A purification apparatus for metallurgically recovering rhenium

Abstract

This application discloses a purification device for metallurgical rhenium recovery, including an evaporation remelting kettle and a control system electrically connected to it. The inner wall of the outer shell of the evaporation remelting kettle is provided with a heat insulation layer, and an inner kettle cavity is provided inside the heat insulation layer. The inner kettle cavity is connected to a vacuum pump. The upper part of the outer wall of the inner kettle cavity is laid with a spiral heating pipe for introducing an external heat source for the evaporation of the raw material liquid. The lower part of the outer wall of the inner kettle cavity is provided with an annular cooling cavity for introducing an external cold source to cool the crystallization. The top of the inner kettle cavity is provided with a steam condensation and reflux device for condensing the steam generated by evaporation. The conical bottom of the inner kettle cavity is provided with a solid-liquid separation component for separating the crystallized product from the mother liquor. A slag discharge port and a mother liquor reflux port are provided near the top of the cone. A stirring component is provided in the inner kettle cavity. This application integrates the three major functions of evaporation, crystallization, and separation into the inner kettle cavity, significantly reducing the equipment footprint, eliminating intermediate material transfer, improving purification efficiency, and reusing the evaporation condensate for adding water to the inner kettle cavity or preheating the raw material liquid, thus saving energy and reducing consumption.

Description

Technical Field

[0001] This application relates to the field of rhenium recovery technology, and in particular to a purification device for metallurgical rhenium recovery. Background Technology

[0002] Traditional evaporation crystallization equipment for rhenium salt purification mainly consists of a three-stage independent structure of "evaporation-cooling-separation," relying on the cooperation of an evaporation kettle and an external cooling crystallization tank to achieve purification. The specific process is as follows: A raw material solution containing rhenium salts (concentration 100~150 g / L, containing impurity ions such as molybdenum and tungsten) is pumped from a raw material storage tank into the evaporation kettle. The raw material solution is heated (90~100℃) by electric heating tubes at the bottom and side walls of the kettle, while simultaneously activating an internal agitator (150~200 r / min) to ensure uniform heating. The steam generated during evaporation is discharged through a steam exhaust pipe; some steam is directly discharged, while some is used to preheat the raw material solution. The temperature inside the kettle is monitored in real time using a thermometer, and a vacuum pump and vacuum gauge are used to maintain the vacuum level inside the kettle at 0.07~0.08 MPa to accelerate water evaporation until the rhenium salt concentration in the raw material solution reaches 250~300 g / L, at which point evaporation stops. Subsequently, the valve at the bottom of the evaporator is opened, and the concentrated rhenium salt solution is introduced into the crystallization tank. Cooling coils are wrapped around the outer wall of the crystallization tank, and cooling water (5~10℃) is circulated into the cooling coils through the cooling water tank to cool the solution. The cooling rate is controlled at 3~5℃ / h. After standing naturally for 8~12 hours, the rhenium salt precipitates in the form of crystals. Finally, the discharge valve at the bottom of the crystallization tank is opened, and the mixture of "crystals + mother liquor" is introduced into the filter funnel. Solid-liquid separation is achieved through gravity filtration. The filter cake (rhenium salt crystals) is collected in the collection bucket, and the mother liquor is returned to the raw material liquid storage tank for recycling.

[0003] The aforementioned traditional rhenium salt purification equipment has the following problems in practical applications:

[0004] 1. The equipment occupies a large area and has low connection efficiency: It adopts a three-section independent structure of evaporation kettle, crystallization tank and filter funnel. Each piece of equipment needs to be arranged separately and connected by pipelines. This not only occupies a large amount of factory space, but also causes residual loss during the solution transfer process. At the same time, the transfer time prolongs the overall purification cycle and reduces production efficiency.

[0005] 2. High heating energy consumption: Relying on electric heating tubes for direct heating, heat is transferred from the outer wall of the equipment to the inside, resulting in a significant temperature gradient. The raw material liquid near the heating tube is prone to local overheating to above 105°C, causing the rhenium salts to decompose (e.g., potassium perrhenate easily loses its water of crystallization above 110°C, and ammonium perrhenate decomposes into rhenium heptaoxide above 150°C), resulting in a rhenium loss rate of 3% to 5%. At the same time, the energy conversion efficiency of electric heating is low (only 60% to 70%), and the evaporation energy consumption per unit of rhenium salt product reaches 600 to 800 kWh / t. Moreover, the steam utilization rate during the evaporation process is less than 30%, resulting in serious energy waste.

[0006] 3. Slow cooling and crystallization rate and high energy consumption: The crystallization tank relies on the cooling coils wrapped around the outer wall for indirect cooling. The heat transfer efficiency is low, resulting in a cooling rate of only 3~5℃ / h. It also needs to be left to stand naturally for 8~12 hours to complete crystallization, which takes a long time. At the same time, the steam discharged during the evaporation stage is directly discharged, which wastes heat energy and increases the overall energy consumption.

[0007] 4. Poor solid-liquid separation effect and high impurity residue: The solid-liquid separation is achieved by gravity filtration, but the filtration pressure is insufficient, and the rhenium salt crystals are not completely separated from the mother liquor. Some crystals are easily refluxed with the mother liquor, resulting in a low product recovery rate. In addition, the filter screen material of the filter funnel is not optimized for acidic rhenium-containing solutions. It is prone to corrosion with long-term use, and the pore size of the filter screen becomes larger, making it easier for impurity ions such as molybdenum and tungsten to penetrate the filter screen and remain in the crystals, affecting the purity of the product.

[0008] Therefore, existing evaporation and crystallization equipment for the purification of rhenium salts has problems such as large footprint, high energy consumption and low purification efficiency. It is necessary to propose a new technical solution to solve the problems existing in the current technology. Summary of the Invention

[0009] This application provides a purification device for metallurgical recovery of rhenium, which solves the problems of large footprint, high energy consumption and low purification efficiency of existing evaporation and crystallization equipment for rhenium salt purification.

[0010] To achieve the above objectives, this application provides the following technical solution:

[0011] This application provides a purification device for metallurgical rhenium recovery, including an evaporation and remelting kettle. The evaporation and remelting kettle includes an outer shell, an inner wall of which is provided with a heat insulation layer, and an inner shell is provided inside the heat insulation layer. The inner cavity of the inner shell constitutes an integrated processing chamber for evaporation and crystallization. The outer shell is provided with a raw material liquid inlet communicating with the inner cavity.

