Preparation equipment and method of diarsenic trioxide

Abstract

The application discloses a preparation equipment and a preparation method of diarsenic trioxide, and the preparation equipment of the diarsenic trioxide comprises a filter press and a cooling crystallization device, the filter press comprises a rack, a plurality of filter plates are movably arranged on the rack in a transverse direction, a pressing mechanism is arranged on the rack and is used for pushing and pressing the plurality of filter plates, a multifunctional filter pressing mechanism comprises a boost air inlet assembly used for pushing the filter cloth of the filter plate outward, a plurality of pushing blocks are fixedly arranged on the filter cloth, and a vibrating block is movably arranged between two adjacent pushing blocks; and the cooling crystallization device comprises a cooling crystallization tank, a feeding pipe is arranged on the upper end of the cooling crystallization tank and is connected with a discharging pipe of the filter press, and a stirring mechanism is arranged on the cooling crystallization tank and is used for mixing and stirring materials in the cooling crystallization tank. The application can effectively assist in improving the overall solid-liquid separation rate of arsenic filter cake slurry, and can facilitate pumping of arsenic leaching solution after crystallization and effectively reduce the solid-liquid separation operation amount of subsequent products.

Description

Technical Field

[0001] This invention relates to the field of arsenic filter cake treatment technology obtained from copper smelting flue gas treatment, specifically to an arsenic trioxide preparation device and preparation method. Background Technology

[0002] Existing equipment for preparing arsenic trioxide mainly includes a filter press for solid-liquid separation of arsenic filter cake slurry and a cooling crystallization device for cooling and crystallizing the arsenic leachate. The filter press is used to separate the solid and liquid components of the arsenic filter cake slurry after oxygen pressure leaching to obtain filter cake residue and As-containing residue. 5+ Leachate; then into the As-containing solution 5+ Sulfur dioxide is added to the leachate for reduction treatment. After the reduction treatment is completed, the leachate is cooled and crystallized in a cooling crystallization device to effectively obtain arsenic trioxide product.

[0003] Existing arsenic trioxide preparation equipment using filter presses mainly comprises multiple filter plates and a fixing cylinder for pressing and fixing the filter cake. Under the pressing action of the fixing cylinder, the multiple filter plates close together to form multiple corresponding filtration chambers. Filter cloths set on the filter plates effectively filter the arsenic filter cake slurry entering the filtration chambers, retaining solids in the filtration chambers outside the filter cloths, while the leachate is discharged through the filter cloths for collection and proceed to the next process. To improve the leachate discharge rate, after filtration, a corresponding washing mechanism is often required to wash the completed filter cake. Although this can achieve solid-liquid separation of the arsenic filter cake slurry with high efficiency, the high compactness of the filter cake after filtration means that the washing process does not significantly improve the discharge rate of the remaining leachate.

[0004] Existing arsenic trioxide preparation equipment using cooling crystallization devices mainly consists of a cooling crystallization tank equipped with a heat exchange jacket. A stirring device within the tank effectively agitates the arsenic leachate, ensuring thorough cooling and crystallization to obtain the desired arsenic trioxide product. The crystallized material is then pumped to a solid-liquid separation unit for separation before being transferred to a drying unit for further drying. Because the crystallized material has a relatively high solids content, this process is not only difficult to pump but also results in a relatively large workload for subsequent solid-liquid separation, making it quite cumbersome.

[0005] Therefore, the research objective of this invention is to design an equipment and method for preparing arsenic trioxide that can effectively and significantly improve the discharge rate of residual leachate during the rinsing process, thereby effectively assisting in improving the overall solid-liquid separation rate of arsenic filter cake slurry; and that can effectively perform solid-liquid separation on a portion of the material after crystallization, and promptly output the crystallized material after solid-liquid separation, so as to facilitate the pumping of the crystallized arsenic leachate and effectively reduce the amount of solid-liquid separation work for subsequent products. Summary of the Invention

[0006] In view of the technical problems existing in the prior art, the present invention provides an apparatus and method for preparing arsenic trioxide, which can effectively solve the technical problems existing in the prior art.

[0007] The technical solution of this invention is:

[0008] An apparatus for preparing arsenic trioxide includes a filter press for solid-liquid separation of arsenic filter cake slurry and a cooling crystallization device for cooling and crystallizing arsenic leachate.

[0009] The filter press includes:

[0010] The frame has multiple corresponding filter plates that are movably mounted laterally. Each of two adjacent filter plates has a corresponding filter chamber on its opposite side. The middle part of each filter plate is connected to a guide tube whose end is located in the filter chamber. The filter plates outside the filter chambers are also connected to filter cloths that are closed in the middle and connected to the guide tubes. The bottom side of each filter plate is connected to a corresponding discharge pipe, and a corresponding discharge valve is fixedly installed on each discharge pipe.

[0011] A pressing mechanism is used to push and press the multiple filter plates together so that two adjacent filter plates form a closed contact with each other. The frame is provided with a pressurized feed pipe whose discharge end is connected to the guide tube of the filter plate located at the end. The pressurized feed pipe is pumped to an external slurry source.

[0012] The multi-functional pressure filter mechanism includes a pressurized air intake component for pushing the filter cloth outward, and several pushing blocks fixed to the filter cloth. Several pointed protrusions are arranged laterally on the outer side of the filter cloth on the pushing blocks. Corresponding vibration blocks are telescopically installed between two adjacent pushing blocks. Corresponding ultrasonic transducers are fixedly embedded in the vibration blocks.

[0013] The cooling crystallization apparatus includes:

[0014] The cooling crystallization tank is equipped with a heat exchange jacket. The heat exchange jacket is provided with a heat exchange medium inlet pipe and a heat exchange medium outlet pipe. The upper end of the cooling crystallization tank is provided with a feed pipe that is pumped to the discharge pipe of the filter press, and the lower end is provided with a corresponding discharge pipe.

