagram of the desulfurization chamber of an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device proposed in this invention.

[0027] Figure 7 This is a top view schematic diagram of the first defluorination chamber of an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device proposed in this invention.

[0028] Figure 8 for Figure 3 Enlarged view of point A in the middle.

[0029] Legend:

[0030] 1-Gas delivery pipeline; 2-Evaporator; 3-Gas separation tower; 4-First defluorination chamber; 5-Second defluorination chamber; 6-Desulfurization chamber; 7-Defluorination unit; 8-First fixed column; 9-Adsorption coating; 10-Scraper assembly; 11-Scraper; 12-Sliding base; 13-Arc-shaped recovery tank; 14-Positioning assembly; 15-Second fixed column; 16-Rotating block; 17-Ball head clamp; 18-Crank; 19-Spherical positioning groove; 20-Outer wall; 21-Fixing block; 22-V-block; 23-Fixing ring; 24-Rotating ring; 25-Rotating component; 26-Sliding block; 27-Spiral chute; 28-Drip column; 29-Spray ring; 30-Adsorption component; 31-Demister; 32-Drive component; 33-Slag collection section; 34-Baffle; 35-Inspection door; 36-Slag discharge pipeline. Detailed Implementation

[0031] 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.

[0032] Example 1

[0033] Reference Figure 1 This invention provides an embodiment of an easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device, whose core structure consists of two main parts: an evaporator 2 and a gas separation tower 3. The evaporator 2, as the core unit for sulfuric acid concentration, has a filter fixedly connected to one end. The filter pre-treats the rare earth sulfuric acid solution to be concentrated, removing unreacted rare earth oxide fragments and other impurities to prevent subsequent pipeline blockage or scaling on the heating element of the evaporator 2. The other end of the evaporator 2 is fixedly connected to a gas delivery pipe 1 and a liquid delivery pipe, forming a "liquid-gas separation" delivery path. The end of the liquid delivery pipe is fixedly connected to a processing device, which mainly processes the concentrated rare earth solution. The top of the processing device is connected to the gas delivery pipe 1 leading from the evaporator 2 via a pipe, allowing the fluorine-containing mixed acid waste gas, composed of sulfuric acid mist, hydrogen fluoride, sulfur dioxide, etc., volatilized during processing to flow into the gas delivery pipe 1 and ultimately into the gas separation tower 3 for treatment.

[0034] A condensation device is also installed in series on the gas conveying pipeline 1 between the processing equipment and the gas separation tower 3. This device can condense and precipitate some of the sulfuric acid mist and water vapor in the waste gas in advance; the dilute sulfuric acid solution formed by condensation can be returned to the evaporator 2 through the reflux pipe to participate in the concentration cycle again, and the condensate is collected through a separate pipeline and discharged after meeting the standards, reducing the processing load of the subsequent separation tower and realizing resource recovery.

[0035] refer to Figure 1 and Figure 7 The end of the gas conveying pipe 1 passes through the side wall of the gas separation tower 3 and is fixed to the gas diversion device inside the tower. The gas diversion device can evenly divert the waste gas entering the tower to each defluorination unit 7 of the first defluorination chamber 4, ensuring that the waste gas is in full contact with the adsorption medium.

[0036] The gas separation tower 3 is divided into three chambers by longitudinal partitions 34. Along the direction of exhaust gas flow, these are the first defluorination chamber 4, the second defluorination chamber 5, and the desulfurization chamber 6. The exhaust gas flows in an orderly manner through internal channels.

[0037] refer to Figures 1 to 2 The first defluorination chamber 4 is the core area for defluorination of the exhaust gas. Several sets of defluorination units 7 are evenly arranged inside the chamber. Each set of defluorination units 7 consists of an outer wall 20, a fixing block 21, a first fixing column 8, an adsorption coating 9, and a scraper assembly 10. The first fixing column 8 serves as the core support component of the defluorination unit 7. Its bottom is fixedly connected to the bottom partition 34 of the first defluorination chamber 4, and its top is coaxially fixedly connected to the drip column 28 in the second defluorination chamber 5, providing an installation base for the adsorption coating 9 and the scraper assembly 10.

