Three-cathode electrolytic furnace metal lifting-out automatic production line

Abstract

This invention relates to the field of rare earth electrolytic smelting technology, specifically disclosing an automated production line for metal extraction from a three-cathode electrolytic furnace. The production line includes a three-cathode electrolytic furnace body, a three-cathode electrolysis and positioning system, a single-arm lightweight crucible-lifting robot, an automatic casting table, and a control unit. The three-cathode electrolysis and positioning system achieves dynamic and precise centering and positioning of the cathodes during electrolysis through asymmetrically arranged three-cathode components, current density detection, and a collaborative control algorithm. The single-arm lightweight crucible-lifting robot shares installation space with the three-cathode components and can efficiently extract the crucible after the cathode has slightly shifted. The automatic casting table is used to receive and cast molten metal. By integrating electrolysis, positioning, crucible lifting, and casting functions, this invention achieves automated continuous production of rare earth metals from electrolysis to metal extraction, effectively solving the problems of low efficiency, high energy consumption, insufficient automation, and high risks associated with manual operation in traditional processes, significantly improving production efficiency and safety.

Description

Technical Field

[0001] This invention relates to the field of rare earth metal electrolytic smelting technology, specifically to an integrated, automated production line with precise control and positioning of three cathodes and extraction of metal from a crucible. Background Technology

[0002] Against the backdrop of global energy structure optimization and the in-depth application and utilization of strategic resources, rare earth resources, as a crucial scarce resource in international competition, require enhanced intelligence and efficiency in electrolytic smelting, which has become a core requirement for the industry's development. Currently, high energy consumption per unit product, low levels of production automation, and reliance on manual intervention are the main pain points hindering the improvement of the competitiveness of my country's rare earth electrolysis industry.

[0003] Rare earth metals and alloys are mainly produced through molten salt electrolytic reduction. The performance of the cathode system in the electrolytic furnace directly determines the current efficiency, metal quality, and energy consumption. Traditional single-cathode structures in electrolytic furnaces have significant drawbacks: uneven current density distribution within the electrolytic cell easily leads to localized overheating or incomplete electrolysis; fixed or coarse cathode positioning fails to optimize the reaction interface, resulting in uncontrollable metal deposition locations; concentrated current at a single point also exacerbates cathode and anode losses, ultimately causing low product yield, high energy consumption, and short cathode lifespan. Three-cathode control technology is an effective solution to these problems. By rationally arranging and independently driving three cathodes, the current field distribution in the electrolytic cell can be significantly improved, and current efficiency enhanced. Furthermore, relying on real-time current density feedback to dynamically adjust the positions of the three cathodes, precise alignment and stable maintenance of the cathode reaction zone can be achieved, improving the uniformity and efficiency of metal deposition. This lays a technological foundation for energy conservation, reduced consumption, increased production, and improved quality in rare earth electrolysis.

[0004] However, the application of triple-cathode technology also places higher demands on the continuity of the production process. After the electrolysis cycle ends, how to safely and quickly remove the crucible containing high-temperature molten metal from the dense triple-cathode array and transfer it to the next process has become a new bottleneck for upgrading the entire process to automation. Traditional manual crucible lifting and scooping methods are not only risky and slow, but also difficult to adapt to the limited space provided by the triple-cathode system. Therefore, developing an automated crucible lifting and unloading production line that can efficiently coordinate with the triple-cathode system and operate with precision is key to realizing the leap from "high-quality electrolysis" to "continuous and intelligent production" in rare earth electrolysis. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an automated production line for crucible extraction from a three-cathode electrolytic furnace. This production line solves the problems of precise positioning and current balance during the electrolysis process through a three-cathode asymmetric drive and feedback control system; it achieves efficient, flexible, and safe crucible extraction through a lightweight crucible-extraction robot integrated under the same gantry; and through linkage with an automatic casting station, it forms a complete automated metal extraction process of "electrolysis-crucible extraction-casting," significantly improving production efficiency, safety, and product durability.

