Zirconium and hafnium separation equipment and method for rectification pyrogenic process

Abstract

The invention provides zirconium and hafnium separation equipment and method for a rectification pyrogenic process, and relates to the technical field of rectification pyrogenic processes. The equipment comprises a first plate tower, a second plate tower, a fused salt storage tank, a reboiler, a waste salt treatment system, a feeding device, a filler stripping tower, a nitrogen generator, a condenser and a cooling separator. The first plate tower and the second plate tower run in parallel and are connected through a material circulating pipeline, so that circulating separation of incompletely separated components is realized. The reboiler provides heat for the two towers, and the filler stripping tower performs stripping separation by using nitrogen. According to the method, the efficiency and purity of zirconium and hafnium separation are remarkably improved through double-tower synergistic separation, dynamic pressure regulation and magnetic field-assisted separation technologies, and meanwhile, energy consumption and environmental pollution are reduced through heat integration and waste salt treatment. The equipment is suitable for a plateau low-pressure environment, has a remote monitoring function, is convenient to operate and stable in operation, and meets strict requirements of nuclear-grade zirconium and hafnium-rich substances.

Description

Technical Field

[0001] The present invention relates to the technical field of rectification pyrometallurgy, and particularly to a zirconium-hafnium separation device and method for rectification pyrometallurgy. Background Art

[0002] Rectification pyrometallurgy for separating zirconium and hafnium is a method of separation carried out at high temperature or high pressure by utilizing the difference in vapor pressures of zirconium and hafnium chlorides.

[0003] In the field of zirconium-hafnium separation, Chinese Patent CN106048242B discloses a method for separating zirconium and hafnium by rectification pyrometallurgy using the low-pressure environment in high-altitude areas. This patent places the equipment in a plateau area with an altitude of more than 4500 meters and utilizes the low-pressure environment to reduce the sublimation point temperatures of zirconium tetrachloride and hafnium tetrachloride, thereby achieving the separation of the two. However, this method has the following defects: 1. Relying solely on the natural low-pressure environment, it is impossible to achieve dynamic and precise control of the pressure inside the tower, which affects the separation efficiency and purity.

[0004] 2. Insufficient consideration of the recovery and reuse of waste salts may lead to resource waste and environmental pollution. Summary of the Invention

[0005] (I) Technical Problems to be Solved Aiming at the deficiencies of the prior art, the present invention provides a zirconium-hafnium separation device and method for rectification pyrometallurgy, which solves the problems raised in the above background art.

[0006] (II) Technical Solutions To achieve the above objectives, the present invention is realized through the following technical solutions: A zirconium-hafnium separation device and method for rectification pyrometallurgy, including a first plate column, a second plate column, a molten salt storage tank, a reboiler, a waste salt treatment system, a feeding device, a packed stripping column, a nitrogen generator, a second condenser, a cooling separator, and a second condenser, characterized in that: the first plate column and the second plate column operate in parallel and are connected to each other through a material circulation pipeline, enabling the incompletely separated components to circulate between the two columns; the reboiler is connected to the first plate column and the second plate column to provide heat for the two columns, and the packed stripping column is connected to the first plate column and the second plate column to perform stripping separation using the nitrogen provided by the nitrogen generator; The molten salt storage tank stores the intermediate molten salt KAlC4 and is connected to the reboiler through a pipeline. The waste salt treatment system is connected to the first plate tower and the second plate tower for treating the waste salt generated during the separation process. The first plate tower and the second plate tower are provided with pressure sensors for real-time monitoring of pressure changes at different positions in the tower. The control system dynamically adjusts the pressure in the tower through the pressure sensor, the micro compressor and the vacuum pump. The first plate tower and the second plate tower are both provided with adjustable electromagnetic coils on the outside for applying a magnetic field to assist separation.

[0007] Preferably, a glass packing ring is provided inside the packed stripping tower to increase the gas-liquid contact area and improve the mass transfer efficiency. The nitrogen generator is connected to the packed stripping tower through a buffer tank to ensure a stable nitrogen supply.

[0008] Preferably, magnetic nanoparticles are added to the molten salt, which cooperate with the electromagnetic coil. The magnetic particles can promote the turbulence of the fluid and increase the diffusion rate of the components under the drive of the electromagnetic coil.

[0009] Preferably, the reboiler is heated by heat transfer oil with precise temperature control to ensure the stability and accuracy of the heating process; the first condenser and the second condenser are cooled by water vapor or water with temperature control to ensure the condensation effect.

