A metal smelting system and method

Abstract

The application belongs to the field of metal smelting, and particularly relates to a metal smelting system and method, which comprises a heating and heat-preserving assembly, a closed flow channel A connected to the heating and heat-preserving assembly at both ends, cavities formed by dense materials and communicated with each other arranged in the heating and heat-preserving assembly and the closed flow channel A, a channel for vacuumizing and / or inert gas filling of the cavities arranged on the heating and heat-preserving assembly, a power structure for driving metal melt in the cavities to circulate in the heating and heat-preserving assembly through the closed flow channel A, and the closed flow channel arranged on the heating and heat-preserving assembly cooperating with the power structure to realize circulation and flow of the internal metal melt, and cooperating with the process of vacuumizing and / or inert gas filling in the heating and heat-preserving assembly to continuously purify the metal melt. The low-vacuum system with low cost can realize high-vacuum effect, and the degassing and deslagging operation can be completed in a clean high-temperature atmosphere environment, so that high metal purity in the large-volume smelting and smelting process can be effectively realized.

Description

Technical Field

[0001] This invention belongs to the field of metal smelting, specifically relating to a metal smelting system and method. Background Technology

[0002] In some applications with extremely high performance requirements, metal alloy ingots must have higher purity, necessitating effective protection and purification of the melting and casting process. Currently, alloy melting and casting equipment both domestically and internationally generally includes resistance heating melting tanks, induction heating melting tanks, and natural gas heating melting tanks. These types of equipment have the following main problems during the melting process: 1. Poor air isolation leads to oxidation of the molten metal at high temperatures, forming impurities. Although inert gas can be introduced to the surface of the molten metal for protection, the porous refractory material contains air which is difficult to expel, resulting in the oxidation reaction still occurring; 2. While a sealed vacuum furnace can effectively isolate oxygen, operations such as testing, purifying, or removing slag from the melt are difficult, easily leading to poor quality in batches or large-scale products. 3. Due to high-temperature burn-off and partial oxidation, the actual ingot alloy composition often differs from the batch composition, and batch fluctuations are uncontrollable, leading to unstable ingot performance across different furnaces. 4. Due to the large capacity of the furnace chamber, impure raw materials, and contact contamination, impurities are present during the smelting process and are difficult to remove, resulting in often low purification efficiency. 5. Currently, a combination of stirring and inert foam adhesion is commonly used to degas the molten metal. However, when the molten metal volume is large, insufficient contact efficiency limits the effectiveness. While online methods can improve the effect, they also waste a large amount of molten metal within the degassing device. In conclusion, achieving accurate control of the ingot alloy composition while simultaneously implementing effective protection and degassing / slag removal during the smelting and casting process is crucial for obtaining high-quality metal alloy materials. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a metal smelting system and method that can achieve accurate composition and high purity.

[0004] This invention provides a metal smelting system, including a heating and heat preservation component and a closed flow channel A connected to the heating and heat preservation component at both ends. The heating and heat preservation component and the closed flow channel A are provided with cavities formed by dense material and interconnected with each other. The heating and heat preservation component is provided with a channel connecting the cavity for vacuuming and / or filling with inert gas. The system also includes a power structure for driving the molten metal located in the cavity to circulate through the closed flow channel A within the heating and heat preservation component.

[0005] Furthermore, the heating and insulation component is a heating and insulation box, with the two ends of the closed flow channel A connected to the upper end and the bottom of the cavity inside the heating and insulation box, respectively, and the power structure is a pump.

[0006] Furthermore, the heating and insulation assembly comprises at least two heating and insulation boxes, which are connected sequentially via a closed flow channel B. The first and last two heating and insulation boxes are connected via a closed flow channel A. The power structure is a pump or a height difference structure between the heating and insulation boxes. Valves are provided on the closed flow channel A and the closed flow channel B or at the interface of the heating and insulation boxes.

[0007] Furthermore, the heating and insulation box includes a box body and a box lid, and the box body and the box lid are provided with a dense heat-resistant protective layer. After the box body and the box lid are fitted together, the two dense heat-resistant protective layers enclose and form a sealed cavity. It also includes a heater for heating or insulating the cavity.

[0008] Furthermore, the lid has an opening and also includes an operating cover for sealing the opening, with a dense, heat-resistant protective layer on the opposite side of the opening and the operating cover.

[0009] Furthermore, the closed flow channel A is provided with a branch, and an online filter component and a molding station are connected in sequence on the branch. A return channel connecting the online filter component and the molding station is provided, which connects to the heating and insulation component. A reversing structure is provided at the connection between the branch and the closed flow channel A and at the connection between the return channel and the branch. It also includes a component fine-tuning system and a degassing rotor that are connected to the cavity of the heating and insulation component.

[0010] Furthermore, the heating and heat preservation component is a heating and heat preservation box, and the composition fine-tuning system includes a conveyor belt and a robotic arm. The robotic arm takes the molten metal through the opening of the heating and heat preservation box for testing or puts in raw materials to fine-tune the composition of the molten metal.