[0012] The upper middle and / or bottom of the outer wall of the inner vessel shell are provided with spiral heating pipes, which are used to introduce an external heat source to heat the raw material liquid in the inner vessel cavity; the lower middle part of the outer wall of the inner vessel shell is provided with an annular cooling cavity, which is used to introduce an external cold source to cool the raw material liquid in the inner vessel cavity; the top of the inner vessel cavity is provided with a steam condensation and reflux device for condensing the steam generated by evaporation; the bottom of the inner vessel cavity is a conical structure, with a solid-liquid separation component for separating the crystallization product and the mother liquor at the bottom of the cone, and a slag discharge port and a mother liquor reflux port near the top of the cone; a temperature sensor and a concentration sensor are provided in the middle of the inner wall of the inner vessel shell; a stirring component is also provided in the inner vessel cavity.

[0013] Furthermore, in the above technical solution, the inlet end of the spiral heating tube is connected to an external hot water source, and the outlet end of the spiral heating tube is connected to a raw material liquid preheating system or an inner vessel cavity water addition system.

[0014] Furthermore, the outer shell of the vessel is provided with a cooling water inlet and a cooling water outlet on the left and right sides, respectively communicating with the annular cooling cavity. The cooling water inlet is connected to an external refrigeration unit, which provides low-temperature cooling water.

[0015] Furthermore, the stirring assembly includes a central stirring shaft driven by a drive motor, on which an inner propulsion paddle located in the lower middle part and an outer wall scraper paddle located at the lower part of the central stirring shaft close to the bottom of the inner vessel shell are mounted.

[0016] Furthermore, the inner propeller includes one or more sets of propeller blade structures arranged at intervals, each propeller blade structure including multiple helical blades located on the same plane, the multiple helical blades being evenly distributed around the central stirring shaft; the outer wall scraper includes a horizontal beam disposed on the central stirring shaft and at least two arc-shaped anchor arms extending from both ends of the horizontal beam toward the inner wall of the inner vessel shell, the rotation trajectory of the arc-shaped anchor arms being adapted to the curved surface shape of the inner wall of the inner vessel shell, and the ends of the arc-shaped anchor arms maintaining a gap of 5-8 mm with the curved surface of the inner wall of the inner vessel shell.

[0017] Furthermore, the maximum rotational diameter of the helical blade is between 200mm and 250mm.

[0018] Furthermore, the steam condensation reflux device includes: a condensation coil arranged around the top opening of the inner vessel cavity, a condensate collection tank located below the condensation coil, and a reflux pump for pumping condensate from the condensate collection tank back to the inner vessel cavity or the raw material liquid preheating system; the condensate collection tank is an annular tank, the outer edge of the condensate collection tank is fixed to the inner wall of the inner vessel shell, and the stirring shaft of the stirring assembly extends into the inner vessel cavity through the center of the condensate collection tank.

[0019] Furthermore, the solid-liquid separation component includes a filter screen horizontally installed at the bottom of the conical structure, a crystal collection chamber is formed below the filter screen, the slag discharge port and the mother liquor return port are provided on the side wall of the crystal collection chamber, a pneumatic slag discharge valve is provided at the slag discharge port, and the mother liquor return port is connected to the raw material liquid storage tank through a pipeline.

[0020] Furthermore, the heat source control end of the spiral heating tube, the cold source control end of the annular cooling chamber, the drive motor of the stirring assembly, the temperature sensor, the concentration sensor, and the pneumatic slag discharge valve installed at the slag discharge port are all electrically connected to the control system; wherein, the temperature sensor is used to detect the temperature of the solution in the inner vessel cavity in real time, and the concentration sensor is used to detect the concentration of rhenium salt in the inner vessel cavity in real time.

[0021] Furthermore, the outer shell of the vessel is provided with a vacuum interface, which is connected to the inner vessel cavity through a pipe. The vacuum interface is connected to a vacuum pump and is used to adjust the vacuum level of the inner vessel cavity.

[0022] Furthermore, the outer shell of the vessel is provided with an observation window, which is made of high-temperature resistant quartz glass, for observing the state of the material inside the inner vessel cavity.

[0023] Furthermore, a safety valve is provided on the top of the outer shell of the vessel;

[0024] Furthermore, the insulation layer is made of aluminum silicate fiber, with a thickness ranging from 50 to 80 millimeters.

[0025] Compared with the prior art, this application has at least the following beneficial effects:

[0026] 1. Based on further analysis and research of existing technologies, this application recognizes that existing evaporation and crystallization equipment for rhenium salt purification is structurally dispersed, energy-intensive, and has low purification efficiency. Therefore, this application provides a highly integrated device that integrates evaporation, crystallization, and separation functions into the inner cavity of a single evaporation remelting kettle. This directly replaces the three separate devices and their connecting pipelines required in traditional processes: an evaporation kettle, a crystallization tank, and a filtration device. The equipment layout changes from horizontal series to vertical stacking, significantly reducing the equipment footprint and plant space requirements, and simplifying the plant layout. Secondly, this application arranges the spiral heating tube and annular cooling chamber vertically within the kettle, installs a steam condensation and reflux device at the top, and provides a heat insulation layer on the inner wall of the kettle shell. In this process, evaporation is carried out first in the reactor, followed by cooling and crystallization, and finally filtration and separation. The reactor serves multiple purposes without the need for material transfer. Simultaneously, the steam condensation reflux device releases the latent heat of evaporation through the condensation coil and recovers the condensate, avoiding the energy waste and solvent loss from direct steam discharge. This forms a closed-loop cycle, reducing energy and water consumption. Furthermore, this application integrates the evaporation, crystallization, and separation processes into a continuous process in the evaporation remelting reactor. After crystallization, solid-liquid separation is performed at the bottom of the cone. The process is seamlessly connected, with no intermediate material transfer, shortening the production cycle. This completely avoids the heat loss, pipeline blockage due to hot concentrate pumping to the crystallization tank, material adhesion loss, and possible contamination in traditional processes, directly improving the purification efficiency of rhenium.

[0027] 2. In this application, an external hot water source is used to heat the spiral heating tube. The inner vessel cavity and the spiral heating tube are integrated as one unit. The spiral heating tube adopts "hot water circulation heating" instead of traditional electric heating. The hot water temperature is controlled at 80~85℃. The spiral structure allows heat to be evenly transferred to the raw material liquid. With the help of the insulation layer, heat loss is reduced, and the thermal efficiency is increased to over 90%. At the same time, the use of hot water circulation heating also facilitates the use of waste heat from the factory, solar energy and other low-grade heat energy, realizing the cascade utilization of energy and further reducing the consumption of high-grade electricity or steam, thus achieving energy saving and consumption reduction. In addition, an external refrigeration unit is used to provide a cold source for the annular cooling chamber, ensuring that the cooling power and temperature can be accurately and stably controlled, and ensuring the reproducibility of crystallization process conditions.

[0028] 3. This application includes a steam condensation reflux device in the evaporation remelting kettle to condense the steam generated by evaporation into water. Part of the condensate is returned to the inner kettle cavity via a reflux pump, which can adjust the solution concentration and avoid local over-concentration. Part of the condensate is used to preheat the raw material liquid, so that the temperature of the raw material liquid before entering the inner kettle cavity is raised to 40~50℃, further reducing evaporation energy consumption.