[0015] The stirring mechanism is provided, with a corresponding sulfur dioxide addition pipe connected in parallel to the feed pipe. The stirring mechanism is used to mix and stir the materials entering the cooling crystallization tank.

[0016] The stirring mechanism includes a hollow rotating shaft rotatably disposed inside the cooling crystallization tank. The central part of the hollow rotating shaft is connected to corresponding arc-shaped stirring plates via multiple collecting pipes, and the hollow rotating shaft is driven by a corresponding drive motor. The bottom of the hollow rotating shaft is sealed and extends through to the outside of the cooling crystallization tank, and a corresponding discharge check valve is provided at the bottom of the hollow rotating shaft. A corresponding baffle plate is vertically mounted inside the hollow rotating shaft on the upper side of the collecting pipes. The baffle plate is rotatably connected to the piston rod end of a corresponding lifting drive cylinder via a corresponding connecting shaft, and at least one liquid removal check valve for discharging liquid material is installed on the baffle plate. A corresponding filter screen is fixed to the bottom side of the liquid removal check valve, and the opening pressure of the liquid removal check valve is less than the opening pressure of the discharge check valve.

[0017] A corresponding support is fixedly installed on the bottom side of the hollow rotating shaft. The discharge check valve includes a fixed bearing connected to the upper part of the support via a first helical spring. A spherical abutment seal is fixedly installed on the inner ring of the fixed bearing. The upper part of the abutment seal seals against the bottom end of the hollow rotating shaft. A corresponding guide hole is provided in the middle of the abutment seal. The connecting shaft can move through the guide hole and rotatably connect to the piston rod end of the lifting drive cylinder. A set of sealing gaskets with their inner ends abutting against the connecting shaft are embedded in the guide hole. The push plate has corresponding stepped holes at positions corresponding to the liquid removal check valve. The liquid removal check valve includes a spherical valve core for sealing the stepped holes and a second helical spring for fixing the spherical valve core. The stiffness of the second helical spring is less than that of the first helical spring.

[0018] A corresponding isolation cover is provided on the hollow rotating shaft on the lower side of the collecting pipe. Multiple corresponding filter holes are evenly distributed on the hollow rotating shaft in the area where the isolation cover is located, and several corresponding liquid discharge pipes are arranged at intervals on the outside of the isolation cover. The liquid discharge pipes are distributed in an arc shape, and the arc trajectory of the liquid discharge pipes is opposite to the rotation direction of the hollow rotating shaft. The arc trajectory of the arc-shaped stirring plate is consistent with the rotation direction of the hollow rotating shaft.

[0019] The bottom side of the push plate is provided with at least one corresponding fixed mounting groove, and the push plate is provided with a connecting hole whose bottom is connected to the fixed mounting groove. A mounting block that can close the connecting hole is oscillatingly installed in the fixed mounting groove. The mounting block is hollow. When the push plate moves downward, the mounting block contacts the material and swings upward after being subjected to force to close the connecting hole.

[0020] The vibrating blocks are connected to the corresponding filter plates via rubber tubing with pre-embedded helical springs, and the pushing blocks are connected to the filter plates via corresponding elastic elements. The pressurized air intake assembly includes an air intake pipe connected to the filter chamber of the filter plate, and the air intake pipe is connected to an external air compressor via a corresponding pressurizing pipe. The rubber tubing is connected in parallel to the air intake pipe via corresponding solenoid valves, and the rubber tubing is connected in parallel to the outside via a corresponding pressure relief valve. The external air compressor starts to inject high-pressure air into the filter chamber of the filter plate to push the filter cloth to expand outward and squeeze the filter cake for filtration. After filtration is completed, the discharge valve on the discharge pipe opens, and the elastic element drives the pushing blocks to leave the filter cake, forming multiple evenly distributed pointed grooves on the surface of the filter cake. The ultrasonic transducer starts to generate high-frequency vibration. The high-frequency vibration is transmitted through the pointed grooves, causing the filter cake to quickly form cracks. Then, the pressure relief valve opens to release pressure, and the vibrating blocks reset.

[0021] The upper part of the filter chamber of the filter plate is connected to a corresponding rinsing pipe. The rinsing pipe is connected to an external rinsing liquid source through a corresponding rinsing solenoid valve pump. After the vibrating block is reset, the rinsing solenoid valve is opened, and the external rinsing liquid enters the filter chamber of the filter plate through the rinsing pipe to rinse the broken filter cake. After rinsing is completed, the external air compressor is started to pump high-pressure air into the filter chamber of the filter plate to push the filter cloth to expand outward again to squeeze and filter the filter cake.

[0022] The clamping mechanism includes a fixed end plate fixedly installed on the frame and a movable plate movably disposed on the frame. The fixed end plate and the movable plate are respectively located on the outer side of the plurality of filter plates. The movable plate is connected to the piston rod end of the corresponding push hydraulic cylinder. When the piston rod of the push hydraulic cylinder extends, the plurality of filter plates form a closed connection with each other under the clamping action of the fixed end plate and the movable plate.

[0023] The push blocks are fixed to the filter cloth in a circular array, and the push blocks on two adjacent filter cloths are staggered. The ultrasonic transducer is connected to an external ultrasonic generator. The lower part of the frame is provided with a hopper for collecting the broken filter cake.

[0024] A method for preparing arsenic trioxide, based on the aforementioned arsenic trioxide preparation equipment, includes the following specific steps:

[0025] S1, the arsenic filter cake slurry that has undergone oxygen pressure leaching is pumped through the pressurized feed pipe to the space between two adjacent filter plates of the filter press for solid-liquid separation;

[0026] S2, the arsenic leaching solution after solid-liquid separation is pumped through the discharge pipe into the cooling crystallization tank of the cooling crystallization device, and the filter residue is discharged.