[0011] Furthermore, the heating and insulation component is a heating and insulation box, and the degassing rotor extends into the cavity through the opening of the heating and insulation box to degas.

[0012] Furthermore, the online filtration assembly includes one or more of the following: an online degassing device, a plate filter, a tubular filter, an ultrasonic treatment device, or an electromagnetic treatment device, all mounted on a branch.

[0013] Furthermore, one or more of the online degassing device, plate filter, tubular filter, ultrasonic treatment device, or electromagnetic treatment device are connected in parallel with the branch, and a reversing structure is provided at the connection with the branch.

[0014] The present invention also provides a metal smelting method, including a metal smelting system, comprising the following steps:

[0015] S1. Place the metal to be melted or the molten metal into the heating and heat preservation component. The heating and heat preservation component heats and melts the metal or keeps the molten metal at a constant temperature. The composition of the molten metal is adjusted by the composition fine-tuning system.

[0016] S2. Open the power structure and degassing rotor to allow the molten metal to circulate in the heating and insulation components and the closed flow channel A to degas the molten metal;

[0017] S3. Determine whether the molten metal meets the degassing requirements. If it does, shut down the power structure and degassing rotor 19 and proceed to step S4. If it does not meet the requirements, repeat step S2.

[0018] S4. Determine whether the amount of oxidized slag in the molten metal meets the requirements. If it does, proceed to step S6 via a branch; otherwise, proceed to step S5.

[0019] S5. The molten metal is filtered through the online processing device by the reversing structure. After filtration, it is determined again whether the molten metal meets the requirements for the amount of oxide inclusions. If it does, proceed to step S6. Otherwise, the filtered molten metal is allowed to enter the heating and heat preservation component through the reflux channel by the reversing structure, and proceed to step S2.

[0020] S6. Proceed to the forming station for casting.

[0021] Step S1 includes:

[0022] S11. Place the metal to be heated in the cavity inside the box and close the box lid.

[0023] S12. Vacuum the sealed cavity through the channel until the required vacuum level is reached, then turn off the vacuum pumping equipment.

[0024] S13. After the vacuum equipment is turned off, fill the sealed cavity with inert gas through the channel within 15-150 seconds to make the cavity reach positive pressure and maintain positive pressure.

[0025] S14. The cavity is heated and kept warm by a heater;

[0026] S15. Determine whether the degassing requirements are met. If they are met, allow the smelted metal to proceed to step S2. Otherwise, maintain S14 and repeat S12 and S13. Each time step S12 is repeated, stop the inert gas filling and then evacuate again, and the vacuum rate is lower than the previous evacuation. When step S13 is repeated, the time to fill with inert gas is shorter than the previous time.

[0027] Step S2 includes:

[0028] S21. Open the power structure to allow the molten metal to circulate in the heating and heat preservation components and the closed flow channel A. At the same time, open the degassing rotor in the heat preservation components. During the process, maintain the positive pressure of the inert gas in the cavity through the channel until the molten metal meets the degassing requirements.

[0029] S22. Vacuum the sealed cavity through the channel until the required vacuum level is reached, then turn off the vacuum pumping equipment.

[0030] S23. Fill the sealed cavity with inert gas through the channel within 15-150s to bring the cavity to positive pressure and maintain the positive pressure.

[0031] Step S2 also includes:

[0032] If the molten metal does not meet the degassing requirements in step S3, proceed to step S24.

[0033] S24. Turn off the heating and heat preservation components to allow the molten metal to solidify on the surface of the cavity 10.

[0034] S25. Turn on the heating and heat preservation components, and repeat S22-S23. Each time step S22 is repeated, stop the inert gas filling and then evacuate, and the vacuum rate is lower than the previous evacuation. When step S23 is repeated, the time to fill with inert gas is shorter than the previous time.

[0035] The beneficial effects of this invention are as follows: A closed flow channel is set in the heating and insulation component, combined with a power structure, to achieve the circulation of the internal molten metal. Furthermore, the molten metal is continuously purified through vacuuming and / or filling with inert gas within the heating and insulation component. Firstly, the protective heating system and method employed can achieve a high vacuum effect through a low-cost low-vacuum system, completing degassing and slag removal operations in a clean, high-temperature atmosphere. This effectively achieves high metal purity during large-scale smelting and casting processes and avoids the high-temperature burn-off of alloying elements during pure vacuum smelting.

[0036] This invention provides a metal smelting method that utilizes a small-scale degassing circulation system and a combined large-scale circulation system of degassing and online filtration. Alternatively, it can be selectively used via valves and reversing mechanisms. Specifically, there are three main operating modes: 1. After degassing, the metal directly enters the forming station for forming; 2. After degassing, the metal is filtered through an online filtration assembly before entering the forming station for forming; 3. After degassing, the metal is filtered through an online filtration assembly and then flows back to the metal smelting system via a reflux channel. This approach maximizes casting quality while ensuring efficiency, and improves degassing and slag removal effects. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the present invention.

