A vacuum atmosphere melting furnace for high-purity magnesium and its melting process

Abstract

A vacuum atmosphere melting furnace for high-purity magnesium includes a control mechanism, a support frame and a vertical double-layer shell. A main heating component is arranged inside the vertical double-layer shell, a feed port is provided on the top, a heat shield valve is provided at the feed port, and a vacuum component connection port, an inert gas inlet, an additive inlet and a discharge port are also provided on the top of the vertical double-layer shell, wherein the vacuum component connection port is connected to an external vacuum pumping component, the inert gas inlet is connected to an external inert gas source, and an internal multi-ring stirring component for stirring the internal material is also provided on the vertical double-layer shell. The present invention realizes energy-saving, high-efficiency, high-automation and safe and reliable melting production of magnesium crystals under relatively low melting temperature and atmosphere protection conditions by improving the structure and melting process of conventional melting furnaces, so as to prepare high-purity metallic magnesium liquid for subsequent smelting.

Description

Technical Field

[0001] The invention relates to the technical field of industrial magnesium purification equipment, in particular to a vacuum atmosphere melting furnace for high-purity magnesium and a melting process thereof. Background Art

[0002] Magnesium alloy is a high-performance lightweight structural material made of magnesium. Its specific gravity is similar to that of plastics, and its stiffness and strength are no less than that of aluminum. It has excellent properties such as strong anti-seismic, anti-electromagnetic, thermal conductivity, and electrical conductivity, and it can be fully recycled without pollution. Magnesium alloy is light in weight, with a density of only 1.7 kg / m3, which is 2 / 3 of aluminum and 1 / 4 of steel. Its strength is higher than that of aluminum alloy and steel, and its specific stiffness is close to that of aluminum alloy and steel. It can withstand a certain load, has good castability and dimensional stability, is easy to process, has a low scrap rate, has a good damping coefficient, and has a greater vibration reduction than aluminum alloy and cast iron. It is very suitable for use in automobile production. At the same time, it has a wide range of applications in aerospace, portable computers, mobile phones, electrical appliances, sports equipment and other fields.

[0003] The main disadvantage of ordinary magnesium alloys is their poor corrosion resistance. In certain environments, the functions of magnesium alloys can be easily lost due to corrosion in a short period of time. The main impurity harmful elements in magnesium alloys are Fe, Ni, Cu, Be, Si, Sr, Sb, Sn, etc. The presence of these trace elements directly affects the performance and service life of magnesium alloys.

[0004] Magnesium metal is the matrix of magnesium alloy. The magnesium content in the national standard magnesium metal is 99.92-99.98%, but the national standard measurement method is to only measure the content of some impurities. The main element content of these impurities used for measurement is between 0.0001-0.02%. Then, the total amount of the alloy is subtracted from several measured impurity contents, and the remaining amount is assumed to be the magnesium content. In fact, due to the presence of more harmful impurities in magnesium metal, the actual magnesium content of standard industrial magnesium is less than 99.9%. Magnesium alloys containing harmful impurities are significantly inferior to magnesium alloys prepared from high-purity magnesium metal in all properties. That is, in the preparation process of magnesium alloys, how to first prepare high-purity magnesium metal with higher purity, and then quantitatively add other alloying elements will directly affect the quality and performance of the finished magnesium alloy.

[0005] At present, the containers used for smelting magnesium metal in the prior art mainly include low-carbon steel crucibles and stainless steel containers. These devices usually have the following significant defects when smelting or melting high-purity magnesium metal: 1. Since the existing melting equipment only heats the outside of the equipment, the thermal conductivity is low and the heat loss is large. The low-carbon steel crucible and stainless steel container have poor corrosion resistance at high temperatures, and impurities are easily generated in the container to contaminate the magnesium metal; 2. The melting process of magnesium metal is usually carried out in the air, and magnesium metal at high temperature is very easy to oxidize due to its active chemical properties. In order to prevent the oxidation of magnesium metal, it is necessary to add a covering agent and nitrogen, and the covering agent will also cause secondary pollution; 3. The existing melting equipment has low melting efficiency, resulting in a long preparation process cycle, and the equipment is usually large in size and safety cannot be guaranteed.