[0006] To achieve the above objectives, this invention provides an automated production line for metal extraction from a three-cathode electrolytic furnace, comprising: a three-cathode electrolytic furnace body, a three-cathode assembly, a single-arm lightweight crucible lifting robot, an automatic casting table, and a control unit. The furnace body of the three-cathode electrolytic furnace has a furnace chamber structure specifically designed for the collaborative operation of the three cathodes, capable of accommodating three cathode rods arranged side-by-side inserted into the electrolyte. The anode system employs ten anode plates evenly distributed circumferentially: each cathode rod is enclosed by four anode plates to form its independent electrolytic reaction unit, and adjacent cathode units share the two anode plates located in the middle. This layout ensures uniform current distribution at each cathode and optimized reaction interface while improving anode utilization efficiency, forming a compact and efficient electrolysis field structure. The current density detection device corresponds to this layout and measures the current density between each cathode rod and its four surrounding dedicated anode plates, providing precise feedback signals for subsequent control. The three-cathode assembly includes three cathode rods, a controllable insulating device above the cathode rods, and a three-cathode drive device mounted on the top truss. The three-cathode drive device includes a three-cathode lifting device and a translational guide device. The three-cathode assembly can achieve three-axis motion: lifting, lateral translation, and longitudinal translation. The motion drive mechanism includes a lifting mechanism and a translational mechanism. The lifting mechanism uses a screw, herringbone gear, and rack to achieve the vertical movement of the three-cathode assembly. The translational mechanism uses a high-precision ground lead screw to achieve lateral and longitudinal translation of the three-cathode assembly. The single-arm lightweight crucible lifting robot is also suspended on the top truss, located on one side of the three-cathode assembly, sharing the top motion space with it. It includes a lightweight arm, a high-temperature resistant end effector, and a drive mechanism, capable of horizontal movement and featuring Z-axis lifting functionality. The automatic casting platform is located on the side of the electrolytic furnace, used to receive crucibles containing molten metal transferred by the crucible lifting robot and perform automatic casting operations. The control unit uses a medium-to-large-sized industrial programmable logic controller (PLC) as its central processing unit. The control unit is electrically connected to the current density detection device and the motion drive mechanism, receiving detection data from the current density detection device, converting current density values ​​in different directions into pulse data for three-axis motion, and controlling the motion drive mechanism to drive the three-cathode assembly to achieve automatic furnace core positioning. The control unit also has an interface for external communication and reserves space for future management system upgrades. The current density detection device measures the current density values ​​of the cathode rod and four evenly distributed anode graphite plates in four directions.

[0007] The top of the three-cathode assembly includes a welded profile frame that is detachably connected to the three-cathode assembly, facilitating the removal and replacement of the cathode copper busbar.

[0008] The control unit is characterized by stable operation in electromagnetic interference, high temperature and dust environments. The control unit can control the three cathode components to move and descend to the electrolysis working position at the upper edge of the crucible at the bottom of the furnace, and automatically connect the low-voltage DC power supply to start the electrolysis cycle.

[0009] The control unit has two preset crucible lifting control logics: the first logic is that after the three cathode components are completely moved out of the space above the electrolytic furnace, the crucible lifting robot enters to pick up the crucible; the second logic is that the three cathode components perform coordinated micro-translation in the horizontal plane to make way for the central vertical channel, and after the cathode current is disconnected by the insulation control device, the crucible lifting robot directly descends vertically to pick up the crucible.

[0010] The current density data detected by the current density detection device in four directions, after being processed by the control unit, forms pulse data that can drive the three-cathode assembly to always remain at the center point of the anode graphite plate.

[0011] The electrolytic furnace cathode automatic control and positioning device can achieve centralized control, reduce human intervention, and provide guidance for smelting production through parameters obtained by big data calculation.

[0012] The triaxial motion of the three-cathode assembly ensures that the molten liquid metal attached to the cathode remains within the diameter range of the graphite crucible during the dripping process, reducing molten metal overflow and slag accumulation at the bottom of the furnace.

[0013] To achieve the above objectives, the present invention also provides a three-cathode coordinated control method for the production line, which performs independent and coordinated three-axis position control on an asymmetrically arranged three-cathode assembly based on current density feedback. The method includes the following steps:

[0014] The current density data acquisition and preprocessing involves setting up an independent current detection unit for each cathode rod to collect the current density values ​​between it and the four surrounding dedicated anode plates in real time, which are denoted as follows: The four current density values ​​for each cathode are normalized to eliminate the influence of dimensions.

