Continuous electrolysis preparation device and method for elemental boron

Abstract

The invention provides a continuous electrolytic preparation device and method for elemental boron. The device comprises an electrolytic bath composed of a corrosion-resistant alloy crucible and a nested graphite inner container; the flange cover is arranged at the top opening of the alloy crucible; the anodes, the cathodes and the material rods respectively penetrate through the flange cover and extend into the electrolytic bath; the gas inlet and outlet channel is used for introducing inert gas into the tank body and discharging electrolytic waste gas; the discharge port is arranged at the bottom of the electrolytic bath and can be automatically opened and closed, a waste collecting box is arranged below the discharge port, chloride salt for cooling is contained in the box, and an automatic weighing device is arranged; the inert gas sealing cover is arranged outside the electrolytic cell in a covering manner and is used for introducing inert gas, forming a closed atmosphere and guiding electrolytic waste gas to be discharged through the gas inlet and outlet channel; the controller is electrically connected with the anodes, the cathodes and the material bars which can be independently lifted, and the discharge opening; the continuous production of the simple substance boron can be realized, and the requirement of large-scale continuous preparation of the high-purity boron material is met.

Description

Technical Field

[0001] This invention relates to the field of molten salt electrolysis technology, and in particular to a continuous electrolytic preparation apparatus and method for elemental boron. Background Technology

[0002] Boron is the only electron-deficient metallic element in the periodic table, possessing unique physicochemical properties and important applications in nuclear energy, aerospace, semiconductors, permanent magnet materials, and new energy sources. For example, boron is often used in nuclear reactor control rods and radiation shielding. 10 Materials of boron; boron fibers can be used for weight reduction in aerospace structures; amorphous boron thin films serve as dielectric layers in high-frequency radio frequency devices; neodymium iron boron magnets are widely used in intelligent equipment, new energy vehicles, and wind power systems; boron-doped graphene can improve the energy density and cycle life of battery anodes. High-purity elemental boron can serve as a precursor for various high-purity boron-based materials, and its preparation technology plays a supporting role in the development of related industries.

[0003] my country has established a relatively complete boron chemical industry chain, but there is an imbalance in the product structure: the production capacity of basic boron chemicals is sufficient, while high-end products such as high-purity boron powder, electronic-grade boric acid, and hexagonal boron nitride single crystals mainly rely on imports, resulting in a high degree of dependence on foreign countries. To reduce the risk of being dependent on others for key materials, relevant policies have listed high-purity boron materials as a key research target, among which the independent preparation of high-purity elemental boron is particularly crucial.

[0004] Existing methods for preparing elemental boron include magnesothermic reduction, halogen reduction, carbothermic reduction, vapor deposition, and self-propagating high-temperature synthesis. These methods generally suffer from complex processes, difficulty in controlling product purity, and challenges in scaling up production. Molten salt electrolysis, due to its relatively simple process, low energy consumption, and fewer byproducts, is considered a promising route. However, in actual operation, existing molten salt electrolysis processes are limited by the control of electrolysis conditions and the insulating properties of elemental boron itself, typically requiring intermittent production. This inability to stably achieve continuous electrolysis and continuous output hinders capacity expansion and industrial-scale adoption.

[0005] Therefore, there is an urgent need for a device and method that can realize continuous electrolysis of elemental boron in a molten salt system to overcome the shortcomings of existing processes that are difficult to produce continuously and to meet the needs of large-scale preparation of high-purity boron materials. Summary of the Invention

[0006] The purpose of this invention is to provide a continuous electrolytic preparation apparatus and method for elemental boron, aiming to solve the technical problem that continuous production of elemental boron by molten salt electrolysis is difficult due to the insulating properties of the products.

[0007] To achieve the above objectives, in a first aspect, the present invention provides a continuous electrolytic preparation apparatus for elemental boron, comprising:

[0008] An electrolytic cell for containing electrolytes includes a corrosion-resistant alloy crucible with an opening at the top and a graphite liner nested inside the inner wall of the corrosion-resistant alloy crucible.

[0009] A flange cover is provided at the top opening of the corrosion-resistant alloy crucible, and a circulating water cooling channel is also provided on the outside of the contact part of the corrosion-resistant alloy crucible that contacts it.

[0010] Multiple independently liftable anodes, cathodes, and material rods pass through the flange cover and extend into the electrolytic cell;

[0011] The gas inlet and outlet channel is located on the tank body below the flange cover, and is used to introduce inert gas into the tank body and discharge electrolysis waste gas.

[0012] The discharge port is located at the bottom of the electrolytic cell and can be opened and closed automatically. Below it is a waste collection box containing chloride salts for cooling and equipped with an automatic weighing device.

[0013] An inert gas sealing hood is installed outside the electrolytic cell to introduce inert gas and create a sealed atmosphere, thereby preventing air from entering the electrolytic cell and guiding the electrolytic waste gas to be discharged through the gas inlet and outlet channels.

[0014] The controller is electrically connected to each independently liftable anode, cathode, and material rod, and is used to automatically lift and replace each electrode and material rod according to changes in current value and insertion depth; it is also electrically connected to the discharge port.

[0015] As a further improvement to the above solution, a lifting device is also included, which includes several independently controlled motors, each connected to a corresponding anode, cathode and material bar, to drive each anode, cathode and material bar to lift independently.

[0016] As a further improvement to the above solution, the anode includes an anode guide rod and an anode rod, and the anode guide rod is provided with a first platform-shaped sealing plug;

[0017] Correspondingly, the flange cover is provided with an anode opening, the anode rod passes through the anode opening and extends into the electrolytic cell to contact the electrolyte, and is sealed and locked in the anode opening by the first platform-shaped sealing plug.

[0018] As a further improvement to the above solution, the cathode includes a cathode guide rod and a cathode rod, and the cathode guide rod is provided with a second platform-shaped sealing plug;

[0019] Correspondingly, the flange cover is provided with a cathode opening, the cathode rod passes through the cathode opening and extends into the electrolytic cell to contact the electrolyte, and is sealed and locked in the cathode opening by the second platform-shaped sealing plug.

[0020] As a further improvement to the above solution, the material rod includes a material guide rod and a material rod body detachably disposed on the material guide rod;

[0021] The material guide rod is provided with a sealing sleeve with internal threads, and the upper end of the material rod is provided with an external thread that mates with the internal thread;

[0022] Correspondingly, the flange cover is provided with a material rod opening; the material rod passes through the material rod opening and extends into the electrolytic cell to contact the electrolyte, and is secured in the material rod opening by the sealing sleeve.

[0023] As a further improvement to the above scheme, several anode openings, cathode openings and material rod openings are respectively set on different diameters of the flange cover and are staggered.

[0024] Furthermore, the anode openings, cathode openings, or material rod openings on the same diameter are evenly distributed circumferentially along the corresponding diameter.

[0025] As a further improvement to the above scheme, each platform-shaped sealing plug and sealing sleeve is made of polytetrafluoroethylene; the anode guide rod, cathode guide rod and material guide rod are all made of corrosion-resistant alloy.

[0026] As a further improvement to the above scheme, the electrolytic waste gas discharged from the gas inlet and outlet channel is treated by alkaline solution absorption to remove F2 and BF3 gases.