[0006] Therefore, how to prepare a vacuum atmosphere melting furnace that can prevent metal magnesium from being oxidized or secondary contamination during the melting process of magnesium crystals, and can effectively control the impurity content in the metal magnesium in the furnace, with a high degree of automation and good safety, is necessary for the production of high-purity magnesium. Summary of the invention

[0007] The technical purpose of the present invention is to improve the structure of a conventional melting furnace and the melting process, so as to achieve energy-saving, high-efficiency, high-automatic, safe and reliable melting production of magnesium crystals under relatively low melting temperature and atmosphere protection conditions, so as to prepare high-purity metallic magnesium liquid for subsequent smelting.

[0008] The technical solution adopted by the present invention to solve the above technical problems is: a vacuum atmosphere melting furnace for high-purity magnesium, comprising a control mechanism, a support frame and a vertical double-layer shell arranged above the support frame, a main heating component is arranged inside the vertical double-layer shell, and the vertical double-layer shell comprises an inner shell and an outer shell, a resistance wire for auxiliary heating is wound on the outer surface of the side wall of the inner shell, and a thermal insulation material is also filled between the inner shell and the outer shell, the main heating component and the resistance wire are both connected to the control mechanism, a feed port is opened on the top of the vertical double-layer shell, the feed port is connected to the discharge port of the process upstream vacuum receiver, and the feed port of the vertical double-layer shell and the discharge port of the vacuum receiver are both provided with vacuum valves for controlling the on and off thereof, and the feed port is located below the vacuum valve. A heat shield valve is also provided at the position, and a vacuum component connection port, an inert gas inlet, an additive inlet and a discharge port are also provided on the top of the vertical double-layer shell, wherein the vacuum component connection port is connected to an external vacuum pumping component, the inert gas inlet is connected to an external inert gas source, and a discharge pipe is provided at the discharge port, one end of the discharge pipe is placed below the metal liquid level inside the vertical double-layer shell, and the other end of the discharge pipe is connected to a vacuum magnesium alloy melting furnace or a forming mold downstream of the process, and an electric control valve and a metering pump are also provided on the discharge pipe, and an internal multi-ring stirring component for stirring the material inside the vertical double-layer shell is also provided on the vertical double-layer shell, and the vacuum valve, heat shield valve, vacuum pumping component, inert gas source, electric control valve, metering pump and internal multi-ring stirring component are all connected to the control mechanism.

[0009] Preferably, the feed port is arranged at the top center of the vertical double-layer shell.

[0010] Preferably, the discharge port is arranged on one side inside the vertical double-layer shell.

[0011] Preferably, the main heating assembly includes a plurality of in-furnace heating tubes vertically arranged inside the inner shell body, the lower ends of the in-furnace heating tubes extend out of the inner shell body to the inner bottom surface of the outer shell body, and are in an open structure, an inverted U-shaped heating element is provided inside each in-furnace heating tube, and a support cover is also provided under each in-furnace heating tube, and a clamping device for fixing the heating element is provided on the support cover.

[0012] Preferably, the in-furnace heating tube is vertically welded on the lower bottom surface of the inner shell, and a plurality of in-furnace heating tubes are evenly arranged inside the inner shell.

[0013] Preferably, the internal multi-ring stirring assembly is composed of a driving motor and a multi-ring agitator, the driving motor is arranged on the top of the vertical double-layer shell and is connected to the control mechanism, the multi-ring agitator is arranged inside the vertical double-layer shell, the multi-ring agitator includes a plurality of horizontal ring groups arranged in parallel up and down and a stirring shaft, each horizontal ring group includes a plurality of concentric rings, and the concentric rings are arranged to avoid the main heating assembly in the vertical double-layer shell, and vertical fixing rods are connected between the upper and lower parallel concentric rings, the upper end of the stirring shaft extends out of the vertical double-layer shell and is connected to the output shaft of the driving motor, and the lower end of the stirring shaft is connected to a horizontal ring group located at the top, and the horizontal ring group located at the top is also radially provided with a plurality of horizontal fixing rods, and the plurality of horizontal fixing rods are welded to the stirring shaft.

