Large vertical reduction tank structure for magnesium smelting and manufacturing method thereof

Abstract

This invention provides a large vertical reduction tank structure and its manufacturing method for magnesium smelting, relating to the field of magnesium smelting equipment technology. It includes a crude magnesium collector, a reduction tank body, and a central tube disposed within the tank body. An upper water jacket assembly is provided at the top of the tank body for opening and sealing the top, and when sealed, cooling water is connected to cool the top of the tank body. A lower water jacket assembly is provided at the bottom of the tank body for opening and sealing the bottom, and when sealed, it is used to create a vacuum inside the tank, and cooling water is connected to cool the crude magnesium collector and collect magnesium under vacuum conditions. This invention can reduce magnesium oxide in calcined white metal into magnesium vapor for collection under high-temperature heating and vacuum conditions. Compared to existing small-diameter tanks or horizontal tanks used in magnesium smelting, it increases production capacity, reduces energy consumption, and extends service life, meeting the requirements for long-term service and high production capacity under high-temperature vacuum conditions.

Description

Technical Field

[0001] This invention relates to the field of magnesium smelting equipment technology, and more specifically, to a structure of a large vertical reduction tank for magnesium smelting and its manufacturing method. Background Technology

[0002] The Pidgeon process is currently the mainstream process for producing metallic magnesium. It refers to a thermal reduction method in which calcined dolomite is reduced to metallic magnesium using ferrosilicon reducing agents in a reduction furnace heated outside the tank, with materials added inside the reduction tank. Named after its inventor, L.M. Pidgeon, this method has been used for a long time and can be considered a classic method of silicothermic magnesium production. Compared with other methods, this method has advantages such as fast plant construction, low investment, the ability to utilize multiple heat sources, and high product quality.

[0003] Currently, most of the reduction tanks used in magnesium smelting are small-diameter tanks or horizontal tanks, which have low capacity, high energy consumption, and short service life, making it difficult to meet the requirements of long-term service and high capacity under high temperature (such as 1200-1300℃) vacuum conditions. Summary of the Invention

[0004] The present invention aims to solve the problem that the reduction tanks used in existing magnesium smelting are mostly small-diameter tanks or horizontal tanks, which have low capacity, high energy consumption, and short service life, making it difficult to meet the requirements of long-term service and high capacity under high temperature and vacuum conditions.

[0005] To address the aforementioned problems, this invention provides a large vertical reduction tank structure for magnesium smelting, comprising a crude magnesium collector, a reduction tank body, and a central tube disposed within the reduction tank body. The top of the reduction tank body is provided with an upper water jacket assembly, which is used to open and seal the top of the reduction tank body. When sealed, cooling water is connected to cool the top of the reduction tank body. The bottom of the reduction tank is equipped with a water jacket assembly, which is used to open and seal the bottom of the reduction tank. When sealed, it is used to evacuate the tank and connect cooling water to the crude magnesium collector to cool and collect magnesium in a vacuum environment.

[0006] The present invention provides a large vertical reduction tank structure for magnesium smelting, which, compared with the prior art, has the following beneficial effects, but is not limited to: This magnesium smelting system utilizes a large vertical reduction tank structure. The tank is used vertically, with both the top and bottom open initially. A central tube is then installed inside. Calcined white metal, ferrosilicon, and fluorite are ground and granulated in a specific ratio and added to the gap between the tank body and the central tube. The top of the tank is sealed by an upper water jacket assembly, and the bottom by a lower water jacket assembly. A coarse magnesium collector is installed in the lower water jacket assembly. Cooling water is connected to the upper water jacket assembly to cool the top of the tank, and to the lower water jacket assembly to cool the coarse magnesium collector. The process involves cooling and vacuuming the tank via a lower water jacket assembly. Under heating conditions of 1200-1300℃ and vacuum, magnesium oxide in the calcined white metal is reduced to magnesium vapor. Under vacuum conditions, the magnesium vapor is continuously transported from the central tube to the crude magnesium collector, where it cools and crystallizes on the inner wall, thus completing the collection of crude magnesium. This process boasts high capacity (e.g., a single tank can produce 530 kg of magnesium, five times the capacity of traditional small tanks), low energy consumption, and long service life. It can meet the demands of long-term service under high-temperature vacuum conditions (over 2000 hours of service at 1300℃ in a vacuum environment) and high capacity requirements.

