A rare earth chloride concentration crystallization system

Abstract

The utility model discloses a kind of chlorinated rare earth concentration crystallization systems, belong to rare earth production technical field.It include heating kettle, still include steam condensation recovery and high-efficiency vapor-liquid separator, the steam condensation recovery is installed on heating kettle, steam condensation recovery is communicated with heating kettle by high-efficiency vapor-liquid separator, liquid inlet metering device and steam condensate metering device are also communicated and arranged on heating kettle, steam condensation recovery is communicated and arranged with distilled water outlet metering device, and distilled water outlet metering device is connected with vacuum system.The utility model uses "low-temperature steam crystallization system" treatment process to carry out normal temperature deep evaporation, remove heavy metal, salt and most organic matter, evaporated water can be reused, and evaporated chlorinated rare earth crystalline salt is directly packaged into product.

Description

Technical Field

[0001] This utility model relates to the field of rare earth production technology, specifically to a rare earth chloride concentration and crystallization system. Background Technology

[0002] Rare earth chlorides, as important rare earth compounds, are widely used in rare earth metals, petrochemicals, agriculture, medicine, electronic equipment and communications, optoelectronics, energy, and environmental protection. In agriculture, rare earth chlorides can improve plant stress resistance; in medicine, lanthanum chloride can inhibit the growth of tumor cells; in functional materials, lanthanum chloride hydrate is an antiferromagnetic material that can be used as a storage medium for data storage and can also be used to prepare magnetic sensors and other devices; in light industry, rare earth chlorides are used in leather tanning and textile dyeing; and in environmental protection, rare earth chlorides can be used to treat fluoride-containing and phosphorus-containing wastewater.

[0003] In addition, rare earth chlorides are also raw materials for the preparation of rare earth metals by chloride electrolysis. Rare earth chlorides can also be used to prepare high-temperature ceramic materials and electronic components such as piezoelectric ceramics. Cerium chloride is an indispensable and important raw material for petroleum catalytic cracking FCC.

[0004] Industrially, rare earth ores or rare earth-containing raw materials are usually decomposed by acid or alkali methods. After impurity removal or transformation, a mixed rare earth chloride solution is obtained, which is then extracted and separated to obtain a single rare earth chloride solution or a rare earth-enriched chloride solution.

[0005] The crystallization and drying process of rare earth chloride solution typically uses a steam-jacketed vacuum crystallization enamel tank. Indirect steam heating and vacuum lower the boiling point to promote crystal formation. After the rare earth solution is concentrated to the required content, it is discharged from the enamel-lined reactor in a high-temperature viscous flow state. It is then cooled and solidified by a rotary belt condenser to become solid rare earth chloride. Finally, it is manually crushed and packaged to complete the production process.

[0006] Commonly used concentration equipment (steam-jacketed vacuum crystallization enamel tank) requires heating the temperature to above 100°C and boiling for a long time. After one batch of material is concentrated, it is transferred away and then another batch is transferred in and heated again. The equipment occupies a large area, the concentration efficiency is low, the concentration cost is high, and the output is affected.

[0007] The main operating procedures of commonly used concentration equipment, enamel-lined kettle vacuum crystallization, are as follows: 1) Check that the concentration vacuum system is normal. 2) Measure and add rare earth chloride solution to the concentration tank, open the steam valve for heating, open the water inlet valve of the vacuum jacket condenser, and start the jet pump. 3) After the volume of the concentrated liquid in the concentration tank decreases, add a quantitative amount of liquid. 4) When the amount of liquid added reaches the upper limit / requirement for processing, stop adding liquid and take a sample to analyze the purity of REO (rare earth element oxides). If the requirement is not met, continue heating until the requirement is met. 5) Under negative pressure, open the bottom valve of the kettle, then open the kettle lid, close the vacuum system, and after the hot material has settled and stabilized, start discharging. Let the hot material flow naturally into the cooling crystallization tray after passing through a 140-mesh sieve, and cool it through a rotary belt condenser granulator to achieve solidification and molding, becoming solid rare earth chloride, which is then packaged as the product. 6) After the material is discharged, close the kettle lid, start the vacuum system, suck the remaining material in the bottom valve of the kettle into the tank, then close the bottom valve of the tank and start the next production process.

