Device and method for condensing and collecting magnesium-argon mixed steam under vacuum condition

Abstract

The invention discloses a device and a method for condensing and collecting magnesium-argon mixed steam under a vacuum condition, and the device comprises a first-stage liquid condensing device, a second-stage solid crystallizing device, a third-stage heat exchanger, a collecting crucible, a vacuum pump set and a waste heat boiler, the first-stage liquid condensation device, the second-stage solid crystallization device and the third-stage heat exchanger are of a shell-and-tube structure and are sequentially communicated, a first-stage condenser heat preservation layer is arranged on the first-stage liquid condensation device, and a first-stage condensation pipe is arranged in the first-stage liquid condensation device; a second-stage crystallizer insulating layer is arranged on the second-stage solid crystallization device, and a second-stage crystallization pipe is arranged in the second-stage solid crystallization device; a third-stage cooling pipe is arranged in the third-stage heat exchanger; the collecting crucible is arranged below the primary liquid condensing device and is used for recovering liquid magnesium; the vacuum pump set is used for controlling vacuum degree; the waste heat boiler is used for recycling waste heat of the first-stage liquid condensing device and the second-stage solid crystallizing device. The invention aims to provide an efficient condensation and collection process designed for vacuum and argon-containing magnesium steam working conditions.

Description

Technical Field

[0001] This invention relates to the field of vacuum liquid injection low-carbon magnesium smelting technology, and more specifically, to a device and method for collecting magnesium-argon mixed vapor under vacuum conditions. Background Technology

[0002] Magnesium, as the lightest metallic structural material, possesses irreplaceable strategic value in aerospace, defense, rail transportation, 3C products, biomedicine, and hydrogen storage materials due to its excellent specific strength, specific stiffness, damping and vibration reduction properties, electromagnetic shielding, and biocompatibility. The global magnesium industry has undergone decades of development, forming a technology route primarily based on thermal reduction. Among these, the Pidgeon process has become the mainstream production process due to its simplicity and lower investment. However, this process has inherent flaws that severely restrict the modernization and large-scale development of the magnesium industry.

[0003] The Pidgeon process is a typical externally heated, solid-phase reaction, batch production process. Its basic principle is to mix calcined white (MgO·CaO), ferrosilicon reducing agent and co-solvent to form pellets, and carry out the reduction reaction in a heat-resistant steel reduction tank under high temperature (1150-1200℃) and high vacuum (<13 Pa) conditions to generate magnesium vapor, which is collected by condensation on the inner wall of the condenser at the tail end of the tank. This process has the following fundamental bottlenecks: (1) Low reaction efficiency: The solid-phase reaction is limited by the contact area between particles, and the heat needs to be conducted from the outside to the inside through the tank wall. The heat and mass transfer efficiency is extremely low, resulting in a single tank reaction cycle of 10-12 hours and a single tank capacity of only 20-50 kg. (2) Poor product morphology: The obtained solid crystalline magnesium has a loose dendritic structure, low bulk density and large volume. Frequent (about every 8-10 hours) shutdowns and vacuum breaking are required for manual cleaning. Continuous and automated production cannot be achieved, resulting in high labor intensity and high safety hazards. (3) Serious energy waste: The high temperature required for the reaction is provided by external gas or electric heating, which consumes a huge amount of energy. At the same time, the latent heat released by the condensation of magnesium vapor (about 5400 kJ / kg) is directly discharged through the water-cooled crystallizer and cannot be effectively recovered. This part of the low-temperature waste heat (<80℃) has a low grade and poor economic efficiency for recovery and utilization, resulting in huge energy waste.

[0004] To overcome the intermittent production bottleneck of the Pidgeon process, improved technologies aimed at achieving semi-continuous or continuous production have been developed internationally, such as the Magnetherm process in France and the MTMP process in South Africa. These processes utilize large electric furnaces, achieving capacities of over 1 ton of magnesium per hour, and attempt to primarily collect liquid magnesium. The Magnetherm process operates at relatively low vacuum levels (5000-10000 Pa) and reaction temperatures of 1550-1600℃, employing a composite condenser of "first-stage liquid condensation + second-stage solid crystallization." However, its liquid collection rate is only about 80%, and residual magnesium vapor still forms solid magnesium, requiring shutdowns every 12-24 hours for cleaning, affecting continuity. More importantly, while lowering the vacuum promotes liquid condensation, it forces a significant increase in reaction temperature, leading to a surge in energy consumption, accelerated erosion of refractory materials inside the furnace, and the unrecovered latent heat of condensation (approximately 1800 kW of heat load per ton of magnesium per hour). The MTMP process goes a step further, operating at atmospheric pressure and higher temperatures of 1700-1750℃, specifically designed for liquid magnesium collection. However, atmospheric pressure operation leads to excessively high reduction temperatures, making energy consumption and impurity volatilization issues more prominent, and its condensation system cannot adapt to operating conditions containing non-condensable gases.

[0005] In recent years, in order to balance energy consumption and reaction conditions, the new generation of magnesium smelting processes (such as vacuum blowing) have adopted a more balanced process window: operating at a medium vacuum (about 2000 Pa) and a low reaction temperature (about 1450 °C). However, such processes require the introduction of argon as a carrier gas to transport powdered raw materials, resulting in 5-10% volume fraction of argon mixed in the produced magnesium vapor. This change brings new technical challenges: (1) Non-condensable gas effect: As a non-condensable gas, argon will continue to accumulate at the condensation interface during the condensation process, forming a gas film thermal resistance barrier, which seriously hinders the heat and mass transfer process of magnesium vapor, resulting in a significant reduction in condensation efficiency. (2) High gas velocity and short residence time: At a vacuum of 2000 Pa, the gas volume expands rapidly, resulting in extremely high vapor velocity in the pipe (up to 20 m / s or more). The traditional condenser structure that relies on simple wall heat dissipation cannot provide sufficient effective heat exchange area and necessary vapor residence time, so that most of the magnesium vapor is carried out by the high-speed gas flow before it can be condensed.

[0006] Therefore, existing magnesium vapor condensation technologies, whether the traditional Pidgeon process or the subsequent semi-continuous / continuous processes, generally reveal the following core technical problems that urgently need to be solved when facing the new generation of medium vacuum and argon-containing carrier gas process conditions: (1) The severe inhibitory effect of non-condensable gas (argon) on the condensation process cannot be effectively overcome, resulting in low condensation efficiency even under the most energy-efficient process window.