[0007] Furthermore, the upper water jacket assembly includes a furnace cover, an upper water jacket, and a top cover plate. The upper water jacket is welded to the top of the reduction tank body. The furnace cover is detachably installed on the top of the upper water jacket. The top cover plate is disposed inside the upper water jacket and is detachably connected to the top of the reduction tank body.

[0008] Furthermore, the water jacket assembly includes a lower cone, a sand tray with small holes, a water jacket, and a bottom cover plate arranged sequentially from top to bottom. The lower cone is welded between the reduction tank body and the water jacket. The bottom cover plate is detachably installed at the bottom of the water jacket. The sand tray is detachably connected to the lower cone. The coarse magnesium collector is disposed inside the water jacket. The interior of the coarse magnesium collector is connected to the interior of the lower cone through small holes on the sand tray.

[0009] Furthermore, the top of the bottom cover plate is provided with a snap-fit ​​groove that engages with the coarse magnesium collector.

[0010] Furthermore, a first water inlet pipe is connected to the lower end of one side of the outer wall of the upper water jacket, and a first water outlet pipe is connected to the upper end of the other side of the outer wall of the upper water jacket.

[0011] Furthermore, the water jacket includes a carbon steel jacket and a stainless steel jacket. The carbon steel jacket is made of carbon steel plate by rolling and welding, and the stainless steel jacket is made of stainless steel plate by rolling and welding. The splicing part of the carbon steel jacket and the stainless steel jacket is connected by double bevel welding. The first water inlet pipe is welded to the stainless steel plate rolling and welding joint, and the first water outlet pipe is welded to the carbon steel plate rolling and welding joint.

[0012] Furthermore, the water jacket includes an outer sleeve and a second inlet pipe, a second outlet pipe, and a vacuum interface installed on the outer sleeve. The input end of the vacuum interface is connected to the inner cavity of the outer sleeve. An inner sleeve that fits with the coarse magnesium collector is provided inside the outer sleeve. Several ring plates are fixedly connected between the inner sleeve and the outer sleeve from top to bottom. An annular cavity is formed between two adjacent ring plates. The output end of the second water inlet pipe is connected to a top annular cavity, and the input end of the second water outlet pipe is connected to a bottom annular cavity. A partition is sealed to one side of the annular cavity. Two adjacent annular cavities are connected by a flow pipe. The output end of the second water inlet pipe and the output end of the flow pipe are both located in front of the corresponding partition, and the input end of the second water outlet pipe is located in rear of the corresponding partition.

[0013] Furthermore, a swirl propeller is provided in the upper water jacket. The swirl propeller is detachably installed between the furnace cover and the top cover plate. The water flow output from the outlet end of the first water inlet pipe acts on the blades of the swirl propeller, causing the swirl propeller to rotate.

[0014] In addition, the present invention also provides a method for manufacturing a large vertical reduction tank structure for magnesium smelting, based on the aforementioned vertical tank magnesium smelting central tube structure, comprising: Step 1: The body, central tube, and lower cone of the reduction tank are manufactured by casting, while the furnace cover, upper water jacket, top cover plate, sand table, lower water jacket, crude magnesium collector, and bottom cover plate are manufactured by machining. Step 2: Weld the upper water jacket, reduction tank body, lower cone, and lower water jacket together to form a whole. Then, put the central tube into the reduction tank body and put the raw materials for magnesium smelting between them. Then, cover the top cover plate and the furnace cover. Install the sand tray and the lower cone. Then, put the crude magnesium collector into the lower water jacket and connect it with the sand tray. Finally, cover the bottom of the lower water jacket with the bottom cover plate to complete the assembly.