[0010] Preferably, the waste salt treatment system includes a waste salt storage tank and a waste salt treatment device for recovering and reusing the waste salt generated during the separation process, and the waste salt treatment system is connected to the bottom of the first plate tower and the second plate tower through a pipeline.

[0011] Preferably, the equipment is suitable for low-pressure plateau environments, and all pumps and nitrogen generators are of high-altitude-adaptable models; key parts of the equipment are provided with sealing devices to ensure operational stability in plateau environments.

[0012] Preferably, the control system includes a data acquisition module and an automatic adjustment module, which are used to monitor the data of the pressure sensor in real time and automatically adjust the working state of the micro compressor and the vacuum pump; The control system is also provided with a remote monitoring function, and can realize remote operation and maintenance through the Internet of Things technology.

[0013] A method for separating zirconium and hafnium by distillation pyrometallurgy is applied to the above-mentioned device for separating zirconium and hafnium by distillation pyrometallurgy, comprising the following steps: S1, dissolving the raw materials containing zirconium tetrachloride and hafnium tetrachloride in KAlCl4 molten salt to form a mixed molten salt solution, and adding the mixed molten salt solution to the first plate tower in a timely and quantitative manner through a feeding device; S2. Pressure sensors are set at different heights of the first plate column and the second plate column to monitor the pressure changes in real time. The control system dynamically adjusts the working states of the micro-compressor and the vacuum pump according to the data of the pressure sensors to optimize the separation conditions. Meanwhile, a magnetic field is applied through an external electromagnetic coil to enhance the turbulent effect of the magnetic nanoparticles in the molten salt, improving the diffusion rate of components and the separation efficiency. S3. The enriched hafnium tetrachloride vapor at the top of the first plate column is transported through a pipeline to the second plate column for further purification. The zirconium tetrachloride at the bottom of the first plate column is transported through a pipeline to the packed stripping column. The components that are not completely separated are returned to the first plate column through the material circulation pipeline for re-separation. S4. The packed stripping column uses the nitrogen provided by the nitrogen generator to strip the zirconium tetrachloride at the bottom of the column into the cooling separator. The waste heat of the first plate column is recovered through a heat exchanger and used for heating the second plate column to reduce energy consumption. S5. The purified zirconium tetrachloride and hafnium tetrachloride are respectively collected in the product collection tanks. The waste salt generated during the separation process is recycled and reused through the waste salt treatment system.

[0014] (III) Beneficial effects The present invention provides a zirconium-hafnium separation device and method for rectification pyrometallurgy, having the following beneficial effects: 1. The present invention realizes the efficient separation of zirconium and hafnium through a dual-column collaborative separation system. The first plate column and the second plate column operate in parallel, and the components that are not completely separated circulate between the two columns through the material circulation pipeline, ensuring the thoroughness of separation. Meanwhile, the dynamic pressure rectification technology adjusts the pressure in real time according to the separation requirements at different positions in the column, optimizing the separation conditions. In addition, the application of the magnetic molten salt and magnetic field-assisted separation technology further enhances the mass transfer efficiency, enabling the separation purity of zirconium tetrachloride and hafnium tetrachloride to reach an unprecedented level, meeting the strict requirements of nuclear-grade zirconium and hafnium-rich substances.

[0015] 2. The present invention performs excellently in terms of energy consumption. Through the heat integration technology, the waste heat of one column is used for heating another column, effectively reducing the energy consumption of the equipment. The reboiler uses heat transfer oil for precise temperature control heating, ensuring the stability and accuracy of the heating process and avoiding unnecessary energy waste. Meanwhile, the introduction of the waste salt treatment system not only reduces environmental pollution but also realizes the recycling and reuse of waste salt, reducing the production cost. The magnetic molten salt and magnetic field-assisted separation technology reduce the required energy input, further reducing the energy consumption during the production process and making the entire separation process more economical and efficient.

[0016] 3. The equipment design of the present invention fully considers the operating stability under different environmental conditions, especially the application in the high-altitude and low-pressure environment. All pumps and nitrogen generators adopt models suitable for high altitudes, and sealing devices are provided at key parts to ensure the stable operation of the equipment under various harsh environments. In addition, the control system integrates a data acquisition module and an automatic adjustment module, which can monitor the data of the pressure sensor in real time and automatically adjust the working states of the micro-compressor and the vacuum pump, realizing the automation and remote monitoring functions of the equipment, and greatly improving the operation convenience and operation efficiency of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic connection diagram of the present invention.