[0014] Preferably, the horizontal plane at which the uppermost horizontal ring group in the vertical double-layer shell is located is higher than the horizontal plane at which the top end of the main heating component is located.

[0015] Preferably, the plurality of horizontal fixing rods are an integrated structure, and the plurality of horizontal fixing rods are evenly arranged along the circumference of the circle in which they are located.

[0016] A melting process for a vacuum atmosphere melting furnace of high-purity magnesium comprises the following steps:

[0017] a. The vacuum valve and the heat shield valve at the feed port of the vertical double-layer shell are closed by controlling the control mechanism, and the vacuum pumping component of the external device is controlled to perform vacuum treatment on the inside of the vertical double-layer shell through the vacuum component connection port;

[0018] b. The vacuum valve at the discharge port of the upstream vacuum receiver and the vacuum valve and heat shield valve at the feed port of the vertical double-layer shell are opened by the control mechanism, so that the high-purity magnesium metal crystals in the vacuum receiver automatically fall into the vertical double-layer shell;

[0019] c. The vacuum valve at the discharge port of the upstream vacuum receiver and the vacuum valve and heat shield valve at the feed port of the vertical double-layer shell are closed by the control mechanism, and the external inert gas source is regulated to fill the interior of the vertical double-layer shell with inert gas through the inert gas inlet until the pressure inside the vertical double-layer shell is 0.1MPa;

[0020] d. The material in the vertical double-layer shell is heated by regulating the main heating component and the resistance wire through the control mechanism, so that the temperature in the vertical double-layer shell is increased to 700-780°C, so that the high-purity magnesium metal crystals are melted;

[0021] e. The internal multi-ring stirring assembly is regulated by the control mechanism to stir the materials for 3-5 minutes;

[0022] f. By controlling the electric control valve and metering pump through the control mechanism, the liquid magnesium sample is extracted from the vertical double-layer shell for testing, and whether it meets the requirements of high-purity magnesium is detected. If it meets the requirements, the electric control valve and metering pump are controlled to open, and the magnesium liquid is extracted through the discharge pipe to the vacuum magnesium alloy melting furnace or forming mold downstream of the process for subsequent processing;

[0023] g. If it does not meet the requirements, the control mechanism is used to add appropriate additives into the vertical double-layer shell through the additive inlet, and the internal multi-ring stirring component is controlled to stir the material, so that the additive reacts with the excessive elements and precipitates at the bottom of the furnace. The internal multi-ring stirring component is controlled to be closed, and the material in the vertical double-layer shell is kept still for 5-10 minutes. After that, the control mechanism is used to control the electric control valve and the metering pump to open, and the magnesium liquid is pumped out through the discharge pipe to the vacuum magnesium alloy melting furnace or forming mold downstream of the process for subsequent processing.

[0024] Beneficial effects of the present invention:

[0025] 1. A vacuum atmosphere melting furnace for high-purity magnesium of the present invention realizes efficient and rapid heating of the material in the furnace body by respectively arranging a main heating component and an auxiliary heating resistance wire with a material heating function inside and outside the inner shell. The entire heating process not only has high heat transfer efficiency and heating efficiency, but also has low heat loss, has significant energy-saving effect, and reduces the production cost of the melting process. More importantly, due to the high heat transfer efficiency of the entire furnace body, the inside and outside of the furnace body do not need to withstand a high temperature much higher than the melting temperature in order to reach the melting temperature of the internal material, thereby avoiding its own corrosion under high temperature conditions and contamination of the metal magnesium crystal, thereby ensuring the high purity of the magnesium crystal during the melting process.