[0015] Furthermore, the material of the reduction tank body is modified ZG35Cr24Ni7SiN, and its process flow is as follows: medium frequency furnace steel smelting → deoxidation and rare earth strengthening in the ladle → centrifugal casting → water cooling. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a large vertical reduction tank for magnesium smelting according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the upper water jacket structure according to an embodiment of the present invention; Figure 3 Embodiments of the present invention Figure 1 A top view of the structure between the upper water jacket and the vortex propeller; Figure 4Embodiments of the present invention Figure 1 A schematic diagram of the structure between the lower water jacket and the crude magnesium collector in the middle; Figure 5 Embodiments of the present invention Figure 4 A top-section diagram of the lower water jacket structure.

[0017] Explanation of reference numerals in the attached figures: 1. Furnace cover; 2. Upper water jacket; 201. First water inlet pipe; 202. First water outlet pipe; 203. Carbon steel sleeve; 204. Stainless steel sleeve; 3. Top cover plate; 4. Reduction tank body; 5. Central pipe; 6. Lower cone; 7. Sand table; 8. Lower water jacket; 801. Second water inlet pipe; 802. Ring plate; 803. Outer sleeve; 804. Flow pipe; 805. Inner sleeve; 806. Second water outlet pipe; 807. Vacuum interface; 808. Circular cavity; 809. Baffle plate; 9. Crude magnesium collector; 10. Bottom cover plate; 11. Snap-fit ​​groove; 12. Swirl propeller; a. Upper water jacket assembly; b. Lower water jacket assembly. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application are described clearly and completely below with reference to the accompanying drawings. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," "comprise," etc., in the specification, claims, and accompanying drawings of this application are open-ended terms, indicating that a method comprises one or more steps, or an apparatus comprises one or more elements, but do not exclude the inclusion of other steps or elements. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or primary / secondary relationship. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] Furthermore, in the attached diagram, the X-axis represents the vertical direction, that is, the front-to-back position, and the positive direction of the X-axis (that is, the direction the arrow points on the X-axis) represents the front, and the negative direction of the X-axis (that is, the direction opposite to the positive direction of the X-axis) represents the back; in the attached diagram, the Z-axis represents the vertical direction, that is, the up-down position, and the positive direction of the Z-axis (that is, the direction the arrow points on the Z-axis) represents the up, and the negative direction of the Z-axis (that is, the direction opposite to the positive direction of the Z-axis) represents the down.

[0022] It should also be noted that the aforementioned X-axis and Z-axis representations are only for the purpose of facilitating the description of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0025] See Figure 1 The present invention provides a large vertical reduction tank structure for magnesium smelting, comprising a crude magnesium collector 9, a reduction tank body 4, and a central tube 5 disposed within the reduction tank body 4. The top of the reduction tank body 4 is provided with an upper water jacket assembly a, which is used to open and seal the top of the reduction tank body 4. When sealed, cooling water is connected to the top of the reduction tank body 4 to cool it down. The bottom of the reduction tank body 4 is provided with a water jacket assembly b, which is used to open and seal the bottom of the reduction tank body 4. When sealed, it is used to draw a vacuum inside the tank and connect cooling water to the crude magnesium collector 9 to cool and collect magnesium in a vacuum environment.