[0029] 4. The stirring assembly in this application adopts a double-layer stirring structure to avoid local overheating and wall formation. The stirring assembly includes an inner layer propeller located in the lower part of the central stirring shaft and an outer layer scraper located below the inner layer propeller and close to the bottom of the inner vessel shell. The inner layer propeller adopts a propulsion structure, which drives the raw material liquid to circulate up and down through a set or multiple sets of propeller blades arranged at intervals, so that the solution is heated evenly and avoids local overheating. The outer layer scraper rotates synchronously with the central stirring shaft, which can scrape off the rhenium salt crystals attached to the inner wall of the inner vessel cavity, prevent uneven heat transfer caused by wall formation, and avoid material loss caused by crystal attachment.

[0030] 5. This application includes a cooling assembly installed in the lower middle part of the inner cavity of the evaporation remelting kettle, and temperature and concentration sensors installed in the middle of the inner cavity to precisely control the temperature and improve crystal purity. The annular cooling chamber can be circulated with low-temperature cooling water at 5~8℃ through the cooling water inlet. The cooling water flows uniformly in the annular chamber and acts directly on the concentrated solution in the lower part of the inner cavity. The cooling rate can be precisely controlled (2~4℃ / h) by adjusting the power of the refrigeration unit through the control system (such as PLC control cabinet) to avoid "crystal bursting". The temperature sensor (measurement accuracy ±0.5℃) and the concentration sensor (measurement accuracy ±1g / L) provide real-time feedback data. When the solution temperature drops to the target value (15~20℃) and the rhenium salt concentration stabilizes, the cooling automatically stops to ensure that the crystals precipitate slowly with uniform particle size (0.5~1mm) and reduce impurity adsorption.

[0031] 6. The filter screen in this application can be made of titanium alloy, which has the characteristics of high temperature resistance and corrosion resistance. The 0.2mm pore size can effectively trap rhenium salt crystals while allowing the mother liquor to pass through. In this application, the crystals are directly separated on the screen after being generated at the bottom of the cone, realizing in-situ filtration and lateral reflux of the mother liquor. The crystal collection chamber is used to store the filtered crystals. When the crystals accumulate to a certain amount (by weight sensor or time setting), the PLC control cabinet automatically opens the pneumatic slag discharge valve to discharge the crystals, which is automatic and efficient. The mother liquor is returned to the raw material liquid storage tank through the mother liquor return port to realize recycling and reduce the loss of rhenium salts.

[0032] 7. This application achieves solvent circulation and zero discharge of process wastewater through steam condensation reflux device and mother liquor reflux, which has outstanding environmental advantages. The recovered condensate can be used as system makeup water to maintain material balance, avoid the loss of valuable materials with water, and further improve the total recovery rate of rhenium.

[0033] 8. This application electrically connects the feeding, heating, cooling, stirring, sensing, and slag discharge units to the control system. The control system can automatically adjust the heating power, cooling intensity, and stirring speed according to the real-time data from the concentration and temperature sensors, and automatically carry out the crystallization and separation process after reaching the set concentration. This not only achieves process consistency and high efficiency repeatability, but also greatly improves production efficiency and product quality stability.

[0034] 9. This application provides a vacuum interface on the outer shell of the evaporation remelting kettle, which communicates with the inner cavity to connect a vacuum pump. This allows the vacuum level to be controlled at 0.085~0.09MPa, reducing the boiling point of the solution to 75~80℃. Combined with the uniform heating of the spiral heating tube and the stirring action of the inner propeller, local overheating is avoided, the rhenium salt decomposition rate is controlled below 0.5%, and the rhenium recovery rate is increased to 97%~98%. At the same time, operating under vacuum can significantly reduce the boiling point of the solution, meaning that the evaporation stage can be carried out at a lower temperature, further reducing heating energy consumption and also reducing the material pressure and risk of long-term high-temperature operation of the equipment.

[0035] 10. This application provides an observation window and a safety valve on the evaporation remelting reactor. The observation window can serve as a safety monitoring point to directly monitor the internal reaction and crystal growth status of the reactor. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing this application. For example, based on the technical concepts disclosed in this application and the exemplary drawings, those skilled in the art are able to easily make conventional adjustments or further optimizations to the addition / reduction / classification, specific shapes, positional relationships, connection methods, and size ratios of certain units (components).

[0037] Figure 1 Flowchart of the evaporation and crystallization process for purifying traditional rhenium salts;

[0038] Figure 2 This is a schematic diagram of the evaporation remelting kettle of the purification equipment provided in this application in one embodiment;

[0039] Figure 3 for Figure 2 A schematic diagram of the stirring component in the image.

[0040] Explanation of reference numerals in the attached figures:

[0041] 01. Raw material liquid storage tank; 02. Transfer pump; 03. Traditional evaporation kettle; 04. Thermometer; 05. Vacuum gauge; 06. Vacuum pump; 07. Crystallization tank; 08. Cooling coil; 09. Cooling water tank; 010. Filter funnel; 011. Collection bucket;

[0042] 1. Outer shell of the vessel; 2. Insulation layer; 3. Inner vessel cavity; 4. Spiral heating tube; 5. Annular cooling cavity; 6. Temperature sensor; 7. Concentration sensor; 8. Stirring assembly; 9. Drive motor; 10. Central stirring shaft; 11. Inner propeller; 12. Outer wall scraper; 13. Arc-shaped anchor arm; 14. Condensate coil; 15. Condensate collection tank; 16. Reflux pump; 17. Filter screen; 18. Crystal collection bin; 19. Pneumatic slag discharge valve. Detailed Implementation

[0043] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] In the description of this application: unless otherwise stated, "a plurality of" means two or more. The terms "first," "second," etc., in this application are intended to distinguish the objects referred to and do not have any special meaning in terms of technical connotation (e.g., they should not be construed as an emphasis on importance or order). Expressions such as "including," "comprising," and "having" also mean "not limited to" (certain units, components, materials, steps, etc.).

[0045] The terms used in this application, such as "upper," "lower," "left," "right," and "middle," are generally used to facilitate intuitive understanding by referring to the accompanying drawings, and are not absolute limitations on the positional relationships in the actual product. Changes in these relative positional relationships, without departing from the technical concept disclosed in this application, should also be considered within the scope of this application.

[0046] See Figure 1 Traditional evaporation and crystallization equipment for the purification of rhenium salts mainly includes the following units:

[0047] 1. Raw material liquid conveying unit: The bottom outlet of the raw material liquid storage tank 01 is sealed to the inlet of the conveying pump 02 through a rigid pipe. A conventional shut-off valve is installed in the middle of the pipe (used to control the on / off of the raw material liquid output); the outlet of the conveying pump 02 is fixedly connected to the inlet of the top of the conventional evaporator 03 through a rigid pipe of the same specification. The pipe joint is sealed with a flange to prevent leakage.