[0007] (2) Traditional condenser structures cannot adapt to the high gas flow rate conditions generated under vacuum conditions, resulting in insufficient heat exchange area and short effective condensation time, which limits the further improvement of equipment capacity.

[0008] (3) The huge amount of latent heat of phase change released during the condensation process has not been effectively recovered and utilized, and the problem of energy waste has become particularly prominent in large-scale continuous production.

[0009] (4) For the residual magnesium vapor that fails to liquefy, the solid crystalline magnesium formed therefrom still restricts the continuity and automation level of production, becoming the last obstacle to achieving continuous production throughout the entire process.

[0010] To address the aforementioned problems, there is an urgent need for a novel, highly efficient condensation and collection system and process specifically designed for vacuum and argon-magnesium vapor conditions. Summary of the Invention

[0011] In view of the above problems, the purpose of the present invention is to provide a device and method for condensing and collecting magnesium-argon mixed vapor under vacuum conditions, so as to solve at least one technical problem existing in the prior art.

[0012] In a first aspect, the present invention provides a magnesium-argon mixed vapor condensation and collection device for use under vacuum conditions, comprising: a primary liquid condensation device, a secondary solid crystallization device, a tertiary heat exchanger, a collection crucible, a vacuum pump group and a waste heat boiler, wherein the primary liquid condensation device, the secondary solid crystallization device and the tertiary heat exchanger are shell-and-tube structures and are connected in sequence. A primary condenser insulation layer for preheating is provided on the primary liquid condensation device, and a primary condenser tube is provided inside the primary liquid condensation device. The primary condenser tube is used to condense high-temperature magnesium-argon mixed vapor to form liquid magnesium. A secondary crystallizer insulation layer for preheating is provided on the secondary solid crystallizer, and a secondary crystallization tube is provided inside the secondary solid crystallizer. The secondary crystallization tube is used to crystallize the magnesium-argon mixed vapor after the primary liquid condensation device to form solid magnesium. A three-stage cooling pipe is installed inside the three-stage heat exchanger. The three-stage cooling pipe is used to cool the argon gas after it has been processed by the two-stage solid crystallization device, and at the same time, to crystallize trace amounts of potassium and sodium vapor. The collecting crucible is located below the primary liquid condensation device and is used to collect the liquid magnesium formed by the condensation of the primary condenser tube; The vacuum pump unit is connected to the three-stage heat exchanger and is used to control the vacuum level of the magnesium-argon mixed vapor condensation and collection device. The waste heat boiler is connected to the cooling systems of the primary liquid condensation device and the secondary solid crystallization device, respectively, and is used to recover the waste heat of the primary liquid condensation device and the secondary solid crystallization device.

[0013] Alternatively, a mixed vapor inlet may be provided on the upper side of one side of the primary liquid condensation device, and a first vapor channel for connecting to the secondary solid crystallization device may be provided on the lower side of the other side of the primary liquid condensation device.

[0014] Alternatively, an alternative is to provide a primary preheating gas inlet communicating with the insulation layer of the primary condenser at the lower end of one side of the primary liquid condensation device, and a primary preheating gas outlet communicating with the insulation layer of the primary condenser at the upper end of the other side of the primary liquid condensation device.

[0015] Alternatively, an alternative is to provide a primary cooling medium inlet at the top of the primary liquid condensation device, which communicates with one end of the primary condenser tube, and a primary cooling medium outlet, which communicates with the other end of the primary condenser tube; and the primary cooling medium outlet is connected to a waste heat recovery pipeline.

[0016] Alternatively, an optional solution is to provide a heat-insulating layer on the collecting crucible, which is used to preheat the collecting crucible; wherein, A crucible preheating gas inlet communicating with the insulation layer of the crucible is provided at one end of the collecting crucible, and a crucible preheating gas outlet communicating with the insulation layer of the collecting crucible is provided at the other end of the collecting crucible.

[0017] Alternatively, a secondary preheating gas inlet communicating with the secondary crystallization insulation layer is provided at the upper end of one side of the secondary solid crystallization device, a secondary preheating gas outlet communicating with the secondary crystallization insulation layer is provided at the lower end of the other side of the secondary solid crystallization device, and a second steam channel communicating with the tertiary heat exchanger is provided at the upper end of the other side of the secondary solid crystallization device.

[0018] Alternatively, a secondary cooling medium inlet connected to one end of the secondary crystallization tube is provided at the top of the secondary solid crystallization device, and a secondary cooling medium outlet connected to the other end of the secondary crystallization tube is provided at the bottom of the secondary solid crystallization device; and the secondary cooling medium outlet is connected to a waste heat recovery pipeline.

[0019] Alternatively, a third-stage cooling medium inlet connected to one end of the third-stage cooling pipe is provided at the bottom of one side of the third-stage heat exchanger, and a third-stage cooling medium outlet connected to the other end of the third-stage cooling pipe is provided at the top of the other side of the third-stage heat exchanger. A gas outlet for the third-stage heat exchanger, which is connected to the vacuum pump unit, is provided at the bottom of the other side of the third-stage heat exchanger.

[0020] Secondly, the present invention provides a method for condensing and collecting magnesium-argon mixed vapor under vacuum conditions, wherein the magnesium-argon mixed vapor is condensed and collected using the aforementioned magnesium-argon mixed vapor condensation and collection device under vacuum conditions, and the method includes: S1: Preheating gas is introduced into the insulation layer of the first-stage condenser, the insulation layer of the collecting crucible, and the insulation layer of the second-stage crystallizer to preheat the first-stage liquid condensation device, the collecting crucible, and the second-stage solid crystallization device. S2: Cooling gas is introduced into the first-stage condenser and the second-stage crystallizer to cool the first-stage liquid condenser and the second-stage solid crystallizer, respectively, while cooling water is introduced into the third-stage cooling pipe to cool the third-stage heat exchanger. S3: The pressure difference of the condensation collection device is controlled within a preset range by the vacuum pump unit; S4: The magnesium-argon mixed vapor is introduced into the first-stage liquid condenser for first-stage condensation, and the liquid magnesium formed by condensation is dripped into the collection crucible; S5: The mixed vapor that has undergone primary condensation treatment flows into the secondary solid crystallization device for secondary crystallization treatment and generates solid magnesium; S6: The mixed vapor that has undergone secondary crystallization is fed into the tertiary heat exchanger for heat exchange treatment to generate solid potassium and sodium.