[0015] The vectorized representation of single cathode position deviation is for the first... For the root cathode, define its current density uniformity deviation vector. :

[0016]

[0017] in, This represents the average current density in the four directions of the cathode. For the first A unit vector in each detection direction (from the cathode to the corresponding anode plate). The magnitude of the value reflects the degree of unevenness in the cathode current distribution, and the direction points towards the area with relatively high current density, i.e., the direction in which the cathode should be moved to approach the center.

[0018] The motion of the three-cathode assembly in the horizontal plane can be decomposed into translations along the X and Y axes and a small rotation θ about the center point. Define the system state vector. This indicates the amount of position and attitude adjustment required for the whole.

[0019] Solve by constructing the following coupling matrix equation. :

[0020]

[0021] Among them, matrix Determined by the initial asymmetric geometric layout of the three cathodes, it reflects the contribution of the individual movement of each cathode to the overall pose change. This is for measuring noise and higher-order error terms.

[0022] Solve using the least squares method or gradient descent method to achieve optimal overall current distribution uniformity:

[0023]

[0024] Three-axis drive command generation and independent control involves calculating the system adjustment values. This is converted into individual three-axis motion commands for each cathode rod.

[0025] For the The root cathode, its required independent motion increment Determined by the following formula:

[0026]

[0027] in These are the polar coordinates of the cathode relative to the center of the assembly. This is the adjustment coefficient for lifting and lowering. The threshold for vertical adjustment is defined above. The control unit, according to the aforementioned instructions, independently drives the high-precision grinding screws (X and Y axes) and the screw-gear rack mechanism (Z axis) corresponding to each cathode, achieving coordinated positioning and attitude correction of the three cathode components.

[0028] The aforementioned three-cathode control steps are executed cyclically at a fixed frequency during electrolysis, forming a real-time closed-loop control. By introducing PID regulation or adaptive filtering, measurement noise and mechanical vibration interference are suppressed, enabling the three-cathode assembly to dynamically stabilize at the optimal current distribution position during electrolysis.

[0029] This invention relates to an automated production line for metal extraction from a three-cathode electrolytic furnace. Through a core design of three-cathode collaborative positioning and asymmetric feedback control, combined with the intelligent linkage between a single-arm lightweight crucible-lifting robot and the casting system, it constructs an automated metal extraction system from electrolysis, positioning, crucible removal to casting. This system not only effectively solves the problems of uneven current distribution, coarse positioning, and discontinuous production in traditional single-cathode electrolysis, but also achieves a systematic upgrade in rare earth electrolysis production in terms of increased production and efficiency, energy saving and consumption reduction, process stability, and intelligent operation through multi-component collaborative scheduling and precise control. It has significant practical value and broad prospects for promotion. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0031] Figure 1 This is a schematic diagram of the structure of the three cathodes and the positioning device of the electrolytic furnace in an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the layout of a metal production line for a three-cathode electrolytic furnace in an embodiment of the present invention.

[0033] Figure 3 This is a top view of the three-cathode driving device according to an embodiment of the present invention.

[0034] Figure 4 This is a flowchart of an automated production line for removing metal from a three-cathode electrolytic furnace according to an embodiment of the present invention.

[0035] In the diagram: 1-1: Welded main frame; 1-2: Three-cathode lifting device; 1-3: Translational guide device; 1-4: Three-cathode electrolytic furnace; 2-1: Three-cathode drive device; 2-2: Insulation control device; 2-3: Lightweight crucible lifting robot; 2-4: Automatic casting table; 2-5: Crucible. Detailed Implementation

[0036] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0037] Please see Figures 1 to 4 . Figure 1 This invention demonstrates the core structure of the three-cathode and electrolytic furnace positioning device. Figure 2 The production line layout, which includes a three-cathode system, a lightweight crucible lifting robot, and a casting table, is shown. Figure 3 This is a top view of the three-cathode drive unit, clearly showing its structure; Figure 4This invention provides an automated production line for the entire automated production line, including a three-cathode electrolytic furnace body, a three-cathode electrolysis and positioning system, a single-arm lightweight crucible lifting robot, an automatic casting table, and a control unit. This solution addresses the current problems of low finished product output, high energy consumption, and low automation levels, which severely restrict the sustainable development of the rare earth processing industry.