[0026] 2. The vacuum atmosphere melting furnace for high-purity magnesium of the present invention can detect and regulate the impurity content of the metallic magnesium liquid inside the furnace body during the melting process of crystalline magnesium through the arrangement of the additive inlet, discharge pipe, metering pump and electric control valve in the device, so that it meets the purity requirements of subsequent processes, has strong operability, and good safety and reliability.

[0027] 3. The vacuum atmosphere melting furnace for high-purity magnesium of the present invention can homogenize the metal materials in the furnace better during the melting of crystalline magnesium through the arrangement of the internal multi-ring stirring assembly with a unique structure, which can ensure the uniformity of the quality of the finished metal magnesium, and after the addition of additives, the additives can fully contact and react with the impurities in the metal magnesium, and is conducive to the precipitation of the reaction products, thereby greatly improving the purity of the finished metal magnesium liquid after melting to a certain extent.

[0028] 4. The melting process of the present invention has simple steps, convenient control and high degree of automation. The operation steps of first evacuating the melting furnace and then protecting it with an inert gas atmosphere not only ensure that the entire melting process can prevent the metal magnesium from being oxidized or contaminated by impurities, but also realize the pollution-free connection between the melting furnace and the entire upstream and downstream equipment, thereby fundamentally ensuring the purity of the finished magnesium metal. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the present invention;

[0030] Figure 2 It is a schematic cross-sectional view of the interior of the neutral double-layer shell of the present invention;

[0031] Figure 3 It is a structural schematic diagram of a multi-ring agitator;

[0032] Figure numerals: 1. Support frame, 2. Inner shell, 3. Outer shell, 4. Resistance wire, 5. Insulation material, 6. Feed inlet, 7. Vacuum receiver, 8. Vacuum valve, 9. Heat shield valve, 10. Vacuum component connection port, 11. Inert gas inlet, 12. Additive inlet, 13. Vacuum assembly, 14. Inert gas source, 15. Discharge pipe, 16. Electric control valve, 17. Metering pump, 18. Furnace heating tube, 19. Heating element, 20. Support cover, 21. Drive motor, 22. Stirring shaft, 23. Concentric rings, 24. Vertical fixing rod, 25. Horizontal fixing rod. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below in conjunction with the accompanying drawings:

[0034] As shown in the figure, a vacuum atmosphere melting furnace for high-purity magnesium includes a control mechanism, a support frame 1 and a vertical double-layer shell arranged above the support frame 1, a main heating component is arranged inside the vertical double-layer shell, and the vertical double-layer shell includes an inner shell 2 and an outer shell 3. A resistance wire 4 for auxiliary heating is wound on the outer surface of the side wall of the inner shell 2, and a thermal insulation material 5 is also filled between the inner shell 2 and the outer shell 3. The main heating component and the resistance wire 4 are both connected to the control mechanism, and a feed port 6 is opened on the top of the vertical double-layer shell. The feed port 6 is arranged at the top center of the vertical double-layer shell, and the feed port 6 is connected to the discharge port of the process upstream vacuum receiver 7, and the feed port 6 of the vertical double-layer shell and the discharge port of the vacuum receiver 7 are both provided with a vacuum valve 8 for controlling the on and off thereof, and a heat shield valve 9 is also provided at the position below the vacuum valve 8 at the feed port 6. The top of the layer shell is also provided with a vacuum component connection port 10, an inert gas inlet 11, an additive inlet 12 and a discharge port, wherein the vacuum component connection port 10 is connected to an external vacuum pumping component 13, the inert gas inlet 11 is connected to an external inert gas source 14, the discharge port is arranged on one side inside the vertical double-layer shell, and a discharge pipe 15 is arranged at the discharge port, one end of the discharge pipe 15 is placed below the metal liquid level inside the vertical double-layer shell, and the other end of the discharge pipe 15 is connected to a vacuum magnesium alloy melting furnace or a forming mold downstream of the process, and an electric control valve 16 and a metering pump 17 are also arranged on the discharge pipe 15, and an internal multi-ring stirring component for stirring the internal material is also arranged on the vertical double-layer shell, and the vacuum valve 8, heat shielding valve 9, vacuum pumping component 13, inert gas source 14, electric control valve 16, metering pump 17 and internal multi-ring stirring component are all connected to the control mechanism.