[0021] Alternatively, in S1, during the preheating process, the preheating temperature of the primary liquid condensation device is 680-700℃; the preheating temperature of the collecting crucible is 700±5℃; and the preheating temperature of the secondary solid crystallization device is 680-700℃.

[0022] Alternatively, in S2, the cooling gas passing through the primary condenser and the secondary crystallizer flows into the waste heat boiler to provide waste heat for the waste heat boiler.

[0023] Alternatively, in S4, during the first-stage condensation process, the temperature of the first-stage liquid condensation device is 650-700°C. In S5, during the secondary crystallization process, the temperature of the secondary solid crystallization device is 400-470℃; In S6, during the three-stage heat exchange process, the temperature of the three-stage heat exchanger is 50±5℃.

[0024] As can be seen from the above technical solution, the magnesium-argon mixed vapor condensation and collection device and method provided by the present invention, compared with the prior art, have the following beneficial effects: (1) The condensation structure adopted in this invention (the first-stage condenser tube set inside the first-stage liquid condensation device, the second-stage crystallization tube set inside the second-stage solid crystallization device, and the third-stage cooling tube set in the third-stage heat exchanger) can effectively overcome the inhibitory effect of non-condensable gases (such as argon) on the condensation process. That is, by increasing the specific surface area and inducing turbulence, the inhibitory effect of argon gas film on heat and mass transfer is effectively overcome, and the condensation efficiency and stability under the condition of argon-magnesium vapor are significantly improved.

[0025] (2) The present invention adopts a preheating system, namely: a first-stage condenser insulation layer for preheating is provided on the first-stage liquid condensation device, a second-stage crystallizer insulation layer for preheating is provided on the second-stage solid crystallization device, and a collection crucible insulation layer is provided on the collection crucible, which ensures that the entire process from start-up to stable operation is carried out at a safe and efficient temperature, avoiding local overcooling and magnesium powder generation.

[0026] (3) The present invention adopts a high-efficiency waste heat recovery device, which connects the cooling circuits of the first-stage liquid condensation device and the second-stage solid crystallization device with the waste heat boiler, thereby realizing the centralized and efficient recovery of the latent heat of condensation at medium and high temperatures.

[0027] (4) The above method of the present invention can realize online, continuous and automated processing of solid crystalline magnesium, avoid blockage of channels, reduce or eliminate unplanned downtime, and ensure that the system can operate in a long-term, stable, continuous and safe manner, laying the foundation for realizing fully automated magnesium smelting.

[0028] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to encompass all such aspects and their equivalents. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of a magnesium-argon mixed vapor condensation and collection device under vacuum conditions according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the logic structure of a magnesium-argon mixed vapor condensation and collection device under vacuum conditions according to an embodiment of the present invention. Figure 3 This is a schematic diagram of a method for collecting magnesium-argon mixed vapor under vacuum conditions according to an embodiment of the present invention.

[0031] The attached figures are labeled as follows: 1. Primary liquid condenser; 101. Mixed steam inlet; 102. First steam passage; 103. Insulation material; 104. Primary cooling medium inlet; 105. Primary cooling medium outlet; 106. Primary condenser tube; 107. Primary preheating gas inlet; 108. Primary preheating gas outlet; 109. Primary condenser insulation layer; 110. Insulation material; 111. Collection crucible; 112. Crucible preheating gas inlet; 113. Crucible preheating gas outlet; 114. Collection crucible insulation layer; 115. Insulation material. 2. Secondary solid-state crystallization device; 201. Second steam passage; 202. Insulation material; 203. Secondary cooling medium inlet; 204. Secondary cooling medium outlet; 205. Secondary crystallization tube; 206. Secondary preheating gas inlet; 207. Secondary preheating gas outlet; 208. Secondary crystallizer insulation layer; 209. Insulation material; 3. Three-stage heat exchanger; 301. Gas outlet of three-stage heat exchanger; 302. Insulation material; 303. Inlet of three-stage cooling medium; 304. Outlet of three-stage cooling medium; 305. Three-stage cooling pipe; 4. Vacuum pump unit; 5. Waste heat boiler; 501. Waste heat recovery pipeline.

[0032] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0033] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details. In other instances, well-known structures and devices are shown in block diagram form for ease of description of one or more embodiments.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0035] This invention can be modified and has various embodiments, with specific embodiments illustrated in the accompanying drawings. However, this invention is not limited to this particular implementation and all modifications, equivalents, and substitutions falling within the spirit and technical scope of this invention are to be understood as included.

[0036] Ordinal terms such as "first," "second," etc., may be used to describe various constituent elements, but the constituent elements are not limited to these terms. The terms are used only to distinguish one constituent element from another. For example, without departing from the scope of the claims of this invention, a second constituent element may be named a first constituent element, and similarly, a first constituent element may be named a second constituent element. Terms and / or include combinations of multiple associated items or one of multiple associated items.

[0037] It should be understood that when referring to a constituent element being "connected" or "in contact" with other constituent elements, this includes not only cases where it is directly connected or in contact with other constituent elements, but also cases where other constituent elements exist between them. Conversely, when referring to a constituent element being "directly connected" or "directly in contact" with other constituent elements, it should be understood that no other constituent elements exist between them.

[0038] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0039] To illustrate the magnesium-argon mixed vapor condensation and collection device under vacuum conditions provided by the present invention, Figure 1 The structure of a magnesium-argon mixed vapor condensation and collection device for vacuum conditions according to an embodiment of the present invention is shown. Figure 2 The logical structure of a magnesium-argon mixed vapor condensation and collection device under vacuum conditions according to an embodiment of the present invention is shown.