[0038] The outer wall of the first fixed column 8 is coated with an adsorption coating 9. The material of the adsorption coating 9 is selected to have a high selective absorption rate of hydrogen fluoride waste gas. The adsorption coating 9 is impregnated with a chemical absorption solution of calcium hydroxide. This solution is continuously dripped and permeated from the nozzle at the bottom of the drip column 28 above. When the waste gas is sprayed out from the gas diversion device and comes into contact with the adsorption coating 9, the hydrogen fluoride will first be adsorbed by the coating and then react with the internal chemical solution to generate solid calcium fluoride particles, thereby realizing the immobilization of hydrogen fluoride.

[0039] refer to Figures 2 to 4 In order to remove the calcium fluoride particles generated on the surface of the adsorption coating 9 in a timely manner, a scraper assembly 10 is sleeved on the outside of the first fixed column 8, the core of which is two symmetrically distributed semi-conical scrapers 11.

[0040] A horizontal connecting column and a vertical connecting column are fixedly connected to the outer conical surface of the scraper 11. The end of the vertical connecting column is slidably fitted into the groove of the fixing ring 23, while the end of the horizontal connecting column is integrally formed with a V-shaped block 22. A rotating ring 24 is rotatably connected to the inner side of the fixing ring 23 through bearings or other means. A fixing rod is evenly fixedly connected to the top of the rotating ring 24 along the circumferential direction. The other end of the fixing rod extends into the spiral slider and is fixed thereto. The spiral slider is slidably fitted in the spiral groove 27. The spiral groove 27 is respectively opened on the outer wall of the first fixing column 8 and the inner wall of the drip column 28, forming a "double guide inside and outside".

[0041] Several rotating parts 25 are fixedly connected to the bottom of the rotating ring 24, and each rotating part 25 has a spike at its end. When the scraper 11 is subjected to force and rises along the fixed column, the spiral slider will move spirally along the spiral groove 27, thereby driving the rotating ring 24 to rotate synchronously; when the rotating parts 25 rotate with the rotating ring 24, their spikes can puncture the bubbles on the surface of the adsorption coating 9 that have not been fully reacted, ensuring that the hydrogen fluoride gas is fully absorbed and reacted.

[0042] refer to Figure 8 To enable the scraper 11 to switch between "adhering during slag removal and avoiding during descent," the defluorination unit 7 is also equipped with a locking component 14. A protrusion is integrally formed on the bottom of the scraper 11, which slides into the sliding groove of the sliding base 12. A compression spring is installed at the end of the sliding groove away from the center of the base. The spring is initially in a pre-compressed state and can continuously apply a spring force pointing towards the first fixed post 8 to the scraper 11, ensuring that the scraper 11 always adheres tightly to the adsorption coating 9 during slag removal, preventing residue residue.

[0043] The sliding base 12 is fixedly connected to the fixed end of the locking assembly 14, namely the second fixed post 15. The top end of the second fixed post 15 is rotatably connected to the rotating block 16. A spiral spring is also provided between the second fixed post 15 and the rotating block 16. The center of the rotating block 16 is fixedly connected to the ball head locking member 17. The two ends of the ball head locking member 17 are spherical structures, and the middle is a cylindrical connecting rod. At the same time, the rotating block 16 is also rotatably connected to the crank 18 through the rotating shaft. The other end of the crank 18 is rotatably connected to the scraper 11. The scraper 11 has grooves corresponding to the positions of the second fixed post 15, the rotating block 16 and the ball head locking member 17. The scraper 11 also has a spherical locking groove 19 corresponding to the center of the ball head locking member 17.