[0038] Figure 2 This is a schematic diagram of the heating and insulation box in this invention.

[0039] Figure 3 This is a schematic diagram of the metal smelting method in this invention.

[0040] Figure 4 This is a schematic diagram of step S1 in the metal smelting method of the present invention.

[0041] Figure 5 This is a schematic diagram of step S2 in the metal smelting method of the present invention.

[0042] In the diagram, 100-heating and insulation box; 1-box body; 2-box cover; 201-opening; 3-dense heat-resistant protective layer; 4-heater; 5-channel; 6-operating cover; 9-crucible; 10-cavity; 14-closed flow channel A; 15-closed flow channel B; 16-valve; 17-component fine-tuning system; 171-conveyor belt; 18-robotic arm; 19-degassing rotor; 20-degassing device; 21-plate filter device; 22-ultrasonic treatment device; 23-forming station; 24-fresh air assembly; 25-preheating assembly; 26-branch; 27-return channel; 28-reversing structure. Detailed Implementation

[0043] The following detailed description will illustrate the general principles of the invention, examples of which are further shown in the accompanying drawings. The same reference numerals identify the same or functionally similar elements.

[0044] like Figure 1-5 As shown, the present invention provides a metal smelting system, including a heating and heat preservation component and a closed flow channel A14 connected to the heating and heat preservation component at both ends. The heating and heat preservation component and the closed flow channel are provided with cavities 10 formed by dense material and interconnected with each other. The heating and heat preservation component is provided with a channel 5 connected to the cavity 10 for vacuuming and / or filling with inert gas. The system also includes a power structure for driving the molten metal located in the cavity 10 to circulate within the heating and heat preservation component through the closed flow channel A14.

[0045] The metal smelting system of this invention features a closed flow channel A14 on the heating and insulation component, which, in conjunction with a power structure, enables the circulation of the internal molten metal. This is further enhanced by continuously purifying the gas composition of the molten metal through vacuuming and / or inert gas filling within the heating and insulation component. Maintaining the circulation of the molten metal increases the contact area between the vacuuming and / or inert gas filling processes and the molten metal, continuously improving the purity of the molten metal. Compared to the method of degassing the molten metal by introducing inert gas through a degassing rotor 19, this invention achieves better degassing through the circulation of the molten metal combined with vacuuming and / or inert gas filling, allowing for comprehensive degassing of the molten metal. Furthermore, the closed flow channel A14 and the heating and insulation components used to hold and circulate the molten metal in the cavity 10 are both formed by a dense material, ensuring that the content ratio of vacuuming and / or filling with inert gas meets the requirements. This has less impact compared to the conventional method of making the box body from porous materials. Conventional boxes are prone to storing moisture and gases such as oxygen, hydrogen, and nitrogen in porous materials, which can easily react with active metals during the metal smelting process, leading to changes in the structure and a decline in the performance of the material or workpiece after heating. The present invention uses the cavity 10 formed directly from a dense heat-resistant material, which can solve and avoid this problem.

[0046] Specifically, the heating and heat preservation component can be a heating and heat preservation box 100. The two ends of the closed flow channel A14 are respectively connected to the upper end and the bottom of the cavity 10 inside the heating and heat preservation box 100. The power structure is a pump, that is, the power of the pump draws the molten metal in the heating and heat preservation box 100 to the upper end of the heating and heat preservation box 100 to realize the circulation of the molten metal. This allows the outer wall of each flow column of the molten metal to effectively come into full contact with the vacuum and / or inert gas filling during the flow process, which greatly improves the degassing effect. Furthermore, the degassing effect is continuously improved during the continuous circulation, and there are no other factors that affect or contaminate the purity of the molten metal. The present invention also provides another embodiment, wherein the heating and heat preservation assembly comprises at least two heating and heat preservation boxes 100, the at least two heating and heat preservation boxes 100 are connected sequentially through a closed flow channel B15, the first and last heating and heat preservation boxes 100 are connected through a closed flow channel A14, the power structure is a pump or a height difference structure between the heating and heat preservation boxes 100, and valves 16 are provided on the closed flow channel A14 and the closed flow channel B15 or at the interface of the heating and heat preservation box 100 for controlling the flow of molten metal in each heating and heat preservation box 100.

[0047] In this embodiment, the heating and heat preservation assembly can consist of only two heating and heat preservation boxes 100. Both closed flow channels A14 and B15 are connected to the two heating and heat preservation boxes 100, and both flow in one direction to achieve circulation of the molten metal. Alternatively, the heating and heat preservation assembly can consist of three or more heating and heat preservation boxes 100. In this case, closed flow channels A14 and B15 are sequentially connected to multiple heating and heat preservation boxes 100 to form a circulation loop.