[0027] As a further improvement to the above solution, the corrosion-resistant alloy crucible is equipped with a heating, heat preservation and temperature measuring device on the outside, which can heat the electrolytic cell to a set temperature.

[0028] In a second aspect, the present invention also provides a method for the continuous electrolytic preparation of elemental boron, using a continuous electrolytic preparation apparatus for elemental boron as provided in the first aspect, the steps of which include:

[0029] S1. Insert the cathode, anode, and material rods used to replenish electrolyte into the graphite inner liner containing molten electrolyte from the top of the electrolytic cell.

[0030] S2. Independently adjust the current magnitude of each cathode and the insertion depth of each electrode and each material rod, and control the descent rate of the material rod according to the current density.

[0031] S3. When the current value of a cathode drops to a set percentage of the initial value, the corresponding cathode is lifted and a replacement signal is sent.

[0032] S4. When the material bar is consumed to the set depth, the corresponding material bar is lifted and a replacement signal is sent.

[0033] S5. When it is necessary to adjust the electrolyte composition, open the discharge port at the bottom of the electrolytic cell to discharge a certain amount of electrolyte, then close the discharge port and weigh the discharged electrolyte after cooling.

[0034] As a further improvement to the above scheme, the electrolyte comprises KBF4 and at least one halide, and the electrolysis temperature is controlled at 600~900℃.

[0035] The electrolytic raw material is KBF4 or B2O3;

[0036] The material bar is formed by pressing KBF4, B2O3 and at least one halide;

[0037] Preferably, the halide is LiF, NaF, KF, LiCl, NaCl, or KCl.

[0038] As a further improvement to the above scheme, before electrolysis begins, the electrolytic cell and the inside of the inert gas sealing cover are evacuated multiple times and filled with argon gas to replace other gas components.

[0039] As a further improvement to the above scheme, only some cathodes are energized in the initial stage of electrolysis, and after the energization reaches the first preset time (preferably 1.5 hours), all cathodes are switched to be energized.

[0040] As a further improvement to the above scheme, the magnitude of the current applied to the cathode is determined based on its insertion depth, and the cathode current density does not exceed 0.5A / cm².

[0041] As a further improvement to the above scheme, in step S3, when the cathode continues to work for more than a second preset time (preferably 3 hours) or its current value drops to 20% of the initial value, the conditions for upgrading and replacement are met.

[0042] Because the present invention adopts the above technical solutions, the beneficial effects of this application are as follows:

[0043] 1. The present invention provides a continuous electrolytic boron preparation apparatus. Firstly, it is equipped with multiple independently liftable cathodes, anodes, and material rods. The controller automatically lifts and replaces each electrode and material rod according to changes in current value and insertion depth. When a cathode is affected by product adhesion or the current drops to a set value, it can be lifted and replaced in time. At the same time, the material rods descend at a rate controlled by current density to replenish electrolyte components. This eliminates the need for a complete shutdown of the electrolysis process, thereby maintaining continuous boron production and improving equipment utilization and production efficiency.

[0044] Secondly, the independent and precise lifting and lowering of each electrode and material bar in this invention is uniformly managed by the controller, and intelligent decision-making is achieved based on parameters such as current and depth, reducing frequent manual intervention and avoiding parameter fluctuations caused by manual adjustment. This keeps key process conditions such as electrolyte concentration and electrode position stable, thereby improving product consistency and quality repeatability, while reducing dependence on operator skills and labor intensity.

[0045] Furthermore, the electrolytic cell is equipped with an inert gas sealing hood and gas inlet / outlet channels, which can create a sealed inert atmosphere inside the cell, preventing oxygen and moisture in the air from reacting with the high-temperature electrolyte or electrodes, reducing raw material oxidation and the generation and leakage of harmful gases; combined with subsequent waste gas alkaline absorption treatment, the environmental impact can be reduced and emission requirements can be met. An automatically opening and closing discharge port and a weighing collection box are provided at the bottom, allowing waste electrolyte to be discharged in a measured quantity.

[0046] The electrolytic cell employs a composite structure of a corrosion-resistant alloy crucible and a graphite inner liner. The alloy provides sufficient mechanical strength, while the graphite inner liner withstands high temperatures and exhibits good chemical stability, reducing electrolyte corrosion of the crucible and extending its service life. A circulating water cooling channel is incorporated at the flange cover-crucible contact area to suppress excessive temperature caused by heat conduction, preventing seal failure and structural deformation. The trapezoidal sealing plugs and threaded screw-in connection design between the electrodes and material rods maintain excellent sealing performance under high-temperature conditions and supports rapid online replacement, minimizing downtime. The modular automatic control architecture facilitates system maintenance and functional expansion, contributing to the reliability of continuous industrial operation.

[0047] 2. This invention provides a continuous electrolytic preparation apparatus for elemental boron. The material rod comprises a material guide rod and a material rod body detachably mounted on the guide rod. The material rod body contains raw materials (such as KBF4, B2O3, and halides) pre-filled with components compatible with the electrolyte. Upon entering the molten electrolyte, these raw materials slowly release their effective components through dissolution or reaction, achieving in-situ, continuous replenishment of the electrolyte. When a single material rod is consumed to a set depth, the controller automatically raises and prompts for replacement, and a new rod then descends to continue feeding. Since the raw material replenishment is completed while maintaining the original operating temperature of the electrolytic cell, it eliminates the need for shutdown, cooling, emptying the cell, adding new electrolyte, and reheating, as is required for traditional batch electrolyte replacement. This setup and operation eliminate the need for cooling and reheating, ensuring that the raw material replacement process has almost no impact on the continuous electrolysis process, thereby increasing the output per unit time. Furthermore, it avoids the significant heat dissipation of the high-temperature melt and the energy required for repeated heating, contributing to energy conservation and reduced production costs. This invention replenishes raw materials by replacing material bars, enabling raw material supply without shutting down the machine or lowering the temperature. This fundamentally avoids the production stoppages, energy consumption, and equipment damage caused by the complete replacement of the electrolyte in traditional methods, and enhances the continuous production capacity and process stability of this invention in the molten salt electrolysis of elemental boron.

[0048] 3. The present invention also provides a method for the continuous electrolytic preparation of elemental boron. By independently replacing the electrodes and material rods online, intelligent control based on current and depth, and quantitative adjustment of electrolyte composition, a process path is formed that can stably operate in a molten salt system and continuously produce elemental boron. This not only solves the problem of continuous production caused by the insulation of the product, but also achieves comprehensive improvement in energy consumption, safety, product quality and equipment life.

[0049] Specifically, this is reflected in the following aspects:

[0050] Firstly, continuous operation of the electrolysis process can be achieved: Multiple independently movable cathodes, anodes, and material rods are used, and the control system independently adjusts the current of each cathode and the insertion depth of each electrode and material rod. Furthermore, the descent rate of the material rod is linked to the current density passing through it. When the current value of a cathode drops to a set percentage of its initial value, the cathode is automatically raised and replaced; when the material rod is consumed to a set depth, the material rod is automatically raised and replaced. This allows for the replenishment of electrodes and raw materials without shutting down the system, avoiding interruptions to the overall electrolysis process due to replacements. Thus, continuous boron production is maintained even when the product is insulating, improving equipment utilization and production capacity.