[0040] like Figure 1 and Figure 2As shown, this invention provides a magnesium-argon mixed vapor condensation and collection device under vacuum conditions, mainly comprising: a primary liquid condensation device 1, a secondary solid crystallization device 2, a tertiary heat exchanger 3, a collection crucible 111, a vacuum pump group 4, and a waste heat boiler 5. The primary liquid condensation device 1, the secondary solid crystallization device 2, and the tertiary heat exchanger 3 are sequentially connected. A primary condenser insulation layer 109 for preheating is provided on the primary liquid condensation device 1. A primary condenser tube 106 is provided inside the primary liquid condensation device 1, which is used to condense the high-temperature magnesium-argon mixed vapor to form liquid magnesium. A secondary solid crystallization device 2 is provided with a secondary crystallizer insulation layer 208 for preheating. A secondary crystallization tube 205 is provided inside the secondary solid crystallization device 2. The secondary crystallization tube 205 is used to crystallize the magnesium-argon mixed vapor after treatment by the primary liquid condenser 1 to form solid magnesium; a tertiary cooling tube 305 is provided inside the tertiary heat exchanger 3, which is used to cool the argon gas after treatment by the secondary solid crystallization device 2, and at the same time crystallize trace amounts of potassium and sodium vapor; the collection crucible 111 is located below the primary liquid condenser 1 and is used to collect the liquid magnesium formed by condensation by the primary condenser tube; the vacuum pump group 4 is connected to the tertiary heat exchanger 3 and is used to control the vacuum degree of the magnesium-argon mixed vapor condensation collection device; the waste heat boiler 5 is connected to the cooling systems of the primary liquid condenser 1 and the secondary solid crystallization device 2 respectively, and is used to recover the waste heat of the primary liquid condenser 1 and the secondary solid crystallization device 2.

[0041] In embodiments of the present invention, a complete metal mixed vapor condensation, collection, and energy recovery device is formed by sequentially connecting a primary liquid condensation device 1, a secondary solid crystallization device 2, and a tertiary heat exchanger 3 via sealed pipes. Specifically, in the primary liquid condensation device 1, the primary condenser tube 106 can be a U-shaped tube or a spiral tube; the specific structure is determined according to actual needs in specific applications. A mixed vapor inlet 101 is provided at the upper end of one side of the primary liquid condensation device 1, and a first vapor channel 102 for connecting to the secondary solid crystallization device 2 is provided at the lower end of the other side of the primary liquid condensation device 1.

[0042] A primary preheating gas inlet 107 communicating with the primary condenser insulation layer 109 is provided at the lower end of one side of the primary liquid condensing device 1, and a primary preheating gas outlet 108 communicating with the primary condenser insulation layer 109 is provided at the upper end of the other side of the primary liquid condensing device 1.

[0043] A primary cooling medium inlet 104, communicating with one end of the primary condenser tube 106, is provided at the top of the primary liquid condenser 1, and a primary cooling medium outlet 105, communicating with the other end of the primary condenser tube 106, is also provided; and the primary cooling medium outlet 105 is connected to the waste heat recovery pipe 501. In the primary liquid condenser 1, insulation material 103 is provided around the first steam channel 102, insulation material 110 is also provided on the primary condenser insulation layer 109, and insulation material 115 is also provided on the collecting crucible insulation layer 114, so that the insulation layers can better retain heat during preheating.

[0044] In the collecting crucible 111, a collecting crucible insulation layer 114 is provided on the collecting crucible 111, and the collecting crucible insulation layer 114 is used to preheat the collecting crucible 111; wherein, a crucible preheating gas inlet 112 communicating with the collecting crucible insulation layer 114 is provided at one end of the collecting crucible 111, and a crucible preheating gas outlet 113 communicating with the collecting crucible insulation layer 114 is provided at the other end of the collecting crucible 111.

[0045] In the secondary solid crystallization device 2, a secondary preheating gas inlet 206 communicating with the secondary crystallization insulation layer 208 is provided at the upper end of one side of the secondary solid crystallization device 2, a secondary preheating gas outlet 207 communicating with the secondary crystallization insulation layer 206 is provided at the lower end of the other side of the secondary solid crystallization device 2, and a second steam channel 201 communicating with the tertiary heat exchanger 3 is provided at the upper end of the other side of the secondary solid crystallization device 2.

[0046] A secondary cooling medium inlet 203, communicating with one end of the secondary crystallization tube 205, is provided at the top of the secondary solid-state crystallization device 2, and a secondary cooling medium outlet 204, communicating with the other end of the secondary crystallization tube 205, is provided at the bottom of the secondary solid-state crystallization device 2; furthermore, the secondary cooling medium outlet 204 is connected to the waste heat recovery pipe 501. The secondary crystallization tube 205 can be a U-shaped tube or a spiral tube; the specific structure is determined according to actual needs in specific applications. Thermal insulation material 202 is provided on the second steam channel 201, and thermal insulation material 209 is provided on the secondary crystallizer insulation layer 208, so that the second steam channel 201 and the secondary crystallizer insulation layer 208 can be better insulated during preheating.

[0047] In the three-stage heat exchanger 3, a gas outlet 301 connected to the vacuum pump group 4 is provided at the bottom of the other side of the three-stage heat exchanger 3, and a heat insulation material 302 is provided on the outer periphery of the gas outlet 301; a three-stage cooling medium inlet 303 connected to one end of the three-stage cooling pipe 305 is provided at the bottom of one side of the three-stage heat exchanger 3, and a three-stage cooling medium outlet 304 connected to the other end of the three-stage cooling pipe 305 is provided at the top of the other side of the three-stage heat exchanger 3.

[0048] In this invention, the cooling circuits of the primary liquid condensation device 1 and the secondary solid crystallization device 2 are connected to the waste heat boiler 5 via a waste heat recovery pipe 501, achieving centralized and efficient recovery of the latent heat of condensation at medium and high temperatures. It should be noted that, in addition to the waste heat boiler, the recovered heat can also be used to drive a steam turbine for power generation, preheat raw materials, or provide a heat source for other processes in the plant. In specific applications, a multi-stage heat exchange system can be used to achieve cascaded utilization of heat, depending on actual needs.

[0049] In embodiments of the present invention, the primary condenser, secondary crystallizer, and tertiary cooling tube can employ enhanced heat transfer structures such as spiral tubes, U-shaped tubes, or finned tubes. In particular, finned tubes can further increase the heat transfer area and improve heat transfer efficiency; spiral tube structures can extend the airflow path and increase the effective condensation time. In specific applications, the appropriate shape and structure are selected based on the actual situation.