[0048] In this embodiment, when the power structure is a pump, the molten metal can be driven to circulate in two or more heating and insulation boxes 100. When the molten metal is driven to flow through a height difference structure, the heating and insulation boxes 100 arranged in sequence can be lowered in height, and at least one at the beginning and end can be raised and lowered. When this method is adopted, a valve 16 is provided at the closed flow channel or the inlet and outlet of the heating and insulation box 100 to ensure the flow of molten metal by gravity.

[0049] The heating and insulation box 100 can be used as a melting box for melting metal. When used as a melting box, its heater can be a medium-frequency heater to improve melting efficiency and thus improve the overall efficiency of the system. It can also be used as an insulation box. Preferably, there are two heating and insulation boxes 100, one melting box and one insulation box, working in a cycle. Alternatively, one melting box can be used with two insulation boxes, for a total of multiple heating and insulation boxes 100. This method refers to the connection method when the heating and insulation component has only two heating and insulation boxes 100, that is, the melting box and each insulation box are cyclically connected through a closed flow channel A14 and a closed flow channel B15.

[0050] Specifically, the heating and heat preservation box 100 includes a box body 1 and a box cover 2. A dense, heat-resistant protective layer 3 is provided on the box body and the box cover 2. After the box body 1 and the box cover 2 are fitted together, the two dense, heat-resistant protective layers 3 enclose and form a sealed cavity 10. A crucible 9 for holding metal is provided inside the cavity 10, improving the service life of the heating and heat preservation box 100. It also includes a heater 4 for heating or heat preservation of the cavity 10. The channel 5 connects to the cavity 10, and a connecting channel connecting the closed flow channel A14 and the cavity 10 is also included. This invention, by providing a dense, heat-resistant protective layer 3 on the box body 1 and the box cover 2, allows the dense, heat-resistant protective layer 3 to enclose and form a cavity 10 enclosed by a dense, heat-resistant material after the box body 1 and the box cover 2 are fitted together. The metal to be melted undergoes melting, degassing, or heat preservation processes within this cavity 10. This arrangement allows for vacuuming or filling the cavity 10 with inert gas through the channel 5, ensuring the vacuum level or inert gas content.

[0051] The box cover 2 is provided with an opening 201, and also includes an operating cover 6 for sealing the opening 201. The size of the opening 201 is much smaller than the opening size of the box body 1. A dense heat-resistant protective layer 3 is provided on the opposite side of the opening 201 and the operating cover 6. By providing the opening 201 and the operating cover 6, the box cover 2 is used when feeding and cleaning the cavity 10. During the smelting process, sampling or feeding for fine-tuning the composition, operation of the degassing rotor 19, refining, slag removal or inspection, etc. are all carried out through the opening 201. In this embodiment, a channel 5 for filling inert gas can be provided on the side of the opening 201. While operating through the opening 201, inert gas can be filled into the channel 5 on the side of the opening 201, so that the cavity 10 is always kept under positive pressure of inert gas, preventing air from the outside of the device from entering the cavity at this time. It is not necessary to repeat the degassing operation after opening the operating cover 6 to increase the vacuum degree or inert gas content ratio in the cavity 10. By setting an opening 201 and an operating cover 6, inert gas is filled into the cavity 10 when the operating cover 6 is opened, so that the cavity 10 is always kept under positive pressure. This allows for the sampling or feeding of components for fine adjustment, operation of the degassing rotor 19, refining, slag removal or inspection, etc., without affecting the vacuum degree or inert gas content in the cavity 10, which greatly improves work efficiency and saves energy.

[0052] The closed flow channel A14 is provided with a branch 26, and an online filter component and a molding station 23 are connected in sequence on the branch 26. A return channel 27 connecting the online filter component and the molding station 23 is provided, which is connected to the heating and heat preservation component. A reversing structure 28 is provided at the connection between the branch 26 and the closed flow channel A14 and at the connection between the return channel 27 and the branch 26. It also includes a component fine-tuning system 17 and a degassing rotor 19 connected to the cavity 10 of the heating and heat preservation component.

[0053] This metal smelting system ensures precise composition through a fine-tuning system and utilizes a degassing rotor for cyclic degassing. The system's structure and circulation method ensure that the fine-tuning system and degassing rotor operation do not affect the atmosphere protection within the cavity, significantly improving system stability. An online filtration component allows for pre-forming filtration of the molten metal, such as slag removal, further enhancing its purity. A return channel between the forming station and the online filtration component allows the molten metal to return to the smelting system for further degassing and filtration, repeating the cycle until the desired purity is achieved. This system offers both small-cycle degassing and large-cycle combinations of degassing and online filtration, eliminating the need for refining agents and thoroughly removing gaseous impurities, residues, and solid slag, thus greatly improving the purity of the molten metal.