[0051] Secondly, it can improve process stability and product consistency: because the current of each electrode can be adjusted independently and replaced according to real-time conditions, it avoids overall process fluctuations caused by the failure of a single cathode; the material rod's descent rate is controlled according to the current density, matching the raw material release rate with the electrolysis consumption rate and reducing sudden changes in electrolyte concentration. These control strategies, combined with the alloy-graphite composite tank and circulating water cooling channel of the device, can maintain stable temperature and atmosphere within the tank, thereby reducing batch-to-batch variations and improving the quality consistency of high-purity boron.

[0052] Furthermore, it reduces energy consumption and operational complexity: the material rods dissolve in situ in the molten electrolyte to replenish raw materials, eliminating the traditional process of cooling, venting, feeding, and reheating the electrolytic cell. This significantly reduces heat loss and energy consumption, and minimizes thermal stress damage to the cell caused by thermal cycling. The automatic replacement strategy reduces manual intervention, lowers reliance on operator experience, and alleviates labor intensity.

[0053] In addition, it enables precise control and traceability of electrolyte composition: when the electrolyte composition needs to be adjusted, the method discharges electrolyte quantitatively through the bottom discharge port and cools and weighs it. With the execution of the automatic control system, the composition correction can be completed while maintaining the tank operating temperature. Furthermore, the weight data of the discharged electrolyte can be used to calculate the remaining amount and replenishment amount in the tank, realizing process monitoring and traceability, which helps to ensure long-term stable operation. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a schematic diagram of the structural principle of a continuous electrolytic preparation device for elemental boron disclosed in this invention;

[0056] Figure 2 This is a top view schematic diagram of the distribution of electrode openings and material bar openings on the flange cover disclosed in this invention.

[0057] Figure 3 This is a partially enlarged schematic diagram of the anode structure disclosed in this invention and its sealing with the flange cover;

[0058] Figure 4 This is a partially enlarged schematic diagram of the cathode structure disclosed in this invention and its sealing with the flange cover;

[0059] Figure 5 This is a partially enlarged schematic diagram of the material bar structure disclosed in this invention and its sealing with the flange cover.

[0060] Figure label:

[0061] 1. Electrolytic cell; 11. Alloy crucible; 12. Graphite inner liner; 2. Flange cover; 21. Anode opening; 22. Cathode opening; 23. Material rod opening; 3. Circulating water cooling channel; 4. Anode; 41. Anode guide rod; 42. Anode rod; 43. First V-shaped sealing plug; 5. Cathode; 51. Cathode guide rod; 52. Cathode rod; 53. Second V-shaped sealing plug; 6. Material rod; 61. Material guide rod; 62. Material rod body; 63. Sealing sleeve; 7. Gas inlet / outlet channel; 8. Discharge port; 9. Inert gas sealing cover; 10. Control motor; 011. Waste collection box; 012. Electrolyte; 013. Controller; 014. Power module. Detailed Implementation

[0062] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] It should be noted that all directional indicators (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0064] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0065] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0066] Example 1

[0067] See Figure 1 This invention provides a continuous electrolytic preparation device for elemental boron, including an electrolytic cell 1, a flange cover 2, multiple independently liftable anodes 4, cathodes 5, material rods 6, a gas inlet and outlet channel 7, a discharge port 8, an inert gas sealing cover 9, a controller 013, and a power module 014. The functions and structures of each component are described below.

[0068] Electrolytic cell 1 includes a corrosion-resistant alloy crucible 11 with an opening at the top and a graphite inner liner 12 nested within its inner wall. The alloy crucible 11 provides sufficient mechanical strength to support the cell structure, while the graphite inner liner 12 maintains its structural integrity at electrolysis temperatures ranging from 600°C to 900°C, without significantly reacting with potassium fluoroborate and the halide electrolyte O12, thus preventing impurities from entering the melt and affecting the purity of boron. Simultaneously, the good conductivity of graphite helps to distribute the current more evenly in the molten salt, reducing uneven decomposition of electrolyte O12 or excessively rapid electrode wear caused by excessively high local current densities. This composite structure also prevents direct corrosion of the alloy crucible 11 by the electrolyte O12, extending the service life of the cell.

[0069] A flange cover 2 is located at the top opening of the alloy crucible 11, and a circulating water cooling channel 3 is provided on the outside of the part in contact with the alloy crucible 11. In this embodiment, the flange cover includes a cover body and a graphite layer disposed on the inner surface of the cover body, and the graphite layer is matched with the graphite inner liner 12 to form a cavity for holding electrolytes; during operation, the circulating water carries away the heat generated by high-temperature conduction or thermal radiation in the corresponding part, suppresses the temperature rise of the flange cover 2, prevents sealing failure due to thermal deformation, and ensures the sealing reliability at the penetration point between the upper electrode and the material rod 6.

[0070] Multiple independently liftable anodes 4, cathodes 5, and material rods 6 pass through flange cover 2 and extend into the molten electrolyte 012 within the graphite inner liner 12. Each electrode and material rod 6 is driven by an independent lifting device and equipped with an independent control motor 10, which can individually adjust the insertion depth under the command of controller 013. The setting of the number of cathodes 5 and independent current control allow a single cathode 5 to be lifted and replaced individually when product adheres or the current drops to a set ratio, without affecting the continued operation of other cathodes 5. This avoids overall machine shutdown, achieves continuous production of boron, and improves equipment utilization and production efficiency.

[0071] The gas inlet / outlet channel 7, located on the tank body below the flange cover 2, is used to introduce inert gases such as argon into the tank and discharge electrolytic waste gas. Together with the inert gas sealing hood 9, it creates a sealed inert atmosphere within the tank, preventing oxygen and moisture from the air from entering and reacting with the high-temperature electrolyte O12 or electrodes, thus reducing raw material oxidation and the generation and leakage of harmful gases. The waste gas is then treated by alkaline absorption, reducing its environmental impact and ensuring compliance with emission standards. This fully enclosed protection system also helps maintain stable process parameters and improve product consistency.

[0072] The discharge port 8, located at the bottom of the electrolytic cell 1, is automatically openable and closeable. Below it is a waste collection box 011, containing chloride salts for cooling and equipped with an automatic weighing device. When the composition of the electrolyte 012 needs adjustment, the controller 013 can open the discharge port 8 to discharge a fixed amount of electrolyte 012. After closing, the discharge port is cooled and weighed to monitor the remaining amount and replenishment of electrolyte 012 in the cell, achieving precise composition control and process traceability. This quantitative discharge and cooling weighing design allows for the safe and controllable disposal of waste electrolyte 012 during high-temperature electrolysis without interruption, reducing heat loss and safety hazards.

[0073] The controller 013 is electrically connected to each independently lifting anode 4, cathode 5, and material rod 6. It is used to automatically lift and replace each electrode and material rod 6 based on changes in current value and insertion depth. It is also electrically connected to the discharge port 8 actuator to realize automatic discharge control. Since the electrodes and material rods 6 can be replaced without stopping the machine, and the material rods 6 slowly descend in the electrolyte 012 at a rate controlled by current density to release raw materials, the traditional process of cooling, evacuating, feeding, and reheating the electrolytic cell 1 can be eliminated. This significantly reduces energy consumption and the impact of thermal stress on the equipment, and maintains a stable temperature and atmosphere in the cell, thereby supporting continuous production.