[0026] In this embodiment, the large vertical reduction tank structure for magnesium smelting is based on the tank body 4 (e.g., the outer diameter of the tank body 4 is 1100mm, the length is 6800mm, and the thickness is 105mm). It is used vertically, with the top and bottom of the tank body 4 initially open. A central tube 5 (e.g., the outer diameter of the central tube 5 is 630mm, the length is 6800mm, and the wall thickness is 25mm) is then installed inside. Calcined white metal, ferrosilicon, and fluorite are ground and granulated in a specific ratio and added to the gap between the tank body 4 and the central tube 5. The top of the tank body 4 is sealed by the upper water jacket assembly a, and the bottom of the tank body 4 is sealed by the lower water jacket assembly b. A coarse magnesium collector 9 is installed in the lower water jacket assembly b. The upper water jacket assembly a is connected to cooling water to cool the top of the reduction tank body 4, and the lower water jacket assembly b is connected to cooling water to cool the crude magnesium collector 9. The lower water jacket assembly b is also used to evacuate the tank. Under heating at 1200-1300℃ and vacuum environment, the magnesium oxide in the calcined white is reduced to magnesium vapor. Under vacuum conditions, the magnesium vapor is continuously transported from the central tube 5 to the crude magnesium collector 9, where it is cooled and crystallizes on the inner wall of the crude magnesium collector 9, thus completing the collection of crude magnesium. It has high production capacity (for example, the magnesium output of a single tank is 530kg, which is five times the production capacity of traditional small tanks), low energy consumption, and long service life. It can meet the requirements of long-term service under high temperature and vacuum conditions (service time of more than 2000 hours at 1300℃ in a vacuum environment) and high production capacity.

[0027] See Figure 1 Optionally, the upper water jacket assembly a includes a furnace cover 1, an upper water jacket 2, and a top cover plate 3. The upper water jacket 2 is welded to the top of the reduction tank body 4. The furnace cover 1 is detachably installed on the top of the upper water jacket 2. The top cover plate 3 is located inside the upper water jacket 2 and is detachably connected to the top of the reduction tank body 4.

[0028] In this embodiment, during initial use, the furnace cover 1 and the top cover plate 3 are opened in sequence to facilitate opening the top of the reduction tank body 4, and to facilitate the installation of the central tube 5 into the reduction tank body 4. This further facilitates the addition of calcined white metal, ferrosilicon, and fluorite, which are ground and shaped into balls in proportion, into the gap between the reduction tank body 4 and the central tube 5. After completing the above actions, the top cover plate 3 is first closed on the top of the reduction tank body 4 for high-temperature sealing, and then the furnace cover 1 is closed on the top of the upper water jacket 2.

[0029] See Figure 1Optionally, the water jacket assembly b includes a lower cone 6, a sand tray 7 with small holes, a water jacket 8, and a bottom cover plate 10 arranged sequentially from top to bottom. The lower cone 6 is welded between the reduction tank body 4 and the water jacket 8. The bottom cover plate 10 is detachably installed at the bottom of the water jacket 8. The sand tray 7 is detachably connected to the lower cone 6. The coarse magnesium collector 9 is disposed inside the water jacket 8. The interior of the coarse magnesium collector 9 is connected to the interior of the lower cone 6 through the small holes on the sand tray 7.

[0030] In this embodiment, after sealing and closing the top cover plate 3 and the furnace cover 1, the sand tray 7 is placed from the bottom of the lower water jacket 8 and then installed at the bottom of the lower cone 6. Next, the crude magnesium collector 9 is placed from the bottom of the lower water jacket 8, so that its interior is connected to the interior of the lower cone 6 through the small holes on the sand tray 7. Finally, the bottom cover plate 10 is installed at the bottom of the lower water jacket 8 for sealing. On the one hand, the sand tray 7 prevents the slag in the reduction tank body 4 from falling into the crude magnesium collector 9, and on the other hand, allows the magnesium vapor in the central tube 5 to enter the crude magnesium collector 9 through the small holes on the sand tray 7. The vacuum heating condition is maintained for 24 hours. After 24 hours, the vacuum is broken, the bottom cover plate 10 is opened, the crude magnesium collector 9 and the sand tray 7 are removed, the furnace cover 1 and the top cover plate 3 are opened, the central tube 5 is lifted, and the slag in the reduction tank body 4 flows out from the bottom due to gravity. Then, a new crude magnesium collector 9 and the sand tray 7 are installed, and the above actions are repeated to carry out the next 24 hours of magnesium smelting.

[0031] See Figure 4 Optionally, the top of the bottom cover plate 10 is provided with a snap-fit ​​groove 11 that engages with the coarse magnesium collector 9.