[0048] 2. Traditional Evaporation Kettle Unit: The traditional evaporation kettle 03 has two pre-installed mounting interfaces on its top, for fixing a vacuum gauge 05 and a thermometer 04 respectively. The probes of both instruments extend through the kettle wall into the solution area inside the kettle for real-time monitoring of the internal environment. The traditional evaporation kettle 03 also has a suction port on its top, which is connected to the exhaust port of the vacuum pump 06 via a pipe. The pipe is fixed with a snap-fit ​​seal. The stirring paddle extends vertically into the kettle through the mounting hole in the center of the top of the traditional evaporation kettle 03. The motor of the stirring paddle is fixed to the outside of the top of the kettle body. The motor output shaft is connected to the stirring paddle shaft via a coupling, and a sealing gasket is installed at the connection to prevent vacuum leakage. The bottom and side walls of the traditional evaporation kettle 03 have built-in electric heating tubes (integrated with the equipment body and arranged according to the conventional industrial heating kettle structure). The wiring terminals of the electric heating tubes are led out from the pre-installed holes in the side wall of the kettle body and connected to an external power supply and control device.

[0049] 3. Cooling Crystallization Unit: The discharge port at the bottom of the traditional evaporator 03 is connected to the inlet at the top of the crystallization tank 07 via a pipe, and a manual shut-off valve is installed on the pipe; the cooling coil 08 is spirally wound and fixed to the outer wall of the crystallization tank 07, and the water inlet of the cooling coil 08 is connected to the water outlet of the cooling water tank 09 via a pipe, and the water outlet of the cooling coil 08 flows back to the return water inlet of the cooling water tank 09 via a pipe, forming a cooling water circulation path, and a conventional valve is installed on the circulation pipe to control the water flow; the discharge port is set at the bottom of the crystallization tank 07, and is aligned and connected to the inlet of the filter funnel 010 via a short pipe, and a manual discharge valve is installed on the short pipe.

[0050] 4. Solid-liquid separation and collection unit: The filter funnel 010 is fixed above the collection tank 011 by a bracket. The outlet of the filter funnel 010 is vertically aligned with the opening of the collection tank 011 to ensure that the filter cake can fall directly into the collection tank 011. The bottom side of the filter funnel 010 has a reserved mother liquor outlet, which is connected to the return port of the raw material liquid storage tank 01 through a pipeline to form a mother liquor circulation path. A shut-off valve is installed on the pipeline to control the return of the mother liquor.

[0051] The working steps and operation mode of traditional evaporation crystallization equipment used for the purification of rhenium ions are as follows:

[0052] Step 1: Raw material liquid transportation. First, check the sealing of all component connection interfaces to ensure no leakage. Open the shut-off valve of the bottom pipeline of the raw material liquid storage tank 01 and start the transfer pump 02. The raw material liquid containing rhenium salts (concentration 100~150g / L, containing impurity ions such as molybdenum and tungsten) is transported from the raw material liquid storage tank 01 to the conventional evaporator 03 through the pipeline under the power of the transfer pump 02. By observing the liquid level gauge (conventional built-in liquid level gauge) of the conventional evaporator 03, control the raw material liquid transportation rate. When the liquid level reaches two-thirds of the effective volume of the vessel, close the shut-off valves of the transfer pump 02 and the outlet of the raw material liquid storage tank 01 to complete the raw material liquid transportation. In this process, the transfer pump 02 converts mechanical energy into liquid kinetic energy to achieve directional transportation of the raw material liquid. The sealing structure of the pipeline flanges and interfaces ensures no leakage during transportation. The liquid level gauge is used to accurately control the feed rate to avoid excessive or insufficient raw material liquid affecting the evaporation effect.

[0053] Step 2: Evaporation and Concentration. Start the electric heating elements at the bottom and side walls of the conventional evaporator 03, setting the heating temperature to 90-100℃ to heat the raw material liquid inside the vessel. Simultaneously, start the drive motor of the stirring paddle, setting the speed to 150-200 r / min. The stirring paddle rotates inside the vessel to ensure thorough mixing of the raw material liquid and prevent uneven heating in certain areas. Start the vacuum pump 06 to extract air from the conventional evaporator 03 through the pipeline. The vacuum gauge 05 displays the vacuum level inside the vessel in real time. By adjusting the pumping power of the vacuum pump 06, maintain the vacuum level inside the vessel at 0.07-0.08. MPa accelerates the evaporation of water in the raw material liquid; thermometer 04 monitors the temperature inside the vessel in real time. If the temperature exceeds 100℃, the electric heating tube is automatically powered off and cooled down through the temperature control switch. If the temperature is below 90℃, the electric heating tube is automatically powered on and heated up to ensure stable heating temperature; the steam generated by evaporation is discharged through the steam exhaust pipe reserved at the top of the traditional evaporation vessel 03. Some of the steam is discharged directly, and some is used to preheat the raw material liquid to be transported later; when the concentration of rhenium salt in the raw material liquid reaches 250~300g / L, the electric heating tube, stirring paddle and vacuum pump 06 are turned off, and the evaporation and concentration process is completed. During this process, the electric heating element alternately switches on and off according to the temperature control signal to maintain the set temperature; the stirring paddle rotates at a constant speed, and the motor output shaft and the stirring paddle shaft rotate synchronously through a coupling; the vacuum pump 06 adjusts the pumping power according to the feedback signal from the vacuum gauge 05 to maintain a stable vacuum; the thermometer 04 provides real-time temperature data to support temperature control; the electric heating element converts electrical energy into heat energy, which is transferred to the raw material liquid through heat conduction to achieve the vaporization of water; the rotation of the stirring paddle disrupts the laminar flow state of the liquid, making the heat evenly distributed; the vacuum environment lowers the boiling point of water, accelerates water evaporation, and shortens the concentration time; real-time monitoring and control of temperature and vacuum ensure that the concentration process is stable and controllable, and prevents the raw material liquid from deteriorating due to overheating.