[0027] S3, sulfur dioxide is added to the cooling crystallization tank through the sulfur dioxide addition pipe, and the stirring mechanism is started to mix and stir the arsenic leaching solution and sulfur dioxide to carry out the reduction reaction of the arsenic leaching solution;

[0028] S4, a cold medium is continuously introduced into the heat exchange jacket, and the stirring mechanism continues to stir the material. After the reduction reaction is completed, the arsenic leachate is effectively crystallized under cooling conditions to obtain arsenic trioxide.

[0029] S5 is used to discharge the material after crystallization.

[0030] Advantages of this invention:

[0031] 1) The multifunctional filter press mechanism of the present invention not only includes a pressurized air intake assembly for pushing the filter cloth outward, but also includes several pushing blocks fixed to the filter cloth, and corresponding vibrating blocks are telescopically installed between adjacent pushing blocks. Most importantly, several pointed protrusions located on the outer side of the filter cloth are arranged laterally on the pushing blocks, and corresponding ultrasonic transducers are fixedly embedded in the vibrating blocks.

[0032] In the solid-liquid separation process, firstly, an external slurry source is pumped into the space between the filter cloths of two adjacent filter plates via a pressurized feed pipe. Under the pressure of the feed, the solid material is isolated between the two adjacent filter cloths, while the leachate passes through the filter cloth and filtration chamber, and is discharged outwards along the discharge pipe. Then, the external slurry source stops pumping in, the discharge valve on the discharge pipe closes, and the pressurized air intake assembly injects compressed air into the inside of the filter cloth to push the filter cloth outwards, further compressing and filtering the filter cake. At this time, the pointed ridges effectively form transverse pointed grooves on the filter cake. After filtration is complete, the discharge valve opens to allow leaching. After the liquid is discharged, the ultrasonic transducer starts to vibrate. When the vibration is transmitted through the various transverse pointed grooves of the filter cake, stress concentration is formed, which causes the filter cake to produce uniform cracks. Finally, external rinsing liquid is injected into the filter cake between the filter cloths to thoroughly clean the filter cake with uniform cracks. Then, the pressurized air intake component is activated again to inject high-pressure air into the filter chamber of the filter plate to push the filter cloth to expand outward again to squeeze and filter the filter cake. This effectively and significantly improves the discharge rate of residual leachate during the rinsing process, thereby effectively helping to improve the overall solid-liquid separation rate of the arsenic filter cake slurry.

[0033] 2) The stirring mechanism of the cooling crystallization device of the present invention includes a hollow rotating shaft rotatably disposed within the cooling crystallization tank. Multiple collecting pipes connect the central part of the hollow rotating shaft to corresponding arc-shaped stirring plates. During the process of the hollow rotating shaft driving the arc-shaped stirring plates to stir the material, it can promptly guide and collect the solid crystals after crystallization, allowing them to flow into the hollow rotating shaft through the collecting pipes. When outputting the solid crystals flowing into the hollow rotating shaft, the lifting drive cylinder drives the push plate downwards, and the liquid material is discharged through the liquid removal check valve. After the liquid material is discharged, the push plate presses against the upper side of the solid crystals. With the increase of thrust, the solid crystals effectively open the discharge check valve and are discharged. In this way, solid-liquid separation of a portion of the crystallized material can be effectively performed, and the crystals after solid-liquid separation can be promptly output, thereby effectively reducing the solid content in the material, facilitating the pumping of the crystallized arsenic leachate, and effectively reducing the workload of subsequent solid-liquid separation operations.

[0034] 3) A corresponding support is fixedly installed on the bottom side of the hollow rotating shaft of the cooling crystallization device of the present invention. The discharge check valve includes a fixed bearing connected to the upper part of the support via a first helical spring, and an abutment seal is rotatably installed on the inner ring of the fixed bearing. A guide hole is provided in the middle of the abutment seal, and a connecting shaft can move through the guide hole and rotatably connect to the piston rod end of the lifting drive cylinder. A set of sealing gaskets with their inner ends abutting the connecting shaft are embedded in the guide hole. In this way, the rotatable setting of the abutment seal and the ball valve core can be effectively realized to adapt to the stirring and rotation requirements of the hollow rotating shaft, and the installation sealing of the connecting shaft can be effectively ensured to ensure the practical effect of the present invention.

[0035] 4) The hollow rotating shaft on the lower side of the collecting pipe of the cooling crystallization device of the present invention is equipped with an isolation cover. Multiple corresponding filter holes are evenly distributed on the hollow rotating shaft in the area where the isolation cover is located. Several corresponding liquid discharge pipes are arranged at intervals outside the isolation cover. These liquid discharge pipes are arc-shaped, and their arc trajectory is opposite to the rotation direction of the hollow rotating shaft, while the arc trajectory of the arc-shaped stirring plate is consistent with the rotation direction of the hollow rotating shaft. In this way, the arc-shaped stirring plate can perform shovel-style stirring of the material as the hollow rotating shaft rotates, thus ensuring both the stirring effect and effectively guiding the solid crystals in the material to the collecting pipe. The liquid discharge pipes, while assisting in stirring the material, effectively throw out the liquid material through centrifugal force, thereby ensuring the smooth collection of solid crystals.

[0036] 5) The bottom side of the baffle plate of the cooling crystallization device of the present invention is provided with at least one corresponding fixed insert groove and a connecting hole that connects to the fixed insert groove at the bottom. An insert block capable of sealing the connecting hole is oscillatingly installed in the fixed insert groove. The insert block is hollow and therefore has a certain buoyancy. When the baffle plate moves downward, the insert block contacts the material and swings upward to seal the connecting hole of the baffle plate, so as to facilitate solid-liquid separation of the material and smooth output of solid crystals. When the baffle plate moves upward, the insert block swings downward under the action of gravity to release the seal of the connecting hole, thereby ensuring that the baffle plate can be smoothly driven upward to reset and effectively guide the material in the upper part of the baffle plate back to its bottom side, so as to further ensure the practical effect of the present invention.