[0044] On the outer wall 20 of the defluorination unit 7, a fixing block 21 is fixedly connected near the top and bottom respectively. The inner side of the fixing block 21 is machined with a wedge-shaped surface that matches the V-shaped block 22 of the scraper 11. The bottom of the sliding base 12 is equipped with a driving component 32 such as a hydraulic drive cylinder or an electric push rod. When the driving component 32 pushes the sliding base 12 to rise, the wedge-shaped surface of the V-shaped block 22 and the wedge-shaped surface of the fixing block 21 are pressed against each other, which can force the scraper 11 to slide along the sliding groove in a direction away from or close to the center of the base, thereby triggering the action of the locking component 14 to realize the state switching of the scraper 11. When the scraper 11 is subjected to force and slides away from the center of the sliding base 12 (it needs to be raised and reset after cleaning), the scraper 11 pushes the rotating block 16 to rotate around the top of the second fixed column 15 through the crank 18. The spherical end of the ball head clamp 17 is embedded in the spherical locking groove 19 of the scraper 11. At this time, the two scrapers 11 remain in the "open state" and will not touch the adsorption coating 9 when descending along the first fixed column 8. When the scraper 11 is subjected to force again (in preparation for cleaning), the rotating block 16 squeezes the spiral spring. The spiral spring releases torque to cause the rotating block 16 to rotate quickly in the opposite direction. The ball head clamp 17 disengages from the spherical locking groove 19, and the scraper 11 closes under the action of the spring force, re-adhering to the adsorption coating 9 to perform particle scraping operation.

[0045] refer to Figures 5 to 6 The second defluorination chamber 5 is located above the first defluorination chamber 4. Its core component is a drip column 28 coaxially connected to the first fixed column 8. Its main function is to perform secondary absorption of hydrogen fluoride waste gas that has not been completely treated in the first defluorination chamber 4.

[0046] A filter screen is fitted on the outside of the drip column 28 to filter calcium fluoride particles entrained in the exhaust gas. A spray ring 29 is fixedly connected to the top of the drip column 28, and several atomizing nozzles are evenly arranged along the circumference at the bottom of the spray ring 29. An alkaline absorption solution is sprayed onto the outside of the drip column 28 through the spray ring 29. This solution can further absorb the remaining hydrogen fluoride in the exhaust gas, ensuring that the fluoride content in the exhaust gas entering the desulfurization chamber 6 is significantly reduced.

[0047] The waste gas treated in the second defluorination chamber 5 enters the desulfurization chamber 6 through a gas diversion plate at the bottom of the chamber. This gas diversion plate, with its porous structure, disperses the waste gas into fine gas particles, increasing the contact area with the adsorbents 30. Multiple layers of adsorbents 30 are vertically arranged within the desulfurization chamber 6. As the waste gas rises, the sulfur dioxide within is efficiently adsorbed by the adsorbents 30. Once the adsorbents 30 are saturated with sulfur dioxide, the inlet and outlet valves of the desulfurization chamber 6 can be closed, while the desorption pipe valves at the top and bottom of the chamber can be opened. High-temperature gas is then introduced into the desulfurization chamber 6, causing the adsorbents 30 to desorb and release sulfur dioxide. The desorbed sulfur dioxide is collected through the top pipe and can be used to prepare sulfuric acid, achieving resource recovery. The desorbed adsorbents 30 can remain in the desulfurization chamber 6 until the next adsorption operation, eliminating the need for frequent disassembly and replacement, thus reducing maintenance costs.

[0048] Demisters 31 are fixedly installed at the top of both the second defluorination chamber 5 and the gas separation tower 3. The demisters 31 in the second defluorination chamber 5 capture absorbent droplets entrained in the exhaust gas, preventing them from entering the desulfurization chamber 6 and affecting the adsorption effect. The captured droplets can be returned to the first defluorination chamber 4 through the reflux hole for recycling. The demisters 31 at the top of the gas separation tower 3 perform final demisting treatment on the purified gas after desulfurization, ensuring that the emitted gas meets environmental emission standards.