[0032] In this embodiment, the snap-fit ​​groove 11 facilitates the snap-fit ​​of the coarse magnesium collector 9 between the lower water jacket 8 and the bottom cover plate 10, thereby achieving limited fixation and making disassembly and assembly convenient.

[0033] See Figure 2 Optionally, a first water inlet pipe 201 is connected to the lower end of one side of the outer wall of the upper water jacket 2, and a first water outlet pipe 202 is connected to the upper end of the other side of the outer wall of the upper water jacket 2.

[0034] In this embodiment, with the furnace cover 1 and the top cover plate 3 sealed, cooling water is continuously supplied to the upper water jacket 2 through the first water inlet pipe 201, and then the cooling water that has absorbed heat is continuously output through the first water outlet pipe 202, which facilitates the cooling of the top of the reduction tank body 4. Furthermore, the cooling water is input from the lower end and output from the higher end, which allows the cooling water to stay in the upper water jacket 2 for a longer period of time, further improving the cooling effect.

[0035] See Figure 2Optionally, the water inlet sleeve 2 includes a carbon steel sleeve 203 and a stainless steel sleeve 204. The carbon steel sleeve 203 is made of carbon steel plate by rolling and welding, and the stainless steel sleeve 204 is made of stainless steel plate by rolling and welding. The splicing part of the carbon steel sleeve 203 and the stainless steel sleeve 204 is connected by double bevel welding. The first water inlet pipe 201 is welded to the stainless steel plate rolling and welding joint, and the first water outlet pipe 202 is welded to the carbon steel plate rolling and welding joint.

[0036] In this embodiment, the upper water jacket 2 adopts a segmented splicing structure of carbon steel sleeve 203 and stainless steel sleeve 204. The lower stainless steel sleeve 204 is close to the high temperature and cooling water area, which has strong corrosion resistance and is not easy to rust and leak. The upper carbon steel sleeve 203 provides structural rigidity and support strength, reducing manufacturing costs. The splicing of carbon steel sleeve 203 and stainless steel sleeve 204 adopts double bevel welding, which can increase the welding bonding area and penetration, improve the weld strength and density, reduce welding deformation, and ensure that the upper water jacket 2 can be stably sealed for a long time under high temperature, vacuum and circulating water cooling conditions, and is not easy to crack or leak, thus improving the overall service life and operational reliability. The first water inlet pipe 201 is welded to the stainless steel plate roll weld joint, and the first water outlet pipe 202 is welded to the carbon steel plate roll weld joint, which facilitates the installation and fixation of the first water inlet pipe 201 and the first water outlet pipe 202 on the stainless steel sleeve 204 and the carbon steel sleeve 203, respectively.

[0037] See Figure 4 and Figure 5 Optionally, the drain sleeve 8 includes an outer sleeve 803 and a second inlet pipe 801, a second outlet pipe 806, and a vacuum port 807 installed on the outer sleeve 803. The input end of the vacuum port 807 is connected to the inner cavity of the outer sleeve 803. The inner sleeve 805 is provided inside the outer sleeve 803 to fit with the coarse magnesium collector 9. Several ring plates 802 are fixedly connected between the inner sleeve 805 and the outer sleeve 803 from top to bottom. An annular cavity 808 is formed between two adjacent ring plates 802. The output end of the second water inlet pipe 801 is connected to a top annular cavity 808, and the input end of the second water outlet pipe 806 is connected to a bottom annular cavity 808. A partition 809 is sealed to one side of the annular cavity 808. Two adjacent annular cavities 808 are connected by a flow pipe 804. The output end of the second water inlet pipe 801 and the output end of the flow pipe 804 are both located in front of the corresponding partition 809, and the input end of the second water outlet pipe 806 is located behind the corresponding partition 809.