[0054] Step 3: Cooling and Crystallization. Open the shut-off valve at the bottom outlet of the conventional evaporator 03 and slowly introduce the concentrated rhenium salt solution into the crystallization tank 07. After the solution has been completely introduced, close the shut-off valve. Open the valve of the outlet pipe of the cooling water tank 09 and the circulation valve of the cooling coil 08, and start the water supply device in the cooling water tank 09 to send cooling water at a temperature of 5~10℃ into the cooling coil 08. The cooling water flows in the coil and absorbs the heat of the solution in the crystallization tank 07 through heat conduction, thereby cooling the solution. The cooling rate is controlled at 3~5℃ / h. After absorbing heat, the temperature of the cooling water rises and flows back to the cooling water tank 09 through the return port of the cooling coil 08, completing the circulation. The solution is left to stand naturally in the crystallization tank 07 for 8~12 hours, and the rhenium salt gradually precipitates in the form of crystals, completing the cooling and crystallization process. During this process, the built-in water pump in the cooling water tank 09 provides the power for cooling water circulation; cooling water continuously flows in the cooling coil 08, and valves control the flow; the crystallization tank 07 serves as a container for solution cooling and crystallization, providing a stable crystallization environment. The cooling coil 08 transfers the cooling energy of the cooling water to the solution in the crystallization tank 07 through its pipe wall, lowering the solution temperature. The solubility of rhenium salts decreases as the temperature decreases, and after exceeding the saturation concentration, they precipitate in crystal form. The continuous circulation of cooling water removes heat, maintaining a stable cooling process; the static settling process ensures sufficient crystal growth and improves the crystallization rate.

[0055] Step 4: Solid-liquid separation and collection. Open the manual discharge valve at the bottom of crystallizer 07. The "crystal + mother liquor" mixture flows into filter funnel 010 under gravity. The filter screen in filter funnel 010 filters the mixture. The rhenium salt crystals are trapped by the filter screen to form a filter cake, while the mother liquor passes through the filter screen and flows into the return pipe through the mother liquor outlet on the bottom side. Open the shut-off valve on the mother liquor return pipe. The mother liquor returns to the raw material storage tank 01 along the pipe for subsequent recycling. After the mixture is completely filtered, close the discharge valve at the bottom of crystallizer 07 and the shut-off valve on the mother liquor return pipe. Remove the filter cake (rhenium salt crystals) from filter funnel 010 and let it fall directly into the collection bucket 011 below, completing the solid-liquid separation and collection. This process utilizes gravity to achieve natural filtration of the mixture. The pore size of the filter screen is smaller than the rhenium salt crystal particle size, but larger than the particle size of impurity ions and water molecules in the mother liquor, thereby achieving the separation of crystals from the mother liquor. The mother liquor is recycled to achieve the reuse of raw materials and improve resource utilization. The collection bucket 011 is used to store the purified rhenium salt crystals.

[0056] Although traditional evaporation crystallization equipment used for the purification of rhenium salts can achieve the purification of rhenium salts, it has many problems in practical industrial applications, such as: large equipment footprint, low connection efficiency, slow cooling crystallization rate, and high energy consumption.

[0057] To address the problems existing in the prior art, this application provides a purification device for metallurgically recovering rhenium, including an integrated evaporation and remelting kettle that integrates evaporation, cooling, and separation functions, effectively solving the problems of high energy consumption, low efficiency, and poor purity in the prior art. The structural principle and working process of this purification device are described in detail below.

[0058] See Figure 2 , 3 This application provides a purification device for metallurgical rhenium recovery, including an evaporation and remelting kettle. The evaporation and remelting kettle includes a kettle shell 1, an insulation layer 2 on the inner wall of the kettle shell 1, and an inner kettle shell 3 inside the insulation layer 2. The inner kettle shell 3 forms an integrated processing chamber for evaporation and crystallization. The kettle shell 1 is provided with a raw material liquid inlet communicating with the inner kettle shell 3. A spiral heating pipe 4 is laid on the upper middle part and / or bottom of the outer wall of the inner kettle shell. The spiral heating pipe 4 is used to introduce an external heat source to heat the raw material liquid in the inner kettle shell 3. An annular cooling chamber 5 is provided in the lower middle part of the outer wall of the shell. The annular cooling chamber 5 is used to introduce an external cold source to cool the raw material liquid in the inner vessel cavity 3. A steam condensation reflux device for condensing and evaporating the steam is provided at the top of the inner vessel cavity 3. The bottom of the inner vessel cavity 3 is a conical structure. A solid-liquid separation component for separating the crystallized product and the mother liquor is provided at the bottom of the cone. A slag discharge port and a mother liquor reflux port are provided near the top of the cone. A temperature sensor 6 and a concentration sensor 7 are provided in the middle of the inner wall of the inner vessel shell. A stirring component 8 is also provided in the inner vessel cavity 3.

[0059] This application integrates evaporation, crystallization, and separation into the inner cavity 3 of a single evaporation remelting kettle, directly replacing the three separate pieces of equipment and their connecting pipelines required in traditional processes: an evaporation kettle, a crystallizer, and a filtration device. The equipment layout changes from horizontal series to vertical stacking, significantly reducing the equipment footprint and factory space requirements, and simplifying the factory layout. Secondly, this application arranges the spiral heating tube 4 and the annular cooling chamber 5 vertically within the kettle, installs a steam condensation and reflux device at the top, and sets an insulation layer 2 on the inner wall of the kettle shell 1. During operation, the evaporation process occurs first inside the kettle, followed by the cooling and crystallization process, and finally filtration and separation, all within a single kettle. It is versatile and requires no material transfer. At the same time, the steam condensation reflux device releases the latent heat of vaporization through the condensation coil 14 and recovers the condensate, avoiding the energy waste and solvent loss from direct steam discharge, forming a closed loop and reducing energy and water consumption. Furthermore, this application integrates the evaporation, crystallization and separation processes in an evaporation remelting kettle for continuous processing. After crystallization, solid-liquid separation is performed at the bottom of the cone. The process is seamlessly connected, with no intermediate material transfer, shortening the production cycle. It completely avoids the heat loss, pipeline blockage, material adhesion loss and possible contamination when the hot concentrate is pumped to the crystallization tank in the traditional process, directly improving the purification efficiency of rhenium.

[0060] In this application, the evaporation remelting kettle is based on the kettle shell 1 as the basic frame. The inner wall of the kettle shell 1 is fitted with a heat insulation layer 2 (made of aluminum silicate fiber, with a thickness of 50~80mm) to reduce heat loss. The inner side of the heat insulation layer 2 is the inner kettle cavity 3, which serves as the integrated evaporation and crystallization processing cavity and is the core area for raw material liquid processing.

[0061] Spiral heating pipes 4 (made of 316L stainless steel, with a diameter of 20~25mm) are laid on the upper middle part and / or bottom of the side wall of the inner vessel cavity 3. The water inlet of the spiral heating pipes 4 is connected to an external hot water source, and the water outlet can be connected to the raw material liquid preheating system or the water supply system of the inner vessel cavity 3. A steam condensation reflux device is installed at the top opening of the inner vessel cavity 3, which consists of a condensation coil 14, a condensate collection tank 15, and a reflux pump 16. The condensation coil 14 is arranged around the top opening of the inner vessel cavity 3, and the condensate collection tank 15 is located below the condensation coil 14. The reflux pump 16 sends the collected condensate back to the inner vessel cavity 3 or the raw material liquid preheating system through a pipeline.