[0035] The main heating assembly includes a plurality of furnace heating tubes 18 vertically arranged inside the inner shell 2, the lower end of the furnace heating tube 18 extends from the inner shell 2 to the inner bottom surface of the outer shell 3, and is in an open structure. The furnace heating tube 18 is vertically welded to the lower bottom surface of the inner shell 2, and the plurality of furnace heating tubes 18 are evenly arranged inside the inner shell 2, as shown in the attached Figure 2 Each furnace heating tube 18 is provided with an inverted U-shaped heating element 19 inside, and a support cover 20 is provided below each furnace heating tube 18 , and a clamping device for fixing the heating element 19 is provided on the support cover 20 .

[0036] Preferably, the internal multi-ring stirring assembly is composed of a driving motor 21 and a multi-ring stirrer, the driving motor 21 is arranged on the top of the vertical double-layer shell and is connected to the control mechanism, the multi-ring stirrer is arranged inside the vertical double-layer shell, the multi-ring stirrer includes a plurality of horizontal ring groups arranged in parallel up and down and a stirring shaft 22, each horizontal ring group includes a plurality of concentric rings 23, and the concentric rings 23 are all arranged away from the main heating assembly in the vertical double-layer shell, and a vertical fixing rod 24 is also connected between the concentric rings 23 parallel to each other. The upper end of the shaft 22 extends out of a vertical double-layer shell and is connected to the output shaft of the drive motor 21. The lower end of the stirring shaft 22 is connected to a horizontal ring group located at the top. The horizontal ring group located at the top is also radially provided with multiple horizontal fixing rods 25. The multiple horizontal fixing rods 25 are an integrated structure, and the multiple horizontal fixing rods 25 are evenly arranged along the circumference of the circle in which they are located. The multiple horizontal fixing rods 25 are all welded to the stirring shaft 22. The horizontal plane of the horizontal ring group located at the top in the vertical double-layer shell is higher than the horizontal plane of the top of the main heating component.

[0037] When the heating tube in the vacuum atmosphere melting furnace for high-purity magnesium of the present invention is damaged, the following method can be used for corresponding maintenance. First, remove the clamping device on the support cover, and then open the mounting flange (i.e., the support cover) at the bottom of the heating tube in the furnace. At this time, the damaged heating element can be taken out from the heating tube in the furnace for corresponding replacement and maintenance. After the maintenance is completed, the mounting flange at the bottom of the heating tube in the furnace is fixed in sequence, and the bottom end of the heating element (U-shaped silicon carbon rod) is fixed on the mounting flange through the clamping device.

[0038] The components in the vertical double-layer shell of the present invention are all made of stainless steel, the heating tube is also made of stainless steel, the upper part of the stainless steel tube is a blind head, and the lower part is welded to the bottom of the vacuum furnace body, the U silicon carbon rod heating element is inserted into the furnace tank from bottom to top, and the cold end of the heating element is provided with a supporting cover-shaped baffle.