[0038] In this specific embodiment, the three-cathode electrolysis and positioning system is the core of the production line, and its control logic is as follows: the three cathode rods are arranged in a specific asymmetrical layout within the electrolysis furnace (e.g., Figure 3 (As shown). Each cathode rod is equipped with an independent current density detection device to collect the current density values ​​between itself and the four surrounding dedicated anode plates in real time, forming a set of vector signals reflecting its spatial position. The collaborative control algorithm in the control unit takes the real-time current density data as input. The core of this algorithm lies in calculating the uniformity deviation of the current density in each direction of each cathode rod, and comprehensively considering the geometric constraints between the three cathodes, to solve for the adjustment amount of the three cathode components to rotate slightly θ in the X, Y, Z axes and in the horizontal plane to achieve the optimal overall current distribution. Subsequently, the control unit drives the high-precision grinding screw (to achieve translation in the X and Y directions) and the screw-herringbone gear rack mechanism (to achieve lifting in the Z direction and fine adjustment in the θ direction) to dynamically and in a closed loop adjust the posture of the three cathode components. This process ensures that the three cathode components can automatically track and stably maintain the optimal electrolysis position throughout the entire electrolysis cycle, thereby significantly improving current efficiency and metal deposition uniformity.

[0039] Based on the aforementioned precise and controllable three-cathode system, the automated operation of the production line is carried out according to the following steps:

[0040] First, electrolysis preparation and production are carried out: the control unit is activated, controlling the three-cathode assembly to move to the electrolysis starting position, and then descending to the predetermined electrolysis working position at the upper edge of the crucible at the bottom of the furnace, and automatically connecting the low-voltage DC power supply to start the electrolysis cycle. During the electrolysis process, the aforementioned current density feedback and positioning correction are continuously performed.

[0041] When the electrolysis cycle ends, the crucible lifting decision and execution phase begins. The control unit provides two crucible lifting modes, with the second logic mode primarily used for efficient continuous production:

[0042] 1) The control unit first issues a command to control the insulating control device installed above each cathode rod to quickly and safely cut off the power supply to the cathode rod.

[0043] 2) Subsequently, the three-cathode drive mechanism is controlled to make the three-cathode assembly move in a coordinated, minute manner within the horizontal plane, ranging from tens to hundreds of millimeters, thus creating a vertical passage directly above the furnace core. Since the cathodes only need to move slightly and are already de-energized, they do not need to be completely moved out of the space above the furnace body.

[0044] 3) The single-arm lightweight crucible lifting robot, which is waiting on one side, descends directly along this vertical channel. Its high-temperature resistant end effector grabs the crucible containing molten metal and lifts it up. If the first backup mode is used, the robot will enter to retrieve the crucible after the three cathode assemblies are fully lifted and moved out of the space above the electrolytic furnace.

[0045] After the crucible is lifted, the process moves to the transfer and casting stage: the crucible lifting robot moves horizontally, precisely transferring the crucible to the automatic casting table located on the side of the production line. The casting table then completes the casting operation according to a preset program.

[0046] Finally, a reset and cycle are performed: After casting, the crucible-lifting robot returns the empty crucible to the center of the electrolytic furnace. The three-cathode assembly moves and descends back to the electrolytic working position, the insulation control device is reconnected, and the DC power supply is restarted, thus beginning the next fully automated production cycle. The control unit integrates all the above control logic, is responsible for the timing scheduling and safety interlocking of the entire process, and has the ability to operate stably in industrial environments with electromagnetic interference, high temperatures, and dust. Through this invention, the entire process of rare earth electrolysis from feeding to casting is automated and intelligently produced, greatly improving efficiency, safety, and product consistency.