[0008] The disadvantages of the aforementioned existing technology are: 1) Limited temperature control; large temperature differences may cause the enamel layer to crack. 2) Regular cleaning and maintenance are required to prevent a decrease in heat transfer efficiency. 3) Sudden temperature changes and impacts from hard objects must be avoided during operation to prevent damage to the enamel layer. 4) Heat exchange efficiency is lower than that of metal containers. 5) Additional drying and crushing processes are required, affecting the efficiency and stability of the equipment. 6) The crystallized material cannot be emptied; the oil suspended on the surface must remain in the concentration tank, and the floating oil in the crystallization tank must be skimmed off frequently to ensure the liquid is clear and the light transmittance meets the standard requirements. 7) The product is in a lumpy, plate-like form; rare earth chloride products have poor water solubility and will produce turbidity after dissolution. 8) Intermittent manual operation results in poor product stability and low efficiency. Utility Model Content

[0009] The purpose of this invention is to provide a rare earth chloride concentration and crystallization system to solve the problems mentioned in the background art.

[0010] The technical solution adopted in this utility model is as follows:

[0011] A rare earth chloride concentration and crystallization system includes a heating kettle, a steam condenser and a high-efficiency vapor-liquid separator. The steam condenser is installed on the heating kettle and is connected to the heating kettle through the high-efficiency vapor-liquid separator. The heating kettle is also connected to an inlet metering device and a steam condensate metering device. The steam condenser is connected to a distilled water outlet metering device, which is connected to a vacuum system.

[0012] The inlet of the liquid metering device is connected to the raw liquid tank via a diaphragm pump, and the outlet of the liquid metering device is connected to the heating kettle.

[0013] The heating vessel is equipped with a jacket, and a heating half-pipe is spirally wound on the outer wall of the heating vessel inside the jacket. The heating half-pipe is connected to the steam condensate outlet located below the vessel body and the heating steam inlet located above the vessel body.

[0014] The drive shaft of the heating vessel is equipped with a single-end mechanical seal. A drip pipe is installed above the mechanical seal, and a water tank with an overflow drain is installed below the mechanical seal.

[0015] The heating vessel is equipped with a stirring system, which includes a guide rod seat, a guide rod, a spring, a scraper seat, and a scraper. The guide rod seat is mounted on the drive shaft of the heating vessel, the guide rod is mounted on the guide rod seat, the scraper seat is mounted on the outer end of the guide rod, the scraper is mounted on the scraper seat, and the scraper blade is attached to the inner wall of the heating vessel. The spring is sleeved on the guide rod between the guide rod seat and the scraper seat.

[0016] The vacuum system includes a water ring vacuum pump, and the distilled water output metering device includes a steam crystallization negative pressure water tank. The top cover of the steam crystallization negative pressure water tank is provided with an air inlet, a vacuum pump exhaust port, and condensate and gas extraction ports. The water ring vacuum pump is connected to the vacuum pump exhaust port. A liquid level sensor is installed inside the steam crystallization negative pressure water tank, and a drain pump is also connected to the steam crystallization negative pressure water tank.

[0017] The steam condensate metering device is connected to the steam condensate outlet of the heating kettle via a steam trap. The steam condensate metering device includes a condensate tank, a level sensor is installed on the condensate tank, and a drain pump is also connected to the condensate tank.

[0018] The gas outlet and condensate outlet of the steam condenser are connected to a vacuum system. Steam is drawn into the shell side of the steam condenser from the steam inlet connected to the high-efficiency vapor-liquid separator. The steam exchanges heat with the cooling water in the heat exchange tubes, releases heat, condenses into liquid, and is discharged from the condensate outlet. Non-condensable gas is discharged from the gas outlet.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0020] 1. This utility model uses a "low-temperature steam crystallization system" process to perform deep evaporation at room temperature, removing heavy metals, salts and most organic matter. The evaporated water can be reused, and the evaporated rare earth chloride crystals can be directly packaged into products.

[0021] 2. This utility model uses a metal vessel body, which is resistant to thermal shock and has high reliability. The scraper in the heating vessel always stays close to the inner wall, keeping the inner wall clean, ensuring heat exchange efficiency, and relatively low energy consumption. The scraper is equipped with a spring device; after the scraper wears down, the spring compensates for the wear distance, and the scraper's close contact with the wall ensures the inside of the vessel is kept clean. The scraper also has a crushing function during stirring, and the crushed material is of uniform size. In the event of a power outage or other special circumstances resulting in a thick crystallization layer, the scraper will overcome the spring force and retract, preventing damage to the scraper mechanism. The scraping and crushing will continue in the next cycle, ultimately achieving uniform crushing. The scraper is made of wear-resistant, self-lubricating material, resulting in a long service life and low maintenance costs.