[0074] The power module 014 is connected to the controller 013 and provides power to each independently controlled motor 10. In this embodiment, the power module 014 includes a main power supply unit suitable for supplying power to the DC electrolysis circuit, and a drive power supply unit configured for each independently controlled motor 10. The DC power output from the main power supply unit is combined and distributed, and then connected to each cathode 5 and anode 4 to meet the voltage and current requirements for molten salt electrolysis; the drive power supply unit provides stable power for the operation of each independently controlled motor 10, so that the lifting and lowering actions of the anode 4, cathode 5, and material rod 6 can be reliably executed.

[0075] This invention, through the synergistic effect of features such as an alloy-graphite composite tank, circulating water cooling, inert gas sealing protection, independently controllable electrode and material rod lifting mechanism, and quantitative discharge and weighing, forms a device scheme for the continuous electrolytic preparation of elemental boron in a molten salt system. It effectively solves the problem of continuous production difficulties caused by the product's insulation properties, enabling raw material replenishment and electrode replacement without interrupting electrolysis or cooling, thus balancing production efficiency, energy consumption control, product purity, and operational safety.

[0076] In a preferred embodiment, each anode 4, cathode 5, and material rod 6 is equipped with an independent control motor 10. The operation of the motors is driven by the controller 013 according to process requirements and real-time status. When a cathode 5 experiences product adhesion or a drop in current to a set ratio, the controller 013 can individually start the motor corresponding to the cathode 5 to lift it and send a replacement signal, without affecting the continued electrolysis operation of other cathodes 5. Similarly, when the material rod 6 is consumed to a set depth, the controller 013 can individually lift and replace the corresponding material rod 6, and the new material rod 6 descends to continue replenishing raw materials. This independent driving method allows the replacement process of electrodes and material rods 6 to be completed without stopping the machine or cooling down, thereby avoiding production interruptions caused by traditional overall shutdown replacement and effectively supporting the continuous production of elemental boron.

[0077] Because each motor is independently controlled, the lifting speed and position can be precisely adjusted based on changes in current value and insertion depth, avoiding positioning errors or mutual interference caused by synchronous actions. This ensures that the depth of the electrode and material rod 6 in the molten electrolyte 012 conforms to the set range. This precise independent control helps maintain the uniformity of the current density distribution in the electrolysis zone, reduces the risk of local electrolyte 012 decomposition or accelerated electrode wear, thereby improving process stability and product consistency.

[0078] The independent control motor 10, along with the controller 013 and power module 014, ensures that the lifting device maintains reliable operation and timely response even in high-temperature molten salt environments, reducing operational fluctuations and safety risks caused by manual adjustments. Simultaneously, the ability to replace parts independently shortens the time required for each maintenance, reduces heat loss and energy consumption, and extends the continuous operating cycle of the equipment, directly contributing to solving continuous production challenges caused by the insulation properties of the products.

[0079] The lifting device, through the design of independent motors driving each anode 4, cathode 5 and material rod 6, realizes online individual replacement and precise positioning of electrodes and raw material rods. This eliminates the need for overall shutdown or cooling of the electrolysis process, significantly improving continuous production capacity and operational stability, while also taking into account energy consumption control and equipment maintenance convenience.

[0080] As a preferred embodiment, see Figure 3 and Figure 4 The anode 4 includes an anode guide rod 41 and an anode rod 42. The anode guide rod 41 is provided with a first trapezoidal sealing plug 43. Correspondingly, the flange cover 2 is provided with an anode 4 opening 21. The anode rod 42 passes through the anode 4 opening 21 and extends into the electrolytic cell 1 to contact the electrolyte 012. It is sealed and locked in the anode 4 opening 21 by the first trapezoidal sealing plug 43.

[0081] Similarly, the cathode 5 includes a cathode guide rod 51 and a cathode rod 52. The cathode guide rod 51 is provided with a second trapezoidal sealing plug 53. Correspondingly, the flange cover 2 is provided with a cathode 5 opening 22. The cathode rod 52 passes through the cathode 5 opening 22 and extends into the electrolytic cell 1 to contact the electrolyte 012. It is sealed and locked in the cathode 5 opening 22 by the second trapezoidal sealing plug 53.

[0082] In this embodiment, the diameters of the anode 4 opening 21 and the cathode 5 opening 22 are slightly larger than the corresponding anode rod 42 and cathode rod 52, respectively, allowing the rod to pass smoothly through and descend to the set depth under the guidance of the guide rod. When the rod reaches the working position, the trapezoidal sealing plug, due to its tapered shape matching the edge of the opening, undergoes radial expansion under axial pressure, tightly adhering to the inner wall of the opening, thereby blocking the path of the high-temperature molten electrolyte 012 to penetrate upward along the outer wall of the guide rod.

[0083] This sealing structure maintains its shape and sealing performance at electrolysis temperatures ranging from 600 to 900 degrees Celsius, preventing corrosion, decreased insulation performance, or electrode-guide rod adhesion caused by molten salt seeping into the upper structure. This ensures the stability and replaceability of the electrode during long-term operation. Since the sealing process is completed automatically as the electrode descends, no additional manual locking or additional sealing components are required. This allows for rapid and reliable electrode sealing without shutting down the system, thereby shortening replacement time and reducing exposure to high-temperature molten salt and heat loss.

[0084] The independently designed sealing structure of the anode 4 and cathode 5 allows each electrode to be lifted and detached from the electrolyte 012 individually during replacement without disrupting the sealing of other electrodes. Combined with an independent lifting device and controller 013, online electrode replacement and continuous electrolysis can be achieved. This combination of reliable sealing and convenient replacement helps maintain stable atmosphere and temperature inside the electrolytic cell 1, reducing process fluctuations and safety risks caused by seal failure. It also directly supports solutions to continuous production challenges arising from product insulation.

[0085] By automatically locking and sealing the first trapezoidal sealing plug 43 of the anode guide rod 41 and the second trapezoidal sealing plug 53 of the cathode guide rod 51 in their corresponding openings, reliable sealing and rapid replacement of the electrodes can be achieved in a high-temperature molten salt environment. This ensures the airtightness and safety of the electrolysis process and meets the requirements of continuous production for convenient electrode maintenance, thereby improving the overall operational stability and production efficiency of the device.

[0086] As a preferred embodiment, see Figure 5 The material rod 6 includes a material guide rod 61 and a material rod body 62 detachably mounted on the material guide rod 61. The material guide rod 61 is provided with a sealing sleeve 63 with internal threads, and the upper end of the material rod body 62 is provided with an external thread that mates with the internal thread. Correspondingly, the flange cover 2 is provided with an opening 23 for the material rod 6. The material rod body 62 passes through the opening 23 and extends into the electrolytic cell 1 to contact the electrolyte 012, and is secured in the opening 23 by the sealing sleeve 63.