[0038] In this embodiment, after the top of the reduction tank body 4 is sealed by the furnace cover 1 and the top cover plate 3, the crude magnesium collector 9 is inserted into the inner sleeve 805 through the bottom inlet / outlet of the outer sleeve 803, and its top is connected to the small hole on the sand table 7. Then, the bottom inlet / outlet of the outer sleeve 803 is sealed by the bottom cover plate 10. The entire tank is evacuated through the vacuum port 807. Then, cooling water is continuously introduced into a circular cavity 808 at the top connected to the second water inlet pipe 801. The cooling water flows circumferentially in each circular cavity 808 through the separation of the partition plate 809. After completing one cycle in one circular cavity 808, it flows into the next adjacent circular cavity 808 through the flow pipe 804 between two adjacent circular cavities 808. The cooling water continues to flow once in each annular cavity 808, then enters the next annular cavity 808, repeating the above action. This causes the cooling water to flow and be transported from top to bottom in a spiral manner outside the coarse magnesium collector 9, and finally exits from the second outlet pipe 806. This significantly extends the heat exchange time between the cooling water and the coarse magnesium collector 9 through the inner sleeve 805, greatly improving the cooling intensity and temperature uniformity of the coarse magnesium collector 9. This allows magnesium vapor to quickly and stably condense and crystallize after entering the coarse magnesium collector 9 from the central tube 5 under vacuum conditions, effectively improving the coarse magnesium collection rate and product density. At the same time, the multi-layer annular plate 802 also has a supporting and reinforcing function, significantly improving the structural rigidity and deformation resistance of the lower water jacket 8 under vacuum negative pressure, circulating water pressure and thermal alternating loads, ensuring long-term stable and reliable operation and no sealing failure.

[0039] See Figure 1 and Figure 3 Optionally, a vortex propeller 12 is provided in the upper water jacket 2. The vortex propeller 12 is detachably installed between the furnace cover 1 and the top cover plate 3. The water flow output from the outlet end of the first water inlet pipe 201 acts on the blades of the vortex propeller 12, causing the vortex propeller 12 to rotate.

[0040] In this embodiment, when cooling water is injected tangentially or directionally into the inner cavity of the upper water jacket 2 through the first inlet pipe 201, the water flow continuously impacts the blades of the vortex propeller 12, driving the vortex propeller 12 to rotate inside the upper water jacket 2, causing the cooling water inside the cavity to form a forced vortex disturbance. This vortex structure can break the additional thermal boundary layer on the inner wall of the cooling water, significantly improving the heat transfer coefficient between the cooling water and the wall of the upper water jacket 2, making the temperature of the top cooling area more uniform and the cooling speed faster, effectively enhancing the cooling effect on the upper part of the reduction tank body 4. At the same time, the vortex disturbance can reduce local water stagnation and low temperature dead zones, avoid thermal stress concentration caused by uneven cooling, and improve the stability and service life of the upper water jacket 2 under high temperature alternating conditions. Meanwhile, the vortex propeller 12 can be detachably installed between the furnace cover 1 and the top cover plate 3, making it easy to take out or put in the vortex propeller 12 when the furnace cover 1 is opened, and making it easy to open the top cover plate 3 when taking it out, thereby facilitating the insertion of the central tube 5 into the reduction tank body 4.

[0041] In addition, another embodiment of the present invention provides a method for manufacturing a large vertical reduction tank structure for magnesium smelting, based on the aforementioned vertical tank magnesium smelting central tube structure, comprising: Step 1: The reduction tank body 4, central tube 5, and lower cone 6 are manufactured by casting (for example, the reduction tank body 4 is centrifugally cast using a horizontal centrifuge; the lower cone 6 is sand cast, and all castings are made of the same material). The furnace cover 1, upper water jacket 2, top cover plate 3, sand tray 7, lower water jacket 8, crude magnesium collector 9, and bottom cover plate 10 are manufactured by machining. Step 2: Weld the upper water jacket 2, the reduction tank body 4, the lower cone 6, and the lower water jacket 8 together to form a whole. Then, put the central tube 5 into the reduction tank body 4 and put the raw materials for magnesium smelting between them. Then, cover the top cover plate 3 and the furnace cover 1 one after the other. Install the sand tray 7 and the lower cone 6. Then, put the crude magnesium collector 9 into the lower water jacket 8 and connect it with the sand tray 7. Finally, cover the bottom cover plate 10 at the bottom of the lower water jacket 8 to complete the assembly.