[0037] 6) The vibrating blocks of the filter press of the present invention are connected to the corresponding filter plates through rubber tubes with pre-embedded helical springs, the push block is connected to the filter plates through corresponding elastic elements, and the rubber tubes of the present invention are connected in parallel to the air inlet pipe of the booster air inlet assembly through corresponding solenoid valves, and the rubber tubes are connected in parallel to the outside of the corresponding pressure relief valves.

[0038] When the filter cloth of the filter press expands outward to compress and filter the filter cake, the discharge valve on the discharge pipe opens. The elastic element drives the push block to promptly move away from the filter cake, creating multiple evenly distributed pointed grooves on the filter cake surface. Meanwhile, the vibrating block maintains full contact with the filter cake. At this point, the ultrasonic transducer restarts, generating high-frequency vibration. This high-frequency vibration, transmitted through the pointed grooves of the filter cake, creates more sufficient stress concentration, ensuring that the filter cake quickly forms evenly distributed cracks. Then, the pressure relief valve opens to release pressure and reset the vibrating block. This significantly improves the practical effect of the invention.

[0039] 7) Since the push blocks of the filter press of the present invention are fixed to the filter cloth in a ring array, and the push blocks on two adjacent filter cloths are staggered, a denser pointed groove is formed at different positions on both sides of the filter cake, thereby increasing the amount of cracks in the filter cake, so as to help improve the discharge rate of residual leachate during the rinsing process. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of the present invention.

[0041] Figure 2 This is a schematic diagram of the filter press installation.

[0042] Figure 3 This is a schematic diagram of a filter press.

[0043] Figure 4 This is a schematic diagram of a filter plate with filter cloth installed on it.

[0044] Figure 5 This is a schematic diagram of the assembly of the booster intake assembly with the filter plate.

[0045] Figure 6 This is a schematic diagram of the assembly of the jacking block and the vibrating block.

[0046] Figure 7 This is a schematic diagram of the installation of the cooling crystallization device.

[0047] Figure 8 This is a schematic diagram of a cooling crystallization apparatus.

[0048] Figure 9 This is a cross-sectional view of the cooling crystallization apparatus.

[0049] Figure 10 This is a schematic diagram of the mixing mechanism assembly.

[0050] Figure 11 This is a cross-sectional view of the assembly of the stirring mechanism.

[0051] Figure 12 This is an assembly diagram of the discharge check valve.

[0052] Figure 13 This is a schematic diagram of the assembly of the liquid removal check valve.

[0053] In the attached diagram: 1. Frame; 2. Filter plate; 201. Filter chamber; 202. Guide tube; 203. Filter cloth; 204. Discharge pipe; 2041. Discharge valve; 3. Pressing mechanism; 3. Fixed end plate; 301. Movable plate; 302. Pushing hydraulic cylinder; 303. Pressurized feed pipe; 4. Multifunctional filter press mechanism; 5. Pressurized air intake assembly; 501. Air intake pipe; 5011. Pressurized pipe; 5012. Pushing block; 502. Sharp vibration block; 6. Shaped convex ridge; 7. Ultrasonic transducer; 8. Cooling crystallization tank; 801. Feed pipe; 802. Discharge pipe; 8021. Discharge pump; 803. Cover plate; 9. Heat exchange jacket; 901. Heat exchange medium inlet pipe; 902. Heat exchange medium outlet pipe; 10. Stirring mechanism; 11. Hollow rotating shaft. 001, Collection pipe 1002, Arc-shaped stirring plate 1003, Drive motor 1004, Sulfur dioxide addition pipe 11, Discharge check valve 12, First helical spring 1201, Fixed bearing 1202, Abutment seal 1203, Baffle plate 13, Connecting shaft 14, Lifting drive cylinder 15, Filter screen plate 16, Liquid removal check valve 17, Ball valve core 1701, Second helical spring 1702, Support 18, Sealing gasket 19, Isolation cover 20, Liquid discharge pipe 21, Fixed embedding groove 22, Embedding block 23, Rubber fittings 24, Elastic element 25, Solenoid valve 26, Pressure relief valve 27, Washing pipe 28, Washing solenoid valve 29, Discharge hopper 30. Detailed Implementation

[0054] To facilitate understanding by those skilled in the art, the structure of the present invention will now be described in further detail with reference to the accompanying drawings:

[0055] Example 1

[0056] refer to Figure 1-13 An apparatus for preparing arsenic trioxide includes a filter press for solid-liquid separation of arsenic filter cake slurry and a cooling crystallization device for cooling and crystallizing arsenic leachate.

[0057] The filter press includes:

[0058] A frame 1 is provided, on which multiple corresponding filter plates 2 are movably mounted laterally. Each of two adjacent filter plates 2 has a corresponding filter chamber 201 on its opposite side. The middle part of each filter plate 2 is connected to a conduit 202 with its end located inside the filter chamber 201. Filter cloth 203 with its middle closed and connected to the conduit 202 is also fixedly attached to the filter plate 2 outside the filter chamber 201. The bottom side of each filter plate 2 is connected to a corresponding discharge pipe 204, and a corresponding discharge valve 2041 is fixedly installed on each discharge pipe 204.

[0059] The pressing mechanism 3 is used to push and press the multiple filter plates 2 so that two adjacent filter plates 2 form a closed contact with each other. The frame 1 is provided with a pressurized feed pipe 4 whose discharge end is connected to the guide pipe 202 of the filter plate 2 located at the end. The pressurized feed pipe 4 is pumped to an external slurry source.