[0087] In this embodiment, the diameter of the opening 23 of the material rod 6 is slightly larger than that of the material rod body 62, allowing the rod body to pass smoothly through and descend to the working position under the guidance of the guide rod. The sealing sleeve 63 at the lower end of the material guide rod 61 is connected and fixed to the mating external thread at the upper end of the material rod body 62 through its internal thread. When the guide rod descends to the set position, the outer edge of the sealing sleeve 63 contacts the edge of the opening of the flange cover 2 and forms radial compression under axial pressure, thereby achieving sealing at high temperature. This structure of threaded insertion and sleeve mating can complete positioning and sealing in one step during assembly, without the need for additional sealing elements, simplifying the assembly process.

[0088] This structure maintains its sealing performance at electrolysis temperatures ranging from 600 to 900 degrees Celsius, preventing molten electrolyte 012 from seeping out along the outer wall of the guide rod and avoiding corrosion of the upper components or impact on electrode insulation. Since the material rod 62 is detachable, once it has been consumed to a set depth in the electrolyte 012, it can be removed by lifting the material guide rod 61 and loosening the threads. After replacing it with a new rod, it can be lowered and tightened again, allowing for online replenishment of raw materials without stopping the machine or cooling it down.

[0089] In conjunction with an independent lifting device and controller 013, the material rod 6 can descend slowly under the rate control corresponding to the current density, matching the raw material release rate with the electrolysis consumption rate, reducing fluctuations in electrolyte 012 concentration, and maintaining process stability. The replacement process is quick and reliable, and a single material rod 6 can be replaced within minutes, significantly shortening the raw material replenishment interval, reducing heat loss and energy consumption, and avoiding the cooling-heating cycle required for traditional batch replacement of electrolyte 012, thereby supporting continuous production.

[0090] By setting a sealing sleeve 63 with internal threads on the material guide rod 61 and threadedly engaging with the material rod body 62, reliable sealing and rapid replacement of the raw material rod are achieved in a high-temperature molten salt environment. This ensures the airtightness and safety of the electrolysis process and meets the requirements for convenient online replenishment of raw materials in continuous production. It plays a direct role in solving the continuous production problem caused by the insulation of the product and helps to improve production efficiency and operational stability.

[0091] In a preferred embodiment, a plurality of anode 4 openings 21, cathode 5 openings 22 and material rod 6 openings 23 are respectively arranged on different diameters of the flange cover 2 and are staggered; and the anode 4 openings 21, cathode 5 openings 22 or material rod 6 openings 23 on the same diameter are evenly distributed circumferentially along the corresponding diameter.

[0092] In this implementation, see Figure 2 The circular plane of flange cover 2 is divided into several concentric diameter regions. The anode 4 opening 21, cathode 5 opening 22, and material rod 6 opening 23 are arranged on circumferential positions of different diameters, with different types of openings staggered on flange cover 2. For openings of the same type on the same diameter, they are evenly spaced along the circumference. This layout allows for the reasonable arrangement of more electrode and material rod 6 insertion positions within the limited area of ​​flange cover 2, avoiding excessive concentration of openings that could weaken local structures or cause thermal stress superposition. The staggered arrangement ensures relatively balanced spacing between adjacent openings, helping to prevent interference during the lifting and lowering of electrodes or material rod 6, reducing the risk of mechanical collisions during movement, and improving the uniformity of heat distribution in flange cover 2. The uniform circumferential distribution keeps the electrodes and material rod 6 in similar radial positions, which is beneficial for more uniform current distribution in the molten salt, avoiding current density deviations caused by excessively dense or sparse local electrodes, thereby reducing local overheating or uneven decomposition of electrolyte O12.

[0093] Since the electrodes and material rods 6 can be raised and lowered independently and controlled separately by the controller 013, the reasonable opening layout combined with the independent drive mechanism ensures that the position and sealing status of adjacent electrodes are not affected when replacing a single electrode or material rod 6, thus maintaining the continuity and stability of the overall electrolysis process. This structural arrangement also facilitates the addition of openings according to the diameter and circumferential pattern during maintenance or expansion, improving the adaptability and scalability of the device.

[0094] This invention optimizes the spatial arrangement of electrodes and material rods 6 by distributing the anode 4 opening 21, cathode 5 opening 22, and material rod 6 opening 23 with different diameters in an alternating and uniform manner, while ensuring the structural strength of flange cover 2. This improves the uniformity of heat and current distribution, reduces mutual interference during replacement, and thus helps to achieve continuous and stable operation of the electrolysis process. It also enhances the maintainability and expandability of the equipment and plays a positive role in solving the continuous production problem caused by the insulation of the product.

[0095] In a preferred embodiment, each of the platform-shaped sealing plugs and sealing sleeves 63 is made of polytetrafluoroethylene, and the anode guide rod 41, cathode guide rod 51 and material guide rod 61 are all made of corrosion-resistant alloy.

[0096] In this embodiment, polytetrafluoroethylene (PTFE) possesses a high melting point and excellent chemical inertness, maintaining shape and dimensional stability even at electrolysis temperatures ranging from 600 to 900 degrees Celsius. It is not prone to adhesion or corrosion reactions with molten fluoroborate or halide electrolyte 012, enabling reliable elastic sealing in high-temperature molten salt environments. The platform-shaped sealing plug and sealing sleeve 63, relying on the material's inherent high-temperature stability and low coefficient of friction, form a tight clamping action with the mating surface of the flange cover 2 opening when the electrode or material rod 6 descends to the working position. This effectively prevents electrolyte 012 from penetrating upwards along the outer wall of the guide rod, thereby avoiding corrosion or degradation of the insulation performance of the upper components.

[0097] The anode guide rod 41, cathode guide rod 51, and material guide rod 61 are made of corrosion-resistant alloys, which can maintain sufficient mechanical strength and corrosion resistance in high-temperature and molten salt environments containing fluorine and chloride ions. This prevents the guide rod surface from developing pits, cracks, or weakening of the cross-section due to corrosion, ensuring smoothness and positioning accuracy during the lifting process. The good thermal conductivity of the corrosion-resistant alloys also helps to quickly conduct and disperse local heat, reducing the temperature gradient at the interface between the guide rod and the seal, and lowering the risk of seal failure due to differences in thermal stress.

[0098] The combination of these materials ensures that the electrodes and material rods 6 maintain structural integrity during long-term operation, while also enabling smooth insertion and removal and reliable resealing during replacement. This reduces replacement difficulties or electrolysis interruptions caused by seal aging or guide rod corrosion. Because both the seals and guide rods possess high-temperature durability and corrosion resistance, the device can perform online replacement of the electrodes and material rods 6 without shutting down or cooling, thus maintaining the continuity of the electrolysis process, reducing maintenance frequency and heat loss. This directly supports the solution to continuous production challenges caused by product insulation.

[0099] In a preferred embodiment, the electrolytic waste gas discharged from the gas inlet / outlet channel 7 is treated with alkaline solution absorption to remove fluorine (F2) and boron trifluoride (BF3) gas.

[0100] In this embodiment, during the electrolysis process, fluoroborates and halides may decompose or undergo electrode reactions at high temperatures, generating waste gas containing fluorine-containing gases such as F2 and BF3. These gases have strong chemical reactivity and toxicity, and direct emission would harm the environment and operational safety. This device connects an alkaline absorption unit to the exhaust end of the gas inlet / outlet channel 7, allowing the discharged waste gas to fully contact the alkaline solution through spraying or bubbling. The alkaline solution neutralizes F2 and BF3, generating relatively stable fluorides and borates, thereby removing these harmful components from the gas stream.