[0018] Among them, 1. The first plate column; 2. The second plate column; 3. The molten salt storage tank; 4. The reboiler; 5. The waste salt treatment system; 6. The feeding device; 7. The packed stripping column; 8. The nitrogen generator; 9. The first condenser; 10. The cooling separator; 11. The second condenser; 12. The control system; 13. The material circulation pump. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0020] Embodiment 1: As Figure 1 shown, the embodiment of the present invention provides a separation zirconium-hafnium device and method for rectification pyrometallurgy, including a first plate column 1, a second plate column 2, a molten salt storage tank 3, a reboiler 4, a waste salt treatment system 5, a feeding device 6, a packed stripping column 7, a nitrogen generator 8, a second condenser 9, a cooling separator 10, a second cooling separator 10, and a second condenser 11. It is characterized in that: the first plate column 1 and the second plate column 2 operate in parallel and are connected to each other through a material circulation pipeline, so that the incompletely separated components can circulate between the two columns; the reboiler 4 is connected to the first plate column 1 and the second plate column 2 to provide heat for the two columns.

[0021] The packed stripping column 7 is connected to the first plate column 1 and the second plate column 2, and uses the nitrogen provided by the nitrogen generator 8 for stripping separation. A glass packing ring is arranged inside the packed stripping column 7 to increase the gas-liquid contact area and improve the mass transfer efficiency. The nitrogen generator 8 is connected to the packed stripping column 7 through a buffer tank to ensure stable nitrogen supply.

[0022] The molten salt storage tank 3 stores the intermediate molten salt KAlC4 and is connected to the reboiler 4 through a pipeline. The reboiler 4 is heated with precise temperature control using heat transfer oil to ensure the stability and accuracy of the heating process; the first condenser 9 and the second condenser 11 are cooled with temperature control using steam or water to ensure the condensation effect.

[0023] The waste salt treatment system 5 is connected to the first plate column 1 and the second plate column 2, and is used to treat the waste salt generated during the separation process. The waste salt treatment system 5 includes a waste salt storage tank and a waste salt treatment device, and is used to recycle and reuse the waste salt generated during the separation process. The waste salt treatment system 5 is connected to the bottoms of the first plate column 1 and the second plate column 2 through pipelines.

[0024] Pressure sensors are installed inside the first plate column 1 and the second plate column 2 to monitor the pressure changes at different positions inside the columns in real time. The control system dynamically adjusts the pressure inside the columns through the pressure sensors, the micro compressor, and the vacuum pump. Adjustable electromagnetic coils are installed outside both the first plate column 1 and the second plate column 2 to apply a magnetic field to assist in separation. Magnetic nanoparticles are added to the molten salt and cooperate with the electromagnetic coils. The magnetic particles can promote the turbulence of the fluid under the drive of the electromagnetic coils, improving the diffusion rate of the components.

[0025] The equipment is applicable to the plateau low-pressure environment. All pumps and nitrogen generators use models suitable for high altitudes; sealing devices are provided at key parts of the equipment to ensure the operating stability in the plateau environment.

[0026] The control system includes a data acquisition module and an automatic adjustment module, which are used to monitor the data of the pressure sensors in real time and automatically adjust the operating states of the micro compressor and the vacuum pump; The control system also has a remote monitoring function, and remote operation and maintenance can be achieved through Internet of Things technology.

[0027] A method for separating zirconium and hafnium by distillation pyrometallurgy, applied to the above-mentioned equipment for separating zirconium and hafnium by distillation pyrometallurgy, includes the following steps: S1. Dissolve the raw material containing zirconium tetrachloride and hafnium tetrachloride in the KAlCl4 molten salt to form a mixed molten salt solution, and add the mixed molten salt solution to the first plate column 1 at regular intervals and in a fixed quantity through the feeding device 6; S2. Install pressure sensors at different heights in the first plate column 1 and the second plate column 2 to monitor the pressure changes in real time; the control system dynamically adjusts the operating states of the micro compressor and the vacuum pump according to the data of the pressure sensors to optimize the separation conditions; at the same time, apply a magnetic field through the external electromagnetic coils to enhance the turbulence effect of the magnetic nanoparticles in the molten salt, improving the diffusion rate of the components and the separation efficiency; S3. Transfer the hafnium tetrachloride vapor enriched at the top of the first plate column 1 to the second plate column 2 through a pipeline for further purification; transfer the zirconium tetrachloride at the bottom of the first plate column 1 to the packed stripping column 7; return the incompletely separated components to the first plate column 1 through the material circulation pipeline for re-separation; S4. The packed stripping column 7 uses the nitrogen provided by the nitrogen generator 8 to strip the zirconium tetrachloride at the bottom of the column into the cooling separator 10; the waste heat of the first plate column 1 is recovered through a heat exchanger and used for heating the second plate column 2 to reduce energy consumption; S5. Collect the purified zirconium tetrachloride and hafnium tetrachloride in the product collection tank respectively; the waste salt generated during the separation process is recovered and reused through the waste salt treatment system 5.