[0054] The heating and insulation component is a heating and insulation box 100. The composition fine-tuning system 17 includes a conveyor belt 171 and a robot arm 18. The robot arm 18 takes molten metal through the opening 201 of the heating and insulation box 100 for testing or puts in raw materials to fine-tune the composition of the molten metal. In addition, a safe operating room isolated from the smelting system can be set at the other end of the conveyor belt 171 to avoid operators from entering the construction site and ensure safety. The composition fine-tuning system 17 of the present invention, by setting up the robot arm 18 and the conveyor belt 171, eliminates the need for manual operation on site and improves the degree of automation. In this embodiment, a preheating component 25 can also be set to preheat the raw materials before they are placed into the heating and insulation box 100 by the robot arm 18.

[0055] The heating and heat preservation component is a heating and heat preservation box 100. The degassing rotor 19 extends into the cavity 10 through the opening 201 of the heating and heat preservation box 100 to perform degassing. The degassing rotor 19 actively degassing by spraying inert gas bubbles through small holes into the molten metal, carrying away impurities and tiny bubbles in the molten metal. Similarly, when operating through the opening 201, inert gas can be filled into the channel 5 on the side of the opening 201 to keep the cavity 10 under positive pressure of inert gas, preventing air from the outside of the device from entering the cavity at this time.

[0056] The online filtration assembly includes one or more of the following: an online degassing device 20, a plate filter device 21, a tubular filter device, an ultrasonic treatment device 22, or an electromagnetic treatment device, all disposed on the branch 26.

[0057] One or more of the following devices are connected in parallel with branch 26: online degassing device 20, plate filter device 21, tubular filter device, ultrasonic treatment device 22, or electromagnetic treatment device. A reversing structure 28 is provided at the connection point with branch 26. By connecting each purification device in parallel with branch 26, selective use can be achieved. When the molten metal meets the requirements directly after degassing in the metal smelting system, the reversing structure 28 prevents each purification device from being connected to branch 26. The molten metal flowing into branch 26 from the closed flow channel A14 directly enters the forming station 23 for ingot casting.

[0058] This invention discloses a metal smelting method, comprising a metal smelting system, and including the following steps:

[0059] S1. Place the metal to be melted or the molten metal into the heating and heat preservation component. The heating and heat preservation box 100 heats and melts the metal or keeps the molten metal warm. The composition of the molten metal is adjusted by the composition fine-tuning system 17.

[0060] S2. Open the power structure and degassing rotor 19 to allow the molten metal to circulate within the heating and insulation components and the closed flow channel A14 to degas the molten metal.

[0061] S3. Determine whether the molten metal meets the degassing requirements. If it does, shut down the power structure and degassing rotor 19 and proceed to step S4. If it does not meet the requirements, repeat step S2.

[0062] S4. Determine whether the amount of oxidized slag in the molten metal meets the requirements. If it does, it flows directly to the forming station 23 for casting through branch 26. Otherwise, the molten metal is filtered through the online processing device via the reversing structure 28. After filtration, determine whether the amount of oxidized slag in the molten metal meets the requirements again. If it does, it flows to the forming station 23 for casting. Otherwise, the filtered molten metal is refluxed through the reversing structure 28 and enters the heating and heat preservation component through the return channel 27, proceeding to step S2.

[0063] This method features a small-loop degassing system for metal smelting and a large-loop system combining metal smelting degassing and online filtration. It can also be selectively used via valves and reversing structures 28. Specifically, it offers three operating modes: 1. After degassing, the metal directly enters the forming station 23 for forming; 2. After degassing, the metal passes through an online filtration assembly before entering the forming station 23 for forming; 3. After degassing, the metal passes through an online filtration assembly and flows back to the metal smelting system via the return channel 27. In this way, while ensuring efficiency, the quality of casting can be guaranteed as much as possible, and the degassing and slag removal effects can be improved.

[0064] Step S1 includes:

[0065] S11. Place the metal to be heated in the cavity 10 inside the box 1, and close the box cover 2.

[0066] S12. Vacuum the sealed cavity 10 through channel 5, and shut down the vacuum equipment after the required vacuum level is reached.

[0067] S13. After the vacuum equipment is turned off, the sealed cavity 10 is filled with inert gas through channel 5 within 15-150 seconds to make the cavity 10 reach positive pressure and maintain positive pressure.

[0068] S14. The cavity 10 is heated and kept warm by the heater 4;

[0069] S15. Determine whether the degassing requirements are met. If they are met, allow the smelted metal to proceed to step S2. Otherwise, maintain S14 and repeat S12 and S13. Each time step S12 is repeated, stop the inert gas filling and then evacuate again, and the vacuum rate is lower than the previous evacuation. When step S13 is repeated, the time to fill with inert gas is shorter than the previous time.

[0070] Step S2 includes:

[0071] S21. Open the power structure to make the molten metal circulate in the heating and heat preservation component and the closed flow channel A14, and at the same time open the degassing rotor 19 in the heat preservation component.

[0072] S22. Vacuum the sealed cavity 10 through channel 5 until the required vacuum level is reached, then turn off the vacuum pumping equipment.

[0073] S23. Within 15-150s, fill the sealed cavity 10 with inert gas through channel 5, so that the cavity 10 reaches positive pressure and maintains positive pressure.