[0042] See Figure 1 Optionally, the material of the reduction tank body 4 is modified ZG35Cr24Ni7SiN, and its process flow is as follows: medium frequency furnace steel smelting → deoxidation and rare earth strengthening in the ladle → centrifugal casting → water cooling.

[0043] In this embodiment, the body 4 of the reduction tank is made of modified ZG35Cr24Ni7SiN material, which significantly improves high-temperature strength, high-temperature oxidation resistance and thermal fatigue resistance. It can be used stably for a long time in a vacuum environment at 1300℃, and is not easy to deform, crack or corrode, effectively extending the service life of the reduction tank and meeting the high capacity and long service life requirements of large magnesium smelting reduction tanks.

[0044] Specifically, the composition requirements for reducing can body 4 are as follows:

[0045] Additionally, trace alloying elements of 0.1%-0.3% titanium and 0.2%-0.5% niobium are added.

[0046] The specific process flow for restoring tank body 4 is as follows: (1) Medium frequency furnace steel melting: The temperature is controlled between 1600℃ and 1650℃ to ensure that the alloy is completely melted and the composition is uniform.

[0047] (2) Deoxidation and rare earth strengthening in steel ladle: The deoxidizer is made of silicon-calcium alloy and aluminum briquettes, with an addition amount of 0.2% and a rare earth addition amount of 0.15%.

[0048] (3) Centrifugal casting: The mold is preheated to 300-400℃ on the inner wall, coated with quartz powder for 1-2mm, the casting temperature is 1520-1560℃, the centrifugal speed is 800-1000r / min, the casting flow rate is 30-40kg / s, and the center casting method is adopted to ensure uniform filling of molten steel.

[0049] (4) Water cooling: After the casting is air-cooled to 1000℃, water cooling spray is used to cool it down to 400℃ for cupping.

[0050] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A structure for a large vertical reduction tank used in magnesium smelting, characterized in that, It includes a crude magnesium collector (9), a reduction tank body (4), and a central tube (5) installed inside the reduction tank body (4). The top of the reduction tank body (4) is provided with an upper water jacket assembly (a) for opening and sealing the top of the reduction tank body (4), and when sealed, cooling water is connected to cool the top of the reduction tank body (4); The bottom of the reduction tank body (4) is provided with a water jacket assembly (b), which is used to open and seal the bottom of the reduction tank body (4). When sealed, it is used to draw a vacuum inside the tank and connect cooling water to the crude magnesium collector (9) to cool and collect magnesium in a vacuum environment.

2. The structure of the large vertical reduction tank for magnesium smelting according to claim 1, characterized in that, The upper water jacket assembly (a) includes a furnace cover (1), an upper water jacket (2) and a top cover plate (3). The upper water jacket (2) is welded to the top of the reduction tank body (4). The furnace cover (1) is detachably installed on the top of the upper water jacket (2). The top cover plate (3) is located inside the upper water jacket (2) and is detachably connected to the top of the reduction tank body (4).

3. The structure of the large vertical reduction tank for magnesium smelting according to claim 1, characterized in that, The water jacket assembly (b) includes a lower cone (6), a sand tray (7) with small holes, a water jacket (8), and a bottom cover plate (10) arranged sequentially from top to bottom. The lower cone (6) is welded between the body (4) of the reduction tank and the water jacket (8). The bottom cover plate (10) is detachably installed at the bottom of the water jacket (8). The sand tray (7) is detachably connected to the lower cone (6). The coarse magnesium collector (9) is set inside the water jacket (8). The interior of the coarse magnesium collector (9) is connected to the interior of the lower cone (6) through the small holes on the sand tray (7).