[0101] Because the waste gas is treated promptly and effectively, the electrolysis process can maintain an inert atmosphere while avoiding the accumulation of harmful gases that could affect the chemical environment inside the tank or corrode equipment components. This helps to maintain stable electrolysis conditions and reduce process fluctuations caused by gas pollution. Combined with continuous electrolysis and online electrode and material rod replacement, this waste gas treatment measure can maintain environmental protection and safety performance for a long time without shutting down the system, directly supporting the continuous and safe production of elemental boron in the molten salt system.

[0102] As a preferred embodiment, the corrosion-resistant alloy crucible 11 is provided with a heating, heat preservation and temperature measuring device on the outside, which can heat the electrolytic cell 1 and maintain it within the set working temperature range.

[0103] In this embodiment, the heating device employs heating elements surrounding the outer wall of the crucible. Heat is transferred to the crucible via electrical energy or other suitable heat sources, raising the temperature of the electrolyte 012 from room temperature to the required electrolysis temperature range of 600 to 900 degrees Celsius. A heat insulation device, constructed of high-temperature resistant insulating material, covers the outside of the heating elements, reducing heat loss to the environment, improving heat utilization efficiency, and minimizing temperature fluctuations within the tank. A temperature measuring device collects real-time temperature signals from the crucible wall or the vicinity of the molten salt and feeds the data back to the controller 013. The controller 013 adjusts the heating power based on the deviation between the set value and the measured value, achieving closed-loop temperature control.

[0104] Because molten salt electrolysis is temperature-sensitive, excessively low temperatures can lead to increased viscosity of the electrolyte O12 and decreased ion mobility, affecting current efficiency and boron deposition rate. Excessively high temperatures may exacerbate O12 volatilization or corrosion, increasing energy consumption and affecting product purity. Through the synergistic effect of heating, insulation, and temperature measurement devices, the tank temperature can be kept stable during long-term operation, reducing process fluctuations caused by temperature drift and thus creating a reliable thermal environment for continuous electrolysis.

[0105] By setting heating, heat preservation and temperature measuring devices on the outside of the corrosion-resistant alloy crucible 11, the temperature of the electrolytic cell 1 can be accurately established and stably maintained. This not only ensures the efficiency of the molten salt electrolysis reaction and the quality of the products, but also reduces the interference of temperature fluctuations on continuous production, and helps to reduce energy consumption and equipment wear, thus serving the goal of this invention to achieve continuous electrolysis of elemental boron.

[0106] Example 2

[0107] The present invention also provides a method for the continuous electrolytic preparation of elemental boron, which is implemented using a continuous electrolytic preparation apparatus for elemental boron as described in Example 1, and the steps include:

[0108] S1. Insert the cathode 5, anode 4 and material rod 6 for replenishing electrolyte 012 from the top of the electrolytic cell 1 into the graphite inner liner 12 containing molten electrolyte 012.

[0109] In this embodiment, each electrode and material rod 6 is driven by an independent lifting device, descending vertically into the electrolyte 012 through the opening of the flange cover 2. After descending to the preset working depth, it is automatically locked and sealed by a platform-shaped sealing plug or sealing sleeve 63, forming a reliable seal at high temperature and preventing molten salt from overflowing along the rod body. This step is carried out under the condition that the electrolytic cell 1 maintains the set temperature and inert atmosphere, and can immediately enter the electrolysis state without additional preheating or atmosphere replacement delay.

[0110] S2. Independently adjust the current magnitude of each cathode 5 and the insertion depth of each electrode and each material rod 6, and control the descent rate of the material rod 6 according to the current density.

[0111] According to the process formula and the real-time acquired current signal, the controller 013 applies the required current to each cathode 5 to make the current density distribution uniform, reduce local overheating or uneven decomposition of electrolyte 012; at the same time, the lifting device precisely controls the insertion depth of the electrode and the material rod 6, and makes the material rod 6 slowly descend at the rate corresponding to the current density, so that the rate of dissolution or reaction release of raw materials matches the electrolysis consumption rate, thereby maintaining the stability of electrolyte 012 composition and reducing the impact of concentration fluctuations on product purity.

[0112] S3. When the current value of a certain cathode 5 drops to a set ratio of the initial value, the corresponding cathode 5 is raised and a replacement signal is sent.

[0113] Because elemental boron and byproducts adhere to the surface of cathode 5, reducing the effective conductive area, the current decreases. The control system continuously monitors the current of each cathode 5. Once it detects that the current value of a certain cathode 5 has dropped to a set percentage of its initial value, it instructs the lifting device corresponding to that cathode 5 to lift it away from electrolyte 012 and issues a replacement prompt. This method allows for the individual replacement of failed cathode 5 without shutting down the system or cooling down, avoiding interruption of the overall electrolysis and thus maintaining continuous boron production.

[0114] S4: When the material bar 6 is consumed to the set depth, the corresponding material bar 6 is raised and a replacement signal is sent.

[0115] Material rod 6 gradually dissolves or reacts in electrolyte 012, releasing raw materials. When its upper end approaches or reaches a set depth, controller 013 instructs the material rod 6 to be raised and prompts for replacement. After a new material rod 6 descends, raw materials can be replenished. This process is also completed while maintaining a constant temperature and atmosphere in the tank, eliminating the cooling-draining-feeding-reheating-melting steps in the traditional process. This significantly reduces energy consumption and the impact of thermal stress on the equipment, and shortens the interval between raw material replenishments.

[0116] S5. When it is necessary to adjust the composition of electrolyte 012, open the discharge port 8 at the bottom of the electrolytic cell 1 to discharge a certain amount of electrolyte 012, then close the discharge port 8, and weigh the discharged electrolyte 012 after cooling.

[0117] Controller 013 initiates the discharge procedure based on process requirements or online analysis results, discharging a quantitative portion of electrolyte 012 through discharge port 8 into a collection tank with cooling medium for cooling. The discharged amount is then obtained via an automatic weighing device to calculate the proportion of electrolyte 012 remaining in the tank, guiding subsequent replenishment. This quantitative discharge and weighing can be performed while maintaining the electrolysis temperature, avoiding overall shutdown. Furthermore, the data can be used for precise control of the electrolyte 012 composition and process traceability, improving process stability and product consistency.

[0118] By combining independently controllable electrodes and material rods 6 within the device, an automatic decision-making mechanism based on current and depth, and a quantitative discharging and weighing function, electrode replacement and raw material replenishment are achieved in the molten salt system without shutdown or cooling. This overcomes the problem of continuous production caused by the product's insulation properties, a problem inherent in traditional processes. This method significantly improves equipment utilization and production efficiency, reduces manual intervention and energy consumption, ensures operational safety and environmental compliance, and helps obtain high-purity elemental boron with stable quality.

[0119] In a preferred embodiment, the electrolyte 012 comprises potassium fluoroborate (KBF4) and at least one halide, and the electrolysis temperature is controlled between 600 and 900 degrees Celsius; the electrolytic raw material is KBF4 or boron trioxide (B2O3); the material rod 6 is formed by pressing KBF4, B2O3, and at least one halide. Preferably, the halide is selected from lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), lithium chloride (LiCl), sodium chloride (NaCl), or potassium chloride (KCl).