[0074] Step S2 also includes:

[0075] If the molten metal does not meet the degassing requirements in step S3, proceed to step S24.

[0076] S24. Turn off the heating and heat preservation components to allow the molten metal to solidify on the surface of the cavity 10.

[0077] S25. Turn on the heating and heat preservation components, and repeat S22-S23. Each time step S22 is repeated, stop the inert gas filling and then evacuate, and the vacuum rate is lower than the previous evacuation. When step S23 is repeated, the time to fill with inert gas is shorter than the previous time.

[0078] S24. Determine whether the degassing requirements are met. If they are met, allow the smelted metal to enter the subsequent heating process stage; otherwise, repeat S22-S24. Each time step S22 is repeated, the vacuum rate is lower than the previous vacuuming. When step S23 is repeated, the time to fill with inert gas is shorter than the previous time.

[0079] This method combines vacuuming and inert gas protection during the S22-S23 process. Specifically, in the repetition of step S22, the vacuum rate of the vacuuming is lower than that of the previous vacuuming, for example, the vacuum rate of the first vacuuming is 95%, the second is 70%, and the third is 50%. Step S23 is performed after each step S22, and in the repetition of step S23, the time for filling with inert gas is shorter than the previous time to reduce the amount of air infiltration, for example, the first time it takes 50 seconds to fill with inert gas, the second time it takes 30 seconds, and the third time it takes 10 seconds. In this way, with each repetition, less and less air infiltrates into the cavity 10 during the vacuuming process, while the inert gas continuously dilutes gaseous impurities and removes them through the vacuuming operation, ultimately resulting in a lower and lower content of gaseous impurities, a higher and higher proportion of inert gas, and a higher and higher purity of the molten metal. Using the above method, air can circulate and dilute unnecessary gas components within cavity 10 without requiring a high vacuum, thereby increasing purity. Simultaneously, it prevents excessive pressure difference between cavity 10 and the outside environment, which could lead to air being drawn into cavity 10. Furthermore, the structural design of cavity 10, made of a dense material, significantly reduces the content of air, other gases, and adsorbates within cavity 10, increasing the vacuum level or the content of inert gases, thus ensuring the purity of the molten metal during smelting. This metal heating method, used in conjunction with a heating and insulation box, can continuously increase the vacuum level or inert gas content ratio within cavity 10, thereby improving the purity of metal materials or workpieces and ensuring the quality of subsequent products. This method can achieve a high vacuum effect through a low vacuum system. Compared to equipment requiring high vacuum, this method only requires multiple evacuations and inert gas fillings, significantly reducing costs. It also solves the problem that the harsh environment of melting and casting can severely affect the short service life of high vacuum systems. Furthermore, maintaining a slight positive pressure within cavity 10 when introducing inert gas can prevent external air from seeping into cavity 10, ensuring environmental stability and facilitating fine-tuning of composition and operation of the degassing rotor.

[0080] In step S24, the molten metal is semi-solidified, and after cooling, the heating and heat preservation components are restarted to repeat S22-S23. In this step, the hydrogen elements remaining in the solution are driven to vaporize by the semi-solid state and the metal elements are prevented from being vaporized and burned off. The gas in the molten state is continuously released by utilizing the solubility difference between the solid and liquid states, thereby improving the degassing effect.

[0081] The conventional smelting process, taking Al-4Cu-1Li alloy ingot casting as an example, involves placing pure aluminum ingots, copper ingots, and other ingredients in crucible 9, covering the crucible, evacuating to a stable 100Pa, and then shutting off the vacuum equipment. Argon gas is then introduced to achieve positive pressure inside the crucible, the gas filling equipment is turned off, and the temperature is raised to 760-800℃ to fully melt the materials. The operating cover is then opened, lithium ingots are added, and the mixture is stirred evenly and allowed to stand for 1-5 hours. The power mechanism is then activated, allowing the molten metal to flow through the heating and insulation components along a closed channel, passing through the online degassing device 20 and the filtration device, finally entering the forming station to obtain the ingot.

[0082] The smelting process 1 of this invention: Taking Al-4Cu-1Li alloy ingot as an example, pure aluminum ingots, copper ingots and other ingredients are placed in crucible 9, the lid is closed, and after evacuation to 100Pa and stabilization, argon gas is introduced, with the gas filling rate controlled at 24L / min. After the pressure inside the box reaches positive, the gas filling equipment is turned off. The heater is turned on and heated to 350℃ and kept at that temperature for 1 hour. During the heat preservation period, evacuation is continuously carried out. After evacuation to 100Pa and stabilization, the vacuum equipment and heater are turned off, and argon gas is introduced again, with the gas filling rate controlled at 24L / min, so that the pressure inside the box reaches positive. Argon gas is continuously introduced, with the gas filling rate controlled at 6L / min, and the temperature is raised to 780℃ to fully melt the materials. Then, the operating cover is opened and lithium ingots are added. The mixture is then stirred evenly, and the alloy melt is degassed through the degassing component. The metal melt is cooled to a semi-solid state, while evacuation is continued for 1-3 hours. The vacuum equipment is turned off, and argon gas is introduced again, with the gas filling rate controlled to quickly reach positive pressure inside the box. The alloy melt is then degassed through the degassing component. The power structure is opened, allowing the molten metal to flow through the heating and insulation components along a closed flow channel, pass through the filtration device, and then be transported to the forming station to obtain an ingot.