4. The structure of the large vertical reduction tank for magnesium smelting according to claim 3, characterized in that, The top of the bottom cover plate (10) is provided with a snap-fit ​​groove (11) that engages with the coarse magnesium collector (9).

5. The structure of the large vertical reduction tank for magnesium smelting according to claim 2, characterized in that, The lower end of one side of the outer wall of the upper water jacket (2) is connected to the first water inlet pipe (201), and the upper end of the other side of the outer wall of the upper water jacket (2) is connected to the first water outlet pipe (202).

6. The structure of the large vertical reduction tank for magnesium smelting according to claim 5, characterized in that, The water jacket (2) includes a carbon steel jacket (203) and a stainless steel jacket (204). The carbon steel jacket (203) is made of carbon steel plate by rolling and welding, and the stainless steel jacket (204) is made of stainless steel plate by rolling and welding. The splicing part of the carbon steel jacket (203) and the stainless steel jacket (204) is connected by double bevel welding. The first water inlet pipe (201) is welded to the stainless steel plate rolling and welding joint, and the first water outlet pipe (202) is welded to the carbon steel plate rolling and welding joint.

7. The structure of the large vertical reduction tank for magnesium smelting according to claim 3, characterized in that, The lower water jacket (8) includes an outer shell (803) and a second water inlet pipe (801), a second water outlet pipe (806), and a vacuum port (807) installed on the outer shell (803). The input end of the vacuum port (807) is connected to the inner cavity of the outer shell (803). The inner shell (805) is provided inside the outer shell (803) and is fitted with a coarse magnesium collector (9). Several ring plates (802) are fixedly connected between the inner shell (805) and the outer shell (803) from top to bottom. The two adjacent ring plates (802) form an annular cavity (808). The output end of the second water inlet pipe (801) is connected to an annular cavity (808) at the top, and the input end of the second water outlet pipe (806) is connected to an annular cavity (808) at the bottom. A partition (809) is sealed to one side of the annular cavity (808). Two adjacent annular cavities (808) are connected by a flow pipe (804). The output end of the second water inlet pipe (801) and the output end of the flow pipe (804) are both located in front of the corresponding partition (809). The input end of the second water outlet pipe (806) is located behind the corresponding partition (809).

8. The structure of the large vertical reduction tank for magnesium smelting according to claim 6, characterized in that, The upper water jacket (2) is provided with a vortex propeller (12). The vortex propeller (12) is detachably installed between the furnace cover (1) and the top cover plate (3). The water flow output from the outlet end of the first water inlet pipe (201) acts on the blades of the vortex propeller (12) to drive the vortex propeller (12) to rotate.

9. A method for manufacturing a large vertical reduction tank structure for magnesium smelting, based on the central tube structure for vertical tank magnesium smelting as described in any one of claims 1-8, characterized in that, include: Step 1: The body (4), central tube (5), and lower cone (6) of the reduction tank are made by casting, and the furnace cover (1), upper water jacket (2), top cover plate (3), sand table (7), lower water jacket (8), crude magnesium collector (9) and bottom cover plate (10) are made by machining. Step 2: Weld the upper water jacket (2), the reduction tank body (4), the lower cone (6) and the lower water jacket (8) together to form a whole. Then, put the central tube (5) into the reduction tank body (4) and put the raw materials for magnesium smelting between them. Then, cover the top cover plate (3) and the furnace cover (1) one after another. Install the sand tray (7) and the lower cone (6). Then, put the crude magnesium collector (9) into the lower water jacket (8) and connect it with the sand tray (7). Finally, cover the bottom cover plate (10) at the bottom of the lower water jacket (8) to complete the assembly.

10. The method for manufacturing the large vertical reduction tank structure for magnesium smelting according to claim 9, characterized in that, The material of the reduction tank body (4) is modified ZG35Cr24Ni7SiN, and its process flow is: medium frequency furnace steel smelting → deoxidation and rare earth strengthening in steel ladle → centrifugal casting → water cooling.

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