[0050] Based on the above-described apparatus, this invention provides a method for condensing and collecting magnesium-argon mixed vapor under vacuum conditions. The method employs the aforementioned apparatus for condensing and collecting magnesium-argon mixed vapor under vacuum conditions to condense and collect the mixed vapor. Figure 3 and Figure 1 As shown, the method for collecting magnesium-argon mixed vapor under vacuum conditions provided by the present invention includes: S1: Preheating gas is introduced into the insulation layer of the first-stage condenser, the insulation layer of the collecting crucible, and the insulation layer of the second-stage crystallizer to preheat the first-stage liquid condensation device, the collecting crucible, and the second-stage solid crystallization device. S2: Cooling gas is introduced into the first-stage condenser and the second-stage crystallizer to cool the first-stage liquid condenser and the second-stage solid crystallizer, respectively, while cooling water is introduced into the third-stage cooling pipe to cool the third-stage heat exchanger. S3: The pressure difference of the condensation collection device is controlled within a preset range by the vacuum pump unit; S4: The magnesium-argon mixed vapor is introduced into the first-stage liquid condenser for first-stage condensation, and the liquid magnesium formed by condensation is dripped into the collection crucible; S5: The mixed vapor that has undergone primary condensation treatment flows into the secondary solid crystallization device for secondary crystallization treatment and generates solid magnesium; S6: The mixed vapor that has undergone secondary crystallization is fed into the tertiary heat exchanger for heat exchange treatment to generate solid potassium and sodium.

[0051] This invention is based on the principles of segmented condensation, multi-stage collection, and energy cascade utilization. By precisely controlling the temperature and pressure conditions at each stage, it realizes the phase change process of magnesium vapor from gaseous to liquid and then to solid, the final sublimation and collection of potassium and sodium vapor, and the heat recovery and utilization of the entire process.

[0052] First: Preheating process steps As shown in S1, before the entire device is started, the preheating components are used to preheat each stage of the device to the set temperature.

[0053] A. Preheating of the primary liquid condenser: Preheating gas enters the insulation layer 109 of the primary condenser from the primary preheating gas inlet 107, preheating the primary liquid condenser 1 to 680-700℃. It then flows out from the primary preheating gas outlet 108 and circulates, preventing magnesium vapor from overcooling on the wall surface and forming magnesium powder during equipment startup. This prevents magnesium powder from flowing out of the condenser with the gas, which could cause vacuum pump unit failure or magnesium powder explosion. After the equipment stabilizes and reaches thermal equilibrium, the preheating gas is reduced or stopped. B. Preheating of the collecting crucible: Preheating gas enters the collecting crucible insulation layer 114 from the crucible preheating gas inlet 112, preheating the collecting crucible 111 to 680-700℃. The gas then flows out through the crucible preheating gas outlet 113 for circulation, preventing liquid magnesium from condensing and crystallizing. After the equipment has stabilized and reached thermal equilibrium, the preheating gas supply is reduced or stopped. C. Preheating of the secondary solid-state crystallization unit: Preheating gas enters the insulation layer 208 of the secondary crystallizer from the secondary preheating gas inlet 206, preheating the secondary solid-state crystallizer to 680-700℃. It then flows out through the secondary cooling medium outlet 204 for circulation, preventing supercooled magnesium vapor from crystallizing on the wall surface and blocking the crystallizer. After the equipment reaches stable operation and thermal equilibrium is achieved, the preheating gas supply is reduced or stopped.

[0054] Second: Cooling process steps Before the entire device is started, as in S2, cooling gas enters the primary condenser tube 106 through the primary cooling medium inlet 104 to achieve heat exchange and condensation in the primary liquid condensation device. Subsequently, it flows out from the primary cooling medium outlet 105 through the waste heat recovery pipeline 501 and enters the waste heat boiler 5. Cooling gas enters the secondary crystallizer tube 205 through the secondary cooling medium inlet 203 to achieve heat exchange and crystallization in the secondary solid crystallizer 2. Subsequently, it flows out from the secondary cooling medium outlet 204 through the waste heat recovery pipeline 501 and enters the waste heat boiler 5. Cooling water enters the tertiary cooling pipe 305 through the tertiary cooling medium inlet 303 to achieve potassium and sodium metal crystallization and argon gas cooling and heat exchange, preventing potassium and sodium metal and high-temperature vapor from entering the vacuum pump group 4. Subsequently, it flows out from the tertiary cooling medium outlet 304 and circulates.

[0055] In the three-stage condensation heat exchange system, the primary liquid condenser (1) and the secondary solid crystallization unit (2) are the main heat exchangers, with heat exchange capacities of 80% and 20%, respectively. Given the high magnesium vapor content, media that do not react with magnesium vapor (including molten salt, low-melting-point metals, and inert gases) are selected as the cooling medium to prevent combustion and explosion in case of leaks in the heat exchange pipes. After passing through the secondary solid crystallization unit (2), almost all the magnesium vapor in the mixed steam is captured. The tertiary heat exchanger (3) primarily collects trace amounts of potassium and sodium metals (340-160℃) from the exhaust gas and reduces the exhaust gas temperature to the required inlet temperature (≤60℃) of the vacuum pump unit (4). The main heat loss is from argon cooling; therefore, cooling water is used as the cooling medium, and no waste heat recovery is performed.

[0056] Third, vacuum control Start the vacuum pump unit and control the pressure of the magnesium-argon mixed vapor condensation and collection device at 2000Pa by evacuation, maintaining the system pressure difference in the range of 1500-3000Pa to ensure the gas flows in the forward direction.

[0057] Fourth, condensation operation When the condensation unit is operating stably, the high-temperature (1200-1400℃) magnesium-argon mixed vapor generated by the reduction furnace moves along the vacuum pipe and enters the first-stage liquid condensation unit 1 through the mixed vapor inlet 101. The high-temperature mixed gas and the low-temperature cooling gas exchange heat through the first-stage condenser tube 106, and the subsequent gas enters the second-stage solid crystallization unit 2 through the first vapor channel 102. During this process, the magnesium vapor undergoes a liquefaction phase change on the outer surface of the tube wall. Stable film condensation is achieved by adjusting parameters such as the flow rate and temperature of the cooling medium using controlled condensation technology. The high-temperature vapor temperature is controlled at 650-700℃. As shown in Table 1, the vapor condensation rate is approximately 88%-73%. The condensed liquid magnesium drips into the collection crucible 111 for collection. It remains liquid in the collection crucible 111 and is subsequently continuously discharged as liquid metal through a siphon drainage mechanism. The primary liquid condensation unit is a shell-and-tube heat exchanger structure. By installing primary condenser tubes inside the shell, the heat exchange area within the condenser is increased. Simultaneously, the primary condenser tubes inside the shell can fully contact the high-speed vapor flow caused by the vacuum, improving the primary liquid condensation rate. Furthermore, by using the shell's insulation layer (primary condenser insulation layer), screening the cooling medium, and controlling parameters such as inlet and outlet temperatures and flow rates, localized supercooling and magnesium powder formation in the primary liquid condensation unit 1 are prevented, reducing the risk of magnesium powder combustion and explosion.