[0120] In this embodiment, KBF4, as the main electrolyte O12 component, can dissociate into boron-fluorine complexes in high-temperature molten salt and provide a boron source. The addition of halides can adjust the conductivity, melting point, and viscosity of the molten salt, ensuring that electrolyte O12 maintains good fluidity and ion transport performance within the selected temperature range, which is beneficial for uniform current distribution and efficient boron deposition. Limiting the electrolysis temperature to 600 to 900 degrees Celsius balances sufficient melting of the molten salt with low volatilization loss, avoiding excessive evaporation or accelerated corrosion of electrolyte O12 components due to excessively high temperatures, and also preventing insufficient ion mobility and decreased reaction rate due to excessively low temperatures.

[0121] The electrolytic feedstock is selected from KBF4 or B2O3, which can be directly introduced as a boron source and is compatible with the O12 electrolyte system. The feedstock rod 6 is formed by pressing KBF4, B2O3, and at least one halide. Its composition matches that of the O12 electrolyte, ensuring the gradual dissolution or reaction release of the required components during descent, achieving in-situ, continuous replenishment of the molten salt. Because the feedstock rod 6 descends in the O12 electrolyte at a rate controlled by current density, the feedstock release rate can be adapted to the electrolytic consumption rate, reducing fluctuations in the O12 electrolyte concentration, maintaining process stability, and thus supporting continuous electrolysis.

[0122] The selection of halides is based on a comprehensive consideration of their melting point, volatility, compatibility with boron compounds, and cost. For example, fluorides such as LiF, NaF, and KF can lower the melting point of molten salts and improve conductivity, while chlorides such as LiCl, NaCl, and KCl can further adjust viscosity and density, resulting in more uniform reaction conditions at the electrode-molten salt interface. Combinations of different halides can optimize the process window for different production capacity and purity requirements, improving the adaptability and economy of the equipment.

[0123] Through the aforementioned composition and temperature control, electrolyte 012 maintains suitable physicochemical properties within the required temperature range, ensuring both boron deposition efficiency and reducing volatilization and corrosion. Combined with the online replaceable material rod 6, raw material replenishment can be completed without shutdown or cooling, avoiding production stoppages and energy waste caused by traditional batch material changes. This directly addresses the continuous production challenges posed by product insulation and helps improve production efficiency, reduce operating costs, and extend equipment lifespan.

[0124] As a preferred embodiment, before electrolysis begins, the electrolytic cell 1 and the inert gas sealing cover 9 are evacuated multiple times and filled with argon gas to replace other gaseous components therein.

[0125] In this embodiment, the electrolytic cell 1 and the inert gas sealing hood 9 form a sealed space. Before startup, a vacuum pump is connected through the exhaust channel of this space to evacuate the air, reducing the internal pressure to a low level and removing as much oxygen, nitrogen, water vapor, and other trace reactive gases as possible from the air. Then, high-purity argon is introduced to the set pressure, and the evacuation-argon introduction process is repeated several times to ensure that the original gases are fully replaced and the internal atmosphere is dominated by argon.

[0126] Since molten salt electrolysis is carried out at high temperatures of 600 to 900 degrees Celsius, residual oxygen or water vapor in the tank may react with the molten fluoroborate or halide electrolyte O12, generating harmful fluorine- or oxygen-containing gases and accelerating the corrosion of electrodes and structural components. Water vapor may also cause splashing of electrolyte O12 or localized temperature fluctuations, affecting process stability. By repeatedly evacuating and purging with argon, a stable atmosphere dominated by inert gases can be established before electrolysis starts, effectively suppressing the occurrence of the above-mentioned adverse reactions.

[0127] By repeatedly evacuating the electrolytic cell 1 and filling the inert gas sealing cover 9 with argon gas to replace the gas before electrolysis, reactive components such as oxygen and water vapor can be effectively removed, a stable inert atmosphere can be established, thereby inhibiting oxidation and corrosion, reducing the generation of harmful gases, and helping to maintain stable electrolysis conditions, providing a reliable starting environment for the continuous electrolytic preparation of elemental boron.

[0128] In a preferred embodiment, only a portion of the cathodes 5 are energized in the initial stage of electrolysis. After the energization reaches a first preset time (preferably 1.5 hours), the energization is switched to energize all the cathodes 5. The purpose is to establish a sustainable cyclic production mode to alleviate the constraint on continuous production caused by the gradual failure of the insulation of the cathodes 5 due to the product.

[0129] In this implementation, when electrolysis starts, the controller 013 applies current to a selected portion of the cathodes 5 according to a preset program, while the remaining cathodes 5 are not connected to the power supply. Since elemental boron and byproducts have a certain degree of insulation after forming on the surface of the cathodes 5, prolonged energization will cause the current of those cathodes 5 to gradually decrease or even lose its effective electrolysis function. By activating a portion of the cathodes 5 first, these cathodes 5 can enter a working state and accumulate products in the early stages of electrolysis, while the remaining cathodes 5 remain in standby mode. When the current value of an energized cathode 5 drops to a set percentage of its initial value due to increased surface insulation, the control system immediately raises and replaces that cathode 5. Meanwhile, the remaining energized or yet-to-be-energized cathodes 5 continue to participate in the electrolysis reaction, maintaining the overall boron production process uninterrupted.

[0130] After the first preset time has elapsed, controller 013 sequentially connects the remaining cathodes 5 to the power supply, bringing all cathodes 5 into operation. During subsequent operation, if any cathode 5 is replaced due to insulation failure, other cathodes 5 will continue to be energized to produce boron, thus forming a continuous cycle of rotation on the production line. This mode effectively distributes the electrolysis task across multiple cathodes 5, preventing the failure of a single cathode 5 from causing a complete shutdown and effectively overcoming the problem of single-point shutdowns caused by the insulation properties of the product.

[0131] In a preferred embodiment, the magnitude of the current applied to the cathode 5 is determined based on its insertion depth, and the current density of the cathode 5 does not exceed 0.5 A / cm².

[0132] In this embodiment, the insertion depth of the cathode 5 is precisely controlled by an independent lifting device. The controller 013 converts the depth signal into a corresponding current setpoint and applies it to the corresponding cathode 5 according to a preset depth-current conversion relationship. This conversion relationship is established based on comprehensive experimental data of the conductivity of the electrolyte 012, the reaction interface area, and the boron deposition rate, ensuring that the current magnitude matches the effective working area of ​​the cathode 5 in the molten salt. Simultaneously, an upper limit is set on the current density of all cathodes 5, preventing it from exceeding 0.5 A / cm², to avoid the rapid formation of insulating products on the electrode surface or localized overheating due to excessive current, thereby delaying the process of insulation failure in a single cathode 5.