[0083] The smelting process 2 of this invention: Taking Al-4Cu-1Li alloy ingot as an example, pure aluminum ingots, copper ingots, and other ingredients are placed in crucible 9, the lid is closed, and after evacuation to a stable 100Pa, argon gas is introduced, with the gas filling rate controlled at 24L / min. After the pressure inside the crucible reaches positive, the gas filling equipment is turned off. The heater is turned on and heated to 350℃ and held for 1 hour. During the holding period, evacuation is continuously performed. After evacuation to a stable 100Pa, the vacuum equipment and heater are turned off, and argon gas is introduced again, with the gas filling rate controlled at 24L / min. The pressure inside the chamber is increased to 24 L / min to achieve positive pressure. Argon gas is continuously introduced at a rate of 6 L / min, and the temperature is raised to 780°C to fully melt the material. The operating cover is then opened, and lithium ingots are added. The mixture is stirred evenly, and the alloy melt is degassed using a degassing component. The molten metal is cooled to a semi-solid state while a vacuum is continuously applied for 1-3 hours. The vacuum equipment is then turned off, and argon gas is introduced again at a rate of 24 L / min to achieve positive pressure inside the chamber. The alloy melt is degassed again using the degassing component. The power structure is then opened, allowing the molten metal to flow through the heating and insulation components along a closed channel, passing through the online degassing device 20 and the filtration device, and finally entering the forming station to obtain the ingot.

[0084] The alloy ingots obtained by the above three processes were weighed and their microstructure was sampled and analyzed. The relevant test data are shown in Table 1 below.

[0085]

[0086] Table 1. Relevant properties of Al-4Cu-1Li alloy ingots obtained by the three processes:

[0087] As can be seen from the comparison between conventional smelting processes and smelting processes 1 and 2 of this invention in Table 1, the content of oxide inclusions in the alloy ingots is significantly reduced. This indicates that the protective heating method of the smelting system of this invention has a good effect on the high-temperature oxidation reaction of the metal, greatly improving the purity during the metal smelting process. The reduction in oxide inclusion content plays an important role in improving the yield and material quality of subsequent products. Secondly, the solid hydrogen content of the ingots produced by the smelting process of this invention is also significantly reduced compared to conventional smelting processes, especially the lowest solid hydrogen content in smelting process 2 of this invention, providing a technical approach for alloy materials products with extreme hydrogen content control requirements. In addition, the metal smelting system and smelting process 1 of this invention significantly improve the utilization rate of raw materials while obtaining high-quality ingots, thereby avoiding the large amount of raw material waste caused by the use of online degassing devices in current conventional smelting systems.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A metal smelting system, characterized in that, The device includes a heating and heat preservation component and a closed flow channel A (14) connected to the heating and heat preservation component at both ends. The heating and heat preservation component and the closed flow channel A (14) are provided with cavities (10) formed by dense material and connected to each other. The heating and heat preservation component is provided with a channel (5) connected to the cavity (10) for vacuuming and / or filling with inert gas. The device also includes a power structure for driving the molten metal located in the cavity (10) to circulate in the heating and heat preservation component through the closed flow channel A (14). A branch (26) is provided on the closed flow channel A (14). An online filter assembly and a molding station (23) are connected in sequence on the branch (26). A return channel (27) connecting the online filter assembly and the molding station (23) is provided to the heating and heat preservation assembly. A reversing structure (28) is provided at the connection between the branch (26) and the closed flow channel A (14) and at the connection between the return channel (27) and the branch (26). It also includes a component fine-tuning system (17) and a degassing rotor (19) connected to the cavity (10) of the heating and heat preservation assembly.

2. The metal smelting system as described in claim 1, characterized in that, The heating and heat preservation component is a heating and heat preservation box (100), and the two ends of the closed flow channel A (14) are respectively connected to the upper end and the bottom of the cavity (10) inside the heating and heat preservation box (100), and the power structure is a pump.

3. The metal smelting system as described in claim 1, characterized in that, The heating and insulation component consists of at least two heating and insulation boxes (100), which are connected in sequence through a closed flow channel B (15). The first and last two heating and insulation boxes (100) are connected through a closed flow channel A (14). The power structure is a pump or a height difference structure between the heating and insulation boxes (100). Valves (16) are provided on the closed flow channel A (14) and the closed flow channel B (15) or at the interface of the heating and insulation box (100).