[0022] 3. In this utility model, the heating is uniform by setting up a coil heating system: the coil is welded to the cylinder body in multiple directions to ensure that the steam heats the tank body in the specified flow direction.

[0023] 4. The heating vessel of this utility model uses a mechanical seal water tank design to cool and lubricate the mechanical seal, thereby improving the service life of the mechanical seal.

[0024] 5. The high-efficiency vapor-liquid separator in this invention ensures the cleanliness of the drainage and effectively reduces the discharge of rare earth chloride solution. During boiling, the solution inevitably carries small droplets. When the vapor-liquid mixture enters the separator tangentially, the spiral baffle forces it downwards. The small droplets collide with the inner wall of the outer cylinder due to inertia. A hanging mesh on the inner wall of the outer cylinder gradually gathers the small droplets into larger droplets, which are then discharged from the liquid outlet under gravity. Clean steam flows upwards along the inner cylinder and exits from the steam outlet. A baffle is installed at the bottom of the separator to prevent the airflow from carrying the separated liquid away from the separator. Filter media can be optionally installed on the upper part of the inner cylinder to further enhance the separation capacity. When the liquid level at the bottom of the separator reaches a certain height, the vapor-water shut-off valve opens, draining the separated water back into the reactor for secondary distillation. The high water content of the crystals ensures product consistency.

[0025] 5. This invention can be automatically integrated with other equipment to achieve functions such as automatic loading and unloading, and automatic material discharge, reducing the possibility of manual intervention and operational errors, and improving production efficiency and consistency. The equipment in this system is a continuous production system, ensuring stable product quality. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of this utility model;

[0027] Figure 2 This is a schematic diagram of the workflow of this utility model;

[0028] Figure 3 This is a schematic diagram of the heating kettle and steam condenser recovery unit in this utility model.

[0029] Figure 4This is a partial cross-sectional view of the heating vessel and steam condenser recovery unit in this utility model;

[0030] Figure 5 for Figure 4 A magnified view of a portion at point A;

[0031] Figure 6 This is a schematic diagram of the steam condenser recovery unit of this utility model;

[0032] Figure 7 This is a schematic diagram of the installation of the high-efficiency vapor-liquid separator of this utility model;

[0033] Figure 8 This is a schematic diagram of the high-efficiency vapor-liquid separator of this utility model;

[0034] Figure 9 This is a schematic diagram of the distilled water output metering device of this utility model;

[0035] Figure 10 This is a schematic diagram of the steam condensate metering device of this utility model;

[0036] Figure 11 This is a schematic diagram of a portion of the stirring system of this utility model;

[0037] In the diagram: 1. Heating vessel; 2. High-efficiency vapor-liquid separator; 3. Steam condenser and recovery unit; 4. Reducer; 5. Steam half-pipe; 6. Steam condensate outlet; 7. Heating steam inlet; 8. Drive shaft; 9. Mechanical seal; 10. Drip pipe; 11. Overflow drain; 12. Water tank; 13. Guide rod seat; 14. Guide rod; 15. Spring; 16. Scraper seat; 17. Scraper. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0040] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0041] Example 1

[0042] like Figure 1-11 This embodiment provides a rare earth chloride concentration and crystallization system, including a heating kettle 1, a steam condenser 3, and a high-efficiency vapor-liquid separator 2. The steam condenser 2 is installed on the heating kettle 1, and the steam condenser 3 is connected to the heating kettle 1 through the high-efficiency vapor-liquid separator 2. The heating kettle 1 is also connected to a liquid inlet metering device and a steam condensate metering device, and the steam condenser 3 is connected to a distilled water outlet metering device, which is connected to a vacuum system.

[0043] The inlet of the liquid metering device is connected to the raw liquid tank via a diaphragm pump, and the outlet of the liquid metering device is connected to the heating vessel 1. The raw liquid is pumped into the liquid metering device via the diaphragm pump, and then vacuum-assisted into the vessel body via the heating vessel to ensure accurate metering.

[0044] The heating vessel is equipped with a jacket, and a heating half-pipe 5 is spirally wound on the outer wall of the heating vessel inside the jacket. The heating half-pipe 5 is connected to the steam condensate outlet 6 located below the vessel body and the heating steam inlet 7 located above the vessel body.