[0062] like Figure 3 A stirring assembly 8 is vertically installed in the center of the inner vessel cavity 3, including a central stirring shaft 10 and an inner layer propeller 11 and an outer layer scraper 12 arranged from top to bottom on the central stirring shaft 10. Specifically, a drive motor 9 (with adjustable speed) is connected to the top of the central stirring shaft 10. The inner layer propeller 11 adopts a propulsion structure and includes one or more sets of propeller blades arranged at intervals. The propeller blades include multiple helical blades located on the same plane, which are evenly distributed around the central stirring shaft 10. The maximum rotation diameter of the helical blades of the inner layer propeller 11 is 200~250mm, and it is installed in the lower part of the central stirring shaft 10.

[0063] In this application, the outer wall scraper 12 adopts an anchor structure. The outer wall scraper 12 includes a horizontal beam set on the central stirring shaft 10 and at least two arc-shaped anchor arms 13 extending from both ends of the horizontal beam to the inner wall of the inner vessel shell. The rotation trajectory of the arc-shaped anchor arms 13 is adapted to the curved surface shape of the inner wall of the inner vessel shell. The end of the arc-shaped anchor arm 13 maintains a gap of 5-8 mm with the curved surface of the inner wall of the inner vessel shell. It is installed at the lower part of the central stirring shaft 10, close to the bottom of the inner vessel cavity 3.

[0064] In this application, a temperature sensor 6 and a concentration sensor 7 are embedded in the middle of the side wall of the inner vessel cavity 3 for real-time monitoring of the solution temperature and rhenium salt concentration. In addition, a vacuum interface is provided on the upper part of the outer shell 1, which is connected to a vacuum pump through a pipe to adjust the vacuum degree of the inner vessel cavity 3; an annular cooling cavity 5 is provided on the lower outer side of the inner vessel cavity 3, with a cooling water inlet on the left side and a cooling water outlet on the right side, and low-temperature cooling water is provided by an external refrigeration unit.

[0065] In this application, the bottom of the inner vessel cavity 3 is a conical structure, and a solid-liquid separation component is installed at the bottom of the conical structure: a filter screen 17 (made of titanium alloy with a pore size of 0.2 mm) is horizontally fixed at the bottom of the conical structure, and below the filter screen 17 is a crystal collection chamber 18. A pneumatic slag discharge valve 19 is installed at the bottom of the crystal collection chamber 18; a mother liquor return port is provided on the side wall of the crystal collection chamber 18, which is connected to the raw material liquid storage tank through a pipeline.

[0066] In this application, a raw material liquid inlet is located on the upper left side of the outer shell 1, which is connected to a raw material liquid storage tank via a feed pump; an observation window (made of high-temperature resistant quartz glass) is located on the middle right side to facilitate observation of the material status inside the inner vessel cavity 3. A safety valve is installed at the top of the outer shell 1 to ensure equipment pressure safety.

[0067] The metallurgical rhenium recovery purification equipment provided in this application also includes a control system, specifically a PLC control cabinet. The PLC control cabinet is connected to the feed pump, spiral heating tube 4, reflux pump 16, drive motor 9 of stirring assembly 8, temperature sensor 6, concentration sensor 7, vacuum pump, external refrigeration unit, pneumatic slag discharge valve 19, etc., through wires to realize automated control.

[0068] In one specific embodiment, the spiral heating tube 4 can be a U-shaped heating tube made of Hastelloy alloy, which has better corrosion resistance and high temperature resistance, is suitable for purifying rhenium-containing solutions with higher concentrations, and has a service life that can be extended to 8 to 10 years. Although the cost is slightly higher, it can meet the requirements of special working conditions.

[0069] In one specific embodiment, the stirring component 8 in this application may adopt a planetary stirring paddle (an existing stirring structure, which typically consists of one or more rotating blades that rotate around their own axis, while these blades also revolve around the central axis of the stirring tank. This composite motion can generate very strong shearing and full-range circulation, with almost no dead zones in the stirring). Through multi-directional stirring, the uniformity of solution mixing is further improved, and local overheating or overcooling is avoided. It is suitable for rhenium-containing solutions with high viscosity and can further optimize the evaporation and crystallization effects.

[0070] In one specific embodiment, the cooling medium in this application is a mixture of cooling water and ethylene glycol. In other embodiments, an aqueous solution of propylene glycol can also be used, which has a lower freezing point (-20°C) and higher heat dissipation efficiency, making it suitable for scenarios requiring higher cooling rates (e.g., 8~10°C / h) and further shortening the crystallization time.

[0071] In one specific embodiment, the filter screen 17, horizontally installed at the bottom of the cone in the inner vessel cavity 3, can be driven to rise and fall by a drive rod, which can be hydraulically or pneumatically driven. During operation, the drive rod moves the filter screen 17 to the working position, closely fitting or approaching the opening at the bottom of the cone, forming an effective filtration surface. At this time, crystals are trapped on the filter screen 17, and the mother liquor flows through the filter screen 17 into the lower crystal collection chamber 18 and is discharged from the mother liquor return port. After filtration is completed, the drive rod drives the filter screen 17 to move upward, forming a larger annular opening between it and the cone wall. At this time, the crystals (filter cake) accumulated on the screen can fall into the lower crystal collection chamber 18 as a whole with the assistance of slight stirring, and finally be discharged through the pneumatic slag discharge valve 19.

[0072] In one specific embodiment, the control system of the metallurgical rhenium recovery purification equipment provided in this application can be a PLC control cabinet or a single-chip microcomputer control system.

[0073] The operating process of the metallurgical rhenium recovery purification equipment provided in this application is as follows:

[0074] After the equipment is installed and debugged, the parameters are set through the PLC control cabinet (evaporation temperature 75~80℃, vacuum degree 0.085~0.09MPa, cooling endpoint temperature 15℃, stirring speed 250r / min). The operation process is as follows:

[0075] Step 1, Feeding stage: Start the feed pump, open the control valve at the raw material liquid inlet, and send the rhenium salt-containing raw material liquid (concentration 100~150g / L) into the inner vessel cavity 3. Observe the liquid level through the observation window. When the liquid level reaches 2 / 3 of the volume of the inner vessel cavity 3, close the feed pump and the control valve at the raw material liquid inlet.

[0076] Step 2, Evaporation and Concentration Stage: Start the vacuum pump to maintain the vacuum level of the inner vessel cavity 3 at 0.085~0.09MPa; introduce hot water at 80~85℃ into the spiral heating tube 4, and simultaneously start the stirring assembly 8 (speed 250r / min); monitor the solution temperature in the inner vessel cavity 3 through the temperature sensor 6 and control it at 75~80℃; the steam generated by evaporation rises to the top, is condensed into water by the condenser coil 14, and is collected in the condensate collection tank 15. Part of the condensate is returned to the inner vessel cavity 3 through the reflux pump 16, and part is used to preheat the raw material liquid; monitor the rhenium salt concentration in real time through the concentration sensor 7. When the concentration reaches 280~300g / L, stop the hot water supply to the spiral heating tube 4 and enter the cooling stage.