[0060] The multi-functional pressure filter mechanism 5 includes a pressurized air intake component 501 for pushing the filter cloth 203 outward, and a plurality of pushing blocks 502 fixed to the filter cloth 203. The pushing blocks 502 are respectively provided with a plurality of pointed protrusions 6 located on the outer side of the filter cloth 203. A corresponding vibration block 503 is telescopically installed between two adjacent pushing blocks 502. A corresponding ultrasonic transducer 7 is fixedly embedded in the vibration block 503.

[0061] The cooling crystallization apparatus includes:

[0062] The cooling crystallization tank 8 is equipped with a heat exchange jacket 9 on its periphery. The heat exchange jacket 9 is provided with a heat exchange medium inlet pipe 901 and a heat exchange medium outlet pipe 902. The upper end of the cooling crystallization tank 8 is provided with a feed pipe 801 that is pumped to the discharge pipe 204 of the filter press, and the lower end is provided with a corresponding discharge pipe 802.

[0063] The stirring mechanism 10 is provided, and a corresponding sulfur dioxide addition pipe 11 is connected in parallel to the feed pipe 801. The stirring mechanism 10 is used to mix and stir the materials entering the cooling crystallization tank.

[0064] The discharge pipe 802 of the cooling crystallization tank 8 is connected in parallel to a set of corresponding discharge pumps 8021 through a set of corresponding discharge valves; the top of the cooling crystallization tank 8 is provided with a corresponding inspection port that can be opened and closed, and a corresponding cover plate 803 is installed at the inspection port.

[0065] In the solid-liquid separation process, firstly, the external slurry source is pumped into the filter cloth 203 between two adjacent filter plates 2 via the pressurized feed pipe 4. Under the pressure of the feed, the solid material is isolated between the two adjacent filter cloths 203, while the leachate passes through the filter cloth 203 and the filter chamber 201, and is discharged along the discharge pipe 204. Then, the external slurry source stops pumping in, the discharge valve 2041 on the discharge pipe 204 is closed, and the pressurized air intake assembly 501 pumps compressed air into the inside of the filter cloth 203 to push the filter cloth 203 outward to further compress and filter the filter cake. At this time, the pointed ridges 6 effectively form transverse pointed grooves on the filter cake. After filtration is completed, the discharge... The material valve 2041 is opened to discharge the leachate. Then, the ultrasonic transducer 7 starts to vibrate. When the vibration is transmitted through the transverse pointed grooves of the filter cake, stress concentration is formed, which causes the filter cake to produce uniform cracks. Finally, external rinsing liquid is injected into the filter cake between the filter cloths 203 to thoroughly clean the filter cake with uniform cracks. Then, the pressurized air intake component 501 is started again to inject high-pressure air into the filter chamber 201 of the filter plate 2 to push the filter cloth 203 to expand outward again to squeeze and filter the filter cake. This effectively and significantly improves the discharge rate of residual leachate during the rinsing process, thereby effectively helping to improve the overall solid-liquid separation rate of the arsenic filter cake slurry.

[0066] The stirring mechanism 10 includes a hollow rotating shaft 1001 rotatably disposed within the cooling crystallization tank 8. A plurality of collecting pipes 1002 connect the central portion of the hollow rotating shaft 1001 to corresponding arc-shaped stirring plates 1003. The hollow rotating shaft 1001 is driven by a corresponding drive motor 1004. The bottom of the hollow rotating shaft 1001 extends through to the outside of the cooling crystallization tank 8, and a corresponding discharge check valve 1 is provided at the bottom of the hollow rotating shaft 1001. 2. A corresponding baffle plate 13 is installed in the hollow rotating shaft 1001 on the upper side of the collecting pipe 1002. The baffle plate 13 is rotatably connected to the piston rod end of the corresponding lifting drive cylinder 15 through a corresponding connecting shaft 14. At least one liquid discharge check valve 17 for discharging liquid material is installed on the baffle plate 13. A corresponding filter screen plate 16 is fixed to the bottom side of the liquid discharge check valve 17. The opening pressure of the liquid discharge check valve 17 is less than the opening pressure of the discharge check valve 12.

[0067] During the process of the hollow rotating shaft 1001 driving the arc-shaped stirring plate 1003 to stir the material, it can promptly guide and collect the solid crystals after crystallization, allowing them to flow into the hollow rotating shaft 1001 through the collection pipe 1002. When the solid crystals flowing into the hollow rotating shaft 1001 are discharged, the lifting drive cylinder 15 drives the push plate 13 downward, and the liquid material is discharged through the liquid removal check valve 17. After the liquid material is discharged in place, the push plate 13 presses against the upper side of the solid crystals. With the increase of thrust, the solid crystals effectively open the discharge check valve 12 and are discharged. In this way, the solid-liquid separation of a portion of the crystallized material can be effectively performed, and the crystals after solid-liquid separation can be promptly discharged, thereby effectively reducing the solid content in the material, facilitating the pumping of the crystallized arsenic leachate, and effectively reducing the workload of subsequent solid-liquid separation operations.

[0068] A corresponding support member 18 is fixedly installed on the bottom side of the hollow rotating shaft 1001. The discharge one-way valve 12 includes a fixed bearing 1202 connected to the upper part of the support member 18 by a first helical spring 1201. An abutment seal 1203 with a spherical top is fixedly installed on the inner ring of the fixed bearing 1202. The upper part of the abutment seal 1203 seals against the bottom end of the hollow rotating shaft 1001. A corresponding guide hole is provided in the middle of the abutment seal 1203. The connecting shaft 14 can move through the guide hole. The piston rod end, rotatably connected to the lifting drive cylinder 15, has a set of sealing gaskets 19 embedded in the guide hole, with their inner ends abutting against the connecting shaft 14. The push plate 13 has corresponding stepped holes at positions corresponding to the liquid removal check valve 17. The liquid removal check valve 17 includes a spherical valve core 1701 for sealing the stepped holes and a second helical spring 1702 for providing fixed support to the spherical valve core 1701. The stiffness of the second helical spring 1702 is less than that of the first helical spring 1201. This effectively achieves the rotatable arrangement of the sealing element 1203 and the spherical valve core 1701, thus adapting to the stirring rotation requirements of the hollow rotating shaft 1001, and effectively ensuring the sealing performance of the connecting shaft 14, thereby ensuring the practical effect of the invention.