[0039] The vacuum atmosphere melting furnace for high-purity magnesium of the present invention has the following characteristics: 1. By opening two vacuum valves on the upper part of the vertical double-layer shell, the metal magnesium crystals collected by the vacuum receiver can be automatically dropped into the vertical double-layer shell made of stainless steel; 2. Before heating, the vacuum atmosphere melting furnace can first close the vacuum valve connected to the vacuum receiver on the upper part of the furnace body, introduce inert gas, and then heat and melt the high-purity magnesium, which is beneficial to reduce the volatilization of magnesium vapor, reduce unnecessary losses, and avoid oxidation of high-purity metal magnesium; 3. Closing the two vacuum valves on the top of the vertical double-layer shell can prevent the inert gas from entering the vacuum receiver, causing waste ; 4. Closing the heat-shielding valve on the top of the vertical double-layer shell can not only avoid the loss of heat in the furnace, but also prevent the heat in the furnace from entering the vacuum receiver upstream of the process, causing the magnesium crystals in the vacuum receiver to melt and cause adhesion on the inner wall of the vacuum receiver; 5. After the magnesium crystals are melted, the magnesium liquid can be transported to the vacuum atmosphere mixing furnace in the subsequent process through a metering pump, or it can be directly transported to the magnesium product mold for molding; 6. The salient feature of the heating component is dual-system heating, that is, the furnace heating system formed by inserting the U-shaped heating element into the furnace tube is the main one, and the electric furnace wire set on the inner surface of the insulation material around the furnace tank is the auxiliary one for coordinated heating. The heating furnace tube is inserted into the furnace tank to heat the material. The heat emitted by the heating element is directly transferred to the material through the furnace tube, which improves the thermal efficiency and achieves energy saving. 7. The internal heating method using the heating tube inserted into the furnace body is conducive to improving the heating efficiency, achieving energy saving, shortening the processing cycle, and reducing the production cost of the melting process. At the same time, the high heat transfer efficiency also makes it unnecessary for the inside and outside of the furnace body to withstand a high temperature much higher than the melting temperature in order to reach the melting temperature of the internal material, thereby avoiding its own corrosion under high temperature conditions and contamination of the metal magnesium crystals, thereby ensuring the high purity of the magnesium crystals during the melting process.

[0040] A melting process for a vacuum atmosphere melting furnace of high-purity magnesium comprises the following steps:

[0041] a. The vacuum valve 8 and the heat shield valve 9 at the feed port 6 of the vertical double-layer shell are closed by controlling the control mechanism, and the external vacuum pumping component 13 is controlled to vacuum the inside of the vertical double-layer shell through the vacuum component connection port 10;

[0042] b. The vacuum valve 8 at the discharge port of the upstream vacuum receiver 7 and the vacuum valve 8 and the heat shield valve 9 at the feed port 6 of the vertical double-layer shell are opened by the control mechanism, so that the high-purity magnesium metal crystals in the vacuum receiver 7 automatically fall into the vertical double-layer shell;

[0043] c. The control mechanism is used to control the vacuum valve 8 at the discharge port of the upstream vacuum receiver 7 and the vacuum valve 8 and the heat shielding valve 9 at the feed port 6 of the vertical double-layer shell to be closed, and the external inert gas source 14 is controlled to fill the interior of the vertical double-layer shell with inert gas through the inert gas inlet 11 until the pressure inside the vertical double-layer shell is 0.1 MPa;

[0044] d. The material in the vertical double-layer shell is heated by regulating the main heating assembly and the resistance wire 4 through the control mechanism, so that the temperature in the vertical double-layer shell is increased to 700-780 ℃, so that the high-purity magnesium metal crystals melt;

[0045] e. The internal multi-ring stirring assembly is regulated by the control mechanism to stir the materials for 3-5 minutes;

[0046] f. The control mechanism controls the electric control valve 16 and the metering pump 17 to extract the liquid magnesium sample from the vertical double-layer shell for testing and to detect whether it meets the requirements of high-purity magnesium. If it meets the requirements, the electric control valve 16 and the metering pump 17 are controlled to open, and the magnesium liquid is extracted through the discharge pipe 15 to the vacuum magnesium alloy melting furnace or the forming mold downstream of the process for subsequent processing;

[0047] g. If it does not meet the requirements, the control mechanism is used to add appropriate additives into the vertical double-layer shell through the additive inlet 12, and the internal multi-ring stirring component is regulated to stir the materials, so that the additives react with the excessive elements and precipitate at the bottom of the furnace. The internal multi-ring stirring component is regulated to be closed, and the materials in the vertical double-layer shell are kept standing for 5-10 minutes. After that, the control mechanism is used to control the electric control valve 16 and the metering pump 17 to open, and the magnesium liquid is extracted through the discharge pipe 15 to the vacuum magnesium alloy melting furnace or forming mold downstream of the process for subsequent processing.