4. The metal smelting system as described in claim 3, characterized in that, The heating and insulation box (100) includes a box body (1) and a box cover (2). The box body and the box cover are provided with a dense heat-resistant protective layer (3). After the box body (1) and the box cover (2) are put together, the two dense heat-resistant protective layers (3) enclose and form a sealed cavity (10). It also includes a heater (4) for heating or heat preservation of the cavity (10).

5. The metal smelting system as described in claim 4, characterized in that, The box cover (2) is provided with an opening (201), and also includes an operation cover (6) for sealing the opening (201). A dense heat-resistant protective layer (3) is provided on the opposite side of the opening (201) and the operation cover (6).

6. The metal smelting system as claimed in claim 1, characterized in that, The heating and heat preservation component is a heating and heat preservation box (100). The composition fine-tuning system (17) includes a conveyor belt (171) and a robot (18). The robot (18) takes the molten metal through the opening (201) of the heating and heat preservation box (100) for testing or puts in raw materials to fine-tune the composition of the molten metal.

7. The metal smelting system as described in claim 1, characterized in that, The heating and heat preservation component is a heating and heat preservation box (100), and the degassing rotor (19) extends into the cavity (10) through the opening (201) of the heating and heat preservation box (100) to degas.

8. The metal smelting system as claimed in claim 1, characterized in that, The online filtration assembly includes one or more of the following: an online degassing device (20), a plate filter (21), a tubular filter, an ultrasonic treatment device (22), or an electromagnetic treatment device, all disposed on the branch (26).

9. The metal smelting system as claimed in claim 1, characterized in that, One or more of the following devices are connected in parallel with the branch (26): online degassing device (20), plate filter device (21), tubular filter device, ultrasonic treatment device (22), or electromagnetic treatment device, and a reversing structure (28) is provided at the connection with the branch (26).

10. A method for smelting metal, characterized in that, The metal smelting system as described in any one of claims 1-9 includes the following steps: S1. Place the metal to be melted or the molten metal into the heating and heat preservation component. The heating and heat preservation component heats and melts the metal or keeps the molten metal warm. The composition of the molten metal is controlled by the composition fine-tuning system (17). S2. Open the power structure and degassing rotor (19) to allow the molten metal to circulate in the heating and insulation components and the closed flow channel A (14) to degas the molten metal; S3. Determine whether the molten metal meets the degassing requirements. If it does, shut down the power structure and degassing rotor 19 and proceed to step S4. If it does not meet the requirements, repeat step S2. S4. Determine whether the amount of oxidized slag in the molten metal meets the requirements. If it does, proceed to step S6 through branch (26); otherwise, proceed to step S5. S5. The molten metal is filtered through the online processing device by the reversing structure (28). After filtration, it is determined whether the molten metal meets the requirements for the amount of oxide inclusions. If it does, proceed to step S6. Otherwise, the filtered molten metal is allowed to enter the heating and heat preservation component through the return channel (27) by the reversing structure (28), and proceed to step S2. S6. Enter the forming station (23) for casting.

11. The metal smelting method as described in claim 10, characterized in that, step S1 includes: S11. Place the metal to be heated in the cavity (10) inside the box (1) and close the box cover (2). S12. Vacuum the sealed cavity (10) through the channel (5) until the vacuum requirement is met, then turn off the vacuum pumping equipment. S13. After the vacuum equipment is turned off, fill the sealed cavity (10) with inert gas through the channel (5) within 15-150s to make the cavity (10) reach positive pressure and maintain positive pressure. S14. The cavity (10) is heated and kept warm by the heater (4); S15. Determine whether the degassing requirements are met. If they are met, allow the smelted metal to proceed to step S2. Otherwise, maintain S14 and repeat S12 and S13. Each time step S12 is repeated, stop the inert gas filling and then evacuate again, and the vacuum rate is lower than the previous evacuation. When step S13 is repeated, the time to fill with inert gas is shorter than the previous time.

12. The metal smelting method as described in claim 10, characterized in that, Step S2 includes: S21. Open the power structure to make the molten metal circulate in the heating and heat preservation component and the closed flow channel A (14), and at the same time open the degassing rotor (19) in the heat preservation component. During the process, the positive pressure of the inert gas in the cavity (10) is maintained through the channel (5) until the molten metal meets the degassing requirements. S22. Vacuum the sealed cavity (10) through the channel (5) until the required vacuum level is reached, then turn off the vacuum pumping equipment. S23. Within 15-150s, fill the sealed cavity (10) with inert gas through the channel (5) to make the cavity (10) reach positive pressure and maintain positive pressure.

13. The metal smelting method as described in claim 12, characterized in that, Step S2 also includes: If the molten metal does not meet the degassing requirements in step S3, proceed to step S24. S24. Turn off the heating and heat preservation components to allow the molten metal to solidify on the surface of the cavity (10); S25. Turn on the heating and heat preservation components, and repeat S22-S23. Each time step S22 is repeated, stop the inert gas filling and then evacuate, and the vacuum rate is lower than the previous evacuation. When step S23 is repeated, the time to fill with inert gas is shorter than the previous time.

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