[0058] The remaining medium-temperature (approximately 700°C) magnesium-argon mixed vapor enters the secondary solid-state crystallization device 2 through the first vapor channel 102. The medium-temperature mixed gas (the mixed gas after being treated by the primary liquid condensation device 1) and the low-temperature cooling gas exchange heat through the secondary crystallization tube 205 and crystallize on the wall surface. The subsequent gas enters the tertiary heat exchanger 3 through the second vapor channel 201. During this process, the heat exchange intensity of the crystallizer is controlled by controlling the cooling gas flow rate and inlet and outlet temperatures, keeping the vapor temperature between 400-470°C. As shown in Table 1, the vapor condensation rate is approximately 99.908%-99.998%. Subsequently, crystalline magnesium is extracted by replacing the secondary crystallization tube or by online remelting. In embodiments of the present invention, for operating conditions where the condensation rate of a mixed vapor-liquid mixture containing non-condensable argon is low under vacuum, a two-stage solid-state crystallization device with a shell-and-tube heat exchanger structure is employed. By arranging secondary crystallization tubes inside the shell, the heat exchange area within the device is increased, enhancing heat transfer. Simultaneously, the internal secondary crystallization tubes can fully contact the high-speed vapor flow caused by the vacuum, preventing magnesium vapor from being carried out of the crystallizer by the high-speed argon flow. Furthermore, the secondary solid-state crystallization device controls magnesium vapor to crystallize only on the walls of the secondary crystallization tubes through a secondary crystallizer insulation layer, maintaining shell cleanliness. When the accumulated crystals in the secondary solid-state crystallization device reach a set amount, a parallel standby device is automatically activated or online cleaning is performed, switching the airflow channel. The replaced device is protected with inert gas, and the crystallized product is heated and melted before being discharged. After cleaning and maintenance, the device is put back into standby mode, achieving continuous and stable system operation.

[0059] After passing through the secondary solid-state crystallization unit, almost all of the magnesium vapor crystallizes into solid magnesium. The remaining gas is argon gas at 450℃ containing trace amounts of potassium and sodium. This mixed gas enters the tertiary heat exchanger 3 through the second vapor channel 201. The mixed gas exchanges heat with the cooling water through the tertiary cooling pipe 305, and potassium and sodium crystallize on the wall surface. The subsequent gas enters the vacuum pump group 4 through the gas outlet 301 of the tertiary heat exchanger. During this process, the heat exchange intensity of the crystallizer is controlled by adjusting the cooling water flow rate and inlet and outlet temperatures, keeping the argon gas temperature ≤60℃ to meet the gas inlet requirements of the vacuum pump.

[0060] Conventional large-scale magnesium vapor collection devices typically use pure magnesium vapor or contain only trace amounts of argon, which has minimal impact on magnesium vapor condensation. They usually employ methods such as reducing the vacuum level and gas flow rate (1-2 m / s) to enhance condensation. Furthermore, since the amount of argon is very small, it has little impact on the operation of the vacuum pump unit, eliminating the need for specific exhaust gas temperature reduction. This invention, however, utilizes a three-stage heat exchanger with a shell-and-tube heat exchanger structure under higher vacuum and higher argon ratio conditions. By arranging three stages of cooling tubes within the three-stage heat exchanger, the heat exchange area within the condenser is increased. Simultaneously, the three-stage cooling tubes arranged inside the shell can fully contact the high-speed vapor flow caused by the vacuum, improving the potassium and sodium crystallization rate and heat exchange rate. At the same time, by controlling parameters such as inlet and outlet temperatures and flow rates, the exhaust gas temperature is ensured to meet the inlet temperature requirements of the vacuum pump unit. When the crystal accumulation in the three-stage heat exchanger reaches a set amount, a parallel standby device is automatically activated or online cleaning is performed, switching the airflow channel. The replaced device is protected with inert gas, and the crystallized products are heated and melted before being discharged. After cleaning and maintenance, it is put back into standby mode, achieving continuous and stable system operation.

[0061] Table 1. Condensation ratio of magnesium vapor upon cooling In embodiments of the present invention, in addition to using inert gases (such as argon), molten salts that do not react with magnesium (such as mixtures of chlorides and fluorides) or low-melting-point metals (such as tin, lead, or their alloys) can also be used as cooling media during cooling. These media have higher heat capacity and thermal conductivity, and can provide superior heat exchange performance under certain operating conditions.

[0062] During preheating, in addition to using preheating gas circulation, electric heating, induction heating, or infrared radiation heating can also be used to preheat the condensing device. In some simplified embodiments, the waste heat flue gas from the reduction furnace can be used directly for preheating, further reducing energy consumption.

[0063] In addition to replacing the secondary crystallizer tube, crystallization on the tube wall can also be removed by mechanical scraping, vibration removal, or pulse backflushing. In some embodiments, an anti-stick coating can be applied to the surface of the secondary crystallizer tube to reduce crystal adhesion and facilitate cleaning.

[0064] To illustrate the process parameters in the apparatus and method of the present invention in detail, see Example 1.

[0065] Example 1 This embodiment provides a three-stage condensation and collection method for processing a mixture of 10 kg of magnesium vapor and 1.84 kg (approximately 10% by volume) of argon vapor per hour. The specific implementation steps are as follows: 1. Preheating stage Before starting the system, a warm-up process is performed: Preheating of the primary liquid condenser: Preheating gas enters the insulation layer 109 of the primary condenser from the primary preheating gas inlet 107, and preheats the entire device to 680-700℃ at a heating rate of 10-15℃ / min. The temperature is maintained for 30 minutes, and then the gas flows out from the primary preheating gas outlet 108 to form a circulation loop.

[0066] Preheating of the collection crucible: Simultaneously, preheating gas enters the heat preservation layer 114 of the collection crucible from the crucible preheating gas inlet 112, preheating the crucible to 700±5℃, maintaining the uniform temperature of the inner wall of the crucible, and keeping it warm for 30 minutes. Subsequently, it flows out from the crucible preheating gas outlet 113 to form a circulation loop.

[0067] Preheating of the secondary solid crystallization device: Preheating gas enters the insulation layer 208 of the secondary crystallizer from the secondary preheating gas inlet 206, preheating the device to 700°C, ensuring that the surface temperature of the secondary crystallization tube reaches the set value, and keeping it at that temperature for 30 minutes. Subsequently, the gas flows out from the secondary preheating gas outlet 207 to form a circulation loop.