[0045] When heating is required inside the heating vessel 1, steam is depressurized by a steam pressure reducing valve and then enters the steam half-pipe 5 wrapped around the outer wall of the vessel through the heating steam inlet 7. The condensate after heat exchange is discharged from the steam condensate outlet 6 at the bottom of the vessel. The heating vessel 1 has an internal temperature sensor. When the internal temperature reaches the set temperature, the steam valve at the heating steam inlet is closed, stopping heating. When the temperature inside the vessel drops below the set valve opening temperature, the steam valve is reopened to ensure the solution operates under stable conditions.

[0046] like Figure 5 The drive shaft 8 of the heating vessel adopts a single-end mechanical seal 9. A drip pipe 10 is provided above the mechanical seal 9, and a water tank 12 with an overflow drain outlet 11 is installed below the mechanical seal 9. The design of the drive shaft 8 adopting a single-end mechanical seal and a drip pipe above the mechanical seal allows clean water to continuously drip onto the friction surface of the mechanical seal during operation, maintaining "water film" lubrication, reducing wear, cooling and lubricating the mechanical seal, and improving the service life of the mechanical seal.

[0047] The heating vessel is equipped with a stirring system, such as... Figure 11 The stirring system includes a guide rod seat 13, a guide rod 14, a spring 15, a scraper seat 16, and a scraper 17. The guide rod seat 13 is mounted on the drive shaft 8 of the heating vessel 1. The guide rod 14 is mounted on the guide rod seat 13. The scraper seat 16 is mounted on the outer end of the guide rod 14. The scraper 17 is mounted on the scraper seat 16, with its blade adhering to the inner wall of the heating vessel 1. The spring 15 is sleeved on the guide rod 14 between the guide rod seat 13 and the scraper seat 14. During operation, the reducer drives the scraper to rotate, and the scraper runs along the wall to remove crystals from the inner wall of the vessel, ensuring good heat exchange performance. The scraper is equipped with auxiliary components such as a scraper seat, guide rod, spring, and guide rod seat. In the later stages of crystallization, as particles in the vessel gradually encounter particularly hard particles on the inner wall, the spring contracts to ensure stable operation of the equipment.

[0048] The vacuum system includes a water ring vacuum pump, such as Figure 9 The distilled water metering device includes a steam crystallization negative pressure water tank. The top cover of the steam crystallization negative pressure water tank is equipped with an air inlet, a vacuum pump extraction port, and condensate and gas extraction ports. The water ring vacuum pump is connected to the vacuum pump extraction port. A liquid level sensor is installed inside the steam crystallization negative pressure water tank, and a drain pump is also connected to the steam crystallization negative pressure water tank. Distilled water is drawn into the distilled water metering device through the vacuum pump. The distilled water metering device is equipped with a liquid level sensor. When the liquid level reaches a certain position, the distilled water is discharged through the drain pump.

[0049] To improve evaporation efficiency, a negative pressure is required inside the deheating vessel to lower the boiling point of the solution. The equipment uses a water ring vacuum pump to provide this negative pressure. A negative pressure sensor is installed on the heating vessel. When the pressure reaches the set shutdown pressure, the water ring pump stops drawing vacuum. When the pressure exceeds the set startup pressure, the water ring pump starts drawing vacuum.

[0050] The steam condensate metering device is connected to the steam condensate outlet of the heating kettle via a steam trap, such as... Figure 10 The steam condensate metering device includes a condensate tank, a level sensor, and a drain pump connected to the tank. Steam condensate is discharged into the condensate tank through a steam trap, and is discharged when the tank level reaches a certain height.

[0051] The gas outlet and condensate outlet of the steam condenser are connected to a vacuum system. Steam is drawn into the shell side of the steam condenser (the space between the outside of the heat exchange tubes and the outer shell of the condenser) from the steam inlet connected to the high-efficiency vapor-liquid separator. The steam exchanges heat with the cooling water in the heat exchange tubes, releases heat, condenses into liquid and is discharged from the condensate outlet. Non-condensable gas is discharged from the gas outlet.

[0052] like Figure 8The high-efficiency vapor-liquid separator ensures the cleanliness of the drainage and effectively reduces the discharge of rare earth chloride solution. During boiling, the solution inevitably carries small droplets. When the vapor-liquid mixture enters the separator tangentially, the spiral baffle forces it downwards. The small droplets collide with the inner wall of the outer cylinder due to inertia. A hanging mesh on the inner wall gradually gathers the small droplets into larger droplets, which are then discharged from the liquid outlet under gravity. Clean steam flows upwards along the inner cylinder and exits from the steam outlet. A baffle is installed at the bottom of the separator to prevent the airflow from carrying the separated liquid away. Filter media can be optionally installed on the upper part of the inner cylinder to further enhance the separation capacity. When the liquid level at the bottom of the separator reaches a certain height, the vapor-water shut-off valve opens, draining the separated water back into the heating vessel for secondary distillation. The resulting crystals have a high water content, ensuring product consistency.