[0047] The automatic control and positioning device for the cathode of the electrolytic furnace in this embodiment is suitable for large-scale rare earth molten salt electrolytic cells and can be widely used in various rare earth metal and alloy production enterprises. It is especially suitable for production scenarios with high requirements for capacity, energy consumption and automation level. It solves the current problems of low product output, high energy consumption and low automation level, which seriously restrict the sustainable development of the rare earth processing industry.

[0048] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. An automated production line for removing metal from a three-cathode electrolytic furnace crucible, characterized in that, It includes a welded main frame, a three-cathode electrolytic furnace body, a three-cathode assembly, a motion drive device, a current density detection device, a single-arm lightweight crucible lifting robot, an automatic casting table, and a control unit. The three-cathode electrolysis furnace body has a furnace chamber structure that accommodates three cathode rods arranged side by side. The anode system uses ten anode plates evenly distributed around the circumference, with each cathode rod surrounded by four anode plates to form an independent electrolysis reaction unit. The three-cathode assembly includes three cathode rods, a controllable insulation device, and a three-cathode drive device mounted on the top truss. The drive device includes a lifting mechanism and a translation mechanism, enabling the three-cathode assembly to move along the X, Y, and Z axes. A current density detection device is used to detect the current density between each cathode rod and the four surrounding anode plates in real time. Current density value; a single-arm lightweight crucible lifting robot, suspended on the top truss and located on one side of the three-cathode assembly, sharing the top motion space, with horizontal movement and Z-axis lifting functions, used to lift crucibles containing molten metal; an automatic casting platform, located on the side of the electrolytic furnace, used to receive and cast molten metal; a control unit, electrically connected to the current density detection device, the three-cathode drive device and the crucible lifting robot, receiving current density data and converting it into motion control commands to realize dynamic positioning control of the three cathodes, collaborative operation of the crucible lifting robot and automated scheduling.

2. The automated production line for removing metal from a three-cathode electrolytic furnace crucible as described in claim 1, characterized in that, The lifting mechanism of the three-cathode drive device uses a screw in conjunction with a herringbone gear and rack, while the translation mechanism uses a high-precision ground lead screw.

3. The automated production line for removing metal from a three-cathode electrolytic furnace crucible as described in claim 2, characterized in that, The main control unit has two preset control logics for lifting the crucible: the first logic is that after the three cathode components are completely moved out of the space above the electrolytic furnace, the lifting robot enters to pick up the crucible; the second logic is that the three cathode components move slightly in coordination in the horizontal plane to make way for the central vertical channel, and the lifting robot directly descends vertically to pick up the crucible.

4. The automated production line for removing metal from a three-cathode electrolytic furnace crucible as described in claim 3, characterized in that, Its features are, The current density detection device detects current density data in four directions, which are then processed by the central control unit to form pulse data, driving the three-cathode assembly to always remain in the center position of the anode plate.

5. The automated production line for removing metal from the crucible of a three-cathode electrolytic furnace as described in claim 4, characterized in that, The top of the three-cathode assembly includes a welded profile frame that is detachably connected to the three-cathode assembly, facilitating the replacement of the cathode copper busbars.

6. The automated production line for removing metal from a three-cathode electrolytic furnace crucible as described in claim 5, characterized in that, The central control unit adopts an industrial programmable logic controller (PLC), which has the ability to operate stably in environments with electromagnetic interference, high temperature and dust.

7. A method for coordinated control of three cathodes in a production line, used in the automated production line for removing metal from the crucible of a three-cathode electrolytic furnace as described in any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Collect the current density values ​​between each cathode rod and the four surrounding anode plates, and normalize them; Step 2: Calculate the current density uniformity deviation vector for each cathode based on the current density value; Step 3: Based on the asymmetric geometric layout of the three cathodes, construct the coupling relationship matrix equation and solve for the overall pose adjustment of the system; Step 4: Convert the system adjustment into independent three-axis motion commands for each cathode, driving each cathode to achieve coordinated positioning and attitude correction; Step 5: Execute the above steps cyclically at a fixed frequency to form a real-time closed-loop control.

8. The method according to claim 7, characterized in that, The coupling matrix equations are solved using the least squares method or gradient descent method to optimize the overall current distribution balance. PID control or adaptive filtering is introduced during electrolysis to suppress measurement noise and mechanical vibration interference.

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