[0069] A corresponding isolation cover 20 is provided on the hollow rotating shaft 1001 on the lower side of the collecting pipe 1002. Multiple corresponding filter holes are evenly distributed on the hollow rotating shaft 1001 in the area where the isolation cover 20 is located. Several corresponding liquid discharge pipes 21 are arranged at intervals on the outside of the isolation cover 20. The liquid discharge pipes 21 are distributed in an arc shape, and the arc trajectory of the liquid discharge pipes 21 is opposite to the rotation direction of the hollow rotating shaft 1001. The arc trajectory of the arc-shaped stirring plate 1003 is consistent with the rotation direction of the hollow rotating shaft 1001. In this way, the arc-shaped stirring plate 1003 can perform shovel-type stirring of the material as the hollow rotating shaft 1001 rotates, thereby ensuring the stirring effect of the material and effectively guiding the solid crystals in the material to the collection pipe 1002. Meanwhile, the liquid discharge pipe 21 can effectively throw out the liquid material through centrifugal force while assisting in the stirring of the material, thereby effectively ensuring that the collection of solid crystals can be carried out smoothly.

[0070] The bottom side of the push plate 13 is provided with at least one corresponding fixed mounting groove 22, and the push plate 13 is provided with a connecting hole whose bottom is connected to the fixed mounting groove 22. A mounting block 23 capable of closing the connecting hole is oscillatingly installed in the fixed mounting groove 22. The mounting block 23 is hollow. When the push plate 13 moves downward, the mounting block 23 contacts the material and swings upward after being subjected to force to close the connecting hole.

[0071] Due to the hollow design of the insert block 23, it possesses a certain degree of buoyancy. When the baffle plate 13 moves downward, the insert block 23, upon contact with the material and subjected to force, swings upward to seal the connecting hole of the baffle plate 13, facilitating solid-liquid separation and the smooth output of solid crystals. Conversely, when the baffle plate 13 moves upward, the insert block 23, under the influence of gravity, swings downward to release the seal of the connecting hole, thereby ensuring that the baffle plate 13 can be smoothly driven upward and reset, and effectively guiding the material on the upper part of the baffle plate 13 back to its bottom side, further ensuring the practical effect of the invention.

[0072] The vibrating blocks 503 are connected to the corresponding filter plates 2 via rubber tubes 24 with pre-embedded helical springs, and the pushing blocks 502 are connected to the filter plates 2 via corresponding elastic elements 25; the pressurized air intake assembly 501 includes an air intake pipe 5011 connected to the filter chamber 201 of the filter plate 2, and the air intake pipe 5011 is connected to an external air compressor via a corresponding pressurizing pipe 5012; the rubber tubes 24 are connected in parallel to the air intake pipes 5011 via corresponding solenoid valves 26, and the rubber tubes 24 are connected in parallel to the outside with corresponding vents. Pressure valve 27; the external air compressor starts to inject high-pressure air into the filter chamber 201 of the filter plate 2, so as to push the filter cloth 203 to expand outward and squeeze the filter cake for filtration. After filtration is completed, the discharge valve 2041 on the discharge pipe 204 opens, and the elastic element 25 drives the push block 502 to leave the filter cake, and multiple evenly distributed pointed grooves are formed on the surface of the filter cake; the ultrasonic transducer 7 starts to generate high-frequency vibration. The high-frequency vibration is transmitted through the pointed grooves to make the filter cake quickly form cracks. Then the pressure relief valve 27 opens to release pressure, and the vibration block 503 resets.

[0073] When the filter cloth 203 of the filter press expands outward to squeeze and filter the filter cake, the discharge valve 2041 on the discharge pipe 204 opens, and the elastic element 25 can drive the push block 502 to leave the filter cake in time, so that multiple evenly distributed pointed grooves are formed on the surface of the filter cake, while the vibrating block 503 still maintains full contact with the filter cake; at this time, the ultrasonic transducer 7 starts again to generate high-frequency vibration, which can make the high-frequency vibration form a more sufficient stress concentration when it is transmitted through the pointed grooves of the filter cake, thereby ensuring that the filter cake can quickly form evenly distributed cracks.

[0074] The upper part of the filter chamber 201 of the filter plate 2 is connected to a corresponding rinsing pipe 28. The rinsing pipe 28 is pumped to an external rinsing liquid source through a corresponding rinsing solenoid valve 29. After the vibrating block 503 is reset, the rinsing solenoid valve 29 is opened, and the external rinsing liquid enters the filter chamber 201 of the filter plate 2 through the rinsing pipe 28 to rinse the broken filter cake. After rinsing is completed, the external air compressor is started to pump high-pressure air into the filter chamber 201 of the filter plate 2 to push the filter cloth 203 to expand outward again to squeeze and filter the filter cake.

[0075] The clamping mechanism 3 includes a fixed end plate 301 fixedly installed on the frame 1 and a movable plate 302 movably installed on the frame 1. The fixed end plate 301 and the movable plate 302 are respectively located on the outside of the plurality of filter plates 2. The movable plate 302 is connected to the piston rod end of the corresponding push hydraulic cylinder 303. When the piston rod of the push hydraulic cylinder 303 extends, the plurality of filter plates 2 form a closed connection with each other under the clamping action of the fixed end plate 301 and the movable plate 302.