[0049] Example 2

[0050] refer to Figures 1 to 3 This second embodiment is a further supplement and explanation of the first embodiment. Specifically, the first defluorination chamber 4, the second defluorination chamber 5, and the desulfurization chamber 6 are physically separated by an acid-resistant stainless steel partition 34 to ensure structural strength. Grooves are formed along the perimeter of the partition 34, and acid-resistant fluororubber sealing strips are embedded in the grooves. The rubber strips are tightly fitted to the outer walls 20 of the adjacent chambers, forming a reliable sealing barrier. The inspection doors 35 of the outer walls 20 of each chamber use stainless steel frames and are equipped with multiple sets of symmetrically distributed quick-release buckles. These quick-release buckles allow for rapid locking or separation of the door from the frame, shortening maintenance time. A transparent observation window is embedded in the middle of the door, and an elastic sealing gasket is added to the contact area between the window edge and the door frame, ensuring both clear observation and enhanced sealing performance. The synergistic effect of the stainless steel partition 34 and the fluororubber strip can completely block the airflow between chambers, preventing the incompletely treated fluorine-containing waste gas in the first defluorination chamber 4 from mixing into the second defluorination chamber 5, or the gas that has not been desulfurized from directly entering the subsequent stages, ensuring that the graded treatment logic of "defluorination-deep defluorination-desulfurization" is strictly implemented; while the quick-release buckle greatly shortens the opening time of the maintenance door 35, and together with the observation window, the running trajectory of the scraper assembly 10 in the chamber, the integrity of the adsorption coating 9 and the thickness of the slag layer accumulation can be observed in real time, which makes it easier for maintenance personnel to predict maintenance needs in advance and reduce unplanned downtime.

[0051] refer to Figures 2 to 3An arc-shaped recovery trough 13 is fixedly connected to the outer wall of the sliding base 12 inside the defluorination unit 7. Corrosion-resistant slag discharge pipes 36 are fixedly connected to both sides of the arc-shaped recovery trough 13. The inner wall of the slag discharge pipes 36 is finely treated to reduce particle conveying resistance. Multiple elastic sealing rings are axially spaced at the part of the pipe that passes through the chamber partition 34. The inner ring of the sealing ring fits tightly with the outer wall 20 of the pipe, and the outer ring is embedded in the pre-set annular groove of the partition 34. Continuous pressure is applied through the pre-tightening structure. This design can achieve dynamic sealing between the pipe and the partition 34. When the pipe moves up and down with the sliding base 12 and produces a slight displacement, the lip of the sealing ring will adaptively open with the displacement direction and tightly fit the pipe surface, preventing acidic waste gas from leaking from the gap without hindering the normal operation of the pipe. During the particle conveying process, the calcium fluoride solid scraped off by the scraper 11 slides along the inner wall of the arc-shaped recovery tank 13 into the slag discharge pipe 36. The arc-shaped design of the arc-shaped recovery tank 13 and the low friction characteristics of the inner wall of the pipe allow the particles to flow smoothly by gravity and finally be completely conveyed to the slag collection section 33, effectively avoiding the problem of chamber contamination or pipe blockage caused by particle scattering.

[0052] Example 3

[0053] refer to Figures 1 to 2 This third embodiment is a further supplement and explanation of the first embodiment. Specifically, the bottom of the sliding base 12 is connected to a drive component 32, such as a servo motor or hydraulic cylinder, via a precision transmission assembly. The servo motor can precisely control the running speed of the sliding base 12 with minimal running error, effectively avoiding damage to the adsorption coating 9 on the inner wall of the cavity due to excessive movement or speed, thus ensuring the long-term stable defluorination efficiency of the equipment. The drive component 32 is fixed to the outer wall of the slag collection section 33 by a high-strength stainless steel bracket. The bracket and the slag collection section 33 are connected by a sealed method such as welding to ensure no exhaust gas leakage at the connection.

[0054] The slag collection section 33 adopts an acid-resistant stainless steel sealed cavity design with an anti-corrosion coating on the inner wall. A small centrifugal filter is fixedly connected to the bottom. When the cumulative treatment volume in the waste gas conveying pipeline reaches the preset threshold, the servo motor and other drive components 32 drive the scraper 11 to move precisely up and down along a set trajectory through the transmission assembly. The scraper 11 moves in contact with the adsorption coating 9 on the cavity wall, thoroughly scraping off the attached calcium fluoride particles. The particles fall into the slag collection section 33 by gravity and are collected. At this time, the centrifugal filter starts, generating centrifugal force through high-speed rotation, so that the solid particles and waste liquid in the slag collection section 33 can be efficiently separated. The denser solid particles are thrown to the inner wall of the drum to form a filter cake, while the clarified fluoride-containing waste liquid is collected at the bottom of the filter. After adjustment and concentration detection, the separated waste liquid can be transported back to the first defluorination chamber 4 or the second defluorination chamber 5 through the return pipeline to continue to participate in the defluorination reaction, greatly reducing the consumption of chemical reagents. The generated calcium fluoride solid filter cake can be dried and used as an industrial raw material in subsequent processing stages, realizing resource recycling.