[0133] Because elemental boron and its byproducts have insulating properties after formation on the surface of cathode 5, excessive current density will accelerate product accumulation, reduce the effective conductive area of ​​the electrode, and shorten the stable operating time of a single cathode 5. By dynamically determining the current based on the insertion depth and limiting the upper limit of the current density in the overall design, the reaction heat and product formation rate distribution on the surface of each cathode 5 can be made more uniform, reducing the risk of local current concentration and premature failure. With the independent lifting and online replacement mechanism, when the current of a certain cathode 5 drops to a set proportion of the initial value due to increased insulation, it can be lifted and replaced individually without affecting the continued operation of other cathodes 5, thereby maintaining the continuity of the overall boron production process.

[0134] In a preferred embodiment, in step S3, when the cathode 5 operates continuously for more than a second preset time (preferably 3 hours) or its current value drops to 20% of the initial value, the conditions for lifting and replacing the cathode 5 are met.

[0135] In this implementation, the controller 013 records the moment each cathode 5 begins to be energized and its real-time current value. When the cumulative energizing time of a cathode 5 reaches a second preset time, it means that the cathode 5 has been operating continuously in the high-temperature molten salt environment for a long time, and its surface may have accumulated a certain thickness of insulating product. Continuing to operate will increase the risk of current drop and failure. Another triggering condition is when the real-time current value drops to less than 20% of the initial current of the cathode 5, which usually indicates that the effective conductive area has been significantly reduced and the electrolysis efficiency has dropped significantly. If either of the above two conditions is met, it is determined that the cathode 5 needs to be taken out of service. The lifting device lifts it away from the electrolyte 012 and sends a replacement signal. The operator or automatic device then replaces it with a new cathode 5, reinserts it, and energizes it.

[0136] Because elemental boron and its byproducts have insulating properties after forming on the surface of cathode 5, prolonged operation or a significant drop in current can prevent cathode 5 from participating in the electrolysis reaction normally. By using a dual criterion of preset time and current thresholds, cathode 5 can be proactively replaced before it completely fails, avoiding sudden changes in current distribution or localized process fluctuations caused by the failure of a single cathode 5. Combined with the device's independent lifting and sealing structure, the replacement process can be completed under stable cell temperature and inert atmosphere conditions, without requiring shutdown or cooling, ensuring that other cathodes 5 continue to produce boron, thereby maintaining the continuity of overall production.

[0137] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural transformations made using the contents of the specification and drawings of the present invention under the inventive concept of the present invention, or direct or indirect applications in other related technical fields, are within the scope of patent protection of the present invention.

Claims

1. A continuous electrolytic preparation apparatus for elemental boron, characterized in that, include: An electrolytic cell for containing electrolytes includes a corrosion-resistant alloy crucible with an opening at the top and a graphite liner nested inside the inner wall of the corrosion-resistant alloy crucible. A flange cover is provided at the top opening of the corrosion-resistant alloy crucible, and a circulating water cooling channel is also provided on the outside of the contact part of the corrosion-resistant alloy crucible that contacts it. Multiple independently liftable anodes, cathodes, and material rods pass through the flange cover and extend into the electrolytic cell; The gas inlet and outlet channel is located on the tank body below the flange cover, and is used to introduce inert gas into the tank body and discharge electrolysis waste gas. The discharge port is located at the bottom of the electrolytic cell and can be opened and closed automatically. Below it is a waste collection box containing chloride salts for cooling and equipped with an automatic weighing device. An inert gas sealing hood is installed outside the electrolytic cell to introduce inert gas and create a sealed atmosphere, thereby preventing air from entering the electrolytic cell and guiding the electrolytic waste gas to be discharged through the gas inlet and outlet channels. The controller is electrically connected to each independently liftable anode, cathode, and material bar, as well as the discharge port.

2. The continuous electrolytic preparation apparatus for elemental boron according to claim 1, characterized in that, It also includes a lifting device, which consists of several independently controlled motors, each connected to a corresponding anode, cathode, and material bar to drive each anode, cathode, and material bar to lift independently.

3. The continuous electrolytic preparation apparatus for elemental boron according to claim 1 or 2, characterized in that, The anode includes an anode guide rod and an anode rod, and the anode guide rod is provided with a first platform-shaped sealing plug; Correspondingly, the flange cover is provided with an anode opening, the anode rod passes through the anode opening and extends into the electrolytic cell to contact the electrolyte, and is sealed and locked in the anode opening by the first platform-shaped sealing plug.

4. The continuous electrolytic preparation apparatus for elemental boron according to claim 3, characterized in that, The cathode includes a cathode guide rod and a cathode rod, and the cathode guide rod is provided with a second platform-shaped sealing plug; Correspondingly, the flange cover is provided with a cathode opening, the cathode rod passes through the cathode opening and extends into the electrolytic cell to contact the electrolyte, and is sealed and locked in the cathode opening by the second platform-shaped sealing plug.

5. The continuous electrolytic preparation apparatus for elemental boron according to claim 4, characterized in that, The material rod includes a material guide rod and a material rod body detachably mounted on the material guide rod; The material guide rod is provided with a sealing sleeve with internal threads, and the upper end of the material rod is provided with an external thread that mates with the internal thread; Correspondingly, the flange cover is provided with a material rod opening; the material rod passes through the material rod opening and extends into the electrolytic cell to contact the electrolyte, and is secured in the material rod opening by the sealing sleeve.

6. The continuous electrolytic preparation apparatus for elemental boron according to claim 5, characterized in that, Several anode openings, cathode openings, and material rod openings are respectively provided on the flange cover of different diameters and are arranged alternately; Furthermore, the anode openings, cathode openings, or material rod openings on the same diameter are evenly distributed circumferentially along the corresponding diameter.

7. A method for continuous electrolytic preparation of elemental boron, using the continuous electrolytic preparation apparatus for elemental boron as described in any one of claims 1-6, characterized in that, The steps include: S1. Insert the cathode, anode, and material rods used to replenish electrolyte into the graphite inner liner containing molten electrolyte from the top of the electrolytic cell. S2. Independently adjust the current magnitude of each cathode and the insertion depth of each electrode and each material rod, and control the descent rate of the material rod according to the current density. S3. When the current value of a cathode drops to a set percentage of the initial value, the corresponding cathode is lifted and a replacement signal is sent. S4. When the material bar is consumed to the set depth, the corresponding material bar is lifted and a replacement signal is sent. S5. When it is necessary to adjust the electrolyte composition, open the discharge port at the bottom of the electrolytic cell to discharge a certain amount of electrolyte, then close the discharge port and weigh the discharged electrolyte after cooling.

8. The method for continuous electrolytic preparation of elemental boron according to claim 7, characterized in that, The electrolyte comprises KBF4 and at least one halide, and the electrolysis temperature is controlled at 600~900℃. The electrolytic raw material is KBF4 or B2O3; The material rod is formed by pressing KBF4, B2O3 and at least one halide.

9. The method for continuous electrolytic preparation of elemental boron according to claim 7, characterized in that, In the initial stage of electrolysis, only some cathodes are energized. After the energizing time reaches the first preset time, the energizing is switched to all cathodes.

10. The method for continuous electrolytic preparation of elemental boron according to claim 7, characterized in that, The magnitude of the current applied to the cathode is determined based on its insertion depth, so that the cathode current density does not exceed 0.5 A / cm². When the cathode operates continuously for more than the second preset time or its current value drops to 20% of the initial value, the conditions for upgrading and replacement are met.

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