[0077] Step 3, Cooling and Crystallization Stage: Start the refrigeration unit of the cooling assembly, and introduce 5~8℃ cooling water into the annular cooling chamber 5 outside the inner vessel cavity 3 through the cooling water inlet. The cooling water flows back to the refrigeration unit through the cooling water outlet. The stirring assembly 8 is kept running, and the solution temperature is monitored by the temperature sensor 6. The cooling rate is controlled at 2~4℃ / h. When the temperature drops to 15℃, stop the refrigeration unit, turn off the cooling water supply, and let it stand for 2~3 hours to allow the rhenium salt crystals to fully precipitate.

[0078] Step 4, Solid-Liquid Separation Stage: After crystal precipitation, the stirring component 8 continues to run for 5-10 minutes to fully mix the crystals with the mother liquor, and then the stirring is stopped; the crystals settle downwards under gravity and are intercepted when passing through the filter screen 17, while the mother liquor passes through the screen and returns to the raw material storage tank through the mother liquor return port; when the crystals accumulate in the crystal collection chamber 18 for 1-2 hours, the PLC control cabinet automatically opens the pneumatic slag discharge valve 19 to discharge the rhenium salt crystals to the collection container, completing one purification cycle.

[0079] To run continuously, simply repeat steps 1 through 4 above.

[0080] Compared with existing technologies, the purification equipment for metallurgical rhenium recovery provided in this application has at least the following advantages:

[0081] 1. Reduce evaporation energy consumption and avoid rhenium salt decomposition: Existing technologies use electric heating tubes for direct heating, which has low thermal efficiency and is prone to local overheating, resulting in a rhenium loss rate of 3%~5% and a unit energy consumption of 600~800 kWh / t. This application achieves optimization through the following design: The spiral heating tube uses hot water circulation heating, combined with an insulation layer, increasing the thermal efficiency from 60%~70% in the existing technology to over 90%; the steam condensation reflux device recovers steam heat for preheating the raw material liquid, further reducing energy consumption, ultimately reducing the energy consumption per unit rhenium salt product to 250~300 kWh / t, a reduction of 50%~60%; simultaneously, a vacuum pump is used to control the vacuum degree of the inner vessel cavity at 0.085~0.09 MPa, lowering the boiling point of the solution to 75~80℃. Combined with the uniform heating of the spiral heating tube and the stirring effect of the inner propeller, local overheating is avoided, the rhenium salt decomposition rate is controlled below 0.5%, and the rhenium recovery rate is increased to 97%~98%.

[0082] 2. Improve cooling crystallization efficiency and optimize crystal purity and particle size: Existing technologies rely on external cooling coils and gravity filtration, resulting in crystal purity of only 98.5%~99%, uneven particle size (0.1~2mm), and a purification cycle of 24~36 hours. This application achieves the following improvements through an integrated structure and precise control: the annular cooling chamber directly acts on the concentrated liquid in the lower part of the inner vessel cavity, and with the precise temperature control of PLC (cooling rate 2~4℃ / h), rhenium salt crystals are slowly precipitated, with the crystal particle size uniformly controlled at 0.5~1mm, and the fine crystal loss rate reduced from 5%~8% in the prior art to 1%~2%; in addition, the amount of impurity ions (molybdenum, tungsten) adsorbed on the surface of the uniformly precipitated crystals is reduced, and with the efficient interception of the impurity ions by the titanium alloy filter screen with a 0.2mm pore size, the purity of the final rhenium salt crystals is increased to 99.5%~99.8%, eliminating the need for an additional acid washing process and reducing the number of process steps by 30%; at the same time, the integrated structure eliminates material transfer time, shortens the single purification cycle to 12~15 hours, and increases production efficiency by 50%.

[0083] 3. Reduce material loss and achieve automated operation: Existing technologies suffer from 5% to 8% material transfer and residue loss due to dispersed equipment, and rely on manual operation. This application solves this problem through the following design: First, the inner vessel cavity integrates the "evaporation-cooling-separation" function, processing materials throughout the entire process within the same cavity, eliminating transfer residues and increasing the total recovery rate of rhenium salts from 88% to 92% in existing technologies to 97% to 98%; Second, the PLC control cabinet achieves fully automated control of the entire process of feeding, heating, cooling, separation, and slag discharge, eliminating the need for manual valve switching or filter operation, reducing operator workload by 70%, and avoiding parameter fluctuations caused by manual operation, thus improving equipment operational stability by 40%.

[0084] 4. Dual-layer stirring and uniform heating synergy: The stirring component's "inner layer propeller + outer layer scraper" combined with the spiral heating tube hot water circulation avoids local overheating and wall formation, ensuring that the rhenium salt does not decompose and is heated evenly, which is the key to reducing energy consumption and improving purity.

[0085] 5. Precise temperature control of the annular cooling chamber: The annular cooling chamber acts directly on the concentrated liquid in the lower part of the inner vessel cavity. Combined with PLC precise control of the cooling rate, it achieves uniform crystal precipitation and is the core means to optimize crystal particle size and purity.

[0086] 6. Built-in titanium alloy screen separation: The solid-liquid separation component adopts a built-in titanium alloy filter screen, which, together with the crystal collection chamber and pneumatic slag discharge valve, achieves efficient solid-liquid separation and automated slag discharge, which is the key to reducing the loss of fine crystals and improving the ease of operation.

[0087] 7. Reduced space occupation and improved connection efficiency: The integrated evaporation and remelting kettle integrates evaporation, crystallization and filtration functions. Compared with the existing three-stage structure, the equipment occupies more than 40% less space. The solution transfer link between equipment is eliminated, avoiding residual loss during the transfer process. At the same time, the overall purification cycle is shortened and the production efficiency is increased by 30% to 40%.

[0088] 8. Accelerate crystallization rate and reduce energy consumption: The built-in cooling chamber and forced circulation system of cooling medium significantly improve heat transfer efficiency, increase the cooling rate to 5~8℃ / h, and shorten the crystallization time from 8~12 hours to 4~6 hours; the steam condensation reflux device recovers the heat energy of the evaporated steam for preheating the raw material liquid, reduces the heating load of the spiral heating tube, and reduces the overall energy consumption by 25%~30%. At the same time, the condensate is recycled to save water resources.

[0089] 9. Optimize separation effect and improve product purity and recovery rate: The TA2 titanium alloy filter screen has strong corrosion resistance and uniform pore size. Combined with high-pressure filtration of 0.1~0.15MPa, it not only effectively blocks impurity ions such as molybdenum and tungsten, increasing the purity of rhenium salt crystals to over 99.5% (the purity of existing technology is usually around 98%), but also avoids crystals from flowing back with the mother liquor, thus improving the product recovery rate.