[0055] refer to Figures 2 to 3 The scraper 11 is made of wear-resistant and corrosion-resistant material, forming a compatible structure with the sliding base 12. The wear-resistant material extends the service life of the scraper 11 and resists long-term wear from acidic particles. In the closed state, the inner diameter of the scraper 11 is slightly smaller than the outer diameter of the adsorption coating 9, while the outer diameter of the scraper 11 is the same as the outer diameter of the sliding base 12. In the open state, the maximum distance between the two scrapers does not exceed the inner diameter of the arc-shaped recovery tank 13, ensuring that the scraper 11 can fully contact the adsorption coating 9 on the cavity wall and completely guide the scraped particles into the arc-shaped recovery tank 13. The compatibility between the scraper 11 and the sliding base 12 ensures stability during slag removal, while the size matching in the open state prevents particles from scattering from the gap between the scraper 11 and the arc-shaped recovery tank 13, ensuring that all calcium fluoride solids fall into the arc-shaped recovery tank 13 and eventually flow into the slag collection section 33. This improves the thoroughness of slag removal and reduces the impact of residual particles on adsorption efficiency.

[0056] Working principle: The rare earth sulfuric acid solution to be processed first enters the filter at the front end of evaporator 2 to provide clean raw materials for sulfuric acid concentration. Subsequently, the pretreated solution enters evaporator 2 for concentration. The concentrated rare earth solution is then transported directly to the processing equipment for further processing via a liquid conveying pipeline. The gas generated by evaporator 2 and the fluorine-containing mixed acid waste gas volatilized during the operation of the processing equipment are combined and flow into gas conveying pipeline 1. During the gas conveying process, a condensation device condenses and precipitates some of the sulfuric acid mist and water vapor in the waste gas. The resulting dilute sulfuric acid is returned to evaporator 2 through a return pipe to participate in the concentration cycle again.

[0057] The gas separation tower 3 is the core area for purifying fluorinated mixed acid waste gas. Through multi-chamber graded treatment and precise control, it achieves deep purification and resource reuse of the waste gas. The condensed waste gas enters the gas separation tower 3 through the gas delivery pipeline 1. The gas diversion device connected to the end of the pipeline evenly distributes the waste gas to each defluorination unit 7 in the first defluorination chamber 4, ensuring that the waste gas is in full contact with the adsorption medium. Inside the first defluorination chamber 4, the defluorination unit 7, supported by the first fixed column 8, adsorbs hydrogen fluoride through the highly selective adsorption coating 9, which is coated with a chemical solution on the outer wall 20, and reacts with it to generate calcium fluoride solid particles. At the same time, the scraper assembly 10, which is sleeved on the outside of the first fixed column 8, uses the spiral movement of the spiral slider along the spiral groove 27, the piercing and bubble breaking of the rotating part 25 driven by the rotating ring 24, and the switching action of the positioning assembly 14 (including the second fixed column 15, the rotating block 16, the ball head clamp 17, etc.) to "fit during slag removal and avoid during descent" to promptly remove calcium fluoride particles on the surface of the adsorption coating 9, ensuring defluorination efficiency. Subsequently, the incompletely defluorinated waste gas enters the second defluorination chamber 5, is filtered through the filter screen outside the drip column 28, and then sprayed with alkaline absorption solution by the spray ring 29 for secondary defluorination. The top demister 31 captures the absorbent droplets entrained in the waste gas. Next, the waste gas is dispersed by the porous gas diverter plate and enters the desulfurization chamber 6, where it comes into contact with the multi-layer adsorbent 30 to adsorb sulfur dioxide. When the adsorbent 30 is saturated, high-temperature gas is introduced to desorb and release sulfur dioxide, which can be recovered and used to prepare sulfuric acid. The adsorbent 30 can be reused without disassembly. Finally, the desulfurized waste gas undergoes final demisting treatment by the top demister 31 to ensure that the emission gas meets environmental protection standards. The calcium fluoride particles scraped off by the first defluorination chamber 4 enter the slag collection section 33 through the arc-shaped recovery tank 13 and the slag discharge pipe 36. After separation, the solid particles and residual solution are separated. The calcium fluoride is recovered as an industrial by-product, and the solution is returned to the defluorination unit 7 for circulation, further improving resource utilization.