[0048] The additive added in the process of the present invention is a trace element additive, and the trace element additive needs to be preheated before being added through the additive inlet, and the preheating temperature is 200±20°C.

[0049] The various pumps and valves described are all electronically controlled components and can be automatically controlled by a PLC-type control mechanism.

Claims

1. A process for melting magnesium metal using a vacuum atmosphere melting furnace, wherein the melting is performed using a vacuum atmosphere melting furnace, the vacuum atmosphere melting furnace comprising a control mechanism, a support frame (1) and a vertical double-layer shell arranged above the support frame (1), a main heating component is arranged inside the vertical double-layer shell, the vertical double-layer shell comprises an inner shell (2) and an outer shell (3), a resistance wire (4) for auxiliary heating is wound around the outer surface of the side wall of the inner shell (2), and a heat-insulating material (5) is filled between the inner shell (2) and the outer shell (3), the main heating component and the resistance wire (4) are both connected to the control mechanism, and the invention is characterized in that: A feed port (6) is provided at the top of the vertical double-layer shell, and the feed port (6) is connected to a discharge port of a process upstream vacuum receiver (7). A vacuum valve (8) for controlling the on-off of the feed port (6) of the vertical double-layer shell and the discharge port of the vacuum receiver (7) are provided. A heat shielding valve (9) is provided at a position below the vacuum valve (8) at the feed port (6). A vacuum component connection port (10), an inert gas inlet (11), an additive inlet (12) and a discharge port are also provided at the top of the vertical double-layer shell, wherein the vacuum component connection port (10) is connected to an external vacuum pumping component (13), and the inert gas inlet (11) is connected to an external inert gas inlet (12). A gas source (14) is connected to the vertical double-layer shell, a discharge pipe (15) is arranged at the discharge port, one end of the discharge pipe (15) is placed below the metal liquid level inside the vertical double-layer shell, and the other end of the discharge pipe (15) is connected to the vacuum magnesium alloy melting furnace or the forming mold downstream of the process, and the discharge pipe (15) is also provided with an electric control valve (16) and a metering pump (17), and an internal multi-ring stirring component for stirring the material inside the vertical double-layer shell is also provided on the vertical double-layer shell, and the vacuum valve (8), the heat shield valve (9), the vacuum pump component (13), the inert gas source (14), the electric control valve (16), the metering pump (17) and the internal multi-ring stirring component are all connected to the control mechanism; The main heating assembly comprises a plurality of furnace heating tubes (18) vertically arranged inside the inner shell (2), the lower ends of the furnace heating tubes (18) extending from the inner shell (2) to the inner bottom surface of the outer shell (3) and presenting an open structure, an inverted U-shaped heating element (19) being arranged inside each furnace heating tube (18), and a support cover (20) being arranged below each furnace heating tube (18), the support cover (20) being provided with a clamping device for fixing the heating element (19); The internal multi-ring stirring assembly is composed of a driving motor (21) and a multi-ring stirrer. The driving motor (21) is arranged on the top of the vertical double-layer shell and is connected to the control mechanism. The multi-ring stirrer is arranged inside the vertical double-layer shell. The multi-ring stirrer includes a plurality of horizontal ring groups arranged in parallel up and down and a stirring shaft (22). Each horizontal ring group includes a plurality of concentric circular rings (23). The concentric circular rings (23) are arranged away from the main heating assembly in the vertical double-layer shell. A vertical fixing rod (24) is also connected between the concentric circular rings (23) parallel to each other. The upper end of the stirring shaft (22) extends out of the vertical double-layer shell and is connected to the output shaft of the driving motor (21). The lower end of the stirring shaft (22) is connected to a horizontal ring group located at the top. The horizontal ring group located at the top is also radially provided with a plurality of horizontal fixing rods (25). The