[0028] Example 2 Based on Example 1, this example further optimizes the waste salt treatment and energy recovery system, and introduces an on-line monitoring and dynamic optimization function to improve the separation efficiency and the operation stability of the equipment. The specific operations are as follows: S1. Based on the first plate column 1 and the second plate column 2, a waste salt pretreatment device is added to preliminarily separate the impurities in the waste salt. A cogeneration system is added between the reboiler 4, the first condenser 9 and the second condenser 11 to convert the waste heat into electric energy for equipment operation, further reducing energy consumption; high-efficiency glass packing rings are added inside the packed stripping column 7 to increase the gas-liquid contact area and the mass transfer efficiency.

[0029] S2. Dissolve the raw material containing zirconium tetrachloride ZrCl4 and hafnium tetrachloride HfCl4 in the KAlCl4 molten salt to form a mixed molten salt solution. Add the mixed molten salt solution to the first plate column 1 regularly and quantitatively through the feeding device 6, and ensure the uniform distribution of the magnetic nanoparticles in the molten salt.

[0030] S3. Set pressure sensors at different heights of the first plate column 1 and the second plate column 2 to monitor the pressure change inside the column in real time. The control system dynamically adjusts the working states of the micro compressor and the vacuum pump according to the sensor data to optimize the separation conditions. Apply a magnetic field through an external electromagnetic coil to enhance the turbulent effect of the magnetic nanoparticles in the molten salt and improve the diffusion rate and separation efficiency of the components.

[0031] S4. Transfer the hafnium tetrachloride vapor enriched at the top of the first plate column 1 to the second plate column 2 for further purification; transfer the zirconium tetrachloride at the bottom of the first plate column 1 to the packed stripping column 7; return the incompletely separated components to the first plate column 1 through the material circulation pipeline for re-separation.

[0032] S5. After the waste salt removes impurities through the pretreatment device, it enters the waste salt treatment system 5 for recovery and reuse. The pretreatment steps include chemical precipitation and physical filtration to ensure that the reuse rate of the waste salt is increased to over 90%.

[0033] S6. The waste heat of the first plate column 1 is recovered through a heat exchanger and converted into electric energy through a cogeneration system for equipment operation, further reducing energy consumption. The packed stripping column 7 uses the nitrogen provided by the nitrogen generator 8 to strip zirconium tetrachloride at the bottom of the column into the cooling separator 10.

[0034] S7. During the separation process, the purity of zirconium tetrachloride and hafnium tetrachloride is analyzed in real time through an on-line monitoring system. According to the analysis results, the control system automatically adjusts the magnetic field strength of the electromagnetic coil and the working state of the micro-compressor to ensure that the separation efficiency and purity reach the optimal state.

[0035] S7. The purified zirconium tetrachloride and hafnium tetrachloride are respectively collected in the product collection tank to ensure that the purity of the separated products meets the requirements of nuclear-grade zirconium and hafnium-rich substances.

[0036] Implementation Effect In this embodiment, through the introduction of waste salt pretreatment, cogeneration system and on-line monitoring function, the reuse rate of waste salt and the energy utilization efficiency of the equipment are significantly improved. The dynamic optimization function ensures the high efficiency and stability of the separation process, further reducing production costs and environmental pollution. The equipment operates stably in the plateau low-pressure environment. The control system realizes the functions of automation and remote monitoring, improving the operation convenience and operation efficiency. Through these improvements, this embodiment is superior to Embodiment 1 in terms of separation efficiency, energy consumption control and environmental friendliness, providing a better solution for industrial applications.