[0058] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A maintenance-friendly rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation device, comprising a gas conveying pipeline (1), characterized in that: One end of the gas conveying pipeline (1) is fixedly connected to the evaporator (2), and the other end is fixedly connected to the gas separation tower (3). The gas separation tower (3) is provided with a first defluorination chamber (4), a second defluorination chamber (5) and a desulfurization chamber (6). The first defluorination chamber (4) is provided with a defluorination unit (7). The defluorination unit (7) includes a first fixed column (8). An adsorption coating (9) is fixedly connected to the outside of the first fixed column (8). A scraper assembly (10) abuts against the outside of the adsorption coating (9). The scraper assembly (10) includes a scraper (11), which is slidably connected to the sliding base (12). An arc-shaped recycling groove (13) is fixedly connected to the outer wall of the sliding base (12), and the fixed end of the locking assembly (14) is fixedly connected to the sliding base (12). The positioning assembly (14) includes a second fixed post (15), a rotating block (16) is rotatably connected to the top of the second fixed post (15), a ball head clamp (17) is fixedly connected to the rotating block (16), and a crank (18) is rotatably connected to the rotating block (16). The other end of the crank (18) is rotatably connected to the scraper (11); a spherical positioning groove (19) is provided in the scraper (11) at the middle position corresponding to the ball head clamp (17).

2. The easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation equipment according to claim 1, characterized in that: The defluorination unit (7) also includes an outer wall (20), and a fixing block (21) is fixedly connected to the outer wall (20) near the top and bottom. A wedge-shaped surface is provided in the fixing block (21). A V-shaped block (22) that matches the wedge-shaped surface is fixedly connected to the scraper (11).

3. The easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation equipment according to claim 1, characterized in that: The scraper (11) is semi-conical, and the top of the scraper (11) is slidably connected to the fixed ring (23) through the connecting column. A rotating ring (24) is slidably connected inside the fixed ring (23). A rotating component (25) is rotatably connected to the bottom of the rotating ring (24). The rotating component (25) is provided with spikes facing the adsorption coating (9).

4. The easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation equipment according to claim 3, characterized in that: The top of the rotating ring (24) is fixedly connected to a sliding block (26) by a fixing rod. The sliding block (26) is slidably connected in the spiral groove (27). The spiral groove (27) is opened in the first fixing column (8) and the drip column (28). The top of the drip column (28) is provided with a spray ring (29), and the bottom of the drip column (28) and the bottom of the spray ring (29) are both provided with nozzles.

5. The easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation equipment according to claim 3, characterized in that: A gas diversion plate is fixedly connected to the bottom of the desulfurization chamber (6), and an adsorption element (30) is provided inside the desulfurization chamber (6). A demister (31) is provided on the top of the desulfurization chamber (6) and the top of the second defluorination chamber (5).

6. The easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation equipment according to claim 1, characterized in that: The bottom end of the sliding base (12) is fixedly connected to the output end of the driving component (32), which is fixedly connected to the outer wall of the slag collection part (33), which is located at the bottom of the gas separation tower (3).

7. The easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation equipment according to claim 1, characterized in that: A partition (34) is fixedly connected between the first defluorination chamber (4), the second defluorination chamber (5) and the desulfurization chamber (6), and an inspection door (35) is provided on the outer wall of the first defluorination chamber (4), the second defluorination chamber (5) and the desulfurization chamber (6).

8. The easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation equipment according to claim 1, characterized in that: The bottom of the arc-shaped recovery tank (13) is fixedly connected to a slag discharge pipe (36), which passes through the partition (34) at the bottom of the first defluorination chamber (4) and is slidably connected to the slag collection section (33).

9. The easy-to-maintain rare earth sulfuric acid concentration and fluorine-containing mixed acid gas separation equipment according to claim 1, characterized in that: The outer diameter of the scraper (11) is the same as the outer diameter of the sliding base (12), and the maximum distance between the scrapers (11) when they are in the open state does not exceed the inner diameter of the arc-shaped recycling trough (13).

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