[0068] 2. Cooling stage After preheating is complete, start the cooling system: Cooling of the primary liquid condenser: Argon gas is used as the cooling medium and enters the primary condenser tube 106 from the primary cooling medium inlet 104 at a flow rate of 0.072 kg / s. The inlet temperature is controlled at 20℃. Subsequently, it flows into the waste heat recovery pipeline 501 from the primary cooling medium outlet 105.

[0069] Cooling of the secondary solid crystallization device: Argon cooling medium enters the secondary crystallization tube 205 from the secondary cooling medium inlet 203 at a flow rate of 0.023 kg / s, with the inlet temperature controlled at 20℃, and then flows into the waste heat recovery pipeline 501 from the secondary cooling medium outlet 204.

[0070] Three-stage heat exchanger cooling: Industrial circulating water enters the three-stage cooling pipe 305 from the three-stage cooling medium inlet 303 at a flow rate of 1 m / s, with an inlet temperature of 25-30℃, and then flows into the water tank from the three-stage cooling medium outlet 304.

[0071] 3. Vacuum control Start the vacuum pump unit and control the system pressure at 2000Pa by evacuation, maintaining the system pressure difference in the range of 1500-3000Pa to ensure the gas flows in the forward direction.

[0072] 4. Condensation process operation Once the system has stabilized, begin processing the magnesium-argon mixed vapor: First-stage liquid condensation: Mixed vapor at 1200-1400℃ enters the first-stage liquid condensation device at a flow rate of 2.778 kg / s. By adjusting the cooling gas flow rate, the condensation temperature is controlled at 680±10℃, and the magnesium vapor condensation rate reaches about 80%. When the liquid magnesium reaches 2 / 3 of the collection crucible, the liquid magnesium is continuously discharged at a rate of 10 kg / h.

[0073] Secondary solid-state crystallization: The remaining gas enters the secondary solid-state crystallization unit. By adjusting the cooling gas flow rate, the temperature of the crystallization zone is controlled at 450±20℃, and the magnesium vapor sublimation rate reaches 99%. The standby crystallization unit is switched on for cleaning and maintenance every 12 hours.

[0074] Three-stage tail gas treatment: The remaining argon gas containing trace amounts of potassium and sodium enters the three-stage heat exchanger. By adjusting the cooling gas flow rate, it is cooled to 50±5℃ in the three-stage device. The potassium and sodium collection efficiency is ≥99%, and the tail gas meets the requirements for vacuum pump inlet.

[0075] This embodiment achieves efficient collection of magnesium vapor under vacuum conditions through the above process conditions, with a total collection rate of over 99% and stable and reliable operation.

[0076] As can be seen from the above technical solution, the magnesium-argon mixed vapor condensation and collection device and method provided by the present invention for vacuum conditions (1) The present invention significantly improves the condensation efficiency under conditions containing non-condensable gases: a modular shell-and-tube heat exchanger structure is adopted, and by arranging heat exchange tubes (first-stage condenser tubes, second-stage crystallizer tubes, or third-stage cooling tubes) in the shell, the effective contact area between the magnesium-argon mixed gas and the condensation wall is greatly increased. At the same time, the residence time of the vapor in the high-temperature zone is extended by the optimized airflow channel design. Compared with the traditional condensation structure that relies on heat dissipation from a single wall, the present invention has optimized the working conditions of magnesium vapor containing 5-10% argon, effectively destroying the gas film barrier formed by non-condensable gases at the condensation interface, so that the condensation efficiency can still maintain a first-stage liquid condensation rate of more than 80% and a total collection rate of more than 99% under a vacuum of 2000Pa. (2) Achieving efficient recovery and utilization of massive latent heat of condensation: This invention integrates the cooling circuit formed by the primary liquid condensation device and the secondary solid crystallization device with the waste heat boiler. The heated cooling gas is collected and flows into the waste heat boiler through the waste heat recovery pipeline, realizing the effective recovery of the massive latent heat of phase change released during the magnesium vapor condensation process (approximately 1800kW of magnesium production capacity per hour). Compared with the existing technology that directly discards heat, this invention forms an energy closed-loop utilization system, significantly reducing the overall energy consumption of the production process. (3) Adapting to harsh working conditions of vacuum and high gas velocity: In response to the characteristics of gas volume expansion and extremely high flow velocity under medium vacuum (2000Pa), this invention adopts a shell-and-tube structure, which can efficiently transfer heat and mass. Compared with the traditional simple flow channel structure, this invention ensures that the vapor has sufficient effective residence time and heat exchange area to complete efficient condensation, solving the technical problem of insufficient condensation time under high gas velocity conditions. (4) Achieving continuous and automated production: Through the modular design and parallel backup mechanism of the three-stage condensation unit, online cleaning and equipment switching of solid crystalline magnesium are realized, overcoming the technical bottleneck of frequent shutdowns for cleaning required by traditional technology. The secondary solid crystallization unit controls the crystallization position through the insulation layer, keeps the shell clean, and with the automatic switching of the backup system, ensures that the system can operate stably and continuously for a long time, providing a reliable guarantee for large-scale industrial production. (5) Comprehensively improving process safety: Through systematic preheating and insulation process (preheating each stage of the equipment to 680-700℃) and precise temperature control, this invention effectively suppresses the generation of magnesium powder in each condensation stage, fundamentally reducing the risk of magnesium powder combustion and explosion. At the same time, the use of inert gas that does not react with magnesium as the cooling medium ensures system safety even in the event of pipeline leakage, greatly improving the safety and reliability of large-scale continuous magnesium smelting process.

[0077] The above are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any changes, modifications, substitutions, integrations, and parameter alterations to these embodiments within the spirit and principles of the present invention, achieved through conventional substitutions or by achieving the same function without departing from the principles and spirit of the present invention, fall within the scope of protection of the present invention.