[0090] 10. Achieve fully automated control and reduce labor costs: The PLC control system automates the operation of each stage of raw material conveying, heating, stirring, cooling, filtering and discharging, reducing manual intervention and the labor intensity of operators; at the same time, it avoids human operation errors, significantly improves the stability of purification effect, and reduces labor costs by more than 50%.

[0091] In summary, this application integrates evaporation, cooling crystallization, and solid-liquid separation functions into an integrated evaporation remelting kettle through a unified design, eliminating the transfer links between independent equipment and effectively solving the problems of large footprint and low connection efficiency in existing technologies. Secondly, the built-in annular cooling chamber in the kettle body jacket, combined with a cooling medium circulation pump, achieves rapid cooling crystallization, improving cooling efficiency and shortening crystallization time. Thirdly, the use of a TA2 titanium alloy filter screen combined with a hydraulically driven lifting rod achieves high-pressure solid-liquid separation, improving product purity and recovery rate. Finally, the use of a steam condensation reflux device to recover the heat energy of the evaporation steam to preheat the raw material liquid achieves heat energy recycling and reduces energy consumption.

[0092] The technical features of the above embodiments can be combined in any way (as long as there is no contradiction in the combination of these technical features). For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; these embodiments not explicitly written should also be considered to be within the scope of this specification.

[0093] The present application has been described in a relatively specific and detailed manner above through general descriptions and specific embodiments. It should be understood that, based on the technical concept of the present application, several conventional adjustments or further innovations can be made to these specific embodiments; however, as long as they do not depart from the technical concept of the present application, the technical solutions obtained by these conventional adjustments or further innovations also fall within the protection scope of the claims of the present application.

Claims

1. A purification device for metallurgically recovering rhenium, characterized in that, The apparatus includes an evaporation remelting kettle, which includes an outer shell, an inner wall of which is provided with a heat insulation layer, an inner shell of which is provided on the inner side of the heat insulation layer, and an inner cavity of which forms an integrated processing chamber for evaporation and crystallization. The outer shell of the kettle is provided with a raw material liquid inlet that communicates with the inner cavity of the kettle. The upper middle and / or bottom of the outer wall of the inner vessel shell are provided with spiral heating pipes, which are used to introduce an external heat source to heat the raw material liquid in the inner vessel cavity; the lower middle part of the outer wall of the inner vessel shell is provided with an annular cooling cavity, which is used to introduce an external cold source to cool the raw material liquid in the inner vessel cavity; the top of the inner vessel cavity is provided with a steam condensation and reflux device for condensing the steam generated by evaporation; the bottom of the inner vessel cavity is a conical structure, with a solid-liquid separation component for separating the crystallization product and the mother liquor at the bottom of the cone, and a slag discharge port and a mother liquor reflux port near the top of the cone; a temperature sensor and a concentration sensor are provided in the middle of the inner wall of the inner vessel shell; a stirring component is also provided in the inner vessel cavity.

2. The metallurgical rhenium recovery purification equipment according to claim 1, characterized in that, The inlet end of the spiral heating tube is connected to an external hot water source, and the outlet end of the spiral heating tube is connected to a raw material liquid preheating system or an inner vessel cavity water addition system. The outer shell of the vessel has a cooling water inlet and a cooling water outlet respectively connected to the annular cooling cavity on the left and right sides. The cooling water inlet is connected to an external refrigeration unit, which provides low-temperature cooling water.

3. The metallurgical rhenium recovery purification equipment according to claim 1, characterized in that, The stirring assembly includes a central stirring shaft driven by a drive motor, on which are mounted an inner propulsion paddle located in the lower middle part and an outer wall scraper paddle located at the lower part of the central stirring shaft close to the bottom of the inner vessel shell.

4. The metallurgical rhenium recovery purification equipment according to claim 3, characterized in that, The inner propulsion paddle includes one or more sets of propulsion paddle structures arranged at intervals. The propulsion paddle structure includes multiple helical blades located on the same plane, and the multiple helical blades are evenly distributed around the central stirring shaft. The outer scraper includes a horizontal beam mounted on the central stirring shaft and at least two arc-shaped anchor arms extending from both ends of the horizontal beam toward the inner wall of the inner vessel shell. The rotation trajectory of the arc-shaped anchor arms is adapted to the curved surface shape of the inner wall of the inner vessel shell, and the ends of the arc-shaped anchor arms maintain a gap of 5 to 8 mm with the curved surface of the inner wall of the inner vessel shell.

5. The metallurgical rhenium recovery purification equipment according to claim 4, characterized in that, The maximum rotation diameter of the helical blade is between 200mm and 250mm.

6. The metallurgical rhenium recovery purification equipment according to claim 1, characterized in that, The steam condensation reflux device includes: a condensation coil arranged around the top opening of the inner vessel cavity, a condensate collection tank located below the condensation coil, and a reflux pump for pumping condensate from the condensate collection tank back to the inner vessel cavity or the raw material liquid preheating system. The condensate collection tank is an annular tank, and the outer edge of the condensate collection tank is fixed to the inner wall of the inner vessel shell. The stirring shaft of the stirring assembly passes through the center of the condensate collection tank and extends into the inner vessel cavity.

7. The metallurgical rhenium recovery purification equipment according to claim 1, characterized in that, The solid-liquid separation component includes a filter screen horizontally installed at the bottom of the conical structure. A crystal collection chamber is formed below the filter screen. The side wall of the crystal collection chamber is provided with a slag discharge port and a mother liquor return port. A pneumatic slag discharge valve is provided at the slag discharge port. The mother liquor return port is connected to the raw material liquid storage tank through a pipeline.

8. The metallurgical rhenium recovery purification equipment according to claim 1, characterized in that, The heat source control end of the spiral heating tube, the cold source control end of the annular cooling chamber, the drive motor of the stirring assembly, the temperature sensor, the concentration sensor, and the pneumatic slag discharge valve installed at the slag discharge port are all electrically connected to the control system. The temperature sensor is used to detect the temperature of the solution in the inner vessel cavity in real time, and the concentration sensor is used to detect the concentration of rhenium salt in the inner vessel cavity in real time.

9. The metallurgical rhenium recovery purification equipment according to claim 1, characterized in that, The outer shell of the vessel is equipped with a vacuum interface, which is connected to the inner vessel cavity via a pipe. The vacuum interface is connected to a vacuum pump and is used to adjust the vacuum level of the inner vessel cavity.

10. The metallurgical rhenium recovery purification equipment according to claim 1, characterized in that, The outer shell of the vessel is provided with an observation window, which is made of high-temperature resistant quartz glass, for observing the state of the material inside the inner vessel cavity; A safety valve is provided on the top of the outer shell of the vessel; The insulation layer is made of aluminum silicate fiber, and its thickness ranges from 50 to 80 mm.

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