[0037] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for separating zirconium and hafnium by distillation pyrometallurgy, comprising a first plate tower (1), a second plate tower (2), a molten salt storage tank (3), a reboiler (4), a waste salt treatment system (5), a feeding device (6), a packed stripping tower (7), a nitrogen generator (8), a second condenser (9), a cooling separator (10), a second cooling separator (10) and a second condenser (11), characterized in that: The first plate tower (1) and the second plate tower (2) are operated in parallel and are interconnected via a material circulation pipeline, so that components that are not completely separated can circulate between the two towers; the reboiler (4) is connected to the first plate tower (1) and the second plate tower (2) to provide heat for the two towers; the packed stripping tower (7) is connected to the first plate tower (1) and the second plate tower (2) to perform stripping separation using nitrogen provided by a nitrogen generator (8); The molten salt storage tank (3) stores the intermediate molten salt KAlC4 and is connected to the reboiler (4) via a pipeline. The waste salt treatment system (5) is connected to the first plate tower (1) and the second plate tower (2) and is used to treat the waste salt generated during the separation process. The first plate tower (1) and the second plate tower (2) are provided with pressure sensors for real-time monitoring of pressure changes at different positions in the tower. The control system dynamically adjusts the pressure in the tower through the pressure sensor, the micro compressor and the vacuum pump. The first plate tower (1) and the second plate tower (2) are both provided with adjustable electromagnetic coils for applying a magnetic field to assist separation.

2. The device for separating zirconium and hafnium by distillation pyrometallurgy according to claim 1, characterized in that: The packed stripping tower (7) is provided with a glass packing ring inside to increase the gas-liquid contact area and improve the mass transfer efficiency. The nitrogen generator (8) is connected to the packed stripping tower (7) via a buffer tank to ensure a stable nitrogen supply.

3. The device for separating zirconium and hafnium by distillation pyrometallurgy according to claim 1, characterized in that: Magnetic nanoparticles are added to the molten salt, and cooperate with the electromagnetic coil. The magnetic particles can promote the turbulence of the fluid and increase the diffusion rate of the components under the drive of the electromagnetic coil.

4. The device for separating zirconium and hafnium by distillation pyrometallurgy according to claim 1, characterized in that: The reboiler (4) uses heat transfer oil for precise temperature control heating to ensure the stability and accuracy of the heating process; the first condenser (9) and the second condenser (11) use water vapor or water for temperature control cooling to ensure the condensation effect.

5. The device for separating zirconium and hafnium by distillation pyrometallurgy according to claim 1, characterized in that: The waste salt treatment system (5) comprises a waste salt storage tank and a waste salt treatment device, which are used to recover and reuse the waste salt generated during the separation process. The waste salt treatment system (5) is connected to the bottom of the first plate tower (1) and the second plate tower (2) through a pipeline.

6. The device for separating zirconium and hafnium by distillation pyrometallurgy according to claim 1, characterized in that: The equipment is suitable for low-pressure plateau environments, and all pumps and nitrogen generators are models adapted to high altitudes; sealing devices are provided at key locations of the equipment to ensure operational stability in plateau environments.

7. The device for separating zirconium and hafnium by distillation pyrometallurgy according to claim 1, characterized in that: The control system includes a data acquisition module and an automatic adjustment module, which are used to monitor the data of the pressure sensor in real time and automatically adjust the working state of the micro compressor and the vacuum pump; The control system is also provided with a remote monitoring function, and can realize remote operation and maintenance through the Internet of Things technology.

8. A method for separating zirconium and hafnium by distillation pyrometallurgy, applied to the device for separating zirconium and hafnium by distillation pyrometallurgy as claimed in claims 1 to 7, characterized in that: The following steps are involved: S1, dissolving a raw material containing zirconium tetrachloride and hafnium tetrachloride in KAlCl4 molten salt to form a mixed molten salt solution, and adding the mixed molten salt solution to the first plate tower (1) in a timely and quantitative manner through a feeding device (6); S2. Pressure sensors are arranged at different heights of the first plate tower (1) and the second plate tower (2) to monitor pressure changes in real time; the control system dynamically adjusts the working state of the micro compressor and the vacuum pump according to the data of the pressure sensors to optimize the separation conditions; at the same time, a magnetic field is applied through an external electromagnetic coil to enhance the turbulence effect of the magnetic nanoparticles in the molten salt, thereby improving the diffusion rate and separation efficiency of the components; S3, transporting the enriched hafnium tetrachloride vapor at the top of the first plate tower (1) to the second plate tower (2) through a pipeline for further purification; transporting the zirconium tetrachloride at the bottom of the first plate tower (1) to a packed stripping tower (7) through a pipeline; and returning the incompletely separated components to the first plate tower (1) through a material circulation pipeline for further separation; S4, the packed stripping tower (7) uses nitrogen provided by the nitrogen generator (8) to strip zirconium tetrachloride at the bottom of the tower into the cooling separator (10); the waste heat of the first plate tower (1) is recovered through a heat exchanger and used for heating the second plate tower (2) to reduce energy consumption; S5. The purified zirconium tetrachloride and hafnium tetrachloride are collected in product collection tanks respectively; the waste salt generated during the separation process is recovered and reused through the waste salt treatment system (5).

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