Claims

1. A device for condensing and collecting magnesium-argon mixed vapor under vacuum conditions, characterized in that, include: The system comprises a primary liquid condensation device, a secondary solid crystallization device, a tertiary heat exchanger, a collection crucible, a vacuum pump unit, and a waste heat boiler, wherein the primary liquid condensation device, the secondary solid crystallization device, and the tertiary heat exchanger are shell-and-tube structures and are connected in sequence. A primary condenser insulation layer for preheating is provided on the primary liquid condensation device, and a primary condenser tube is provided inside the primary liquid condensation device. The primary condenser tube is used to condense high-temperature magnesium-argon mixed vapor to form liquid magnesium. A secondary crystallizer insulation layer for preheating is provided on the secondary solid crystallizer, and a secondary crystallization tube is provided inside the secondary solid crystallizer. The secondary crystallization tube is used to crystallize the magnesium-argon mixed vapor after the primary liquid condensation device to form solid magnesium. A three-stage cooling pipe is installed inside the three-stage heat exchanger. The three-stage cooling pipe is used to cool the argon gas after it has been processed by the two-stage solid crystallization device, and at the same time, to crystallize trace amounts of potassium and sodium vapor. The collecting crucible is located below the primary liquid condensation device and is used to collect the liquid magnesium formed by the condensation of the primary condenser tube; The vacuum pump unit is connected to the three-stage heat exchanger and is used to control the vacuum level of the magnesium-argon mixed vapor condensation and collection device. The waste heat boiler is connected to the cooling systems of the primary liquid condensation device and the secondary solid crystallization device, respectively, and is used to recover the waste heat of the primary liquid condensation device and the secondary solid crystallization device.

2. The magnesium-argon mixed vapor condensation and collection device under vacuum conditions according to claim 1, characterized in that, A mixed vapor inlet is provided at the upper end of one side of the primary liquid condensation device, and a first vapor channel for connecting to the secondary solid crystallization device is provided at the lower end of the other side of the primary liquid condensation device.

3. The magnesium-argon mixed vapor condensation and collection device under vacuum conditions according to claim 1, characterized in that, A primary preheating gas inlet communicating with the insulation layer of the primary condenser is provided at the lower end of one side of the primary liquid condensation device, and a primary preheating gas outlet communicating with the insulation layer of the primary condenser is provided at the upper end of the other side of the primary liquid condensation device.

4. The magnesium-argon mixed vapor condensation and collection device under vacuum conditions according to claim 1, characterized in that, The primary liquid condensation device is provided with a primary cooling medium inlet that communicates with one end of the primary condenser tube and a primary cooling medium outlet that communicates with the other end of the primary condenser tube; and the primary cooling medium outlet is connected to a waste heat recovery pipeline.

5. The magnesium-argon mixed vapor condensation and collection device under vacuum conditions according to claim 1, characterized in that, A heat-insulating layer is provided on the collecting crucible, and the heat-insulating layer is used to preheat the collecting crucible; wherein... A crucible preheating gas inlet communicating with the insulation layer of the crucible is provided at one end of the collecting crucible, and a crucible preheating gas outlet communicating with the insulation layer of the collecting crucible is provided at the other end of the collecting crucible.

6. The magnesium-argon mixed vapor condensation and collection device under vacuum conditions according to claim 1, characterized in that, A secondary preheating gas inlet communicating with the secondary crystallization insulation layer is provided at the upper end of one side of the secondary solid crystallization device, and a secondary preheating gas outlet communicating with the secondary crystallization insulation layer is provided at the lower end of the other side of the secondary solid crystallization device. A second steam channel communicating with the tertiary heat exchanger is provided at the upper end of the other side of the secondary solid crystallization device.

7. The magnesium-argon mixed vapor condensation and collection device under vacuum conditions according to claim 1, characterized in that, A secondary cooling medium inlet, communicating with one end of the secondary crystallization tube, is provided at the top of the secondary solid crystallization device, and a secondary cooling medium outlet, communicating with the other end of the secondary crystallization tube, is provided at the bottom of the secondary solid crystallization device; furthermore, the secondary cooling medium outlet is connected to a waste heat recovery pipeline.

8. The magnesium-argon mixed vapor condensation and collection device under vacuum conditions according to claim 1, characterized in that, A tertiary cooling medium inlet connected to one end of the tertiary cooling pipe is provided at the bottom of one side of the tertiary heat exchanger, and a tertiary cooling medium outlet connected to the other end of the tertiary cooling pipe is provided at the top of the other side of the tertiary heat exchanger. A gas outlet for the third-stage heat exchanger, which is connected to the vacuum pump unit, is provided at the bottom of the other side of the third-stage heat exchanger.

9. A method for collecting magnesium-argon mixed vapor under vacuum conditions, characterized in that, The magnesium-argon mixed vapor is condensed and collected using the magnesium-argon mixed vapor condensation and collection device for vacuum conditions as described in any one of claims 1-8, the method comprising: S1: Preheating gas is introduced into the insulation layer of the first-stage condenser, the insulation layer of the collecting crucible, and the insulation layer of the second-stage crystallizer to preheat the first-stage liquid condensation device, the collecting crucible, and the second-stage solid crystallization device. S2: Cooling gas is introduced into the first-stage condenser and the second-stage crystallizer to cool the first-stage liquid condenser and the second-stage solid crystallizer, respectively, while cooling water is introduced into the third-stage cooling pipe to cool the third-stage heat exchanger. S3: The pressure difference of the condensation collection device is controlled within a preset range by the vacuum pump unit; S4: The magnesium-argon mixed vapor is introduced into the first-stage liquid condenser for first-stage condensation, and the liquid magnesium formed by condensation is dripped into the collection crucible; S5: The mixed vapor that has undergone primary condensation treatment flows into the secondary solid crystallization device for secondary crystallization treatment and generates solid magnesium; S6: The mixed vapor that has undergone secondary crystallization is fed into the tertiary heat exchanger for heat exchange treatment to generate solid potassium and sodium.

10. The method for collecting magnesium-argon mixed vapor under vacuum conditions according to claim 9, characterized in that, In S1, during the preheating process, the preheating temperature of the primary liquid condensation device is 680-700℃; the preheating temperature of the collecting crucible is 680-700℃; and the preheating temperature of the secondary solid crystallization device is 680-700℃.

11. The method for collecting magnesium-argon mixed vapor under vacuum conditions according to claim 9, characterized in that, In S2, the cooling gas passing through the primary condenser and the secondary crystallizer flows into the waste heat boiler to provide waste heat for the waste heat boiler.

12. The method for collecting magnesium-argon mixed vapor under vacuum conditions according to claim 9, characterized in that, In S4, during the first-stage condensation process, the temperature of the first-stage liquid condensation device is 650-700℃; In S5, during the secondary crystallization process, the temperature of the secondary solid crystallization device is 400-470℃; In S6, during the three-stage heat exchange process, the temperature of the three-stage heat exchanger is 50±5℃.

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