plurality of horizontal fixing rods (25) are all welded to the stirring shaft (22). The melting process specifically includes the following steps: a. The vacuum valve (8) and the heat shield valve (9) at the feed port (6) of the vertical double-layer shell are closed by controlling the control mechanism, and the vacuum pumping component (13) of the external device is controlled to perform vacuum pumping on the interior of the vertical double-layer shell through the vacuum component connection port (10); b. The vacuum valve (8) at the discharge port of the process upstream vacuum receiver (7) and the vacuum valve (8) and the heat shield valve (9) at the feed port (6) of the vertical double-layer shell are opened by the control mechanism, so that the high-purity magnesium metal crystals in the vacuum receiver (7) automatically fall into the vertical double-layer shell; c. The vacuum valve (8) at the discharge port of the process upstream vacuum receiver (7) and the vacuum valve (8) and the heat shield valve (9) at the feed port (6) of the vertical double-layer shell are closed by the control mechanism, and the inert gas source (14) of the external device is controlled to fill the interior of the vertical double-layer shell with inert gas through the inert gas inlet (11) until the pressure inside the vertical double-layer shell is 0.1 MPa; d. The material in the vertical double-layer shell is heated by regulating the main heating component and the resistance wire (4) through the control mechanism, so that the temperature in the vertical double-layer shell is increased to 700-780°C, so that the high-purity magnesium metal crystals are melted; e. The internal multi-ring stirring assembly is regulated by the control mechanism to stir the material for 3-5 minutes; f. By controlling the electric control valve (16) and the metering pump (17) through the control mechanism, a liquid magnesium sample is extracted from the vertical double-layer shell for testing, and whether it meets the requirements of high-purity magnesium is detected. If it meets the requirements, the electric control valve (16) and the metering pump (17) are controlled to open, and the magnesium liquid is extracted through the discharge pipe (15) to the vacuum magnesium alloy melting furnace or the forming mold downstream of the process for subsequent processing; g. If the requirements are not met, the control mechanism is used to add a suitable additive into the vertical double-layer shell through the additive inlet (12), and the internal multi-ring stirring component is controlled to stir the material so that the additive reacts with the excessive elements and precipitates at the bottom of the furnace. The internal multi-ring stirring component is controlled to be closed, and the material in the vertical double-layer shell is kept still for 5-10 minutes. Thereafter, the control mechanism is used to control the opening of the electric control valve (16) and the metering pump (17), and the magnesium liquid is pumped out through the discharge pipe (15) to the vacuum magnesium alloy melting furnace or forming mold downstream of the process for subsequent processing.

2. The process for melting magnesium metal using a vacuum atmosphere melting furnace according to claim 1, characterized in that: The feed port (6) is arranged at the top center of the vertical double-layer shell.

3. The process for melting metal magnesium using a vacuum atmosphere melting furnace according to claim 1, characterized in that: The discharge port is arranged on one side inside the vertical double-layer shell.

4. The process for melting magnesium metal using a vacuum atmosphere melting furnace according to claim 1, characterized in that: The in-furnace heating pipe (18) is vertically welded to the lower bottom surface of the inner shell (2), and a plurality of in-furnace heating pipes (18) are evenly arranged inside the inner shell (2).

5. The process for melting magnesium metal using a vacuum atmosphere melting furnace according to claim 1, characterized in that: The horizontal plane where the uppermost horizontal ring group in the vertical double-layer shell is located is higher than the horizontal plane where the top end of the main heating component is located.

6. The process for melting magnesium metal using a vacuum atmosphere melting furnace according to claim 1, characterized in that: The multiple horizontal fixing rods (25) are an integrated structure, and the multiple horizontal fixing rods (25) are evenly arranged along the circumference of the circle in which they are located.

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