[0053] This invention employs a "low-temperature steam crystallization system" process for deep evaporation at room temperature, removing heavy metals, salts, and most organic matter. The evaporated water can be reused, and the evaporated rare earth chloride crystals can be directly packaged into products.

[0054] In this invention, waste liquid enters a low-temperature steam concentration and crystallization system, where it evaporates at a lower temperature. The steam is then discharged and cooled by circulating cooling water to condense into distilled water. The concentrated crystallized liquid or solid is returned to a collection device or entrusted to an external unit for treatment. This method can remove heavy metals and most inorganic salts.

[0055] In this embodiment, the inner wall of the heating vessel is polished to ensure a smooth surface. The scraper remains close to the inner wall to keep it clean, ensuring efficient heat exchange and relatively low energy consumption. The heating vessel body is made of metal, which is resistant to thermal shock and highly reliable. The central connecting shaft of the heating vessel is a solid shaft and machined in one piece to ensure concentricity and reliability.

Claims

1. A rare earth chloride concentration and crystallization system, comprising a heating vessel, characterized in that, It also includes a steam condenser and a high-efficiency vapor-liquid separator. The steam condenser is installed on the heating vessel and is connected to the heating vessel through the high-efficiency vapor-liquid separator. The heating vessel is also connected to a liquid inlet metering device and a steam condensate metering device. The steam condenser is connected to a distilled water outlet metering device, which is connected to a vacuum system.

2. The rare earth chloride concentration and crystallization system according to claim 1, characterized in that: The inlet of the liquid metering device is connected to the raw liquid tank via a diaphragm pump, and the outlet of the liquid metering device is connected to the heating kettle.

3. The rare earth chloride concentration and crystallization system according to claim 1, characterized in that: The heating vessel is equipped with a jacket, and a heating half-pipe is spirally wound on the outer wall of the heating vessel inside the jacket. The heating half-pipe is connected to the steam condensate outlet located below the vessel body and the heating steam inlet located above the vessel body.

4. The rare earth chloride concentration and crystallization system according to claim 1, characterized in that: The drive shaft of the heating vessel is equipped with a single-end mechanical seal. A drip pipe is installed above the mechanical seal, and a water tank with an overflow drain is installed below the mechanical seal.

5. The rare earth chloride concentration and crystallization system according to claim 1, characterized in that: The heating vessel is equipped with a stirring system, which includes a guide rod seat, a guide rod, a spring, a scraper seat, and a scraper. The guide rod seat is mounted on the drive shaft of the heating vessel, the guide rod is mounted on the guide rod seat, the scraper seat is mounted on the outer end of the guide rod, the scraper is mounted on the scraper seat, and the scraper blade is attached to the inner wall of the heating vessel. The spring is sleeved on the guide rod between the guide rod seat and the scraper seat.

6. The rare earth chloride concentration and crystallization system according to claim 1, characterized in that: The vacuum system includes a water ring vacuum pump, and the distilled water output metering device includes a steam crystallization negative pressure water tank. The top cover of the steam crystallization negative pressure water tank is provided with an air inlet, a vacuum pump exhaust port, and condensate and gas extraction ports. The water ring vacuum pump is connected to the vacuum pump exhaust port. A liquid level sensor is installed inside the steam crystallization negative pressure water tank, and a drain pump is also connected to the steam crystallization negative pressure water tank.

7. The rare earth chloride concentration and crystallization system according to claim 3, characterized in that: The steam condensate metering device is connected to the steam condensate outlet of the heating kettle via a steam trap. The steam condensate metering device includes a condensate tank, a level sensor is installed on the condensate tank, and a drain pump is also connected to the condensate tank.

8. The rare earth chloride concentration and crystallization system according to claim 1, characterized in that: The gas outlet and condensate outlet of the steam condenser are connected to a vacuum system. Steam is drawn into the shell side of the steam condenser from the steam inlet connected to the high-efficiency vapor-liquid separator. The steam exchanges heat with the cooling water in the heat exchange tubes, releases heat, condenses into liquid, and is discharged from the condensate outlet. Non-condensable gas is discharged from the gas outlet.

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