[0076] The push blocks 502 are fixed to the filter cloth 203 in a ring array, and the push blocks 502 on two adjacent filter cloths 203 are staggered to form denser pointed grooves at different positions on both sides of the filter cake, thereby increasing the amount of cracks in the filter cake and helping to improve the discharge rate of residual leachate during the rinsing process; the ultrasonic transducer 7 is connected to an external ultrasonic generator; the lower part of the frame 1 is provided with a hopper 30 for collecting the broken filter cake.

[0077] Example 2:

[0078] A method for preparing arsenic trioxide, based on the arsenic trioxide preparation equipment described in Example 1 above, includes the following specific steps:

[0079] S1, the arsenic filter cake slurry that has been oxygen-pressure leaching is pumped through the pressurized feed pipe 4 to the space between two adjacent filter plates 2 of the filter press for solid-liquid separation;

[0080] S2, the arsenic leaching solution after solid-liquid separation is pumped through discharge pipe 204 into the cooling crystallization tank 8 of the cooling crystallization device, and the filter residue is discharged.

[0081] S3, sulfur dioxide is added to the cooling crystallization tank 8 through the sulfur dioxide addition pipe 11, and the stirring mechanism 10 is started to mix and stir the arsenic leaching solution and sulfur dioxide to carry out the reduction reaction of the arsenic leaching solution;

[0082] S4, a cold medium is continuously introduced into the heat exchange jacket 9, and the stirring mechanism 10 continues to stir the material. After the reduction reaction is completed, the arsenic leaching solution is effectively crystallized under cooling conditions to obtain arsenic trioxide.

[0083] S5 is used to discharge the material after crystallization.

[0084] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An apparatus for preparing arsenic trioxide, comprising a filter press for solid-liquid separation of arsenic filter cake slurry and a cooling crystallization device for cooling and crystallizing arsenic leachate, characterized in that, The filter press includes: A frame (1) is provided with multiple corresponding filter plates (2) that are movably mounted laterally. Each of two adjacent filter plates (2) has a corresponding filter chamber (201) on its opposite side. The middle part of each filter plate (2) is connected to a conduit (202) with its end located inside the filter chamber (201). Filter cloths (203) that are closed in the middle and connected to the conduit (202) are also fixedly connected to the filter plates (2) outside the filter chamber (201). The bottom side of each filter plate (2) is connected to a corresponding discharge pipe (204) that is fixedly mounted on the discharge pipe (204). A corresponding discharge valve (2041) is fixedly mounted on each discharge pipe (204). The pressing mechanism (3) is used to push and press the multiple filter plates (2) so that two adjacent filter plates (2) form a closed contact with each other. The frame (1) is provided with a pressurized feed pipe (4). The discharge end of the pressurized feed pipe (4) is connected to the guide pipe (202) of the filter plate (2) located at the end. The pressurized feed pipe (4) is pumped to an external slurry source. The multi-functional pressure filter mechanism (5) includes a pressurized air intake assembly (501) for pushing the filter cloth (203) outward, and a plurality of push blocks (502) fixed to the filter cloth (203). The push blocks (502) are provided with a plurality of pointed ridges (6) located on the outer side of the filter cloth (203) in a horizontal direction. A corresponding vibration block (503) is telescopically installed between two adjacent push blocks (502). A corresponding ultrasonic transducer (7) is fixedly embedded in the vibration block (503). The cooling crystallization apparatus includes: The cooling crystallization tank (8) is equipped with a corresponding heat exchange jacket (9) on its periphery. The heat exchange jacket (9) is provided with a heat exchange medium inlet pipe (901) and a heat exchange medium outlet pipe (902). The upper end of the cooling crystallization tank (8) is provided with a feed pipe (801) that is pumped to the discharge pipe (204) of the filter press, and the lower end is provided with a corresponding discharge pipe (802). The stirring mechanism (10) is connected in parallel to the feed pipe (801) with a corresponding sulfur dioxide addition pipe (11). The stirring mechanism (10) is used to mix and stir the material entering the cooling crystallization tank.

2. The apparatus for preparing arsenic trioxide according to claim 1, characterized in that, The stirring mechanism (10) includes a hollow rotating shaft (1001) rotatably disposed inside the cooling crystallization tank (8). The middle of the hollow rotating shaft (1001) is connected to a corresponding arc-shaped stirring plate (1003) via multiple collecting pipes (1002). The hollow rotating shaft (1001) is driven by a corresponding drive motor (1004). The bottom of the hollow rotating shaft (1001) is sealed and extends to the outside of the cooling crystallization tank (8). A corresponding discharge check valve (12) is provided at the bottom of the hollow rotating shaft (1001). The hollow rotating shaft (1001) on the upper side of the collecting pipe (1002) is equipped with a corresponding baffle plate (13) that can be raised and lowered. The baffle plate (13) is rotatably connected to the piston rod end of the corresponding lifting drive cylinder (15) through the corresponding connecting shaft (14). At least one liquid discharge check valve (17) for discharging liquid material is installed on the baffle plate (13). The bottom side of the liquid discharge check valve (17) is fixed with a corresponding filter screen plate (16). The opening pressure of the liquid discharge check valve (17) is less than the opening pressure of the discharge check valve (12).

3. The apparatus for preparing arsenic trioxide according to claim 2, characterized in that, A corresponding support member (18) is fixedly provided on the bottom side of the hollow rotating shaft (1001). The discharge one-way valve (12) includes a fixed bearing (1202) connected to the upper part of the support member (18) by a first helical spring (1201). An abutment seal (1203) with a spherical top is fixedly installed on the inner ring of the fixed bearing (1202). The upper part of the abutment seal (1203) seals against the bottom end of the hollow rotating shaft (1001). A corresponding guide hole is provided in the middle of the abutment seal (1203), and the connecting shaft (14) can move through the guide hole. The piston rod end is rotatably connected to the lifting drive cylinder (15). A set of sealing gaskets (19) with their inner ends abutting against the connecting shaft (14) are embedded in the guide hole. The push plate (13) is provided with corresponding stepped holes at the positions corresponding to the liquid removal check valve (17). The liquid removal check valve (17) includes a ball valve core (1701) for forming a closure of the stepped hole and a second helical spring (1702) for forming a fixed support for the ball valve core (1701). The stiffness of the second helical spring (1702) is less than the stiffness of the first helical spring (1201).

4. The apparatus for preparing arsenic trioxide according to claim 3, characterized in that, A corresponding isolation cover (20) is provided on the hollow rotating shaft (1001) on the lower side of the collecting pipe (1002). Multiple corresponding filter holes are evenly distributed on the hollow rotating shaft (1001) in the area where the isolation cover (20) is located. Several corresponding liquid discharge pipes (21) are arranged at intervals on the outside of the isolation cover (20). The liquid discharge pipes (21) are distributed in an arc shape, and the arc trajectory of the liquid discharge pipes (21) is opposite to the rotation direction of the hollow rotating shaft (1001). The arc trajectory of the arc-shaped stirring plate (1003) is consistent with the rotation direction of the hollow rotating shaft (1001).

5. The apparatus for preparing arsenic trioxide according to claim 4, characterized in that, The bottom side of the push plate (13) is provided with at least one corresponding fixed mounting groove (22), and the push plate (13) is provided with a connecting hole whose bottom is connected to the fixed mounting groove (22). A mounting block (23) capable of closing the connecting hole is oscillatingly installed in the fixed mounting groove (22). The mounting block (23) is hollow. When the push plate (13) moves downward, the mounting block (23) contacts the material and swings upward after being subjected to force to close the connecting hole.

6. The apparatus for preparing arsenic trioxide according to claim 1, characterized in that, The vibrating blocks (503) are connected to the corresponding filter plates (2) via rubber fittings (24) with pre-embedded helical springs, and the push blocks (502) are connected to the filter plates (2) via corresponding elastic elements (25); the booster air intake assembly (501) includes an air intake pipe (5011) connected to the filter chamber (201) of the filter plate (2), and the air intake pipe (5011) is connected to an external air compressor via a corresponding booster pipe (5012); the rubber fittings (24) are connected in parallel to the air intake pipe (5011) via corresponding solenoid valves (26), and the rubber fittings (24) are connected outward in parallel. There is a corresponding pressure relief valve (27); the external air compressor starts to inject high-pressure air into the filter chamber (201) of the filter plate (2) to push the filter cloth (203) to expand outward and squeeze the filter cake for filtration. After filtration is completed, the discharge valve (2041) on the discharge pipe (204) is opened, and the elastic element (25) drives the push block (502) to leave the filter cake. Multiple evenly distributed pointed grooves are formed on the surface of the filter cake. The ultrasonic transducer (7) starts to generate high-frequency vibration. The high-frequency vibration is transmitted through the pointed grooves to make the filter cake quickly form cracks. Then the pressure relief valve (27) opens to release pressure, and the vibration block (503) is reset.

7. The apparatus for preparing arsenic trioxide according to claim 6, characterized in that, The upper part of the filter chamber (201) of the filter plate (2) is connected to a corresponding rinsing pipe (28). The rinsing pipe (28) is pumped to the external rinsing liquid source through the corresponding rinsing solenoid valve (29). After the vibrating block (503) is reset, the rinsing solenoid valve (29) is opened, and the external rinsing liquid enters the filter chamber (201) of the filter plate (2) through the rinsing pipe (28) to rinse the broken filter cake. After rinsing is completed, the external air compressor is started to pump high-pressure air into the filter chamber (201) of the filter plate (2) to push the filter cloth (203) to expand outward again to squeeze and filter the filter cake.

8. The apparatus for preparing arsenic trioxide according to claim 7, characterized in that, The pressing mechanism (3) includes a fixed end plate (301) fixedly installed on the frame (1) and a movable plate (302) movably installed on the frame (1). The fixed end plate (301) and the movable plate (302) are respectively located on the outside of the plurality of filter plates (2). The movable plate (302) is connected to the piston rod end of the corresponding push hydraulic cylinder (303). When the piston rod of the push hydraulic cylinder (303) extends, the plurality of filter plates (2) form a closed connection with each other under the pressing action of the fixed end plate (301) and the movable plate (302).

9. The apparatus for preparing arsenic trioxide according to claim 8, characterized in that, The push blocks (502) are fixed to the filter cloth (203) in a ring array, and the push blocks (502) on two adjacent filter cloths (203) are staggered. The ultrasonic transducer (7) is connected to an external ultrasonic generator. The lower part of the frame (1) is provided with a feeding hopper (30) for collecting the broken filter cake.

10. A method for preparing arsenic trioxide, based on the arsenic trioxide preparation apparatus according to any one of claims 1-9, characterized in that, It includes the following specific steps: S1, the arsenic filter cake slurry that has been oxygen-pressure leaching is pumped through the pressurized feed pipe (4) to the space between two adjacent filter plates (2) of the filter press for solid-liquid separation; S2, the arsenic leaching solution after solid-liquid separation is pumped through the discharge pipe (204) into the cooling crystallization tank (8) of the cooling crystallization device, and the filter residue is discharged. S3, sulfur dioxide is added to the cooling crystallization tank (8) through the sulfur dioxide addition pipe (11), and the stirring mechanism (10) is started to mix and stir the arsenic leaching solution and sulfur dioxide to carry out the reduction reaction of the arsenic leaching solution; S4, cold medium is continuously introduced into the heat exchange jacket (9), and the stirring mechanism (10) continues to stir the material. After the reduction reaction is completed, the arsenic leaching solution is effectively crystallized under cooling conditions to obtain arsenic trioxide. S5 is used to discharge the material after crystallization.

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